This study examined the effects of pasteurization(PAS),ultrasonic sterilization(ULS),and microwave sterilization(MWS)on the quality and storage characteristics of brine-fermented tofu(BFT)and fermented tofu(FT).Compar...This study examined the effects of pasteurization(PAS),ultrasonic sterilization(ULS),and microwave sterilization(MWS)on the quality and storage characteristics of brine-fermented tofu(BFT)and fermented tofu(FT).Comparative analysis revealed that MWS had a negligible detrimental effect on the structural integrity and organoleptic properties of BFT and FT,while effectively maintaining its water-holding capacity(WHC)and exhibiting the least impact on its texture.In contrast,PAS and ULS increased hardness and chewiness significantly(P<0.05),but ULS also enhanced the brightness of tofu.Throughout the storage period,the WHC,elasticity,and sensory properties of tofu generally decreased,whereas the hardness and chewiness increased.PAS-BFT and MWS-FT maintained sensory quality for the longest periods of 14 and 12 days respectively,and could be decomposed to more small molecule peptides within 0–8 days and 0–6 days,which are more easily to be absorbed by the body.The findings discovered that MWS is the most suitable method for sterilization of tofu,with superior capability in maintaining the quality,extending shelf life,and improving digestibility of tofu.展开更多
Lactic acid bacteria(LAB)exopolysaccharides(EPS)reveal high safety and multiple activities,and are typical postbiotics produced by LAB during fermentation.In this paper,6583 articles on LAB-EPS from Web of Science and...Lactic acid bacteria(LAB)exopolysaccharides(EPS)reveal high safety and multiple activities,and are typical postbiotics produced by LAB during fermentation.In this paper,6583 articles on LAB-EPS from Web of Science and Elsevier databases were retrieved,and 236 articles related to this review were screened.The EPS from 90 LAB strains were summarized in terms of their extraction methods,yield,molecular weight,monosaccharide composition,glycosidic bond configuration and the structural and activity relationships(SARs).However,there exist great challenges as for the low yield and high cost in EPS production.Therefore,this review further elaborated the mechanism of EPS secretion,the anabolic pathway of EPS,the structure and mechanism of key enzymes involving in EPS synthesis process,the prospect of gene regulation for EPS secretion,and proposed the engineering strategies for increasing EPS yield or tailored EPS design in recent years.In addition,CRISPR/Cas9 gene editing technology was also discussed in the production control of EPS in LAB.Finally,the engineering strategy of increasing EPS yield in recent years was proposed.This work might provide important theoretical support for the production and application of LAB-based EPS.展开更多
Hyperuricemia(HUA)is characterized by elevated levels of uric acid(UA)in the bloodstream,resulting from either excessive production or insufficient excretion of UA within the body.If left untreated,progressive or pers...Hyperuricemia(HUA)is characterized by elevated levels of uric acid(UA)in the bloodstream,resulting from either excessive production or insufficient excretion of UA within the body.If left untreated,progressive or persistent HUA can lead to gout,causing significant harm to human health.Lactic acid bacteria(LAB),generally recognized as safe(GRAS)probiotics,have been shown to alleviate symptoms associated with gastrointestinal disorders such as irritable bowel syndrome and inflammatory bowel disease while supporting overall bodily functions and health.Recently,LAB has emerged as a potentially safe,cost-effective and efficient treatment for HUA.This comprehensive review aims to explore the current literature on the mechanisms through which LAB controls HUA.These mechanisms include suppressing purine metabolism,absorbing purine compounds,modulating microbiota to maintain host global purine homeostasis,reducing intestinal permeability,producing metabolites that alleviate HUA symptoms,promoting the expression of urate excretory proteins and inhibiting the expression of urate reabsorption proteins.The findings presented in this review provide a framework for further investigation into how probiotic LAB can alleviate HUA by influencing UA metabolism and elucidating their underlying action mechanisms.展开更多
This study assessed the effects of lactic acid bacteria(LAB), cellulase, cellulase-producing Bacillus pumilus and their combinations on the fermentation characteristics, chemical composition, bacterial community and i...This study assessed the effects of lactic acid bacteria(LAB), cellulase, cellulase-producing Bacillus pumilus and their combinations on the fermentation characteristics, chemical composition, bacterial community and in vitro digestibility of alfalfa silage. A completely randomized design involving a 8(silage additives)×3 or 2(silage days) factorial arrangement of treatments was adopted in the present study. The 8 silage additive treatments were: untreated alfalfa(control); two commercial additives(GFJ and Chikuso-1); an originally selected LAB(Lactobacillus plantarum a214) isolated from alfalfa silage; a cellulase-producing Bacillus(CB) isolated from fresh alfalfa; cellulase(C); and the combined additives(a214+C and a214+CB). Silage fermentation characteristics, chemical composition and microorganism populations were analysed after 30, 60 and 65 days(60 days followed by exposure to air for five additional days). In vitro digestibility was analysed for 30 and 60 days. Compared with the other treatments, selected LAB a214, a214 combined with either C or CB, and Chikuso-1 had the decreased(P<0.001) pH and increased(P<0.001) lactic acid concentrations during the ensiling process, and there were no differences(P>0.05) among them. Fiber degradation was not significant(P≥0.054) in any C or CB treatments. The a214 treatment showed the highest(P=0.009) in vitro digestibility of dry matter(595.0 g kg–1DM) after ensiling and the highest abundance of Lactobacillus(69.42 and 79.81%, respectively) on days 60 and 65, compared to all of other treatments. Overall, the silage quality of alfalfa was improved with the addition of a214, which indicates its potential as an alfalfa silage inoculant.展开更多
This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn bas...This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn based totalmixed ration （TMR） silage. Total mixed ration was ensiled with four treatments： （1） no additives （control）; （2） an inoculant （Lactobacillus plantarum） （L）; （3） propionicacid （P）; （4） propionic acid＋lactic acid bacteria （PL）. All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH （〈3.80） and ammonia nitrogen （NH3-N） contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control （P〈0.05）. After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly （P〈0.05） increased them. L silage had higher （P〈0.05） in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.展开更多
To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and ad...To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and adsorption. Air-dried and chopped rice straw was treated with either fermentation for 30 d after adding 1.5 L nutrient solution（50 m L inocula L–1, 1.2×1012 CFU m L–1 inocula） kg–1 straw dry matter, or spraying a large amount of culture broth（1.5 L kg–1 straw dry matter, 1.5×1011 CFU m L–1 culture broth） on the straw and allowing it to adsorb for 30 min. The feed quality and aerobic stability of the resulting forage were examined. Both treatments improved the feed quality of rice straw, and adsorption was better than fermentation for preserving nutrients and improving digestibility, as evidenced by higher dry matter（DM） and crude protein（CP） concentrations, lower neutral detergent fiber（NDF）, acid detergent fiber（ADF） and NH3-N concentrations, as well as higher lactic acid production and in vitro digestibility of DM（IVDMD）. The aerobic stability of the adsorbed straw and the fermented straw was 392 and 480 h, respectively. After being exposed to air, chemical components and microbial community of the fermented straw were more stable than the adsorbed straw.展开更多
This research was aimed at isolating and identifying the predominant lactic acid bacteria(LAB) in the traditional Chinese salt-fermented soybean food,douchi,from Yunnan,China.The predominant LAB present were isolated ...This research was aimed at isolating and identifying the predominant lactic acid bacteria(LAB) in the traditional Chinese salt-fermented soybean food,douchi,from Yunnan,China.The predominant LAB present were isolated and identified by conventional culture-dependent methods combined with molecular biological methods.Two hundred and sixty isolates were obtained from thirty kinds of traditional fermented douchi from six cities and counties in Yunnan,and those strains were divided into twelve groups by their morphological and biochemical characteristics.Based on 16S ribosomal DNA(rDNA) sequencing and analysis,56 representative strains were identified as belonging to 6 genera and 14 species:Lactobacillus(4 spp.),Weissella(3 spp.),Pediococcus(2 spp.),Staphylococcus(2 spp.),Enterococcus(1 sp.),and Bacillus(2 spp.).The results show that douchi contains a large natural population of LAB of diverse composition from which some strains could be selected as starters for functional fermented foods.This is the first study on the original douchi from Yunnan,and the results suggest that it may be a useful source for the isolation of LAB.This study has also laid a foundation for further research on developing functional douchi products.展开更多
Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was ...Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was to isolate and screen LAB that are well suited to the intestinal characteristics of the Chinese population,with excellent probiotics and high antibacterial activity.After 16S ribosomal RNA(rRNA)homology and phylogenetic tree analysis,potential probiotics were tested for their antibacterial activity,resistance to artificial gastrointestinal fluid and drugs,surface hydrophobicity,and safety.Three strains of LAB with acid resistance,bile salt resistance,epithelial cell adhesion,and no multidrug resistance were selected:Lactobacillus salivarius,Leuconostoc lactis,and Lactobacillus paracasei.Analysis of the antibacterial active substances in the three strains and their fermentation broths revealed that the main antibacterial substances of L.lactis were organic acids,whereas those of L.salivarius and L.paracasei were organic acids and bacteriocins with broad-spectrum antibacterial activity.These three strains of probiotic LAB with high antibacterial activity were identified as bacterial resources that could potentially be used to develop probiotic preparations for the prevention and treatment of intestinal diseases caused by intestinal pathogens.展开更多
The objective of this study was to investigate the effect of lactic acid bacteria(LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage.Corn stover was ensiled without(control) or wit...The objective of this study was to investigate the effect of lactic acid bacteria(LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage.Corn stover was ensiled without(control) or with Lactobacillus plantarum(LP),Enterococcus faecalis(EF),and Enterococcus mundtii(EM) for 45 days.The fermentation characteristics were assessed,and subsequent in vitro dry matter digestibility(DM-D),neutral detergent fiber digestibility(NDF-D),volatile fatty acids(VFA),methane(CH4) production,cellulolytic bacteria proportions and their activities per corn stover silage were also determined.There was no significant difference(P>0.05) among the silage pH,lactic acid,crude protein(CP),water soluble carbohydrates(WSC) and lignocelluloses contents of different treatments.The relative proportions of Ruminococcus flavefaciens and Fibrobacter succinogenes,carboxymethyl-ocellulose and β-glycosidase activities,DM-D,NDF-D,and VFA production of in vitro incubation was higher(P<0.05) for silages inoculated with LP and EF than those of the control silage.Silage inoculated with LP showed the lowest(P<0.05) CH4 production per unit yield of VFA,which was positively corresponded to the lowest(P<0.05) ratio of acetate to propionate.In summary,the ensiling fermentation quality and subsequent utilization of corn stover silage were efficiently improved by inoculated with L.plantarum.展开更多
Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food...Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19(obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.展开更多
Tuberculosis(TB) is a communicable disease caused by Mycobacterium tuberculosis(M. tuberculosis). WHO estimated that 10.4 million new(incident) TB cases worldwide in year 2016. The increased prevalence of drug resista...Tuberculosis(TB) is a communicable disease caused by Mycobacterium tuberculosis(M. tuberculosis). WHO estimated that 10.4 million new(incident) TB cases worldwide in year 2016. The increased prevalence of drug resistant strains and side effects associated with the current anti-tubercular drugs make the treatment options more complicated. Hence, there are necessities to identify new drug candidates to fight against various sub-populations of M. tuberculosis with less or no toxicity/side effects and shorter treatment duration. Bacteriocins produced by lactic acid bacteria(LAB) attract attention of researchers because of its "Generally recognized as safe" status. LAB and its bacteriocins possess an effective antimicrobial activity against various bacteria and fungi. Interestingly bacteriocins such as nisin and lacticin 3147 have shown antimycobacterial activity in vitro. As probiotics, LAB plays a vital role in promoting various health benefits including ability to modulate immune response against various infectious diseases. LAB and its metabolic products activate immune system and thereby limiting the M. tuberculosis pathogenesis. The protein and peptide engineering techniques paved the ways to obtain hybrid bacteriocin derivatives from the known peptide sequence of existing bacteriocin. In this review, we focus on the antimycobacterial property and immunomodulatory role of LAB and its metabolic products. Techniques for large scale synthesis of potential bacteriocin with multifunctional activity and enhanced stability are also discussed.展开更多
According to the sequence of the bile salt hydrolase （BSH） gene of Bifidobacterium and the restriction enzyme cutting sites of expression vector pNZ8148, primers were designed and the bile salt hydrolase （BSH） gen...According to the sequence of the bile salt hydrolase （BSH） gene of Bifidobacterium and the restriction enzyme cutting sites of expression vector pNZ8148, primers were designed and the bile salt hydrolase （BSH） gene was gotten from Bacillus bifidus ATCC 29521 by PCR. BSH gene was inserted into lactic acid bacteria expression vector pNZ8148 to construct the recombinant pNZ8148-BSH. The recombinant pNZ8148-BSH was transferred into lactic acid bacteria NZ9000 with electrotransformation method. And the recombinant which could express BSH protein was obtained. It was identified by SDS-PAGE electrophoresis and activity verification. The result could provide a rationale reference for expressing BSH in lactic acid bacteria.展开更多
[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium contai...[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium containing calcium carbonate, and they were preliminarily identified through morphological, physiological and biochemical experiments. The acid production efficiency was determined. Twelve strains having strong acid-pro- duction ability were selected, and their salt tolerance and acid tolerance were detected. The sequences of their 16 S rDNA were also analyzed. [ Result] A total of 44 lactic acid bacterium strains were isolated from the forage com. As evidenced by the physiological and biochemical experi- ments, the twelve strains having strong acid-production ability belonged to Leuconostoc, Lactobacillus and Enterococcus, respectively, and they had strong salt tolerance and acid tolerance. According to the sequences of 16 S rDNA, A4, B9, B11, B12 and B14 were Lactobacillus plantarum; A1, A2., A7, A11 and B8 were Leuconostoc mesenteroides dextran subspecies; and AB and A9 were Enterococcus hirae. [ Conclusion ] The lactic acid bacterium strains with strong acid-production ability isolated from forage corn can be developed into silage additives.展开更多
Objective: To investigate the antibacterial effect of selected lactic acid bacteria(LAB)biofilms on the planktonic and biofilm population of methicillin-resistant Staphylococcus aureus(MRSA)(S547).Methods: In this stu...Objective: To investigate the antibacterial effect of selected lactic acid bacteria(LAB)biofilms on the planktonic and biofilm population of methicillin-resistant Staphylococcus aureus(MRSA)(S547).Methods: In this study, biofilm-forming LAB were isolated from tairu and kefir. Isolate Y1 and isolate KF were selected based on their prominent inhibition against test pathogens(using spot-on-agar method and agar-well-diffusion assay) and efficient biofilm production(using tissue culture plate method). They were then identified as Lactobacillus casei(L. casei) Y1 and Lactobacillus plantarum(L. plantarum) KF, respectively using16 S r DNA gene sequencing. The influence of incubation time, temperature and aeration on the biofilm production of L. casei Y1 and L. plantarum KF was also investigated using tissue culture plate method. The inhibitory activity of both the selected LAB biofilms was evaluated against MRSA(Institute for Medical Research code: S547) using L. plantarum ATCC 8014 as the reference strain.Results: L. casei Y1 showed the highest reduction of MRSA biofilms, by 3.53 log at48 h while L. plantarum KF records the highest reduction of 2.64 log at 36 h. In inhibiting planktonic population of MRSA(S547), both L. casei Y1 and L. plantarum KF biofilms recorded their maximum reduction of 4.13 log and 3.41 log at 24 h, respectively. Despite their inhibitory effects being time-dependent, both LAB biofilms exhibited good potential in controlling the biofilm and planktonic population of MRSA(S547).Conclusions: The results from this study could highlight the importance of analysing biofilms of LAB to enhance their antibacterial efficacy. Preferably, these protective biofilms of LAB could also be a better alternative to control the formation of biofilms by pathogens such as MRSA.展开更多
Eight cholesterol-lowering lactic acid bacteria(LAB 1 through 8)isolated from pickles and yogurt were evaluated for probiotic potential based on their tolerance to low pH and bile salt and antagonistic activity agains...Eight cholesterol-lowering lactic acid bacteria(LAB 1 through 8)isolated from pickles and yogurt were evaluated for probiotic potential based on their tolerance to low pH and bile salt and antagonistic activity against Staphylococcus aureusand Escherichia coli.Strain LAB 4 had excellent tolerance to low pH and bile salt and all 8 LAB strains had antagonisticactivity against Staphylococcus aureus and Escherichia coli.Moreover,strain LAB4 had synergic cholesterol-lowering effect with 0.0125%licorice root extract,0.025%Chinese wolfberry extract or 0.025%milkvetch root extract.展开更多
In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing e...In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host＇s defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.展开更多
The effects of the co-inoculation of Debaryomyces hansenii separately with 3 lactic acid bacteria(LAB),Lactobacillus sakei,Lactobacillus plantarum and Lactobacillus curvatus,on the taste and odour profi les of dry sau...The effects of the co-inoculation of Debaryomyces hansenii separately with 3 lactic acid bacteria(LAB),Lactobacillus sakei,Lactobacillus plantarum and Lactobacillus curvatus,on the taste and odour profi les of dry sausages were investigated.The co-inoculated sausages showed higher free amino acid and organic acid contents than the non-inoculated control and sausages inoculated with D.hansenii alone.Meanwhile,the sausages inoculated with D.hansenii+L.plantarum,D.hansenii+L.sakei and D.hansenii+L.curvatus had the highest contents of aldehydes,esters and alcohols,respectively.The results of electronic tongue,electronic nose and sensory evaluation demonstrated that compared with the sausage inoculated with D.hansenii,the sour taste and fl oral odour increased and the fatty odour decreased in the sausage inoculated with D.hansenii+L.sakei;this was more favourable for the development of a desirable fl avour in sausages.Moreover,the partial least squares regression analysis indicated that 10 taste and 33 odour compounds were mainly responsible for the differences in the flavour profiles among the sausages.Overall,these findings contributed to a more comprehensive understanding of the formation of sensory characteristics in dry sausages co-inoculated with yeast and LAB.展开更多
Objective: To study some soybean cultivars commonly used in Northern Thailand that exhibit high nutritional profile and to investigate the changes in bioactive principles and antioxidant capacity of the fermented soy ...Objective: To study some soybean cultivars commonly used in Northern Thailand that exhibit high nutritional profile and to investigate the changes in bioactive principles and antioxidant capacity of the fermented soy broth that was prepared using the selected soybean cultivar and Lactobacillus paracasei HII02 mediated fermentation process.Methods: The best soybean cultivar was subjected to fermentation, and then analyzed the phytochemical, antioxidant and nutritional changes by high performance liquid chromatography and spectrophotometric analysis.Results: Sor Jor 2 soybean cultivar showed rich nutritional profile and was subjected to fermentation process. Lactobacillus paracasei HII02 mediated fermentation of Sor Jor 2 soybean exhibited stable physical and chemical characteristics. Lactic acid bacteria mediated fermentation also increased the aglycone forms of isoflavone content, exhibited antioxidant capacity and thereby enhanced the quality of the fermented soy broth. It also prevented the growth of coliforms in fermented soybean.Conclusions: The study results suggest that fermented soybean is rich in nutrition and considered to be safe for consumption for the improvement of health and to treat the malnutrition.展开更多
The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,an...The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.展开更多
In this study,a new type of 3 D printed living biological hydrogel was developed by integrating lactic acid bacteria(LAB)into biocompatible and non-toxic polymer materials.Interestingly,the living materials loaded wit...In this study,a new type of 3 D printed living biological hydrogel was developed by integrating lactic acid bacteria(LAB)into biocompatible and non-toxic polymer materials.Interestingly,the living materials loaded with LAB can be freeze-dried and reused for more than 100 times.The bio-hydrogel can be used to co-culture different LAB and keep its fermentation performance stable in long-term use.The release kinetics model and response surface method were used to simulate and optimize the bacteria release mode in the bio-hydrogel.The results show that the release of bacteria from hydrogel is regulated by the coupling of Fickian diffusion and polymer swelling.The stability of LAB hydrogel was evaluated by reuse experiments.The images of confocal microscopy and scanning electron microscope showed that the bacteria with high cell viability were distributed in the hydrogel and intact structure of the living hydrogel was maintained after 100 times of reuse as yoghurt starter.In conclusion,the 3 D printed LAB bio-hydrogel developed in this study has the advantage of reuse and sustainability,which is expected to open up a new way for the preparation of food culture starter.展开更多
基金supported by the Innovation Talents Project of Harbin Science and Technology Bureau(2022CXRCCGO11)。
文摘This study examined the effects of pasteurization(PAS),ultrasonic sterilization(ULS),and microwave sterilization(MWS)on the quality and storage characteristics of brine-fermented tofu(BFT)and fermented tofu(FT).Comparative analysis revealed that MWS had a negligible detrimental effect on the structural integrity and organoleptic properties of BFT and FT,while effectively maintaining its water-holding capacity(WHC)and exhibiting the least impact on its texture.In contrast,PAS and ULS increased hardness and chewiness significantly(P<0.05),but ULS also enhanced the brightness of tofu.Throughout the storage period,the WHC,elasticity,and sensory properties of tofu generally decreased,whereas the hardness and chewiness increased.PAS-BFT and MWS-FT maintained sensory quality for the longest periods of 14 and 12 days respectively,and could be decomposed to more small molecule peptides within 0–8 days and 0–6 days,which are more easily to be absorbed by the body.The findings discovered that MWS is the most suitable method for sterilization of tofu,with superior capability in maintaining the quality,extending shelf life,and improving digestibility of tofu.
基金supported by the Natural Science Foundation of Heilongjiang Province(LH2021C075)Basic Research Business Expenses and Research Projects of Provincial Higher Education Institutions in Heilongjiang Province(2022-KYYWF-1077).
文摘Lactic acid bacteria(LAB)exopolysaccharides(EPS)reveal high safety and multiple activities,and are typical postbiotics produced by LAB during fermentation.In this paper,6583 articles on LAB-EPS from Web of Science and Elsevier databases were retrieved,and 236 articles related to this review were screened.The EPS from 90 LAB strains were summarized in terms of their extraction methods,yield,molecular weight,monosaccharide composition,glycosidic bond configuration and the structural and activity relationships(SARs).However,there exist great challenges as for the low yield and high cost in EPS production.Therefore,this review further elaborated the mechanism of EPS secretion,the anabolic pathway of EPS,the structure and mechanism of key enzymes involving in EPS synthesis process,the prospect of gene regulation for EPS secretion,and proposed the engineering strategies for increasing EPS yield or tailored EPS design in recent years.In addition,CRISPR/Cas9 gene editing technology was also discussed in the production control of EPS in LAB.Finally,the engineering strategy of increasing EPS yield in recent years was proposed.This work might provide important theoretical support for the production and application of LAB-based EPS.
基金funded by National Natural Science Foundation of China(32360564)the Natural Science and Technology Innovation Development Multiplication Plan of Guangxi University(2022BZRC010)。
文摘Hyperuricemia(HUA)is characterized by elevated levels of uric acid(UA)in the bloodstream,resulting from either excessive production or insufficient excretion of UA within the body.If left untreated,progressive or persistent HUA can lead to gout,causing significant harm to human health.Lactic acid bacteria(LAB),generally recognized as safe(GRAS)probiotics,have been shown to alleviate symptoms associated with gastrointestinal disorders such as irritable bowel syndrome and inflammatory bowel disease while supporting overall bodily functions and health.Recently,LAB has emerged as a potentially safe,cost-effective and efficient treatment for HUA.This comprehensive review aims to explore the current literature on the mechanisms through which LAB controls HUA.These mechanisms include suppressing purine metabolism,absorbing purine compounds,modulating microbiota to maintain host global purine homeostasis,reducing intestinal permeability,producing metabolites that alleviate HUA symptoms,promoting the expression of urate excretory proteins and inhibiting the expression of urate reabsorption proteins.The findings presented in this review provide a framework for further investigation into how probiotic LAB can alleviate HUA by influencing UA metabolism and elucidating their underlying action mechanisms.
基金supported by the National Key R&D Program of China (2017YFD0502102)the National Technology Leader “Ten Thousand People Plan” of China (201502510410040)the National Key Technology R&D Program of China during the 12th Five-year Plan period of China (2011BAD17B02)
文摘This study assessed the effects of lactic acid bacteria(LAB), cellulase, cellulase-producing Bacillus pumilus and their combinations on the fermentation characteristics, chemical composition, bacterial community and in vitro digestibility of alfalfa silage. A completely randomized design involving a 8(silage additives)×3 or 2(silage days) factorial arrangement of treatments was adopted in the present study. The 8 silage additive treatments were: untreated alfalfa(control); two commercial additives(GFJ and Chikuso-1); an originally selected LAB(Lactobacillus plantarum a214) isolated from alfalfa silage; a cellulase-producing Bacillus(CB) isolated from fresh alfalfa; cellulase(C); and the combined additives(a214+C and a214+CB). Silage fermentation characteristics, chemical composition and microorganism populations were analysed after 30, 60 and 65 days(60 days followed by exposure to air for five additional days). In vitro digestibility was analysed for 30 and 60 days. Compared with the other treatments, selected LAB a214, a214 combined with either C or CB, and Chikuso-1 had the decreased(P<0.001) pH and increased(P<0.001) lactic acid concentrations during the ensiling process, and there were no differences(P>0.05) among them. Fiber degradation was not significant(P≥0.054) in any C or CB treatments. The a214 treatment showed the highest(P=0.009) in vitro digestibility of dry matter(595.0 g kg–1DM) after ensiling and the highest abundance of Lactobacillus(69.42 and 79.81%, respectively) on days 60 and 65, compared to all of other treatments. Overall, the silage quality of alfalfa was improved with the addition of a214, which indicates its potential as an alfalfa silage inoculant.
基金supported by the project of Jiangsu Independent Innovation,China(CX(15)1003-3)the Key Technologies R&D Program of China during the 13th Five-Year Plan period(2016YFC0502005)the Special Project of Grass of Tibet Autonomous Region for the 13th Five-Year Plan,China
文摘This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn based totalmixed ration （TMR） silage. Total mixed ration was ensiled with four treatments： （1） no additives （control）; （2） an inoculant （Lactobacillus plantarum） （L）; （3） propionicacid （P）; （4） propionic acid＋lactic acid bacteria （PL）. All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH （〈3.80） and ammonia nitrogen （NH3-N） contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control （P〈0.05）. After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly （P〈0.05） increased them. L silage had higher （P〈0.05） in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.
基金supported by the National Key Technology Research and Development Program of China during the 12th Five-Year Plan period (2012BAD14B01)the Special Fund for Agro-Scientific Research in the Public Interest, China (201303080)
文摘To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and adsorption. Air-dried and chopped rice straw was treated with either fermentation for 30 d after adding 1.5 L nutrient solution（50 m L inocula L–1, 1.2×1012 CFU m L–1 inocula） kg–1 straw dry matter, or spraying a large amount of culture broth（1.5 L kg–1 straw dry matter, 1.5×1011 CFU m L–1 culture broth） on the straw and allowing it to adsorb for 30 min. The feed quality and aerobic stability of the resulting forage were examined. Both treatments improved the feed quality of rice straw, and adsorption was better than fermentation for preserving nutrients and improving digestibility, as evidenced by higher dry matter（DM） and crude protein（CP） concentrations, lower neutral detergent fiber（NDF）, acid detergent fiber（ADF） and NH3-N concentrations, as well as higher lactic acid production and in vitro digestibility of DM（IVDMD）. The aerobic stability of the adsorbed straw and the fermented straw was 392 and 480 h, respectively. After being exposed to air, chemical components and microbial community of the fermented straw were more stable than the adsorbed straw.
基金Project supported by the State Key Laboratory of Food Science and Technology of Jiangnan University (No.SKLF-KF-200805)the Yunnan Provincial Science and Technology Department (No.KKSA200926038),China
文摘This research was aimed at isolating and identifying the predominant lactic acid bacteria(LAB) in the traditional Chinese salt-fermented soybean food,douchi,from Yunnan,China.The predominant LAB present were isolated and identified by conventional culture-dependent methods combined with molecular biological methods.Two hundred and sixty isolates were obtained from thirty kinds of traditional fermented douchi from six cities and counties in Yunnan,and those strains were divided into twelve groups by their morphological and biochemical characteristics.Based on 16S ribosomal DNA(rDNA) sequencing and analysis,56 representative strains were identified as belonging to 6 genera and 14 species:Lactobacillus(4 spp.),Weissella(3 spp.),Pediococcus(2 spp.),Staphylococcus(2 spp.),Enterococcus(1 sp.),and Bacillus(2 spp.).The results show that douchi contains a large natural population of LAB of diverse composition from which some strains could be selected as starters for functional fermented foods.This is the first study on the original douchi from Yunnan,and the results suggest that it may be a useful source for the isolation of LAB.This study has also laid a foundation for further research on developing functional douchi products.
基金the National Key Research and Development Program of China(No.2016YFD0400605)。
文摘Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was to isolate and screen LAB that are well suited to the intestinal characteristics of the Chinese population,with excellent probiotics and high antibacterial activity.After 16S ribosomal RNA(rRNA)homology and phylogenetic tree analysis,potential probiotics were tested for their antibacterial activity,resistance to artificial gastrointestinal fluid and drugs,surface hydrophobicity,and safety.Three strains of LAB with acid resistance,bile salt resistance,epithelial cell adhesion,and no multidrug resistance were selected:Lactobacillus salivarius,Leuconostoc lactis,and Lactobacillus paracasei.Analysis of the antibacterial active substances in the three strains and their fermentation broths revealed that the main antibacterial substances of L.lactis were organic acids,whereas those of L.salivarius and L.paracasei were organic acids and bacteriocins with broad-spectrum antibacterial activity.These three strains of probiotic LAB with high antibacterial activity were identified as bacterial resources that could potentially be used to develop probiotic preparations for the prevention and treatment of intestinal diseases caused by intestinal pathogens.
基金supported by the National Natural Science Foundation of China(31502015,31672488)the Natural Science Foundation of Shanxi Province of China(2015021162)
文摘The objective of this study was to investigate the effect of lactic acid bacteria(LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage.Corn stover was ensiled without(control) or with Lactobacillus plantarum(LP),Enterococcus faecalis(EF),and Enterococcus mundtii(EM) for 45 days.The fermentation characteristics were assessed,and subsequent in vitro dry matter digestibility(DM-D),neutral detergent fiber digestibility(NDF-D),volatile fatty acids(VFA),methane(CH4) production,cellulolytic bacteria proportions and their activities per corn stover silage were also determined.There was no significant difference(P>0.05) among the silage pH,lactic acid,crude protein(CP),water soluble carbohydrates(WSC) and lignocelluloses contents of different treatments.The relative proportions of Ruminococcus flavefaciens and Fibrobacter succinogenes,carboxymethyl-ocellulose and β-glycosidase activities,DM-D,NDF-D,and VFA production of in vitro incubation was higher(P<0.05) for silages inoculated with LP and EF than those of the control silage.Silage inoculated with LP showed the lowest(P<0.05) CH4 production per unit yield of VFA,which was positively corresponded to the lowest(P<0.05) ratio of acetate to propionate.In summary,the ensiling fermentation quality and subsequent utilization of corn stover silage were efficiently improved by inoculated with L.plantarum.
基金supported by the National Natural Science Foundation of China(No.31301587)Key Laboratory of Aquatic Product Processing,Ministry of Agriculture,China
文摘Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19(obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.
基金supported by Sathyabama Institute of Science and Technology,Chennai,Tamil Nadu,India and Indian Council of Medical Research(ICMR),New Delhi,India(Ref.No:5/8/5/19/2014-ECD-I)
文摘Tuberculosis(TB) is a communicable disease caused by Mycobacterium tuberculosis(M. tuberculosis). WHO estimated that 10.4 million new(incident) TB cases worldwide in year 2016. The increased prevalence of drug resistant strains and side effects associated with the current anti-tubercular drugs make the treatment options more complicated. Hence, there are necessities to identify new drug candidates to fight against various sub-populations of M. tuberculosis with less or no toxicity/side effects and shorter treatment duration. Bacteriocins produced by lactic acid bacteria(LAB) attract attention of researchers because of its "Generally recognized as safe" status. LAB and its bacteriocins possess an effective antimicrobial activity against various bacteria and fungi. Interestingly bacteriocins such as nisin and lacticin 3147 have shown antimycobacterial activity in vitro. As probiotics, LAB plays a vital role in promoting various health benefits including ability to modulate immune response against various infectious diseases. LAB and its metabolic products activate immune system and thereby limiting the M. tuberculosis pathogenesis. The protein and peptide engineering techniques paved the ways to obtain hybrid bacteriocin derivatives from the known peptide sequence of existing bacteriocin. In this review, we focus on the antimycobacterial property and immunomodulatory role of LAB and its metabolic products. Techniques for large scale synthesis of potential bacteriocin with multifunctional activity and enhanced stability are also discussed.
基金Supported by 863 Projects (2008AA10Z311)National Science and Technology Support Projects (2009BADB9B06)+1 种基金Started Post-doctoral Research Grant of Heilongjiang Province (LBH-Q07023)Harbin Technological Innovation of Special Funds (2007RFQXN020)
文摘According to the sequence of the bile salt hydrolase （BSH） gene of Bifidobacterium and the restriction enzyme cutting sites of expression vector pNZ8148, primers were designed and the bile salt hydrolase （BSH） gene was gotten from Bacillus bifidus ATCC 29521 by PCR. BSH gene was inserted into lactic acid bacteria expression vector pNZ8148 to construct the recombinant pNZ8148-BSH. The recombinant pNZ8148-BSH was transferred into lactic acid bacteria NZ9000 with electrotransformation method. And the recombinant which could express BSH protein was obtained. It was identified by SDS-PAGE electrophoresis and activity verification. The result could provide a rationale reference for expressing BSH in lactic acid bacteria.
基金supported by the funds from the National Natural Science Foundation of China (30760008)
文摘[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium containing calcium carbonate, and they were preliminarily identified through morphological, physiological and biochemical experiments. The acid production efficiency was determined. Twelve strains having strong acid-pro- duction ability were selected, and their salt tolerance and acid tolerance were detected. The sequences of their 16 S rDNA were also analyzed. [ Result] A total of 44 lactic acid bacterium strains were isolated from the forage com. As evidenced by the physiological and biochemical experi- ments, the twelve strains having strong acid-production ability belonged to Leuconostoc, Lactobacillus and Enterococcus, respectively, and they had strong salt tolerance and acid tolerance. According to the sequences of 16 S rDNA, A4, B9, B11, B12 and B14 were Lactobacillus plantarum; A1, A2., A7, A11 and B8 were Leuconostoc mesenteroides dextran subspecies; and AB and A9 were Enterococcus hirae. [ Conclusion ] The lactic acid bacterium strains with strong acid-production ability isolated from forage corn can be developed into silage additives.
基金Funding for this project was provided by Fundamental Research Grant Scheme(FRGS)of the Ministry of Higher Education,Malaysia(zuhainis@upm.edu.my)(Grant number:5524488)
文摘Objective: To investigate the antibacterial effect of selected lactic acid bacteria(LAB)biofilms on the planktonic and biofilm population of methicillin-resistant Staphylococcus aureus(MRSA)(S547).Methods: In this study, biofilm-forming LAB were isolated from tairu and kefir. Isolate Y1 and isolate KF were selected based on their prominent inhibition against test pathogens(using spot-on-agar method and agar-well-diffusion assay) and efficient biofilm production(using tissue culture plate method). They were then identified as Lactobacillus casei(L. casei) Y1 and Lactobacillus plantarum(L. plantarum) KF, respectively using16 S r DNA gene sequencing. The influence of incubation time, temperature and aeration on the biofilm production of L. casei Y1 and L. plantarum KF was also investigated using tissue culture plate method. The inhibitory activity of both the selected LAB biofilms was evaluated against MRSA(Institute for Medical Research code: S547) using L. plantarum ATCC 8014 as the reference strain.Results: L. casei Y1 showed the highest reduction of MRSA biofilms, by 3.53 log at48 h while L. plantarum KF records the highest reduction of 2.64 log at 36 h. In inhibiting planktonic population of MRSA(S547), both L. casei Y1 and L. plantarum KF biofilms recorded their maximum reduction of 4.13 log and 3.41 log at 24 h, respectively. Despite their inhibitory effects being time-dependent, both LAB biofilms exhibited good potential in controlling the biofilm and planktonic population of MRSA(S547).Conclusions: The results from this study could highlight the importance of analysing biofilms of LAB to enhance their antibacterial efficacy. Preferably, these protective biofilms of LAB could also be a better alternative to control the formation of biofilms by pathogens such as MRSA.
文摘Eight cholesterol-lowering lactic acid bacteria(LAB 1 through 8)isolated from pickles and yogurt were evaluated for probiotic potential based on their tolerance to low pH and bile salt and antagonistic activity against Staphylococcus aureusand Escherichia coli.Strain LAB 4 had excellent tolerance to low pH and bile salt and all 8 LAB strains had antagonisticactivity against Staphylococcus aureus and Escherichia coli.Moreover,strain LAB4 had synergic cholesterol-lowering effect with 0.0125%licorice root extract,0.025%Chinese wolfberry extract or 0.025%milkvetch root extract.
文摘In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host＇s defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.
基金funded by the National Natural Science Foundation of China(32172232 and 31771990)the Major Science and Technology Projects of Heilongjiang Province(2021ZX12B05).
文摘The effects of the co-inoculation of Debaryomyces hansenii separately with 3 lactic acid bacteria(LAB),Lactobacillus sakei,Lactobacillus plantarum and Lactobacillus curvatus,on the taste and odour profi les of dry sausages were investigated.The co-inoculated sausages showed higher free amino acid and organic acid contents than the non-inoculated control and sausages inoculated with D.hansenii alone.Meanwhile,the sausages inoculated with D.hansenii+L.plantarum,D.hansenii+L.sakei and D.hansenii+L.curvatus had the highest contents of aldehydes,esters and alcohols,respectively.The results of electronic tongue,electronic nose and sensory evaluation demonstrated that compared with the sausage inoculated with D.hansenii,the sour taste and fl oral odour increased and the fatty odour decreased in the sausage inoculated with D.hansenii+L.sakei;this was more favourable for the development of a desirable fl avour in sausages.Moreover,the partial least squares regression analysis indicated that 10 taste and 33 odour compounds were mainly responsible for the differences in the flavour profiles among the sausages.Overall,these findings contributed to a more comprehensive understanding of the formation of sensory characteristics in dry sausages co-inoculated with yeast and LAB.
基金Chiang Mai University provided the financial supports for Innovation Center for Holistic Health,Nutraceuticals,and Cosmeceuticals(CMUgrant sanction,Dated:1 October 2016)
文摘Objective: To study some soybean cultivars commonly used in Northern Thailand that exhibit high nutritional profile and to investigate the changes in bioactive principles and antioxidant capacity of the fermented soy broth that was prepared using the selected soybean cultivar and Lactobacillus paracasei HII02 mediated fermentation process.Methods: The best soybean cultivar was subjected to fermentation, and then analyzed the phytochemical, antioxidant and nutritional changes by high performance liquid chromatography and spectrophotometric analysis.Results: Sor Jor 2 soybean cultivar showed rich nutritional profile and was subjected to fermentation process. Lactobacillus paracasei HII02 mediated fermentation of Sor Jor 2 soybean exhibited stable physical and chemical characteristics. Lactic acid bacteria mediated fermentation also increased the aglycone forms of isoflavone content, exhibited antioxidant capacity and thereby enhanced the quality of the fermented soy broth. It also prevented the growth of coliforms in fermented soybean.Conclusions: The study results suggest that fermented soybean is rich in nutrition and considered to be safe for consumption for the improvement of health and to treat the malnutrition.
基金supported by the National Key Research and Development Program of China(2021YFD2100902-3)the National Natural Science Foundation of China(32072258)+5 种基金Major Science and Technology Program of Heilongjiang(2020ZX08B02)Harbin University of Commerce“Young Innovative Talents”Support Program(2019CX062020CX262020CX27)the Central Financial Support for the Development of Local Colleges and Universities,Graduate Innovation Research Project of Harbin University of Commerce(YJSCX2021-698HSD)Training plan of Young Innovative Talents in Universities of Heilongjiang(UNPYSCT-2020218).
文摘The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.
基金supported by Jiangsu Agriculture Science and Technology Innovatioin Fund(CX(21)2003)。
文摘In this study,a new type of 3 D printed living biological hydrogel was developed by integrating lactic acid bacteria(LAB)into biocompatible and non-toxic polymer materials.Interestingly,the living materials loaded with LAB can be freeze-dried and reused for more than 100 times.The bio-hydrogel can be used to co-culture different LAB and keep its fermentation performance stable in long-term use.The release kinetics model and response surface method were used to simulate and optimize the bacteria release mode in the bio-hydrogel.The results show that the release of bacteria from hydrogel is regulated by the coupling of Fickian diffusion and polymer swelling.The stability of LAB hydrogel was evaluated by reuse experiments.The images of confocal microscopy and scanning electron microscope showed that the bacteria with high cell viability were distributed in the hydrogel and intact structure of the living hydrogel was maintained after 100 times of reuse as yoghurt starter.In conclusion,the 3 D printed LAB bio-hydrogel developed in this study has the advantage of reuse and sustainability,which is expected to open up a new way for the preparation of food culture starter.
