Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover re...Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.展开更多
BACKGROUND: Sepsis is a life-threatening inflammatory condition in which the invading pathogen avoids the host's defense mechanisms and continuously stimulates and damages host cells. Consequently, many immune res...BACKGROUND: Sepsis is a life-threatening inflammatory condition in which the invading pathogen avoids the host's defense mechanisms and continuously stimulates and damages host cells. Consequently, many immune responses initially triggered for protection become harmful because of the failure to restore homeostasis, resulting in ongoing hyperinflammation and immunosuppression. METHODS: A literature review was conducted to address bacterial sepsis, describe advances in understanding complex immunological reactions, critically assess diagnostic approaches, and emphasize the importance of studying bacterial bottlenecks in the detection and treatment of sepsis.RESULTS: Diagnosing sepsis via a single laboratory test is not feasible;therefore, multiple key biomarkers are typically monitored, with a focus on trends rather than absolute values. The immediate interpretation of sepsis-associated clinical signs and symptoms, along with the use of specific and sensitive laboratory tests, is crucial for the survival of patients in the early stages. However, long-term mortality associated with sepsis is now recognized, and alongside the progression of this condition, there is an in vivo selection of adapted pathogens.CONCLUSION: Bacterial sepsis remains a significant cause of mortality across all ages and societies. While substantial progress has been made in understanding the immunological mechanisms underlying the inflammatory response, there is growing recognition that the ongoing host-pathogen interactions, including the emergence of adapted virulent strains, shape both the acute and long-term outcomes in sepsis. This underscores the urgent need for novel high-throughput diagnostic methods and a shift toward more pre-emptive, rather than reactive, treatment strategies in sepsis care.展开更多
In this study,two wheat-derived cadmium(Cd)-immobilizing endophytic Pseudomonas paralactis M14 and Priestia megaterium R27 were evaluated for their effects on wheat tissue Cd uptake under hydroponic conditions.Then,th...In this study,two wheat-derived cadmium(Cd)-immobilizing endophytic Pseudomonas paralactis M14 and Priestia megaterium R27 were evaluated for their effects on wheat tissue Cd uptake under hydroponic conditions.Then,the impacts of the biochar(BC),M14+R27(MR),and BC+MR treatments on wheat Cd uptake and the mechanisms involved were investigated at the jointing,heading,and mature stages of wheat plants under field-plot conditions.A hydroponic experiment showed that the MR treatment significantly decreased the above-ground tissue Cd content compared with theM14 or R27 treatment.The BC+MRtreatment reduced the grain Cd content by 51.5%-67.7%and Cd translocation factor at the mature stage of wheat plants and increased the organic matter-bound Cd content by 31%-75%in the rhizosphere soils compared with the BC or MR treatment.Compared with the BC or MR treatment,the relative abundances of the biomarkers associated with Gemmatimonas,Altererythrobacter,Gammaproteobacteria,Xanthomonadaceae,Phenylobacterium,and Nocardioides in the BC+MR-treated rhizosphere microbiome decreased and negatively correlated with the organic matter-bound Cd contents.In the BC+MR-treated root interior microbiome,the relative abundance of the biomarker belonging to Exiguobacterium increased and negatively correlated with the Cd translocation factor,while the relative abundance of the biomarker belonging to Pseudonocardiaceae decreased and positively correlated with the Cd translocation factor.Our findings suggested that the BC+MR treatment reduced Cd availability and Cd transfer through affecting the abundances of these specific biomarkers in the rhizosphere soil and root interior microbiomes,leading to decreased wheat grain Cd uptake in the contaminated soil.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
Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially i...Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially impact carbon(C),nitrogen(N)and phosphorus(P)biogeochemistry through their respective roles.This study characterizes the phytoplankton,bacteria and virus communities and the elemental composition of various C,N and P nutrients flow over three diel cycles in tropical urban lake.Our results show that ratios of C:N:P fluctuated strongly from the lack of dissolved organic phosphorus(DOP)and PO_(4).Specifically,green algae peaked during day time and exudate dissolved organic matter(DOM)that strongly modulate dissolved organic carbon(DOC):DOP ratio to diel DOP limitation.Multiple linear regression and Stella modelling emphasize the roles of viruses together with Synechococcus as important nutrient recyclers of NH_(4)and PO_(4)in nutrients-limited waters.Respective normalised surface PO_(4)and combined surface and bottom NH_(4)concentration selected both viruses and Synechococcus as important drivers.Process model of N and P biogeochemical cycles can achieve 69%and 57%similar to observed concentration of NH_(4)and PO_(4),respectively.A short latent period of 9 hr was calculated,in addition to the calibrated high infectivity of viruses to Synechococcus.Taken together,the rapid turn-over between Synechococcus and viruses has biogeochemical significance,where the rapid recycling of essential nutrients allows for shortcuts in the N and P cycle,supporting a wide range of microbes.展开更多
Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment proc...Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment processes used in wastewater treatment plants have a limited efficiencies of antibiotics resistant bacteria(ARB)disinfection and ARGs degradation and even promote the proliferation of ARGs.Problematically,ARB and ARGs in effluent pose potential risks if they are not further treated.Photocatalytic oxidation is considered a promising disinfection technology,where the photocatalytic process generates many free radicals that enhance the interaction between light and deoxyribonucleic acid(DNA)for ARB elimination and subsequent degradation of ARGs.This reviewaims to illustrate the progress of photocatalytic oxidation technology for removing antibiotics resistant(AR)from wastewater in recent years.We discuss the sources and transfer of ARGs in wastewater.The overall removal efficiencies of ultraviolet radiation(UV)/chlorination,UV/ozone,UV/H_(2)O_(2),and UV/sulfate-radical based system for ARB and ARGs,as well as the experimental parameters and removal mechanisms,are systematically discussed.The contribution of photocatalytic materials based on TiO_(2) and g-C_(3)N_(4) to the inactivation of ARB and degradation of ARGs is highlighted,producingmany free radicals to attack ARB and ARGs while effectively limiting the horizontal gene transfer(HGT)in wastewater.Finally,based on the reviewed studies,future research directions are proposed to realize specific photocatalytic oxidation technology applications and overcome current challenges.展开更多
The Literary Lab at Stanford University is one of the birthplaces of digital humanities and has maintained significant influence in this field over the years.Professor Hui Haifeng has been engaged in research on digit...The Literary Lab at Stanford University is one of the birthplaces of digital humanities and has maintained significant influence in this field over the years.Professor Hui Haifeng has been engaged in research on digital humanities and computational criticism in recent years.During his visiting scholarship at Stanford University,he participated in the activities of the Literary Lab.Taking this opportunity,he interviewed Professor Mark Algee-Hewitt,the director of the Literary Lab,discussing important topics such as the current state and reception of DH(digital humanities)in the English Department,the operations of the Literary Lab,and the landscape of computational criticism.Mark Algee-Hewitt's research focuses on the eighteenth and early nineteenth centuries in England and Germany and seeks to combine literary criticism with digital and quantitative analyses of literary texts.In particular,he is interested in the history of aesthetic theory and the development and transmission of aesthetic and philosophical concepts during the Enlightenment and Romantic periods.He is also interested in the relationship between aesthetic theory and the poetry of the long eighteenth century.Although his primary background is English literature,he also has a degree in computer science.He believes that the influence of digital humanities within the humanities disciplines is growing increasingly significant.This impact is evident in both the attraction and assistance it offers to students,as well as in the new interpretations it brings to traditional literary studies.He argues that the key to effectively integrating digital humanities into the English Department is to focus on literary research questions,exploring how digital tools can raise new questions or provide new insights into traditional research.展开更多
化工科研实验室因学科特性,科研人员在开展研发工作时面临一定安全风险。如何保障实验室科研环境安全、消除潜在安全隐患,是值得深入探讨的问题。Lab Take Two是一种行为安全管理模式,即利用较短时间思考即将开展工作的计划、安全风险...化工科研实验室因学科特性,科研人员在开展研发工作时面临一定安全风险。如何保障实验室科研环境安全、消除潜在安全隐患,是值得深入探讨的问题。Lab Take Two是一种行为安全管理模式,即利用较短时间思考即将开展工作的计划、安全风险及潜在问题,并针对发现的安全风险和潜在问题采取相应控制手段,以消除实验室潜在安全隐患,属于实验室行为安全理论。通过实施Lab Take Two行为安全管理,可引导员工主动发现实验室潜在安全隐患,有效降低实验室风险,减少科研实验室未遂事件和事故,为化工科研工作提供有力保障。展开更多
Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle H...Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.展开更多
Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria asso...Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria associated with three halophytes in an arid land,Northwest China.The bacterial strains were isolated from the roots,shoots,rhizosphere,and bulk soil of three halophytes,i.e.,Salicornia europaea L.,Kalidium foliatum(Pall.)Moq.,and Suaeda aralocaspica(Bunge)Freitag&Schütze,collected from the saline soils near to the Wujiaqu City,Xinjiang,Northwest China.A total of 567 strains were isolated and identified from these three halophytes belonging to 4 phyla,6 classes,25 orders,36 families,and 66 genera,including 147 potential novel species.A total of 213 strains exhibited one or more plant growthpromoting properties,while 20 strains demonstrated multiple in vitro plant growth-promoting activities,including phosphate solubilization,nitrogen fixation,siderophore production,and production of hydrolytic enzymes such as protease and cellulase.Our findings showed that halophytes in the arid land harbor diverse bacteria with the potential to enhance plant growth and adaptability under challenging environmental conditions.展开更多
Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placeb...Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.展开更多
Mastitis is an inflammatory infection of the mammary glands that is frequently observed in animals. The aim of this study was to determine the prevalence of this infection, identify the pathogens responsible and highl...Mastitis is an inflammatory infection of the mammary glands that is frequently observed in animals. The aim of this study was to determine the prevalence of this infection, identify the pathogens responsible and highlight the risk factors in the region of Labé (Republic of Guinea). The survey involved 96 farmers in three prefectures (Koubia, Labé, Lélouma) and covered 3,199 animals, including 611 lactating females. The clinical survey revealed 49 suspected cases of mastitis, mainly in goats. The analysis showed a prevalence of clinical mastitis of 2.95% and a mortality rate of 18.35%. The identified risk factors were the hygiene of the premises, the age of the females, husbandry practices and the lack of regular veterinary care.展开更多
Both the broad-spectrum bactericidal properties of disinfectants and the inhibitory effects of antibiotics pose potential threats to the activity,functionality,and probiotic properties of Lactid acid bacteria(LAB).The...Both the broad-spectrum bactericidal properties of disinfectants and the inhibitory effects of antibiotics pose potential threats to the activity,functionality,and probiotic properties of Lactid acid bacteria(LAB).Therefore,it is essential to systematically evaluate the tolerance of lactic acid bacteria to common disinfectants and antibiotics.This study assessed 60 LAB strains isolated from the fermented foods for their tolerance to seven disinfectants and nine antibiotics.The results indicated that,compared to pathogenic bacteria,most LAB exhibited stronger tolerance to disinfectants.Sub-inhibitory concentrations of disinfectants inhibited biofilm formation in most LAB,while sub-inhibitory concentrations of glutaraldehyde tended to promote biofilm formation.This suggests that commonly used disinfectants can eliminate pathogenic bacteria without killing LAB,providing guidance for disinfectant use.LAB were highly sensitive to ampicillin and chloramphenicol,while showing some tolerance to norfloxacin,polymyxin,and sulfamethoxazole.This indicates LAB have a notable antibiotic resistance profile,which includes both natural resistance characteristics and instances of acquired resistance,along with multiple drug resistance and cross-resistance between antibiotics and disinfectants.This study provides an important guidance for disinfection practices in industrial utilizing LAB,such as food and biomedicine,and offers a reference for the use of antibiotics.展开更多
The Makran Sea is a complex marine environment.The purpose of this research is screening of emulsifier-producing bacteria in this marine environment and optimization of emulsifier production by the best-producing stra...The Makran Sea is a complex marine environment.The purpose of this research is screening of emulsifier-producing bacteria in this marine environment and optimization of emulsifier production by the best-producing strain.Marine samples(seawater and sediments)were collected from four different zones in the Makran Sea.The emulsification activity index(E_(24))and Bacterial Ad-hesion To Hydrocarbons(BATH)were used to select the best emulsifier-producing strains.The prevalent strains were identified by PCR.The optimization of the emulsifier production medium by the best strain was done by two-level factorial design.Seventeen emulsifier-producing strains were isolated from sediments and seawater in the Makran Sea.The strains M6,BS-2,and J6 were select-ed between all isolates because they have 83%,91%,and 85%emulsification activity(E_(24))respectively.The results of sequencing confirmed that these three strains(M6,BS-2,and J6)belong to Cobetia marina,Shewanella alga,and Thalassospira permensis re-spectively.Maximum emulsifier production occurred at crude oil concentration(4%,v/v),peptone(2.5 g/L),yeast extract(1.5 g/L),molasses(2%),and at a temperature of 25℃.The results of this research confirmed that the Makran Sea has the potential to reach ro-bust marine bacteria with different biotechnological applications.展开更多
基金supported by the Key-Area Research and Development Program of Guangdong Province,China(No.2021B0202030002)the Science and Technology Planning Project of Guangdong Province,China(No.2019B030301007)+2 种基金the Guangdong Provincial Special Project of Rural Revitalization Strategy,China(No.(2021)12)the Joint Team Project of Guangdong Laboratory for Lingnan Modern Agriculture,China(No.NT2021010)the Innovation Team Construction Project of Modern Agricultural Industry Technology Systems of Guangdong Province,China(No.2022KJ105).
文摘Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.
基金funded by the Deanship of Scientific Research (DSR) at King Abdulaziz UniversityJeddah+1 种基金Saudi Arabiaunder grant number G-150-248-1443。
文摘BACKGROUND: Sepsis is a life-threatening inflammatory condition in which the invading pathogen avoids the host's defense mechanisms and continuously stimulates and damages host cells. Consequently, many immune responses initially triggered for protection become harmful because of the failure to restore homeostasis, resulting in ongoing hyperinflammation and immunosuppression. METHODS: A literature review was conducted to address bacterial sepsis, describe advances in understanding complex immunological reactions, critically assess diagnostic approaches, and emphasize the importance of studying bacterial bottlenecks in the detection and treatment of sepsis.RESULTS: Diagnosing sepsis via a single laboratory test is not feasible;therefore, multiple key biomarkers are typically monitored, with a focus on trends rather than absolute values. The immediate interpretation of sepsis-associated clinical signs and symptoms, along with the use of specific and sensitive laboratory tests, is crucial for the survival of patients in the early stages. However, long-term mortality associated with sepsis is now recognized, and alongside the progression of this condition, there is an in vivo selection of adapted pathogens.CONCLUSION: Bacterial sepsis remains a significant cause of mortality across all ages and societies. While substantial progress has been made in understanding the immunological mechanisms underlying the inflammatory response, there is growing recognition that the ongoing host-pathogen interactions, including the emergence of adapted virulent strains, shape both the acute and long-term outcomes in sepsis. This underscores the urgent need for novel high-throughput diagnostic methods and a shift toward more pre-emptive, rather than reactive, treatment strategies in sepsis care.
基金supported by the National Natural Science Foundation of China(No.41977199).
文摘In this study,two wheat-derived cadmium(Cd)-immobilizing endophytic Pseudomonas paralactis M14 and Priestia megaterium R27 were evaluated for their effects on wheat tissue Cd uptake under hydroponic conditions.Then,the impacts of the biochar(BC),M14+R27(MR),and BC+MR treatments on wheat Cd uptake and the mechanisms involved were investigated at the jointing,heading,and mature stages of wheat plants under field-plot conditions.A hydroponic experiment showed that the MR treatment significantly decreased the above-ground tissue Cd content compared with theM14 or R27 treatment.The BC+MRtreatment reduced the grain Cd content by 51.5%-67.7%and Cd translocation factor at the mature stage of wheat plants and increased the organic matter-bound Cd content by 31%-75%in the rhizosphere soils compared with the BC or MR treatment.Compared with the BC or MR treatment,the relative abundances of the biomarkers associated with Gemmatimonas,Altererythrobacter,Gammaproteobacteria,Xanthomonadaceae,Phenylobacterium,and Nocardioides in the BC+MR-treated rhizosphere microbiome decreased and negatively correlated with the organic matter-bound Cd contents.In the BC+MR-treated root interior microbiome,the relative abundance of the biomarker belonging to Exiguobacterium increased and negatively correlated with the Cd translocation factor,while the relative abundance of the biomarker belonging to Pseudonocardiaceae decreased and positively correlated with the Cd translocation factor.Our findings suggested that the BC+MR treatment reduced Cd availability and Cd transfer through affecting the abundances of these specific biomarkers in the rhizosphere soil and root interior microbiomes,leading to decreased wheat grain Cd uptake in the contaminated soil.
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.
文摘Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially impact carbon(C),nitrogen(N)and phosphorus(P)biogeochemistry through their respective roles.This study characterizes the phytoplankton,bacteria and virus communities and the elemental composition of various C,N and P nutrients flow over three diel cycles in tropical urban lake.Our results show that ratios of C:N:P fluctuated strongly from the lack of dissolved organic phosphorus(DOP)and PO_(4).Specifically,green algae peaked during day time and exudate dissolved organic matter(DOM)that strongly modulate dissolved organic carbon(DOC):DOP ratio to diel DOP limitation.Multiple linear regression and Stella modelling emphasize the roles of viruses together with Synechococcus as important nutrient recyclers of NH_(4)and PO_(4)in nutrients-limited waters.Respective normalised surface PO_(4)and combined surface and bottom NH_(4)concentration selected both viruses and Synechococcus as important drivers.Process model of N and P biogeochemical cycles can achieve 69%and 57%similar to observed concentration of NH_(4)and PO_(4),respectively.A short latent period of 9 hr was calculated,in addition to the calibrated high infectivity of viruses to Synechococcus.Taken together,the rapid turn-over between Synechococcus and viruses has biogeochemical significance,where the rapid recycling of essential nutrients allows for shortcuts in the N and P cycle,supporting a wide range of microbes.
基金supported by the National Natural Science Foundation of China (Nos.52100182 and 52300204)the the Science and Technology Innovation Program of Hunan Province (No.2023RC3122).
文摘Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment processes used in wastewater treatment plants have a limited efficiencies of antibiotics resistant bacteria(ARB)disinfection and ARGs degradation and even promote the proliferation of ARGs.Problematically,ARB and ARGs in effluent pose potential risks if they are not further treated.Photocatalytic oxidation is considered a promising disinfection technology,where the photocatalytic process generates many free radicals that enhance the interaction between light and deoxyribonucleic acid(DNA)for ARB elimination and subsequent degradation of ARGs.This reviewaims to illustrate the progress of photocatalytic oxidation technology for removing antibiotics resistant(AR)from wastewater in recent years.We discuss the sources and transfer of ARGs in wastewater.The overall removal efficiencies of ultraviolet radiation(UV)/chlorination,UV/ozone,UV/H_(2)O_(2),and UV/sulfate-radical based system for ARB and ARGs,as well as the experimental parameters and removal mechanisms,are systematically discussed.The contribution of photocatalytic materials based on TiO_(2) and g-C_(3)N_(4) to the inactivation of ARB and degradation of ARGs is highlighted,producingmany free radicals to attack ARB and ARGs while effectively limiting the horizontal gene transfer(HGT)in wastewater.Finally,based on the reviewed studies,future research directions are proposed to realize specific photocatalytic oxidation technology applications and overcome current challenges.
文摘The Literary Lab at Stanford University is one of the birthplaces of digital humanities and has maintained significant influence in this field over the years.Professor Hui Haifeng has been engaged in research on digital humanities and computational criticism in recent years.During his visiting scholarship at Stanford University,he participated in the activities of the Literary Lab.Taking this opportunity,he interviewed Professor Mark Algee-Hewitt,the director of the Literary Lab,discussing important topics such as the current state and reception of DH(digital humanities)in the English Department,the operations of the Literary Lab,and the landscape of computational criticism.Mark Algee-Hewitt's research focuses on the eighteenth and early nineteenth centuries in England and Germany and seeks to combine literary criticism with digital and quantitative analyses of literary texts.In particular,he is interested in the history of aesthetic theory and the development and transmission of aesthetic and philosophical concepts during the Enlightenment and Romantic periods.He is also interested in the relationship between aesthetic theory and the poetry of the long eighteenth century.Although his primary background is English literature,he also has a degree in computer science.He believes that the influence of digital humanities within the humanities disciplines is growing increasingly significant.This impact is evident in both the attraction and assistance it offers to students,as well as in the new interpretations it brings to traditional literary studies.He argues that the key to effectively integrating digital humanities into the English Department is to focus on literary research questions,exploring how digital tools can raise new questions or provide new insights into traditional research.
文摘化工科研实验室因学科特性,科研人员在开展研发工作时面临一定安全风险。如何保障实验室科研环境安全、消除潜在安全隐患,是值得深入探讨的问题。Lab Take Two是一种行为安全管理模式,即利用较短时间思考即将开展工作的计划、安全风险及潜在问题,并针对发现的安全风险和潜在问题采取相应控制手段,以消除实验室潜在安全隐患,属于实验室行为安全理论。通过实施Lab Take Two行为安全管理,可引导员工主动发现实验室潜在安全隐患,有效降低实验室风险,减少科研实验室未遂事件和事故,为化工科研工作提供有力保障。
基金The National Natural Science Foundation of China under contract Nos 42206126 and 42076044the Natural Science Foundation of Shandong Province under contract No.ZR2021QD099.
文摘Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.
基金funded by the Key Research and Development Project of Xinjiang Uygur Autonomous Region (2024B02015-3)the Regional Coordinated Innovation Project (Shanghai Cooperation Organization Science and Technology Partnership Program) of Xinjiang Uygur Autonomous Region (2025E01024)
文摘Salt-tolerant bacteria associated with halophytes enhance plant resistance and adaptation to environmental stress.The purpose of this study was to investigate the diversity and plant-beneficial traits of bacteria associated with three halophytes in an arid land,Northwest China.The bacterial strains were isolated from the roots,shoots,rhizosphere,and bulk soil of three halophytes,i.e.,Salicornia europaea L.,Kalidium foliatum(Pall.)Moq.,and Suaeda aralocaspica(Bunge)Freitag&Schütze,collected from the saline soils near to the Wujiaqu City,Xinjiang,Northwest China.A total of 567 strains were isolated and identified from these three halophytes belonging to 4 phyla,6 classes,25 orders,36 families,and 66 genera,including 147 potential novel species.A total of 213 strains exhibited one or more plant growthpromoting properties,while 20 strains demonstrated multiple in vitro plant growth-promoting activities,including phosphate solubilization,nitrogen fixation,siderophore production,and production of hydrolytic enzymes such as protease and cellulase.Our findings showed that halophytes in the arid land harbor diverse bacteria with the potential to enhance plant growth and adaptability under challenging environmental conditions.
文摘Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.
文摘Mastitis is an inflammatory infection of the mammary glands that is frequently observed in animals. The aim of this study was to determine the prevalence of this infection, identify the pathogens responsible and highlight the risk factors in the region of Labé (Republic of Guinea). The survey involved 96 farmers in three prefectures (Koubia, Labé, Lélouma) and covered 3,199 animals, including 611 lactating females. The clinical survey revealed 49 suspected cases of mastitis, mainly in goats. The analysis showed a prevalence of clinical mastitis of 2.95% and a mortality rate of 18.35%. The identified risk factors were the hygiene of the premises, the age of the females, husbandry practices and the lack of regular veterinary care.
基金supported by the National Science Foundation of China (32001663)。
文摘Both the broad-spectrum bactericidal properties of disinfectants and the inhibitory effects of antibiotics pose potential threats to the activity,functionality,and probiotic properties of Lactid acid bacteria(LAB).Therefore,it is essential to systematically evaluate the tolerance of lactic acid bacteria to common disinfectants and antibiotics.This study assessed 60 LAB strains isolated from the fermented foods for their tolerance to seven disinfectants and nine antibiotics.The results indicated that,compared to pathogenic bacteria,most LAB exhibited stronger tolerance to disinfectants.Sub-inhibitory concentrations of disinfectants inhibited biofilm formation in most LAB,while sub-inhibitory concentrations of glutaraldehyde tended to promote biofilm formation.This suggests that commonly used disinfectants can eliminate pathogenic bacteria without killing LAB,providing guidance for disinfectant use.LAB were highly sensitive to ampicillin and chloramphenicol,while showing some tolerance to norfloxacin,polymyxin,and sulfamethoxazole.This indicates LAB have a notable antibiotic resistance profile,which includes both natural resistance characteristics and instances of acquired resistance,along with multiple drug resistance and cross-resistance between antibiotics and disinfectants.This study provides an important guidance for disinfection practices in industrial utilizing LAB,such as food and biomedicine,and offers a reference for the use of antibiotics.
基金supported by Shahid Bahonar Universi-ty of Kerman.
文摘The Makran Sea is a complex marine environment.The purpose of this research is screening of emulsifier-producing bacteria in this marine environment and optimization of emulsifier production by the best-producing strain.Marine samples(seawater and sediments)were collected from four different zones in the Makran Sea.The emulsification activity index(E_(24))and Bacterial Ad-hesion To Hydrocarbons(BATH)were used to select the best emulsifier-producing strains.The prevalent strains were identified by PCR.The optimization of the emulsifier production medium by the best strain was done by two-level factorial design.Seventeen emulsifier-producing strains were isolated from sediments and seawater in the Makran Sea.The strains M6,BS-2,and J6 were select-ed between all isolates because they have 83%,91%,and 85%emulsification activity(E_(24))respectively.The results of sequencing confirmed that these three strains(M6,BS-2,and J6)belong to Cobetia marina,Shewanella alga,and Thalassospira permensis re-spectively.Maximum emulsifier production occurred at crude oil concentration(4%,v/v),peptone(2.5 g/L),yeast extract(1.5 g/L),molasses(2%),and at a temperature of 25℃.The results of this research confirmed that the Makran Sea has the potential to reach ro-bust marine bacteria with different biotechnological applications.
