D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-...D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-utilizing bacteria from pig gut using the Hungate rol-tube method, and to investigate their metabolic characteristicsin vitro. Six different anaerobes were isolated from pig feces, which were identiifed as related toBacteroides fragilis, Bacteroides acidifaciens,Veilonela denticariosi, Veilonela caviae,Bacteroides uniformis, andMegasphaera elsdenibased on the 16S rRNA gene sequences. Al strains had a signiifcant ability to utilize D-lactate, which was concluded afterin vitro fermentation with 25 mmol L–1 D-lactate as the primary carbon source. Of al 6 strains,M. elsdeniJ6 showed the highest efifciency of D-lactate utilization and produced a higher ratio of butyrate in total short chain fatty acids （SCFAs）. Thus, thein vitro fermentation characteristics of this strain in D-, L-, and DL-lactate mixtures （D-lactate：L-lactate=1：1 or 1：2） were further studied. The results showed that M. elsdeni J6 preferred utilizing D-lactate, and produced more SCFA when using D-lactate as the primary carbon source. The ifndings suggest that the administration of D-lactate-utilizing bacteria such asM. elsdeni J6 may have a potential advantage in the aleviation of D-lactic acidosis in the animal gut.展开更多
Background Ginkgo biloba extract(GBE)is evidenced to be effective in the prevention and alleviation of metabolic disorders,including obesity,diabetes and fatty liver disease.However,the role of GBE in alleviating fatt...Background Ginkgo biloba extract(GBE)is evidenced to be effective in the prevention and alleviation of metabolic disorders,including obesity,diabetes and fatty liver disease.However,the role of GBE in alleviating fatty liver hemorrhagic syndrome(FLHS)in laying hens and the underlying mechanisms remain to be elucidated.Here,we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.Results The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet(HFD)-induced FLHS laying hen model by decreasing the levels of TG,TC,ALT and ALP.The lipid accumulation and pathological score of liver were also relieved after GBE treatment.Moreover,GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH,SOD,T-AOC,GSH-PX and reducing MDA,and downregulated the expression of genes related to lipid synthesis(FAS,LXRα,GPAT1,PPARγand Ch REBP1)and inflammatory cytokines(TNF-α,IL-6,TLR4 and NF-κB)in the liver.Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota,particularly elevated the abundance of Megasphaera in the cecum.Meanwhile,targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs,acetate and propionate,which were positively correlated with the GBE-enriched gut microbiota.Finally,we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation(FMT).Conclusions We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota.Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.展开更多
We present variation patterns of trace elements within different sequences of the Ediacaran Doushantuo Formation(DST,635-551 million years ago),and inside the cells of the earliest differentiated multicellular eukaryo...We present variation patterns of trace elements within different sequences of the Ediacaran Doushantuo Formation(DST,635-551 million years ago),and inside the cells of the earliest differentiated multicellular eukaryotic fossils of the Weng'an biota in the Weng'an County of Guizhou Province.The results showed that selenium is the most enriched and significantly varied trace element among the 22 trace elements throughout the DST,followed by arsenic.The highest selenium and arsenic content sequences are consistent with the first appeared sequence of the earliest differentiated multicellular eukaryotic fossils Megasphaera at the middle to upper parts of the DST.Nanoman secondary ion mass spectrometry analyses show that selenium and arsenic have an inhomogeneous and punctate distribution in the nucleus and cytoplasm.The nucleus has anomalously enriched levels of selenium and arsenic among the organelles.The selenium and arsenic concentrations exhibit a positive correlation with the diversity of fossilized Megasphaera.These new findings give us a clue that the anomalous enrichment of selenium and arsenic might contributes to the cell differentiation in Ediacaran Doushantuo period.展开更多
Gram negative aerobic bacteria such as Acetic Acid Bacteria, which include Acetobacter and Gluconobacter, have historically caused significant problems to brewers. Although incidences of spoilage have recently reduced...Gram negative aerobic bacteria such as Acetic Acid Bacteria, which include Acetobacter and Gluconobacter, have historically caused significant problems to brewers. Although incidences of spoilage have recently reduced as a result of improvements in beer packaging, these bacteria are still a concern in dispense systems in pub breweries, public houses and cask conditioned beers. Gram negative facultative bacteria of the genus Zymomonas can spoil primed cask conditioned beer and cider. There is a wide range of Enterobacteraeceace which are found within brewery environments and they serve as indicator microorganisms for hygiene and sanitation. Gram negative strictly anaerobic bacteria such as Pectinatus and Megasphaera have recently emerged as a significant threat due to the improvement in reduction of oxygen levels in beer and an increase in production of unpasteurised beer. Pectinatus and Megasphaera are sensitive to routine cleaning agents used in breweries, but they can survive and proliferate in biofilms eventually causing spoilage of beer. This review focuses on Gram negative aerobic, facultative anaerobic and strictly anaerobic brewery related spoilage bacteria.展开更多
Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrical...Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrically efficient MES cells with a low ohmic resistance of 15.7 mU m^(2)were operated galvanostatically in fed-batch mode,alternating periods of high CO_(2)and H2 availability.This promoted acetic acid and ethanol production,ultimately triggering selective(78%on a carbon basis)butyric acid production via chain elongation.An average production rate of 14.5 g m^(-2)d^(-1)was obtained at an applied current of 1.0 or 1.5 mA cm^(-2),being Megasphaera sp.the key chain elongating player.Inoculating a second cell with the catholyte containing the enriched community resulted in butyric acid production at the same rate as the previous cell,but the lag phase was reduced by 82%.Furthermore,interrupting the CO_(2)feeding and setting a constant pH2 of 1.7e1.8 atm in the cathode compartment triggered solventogenic butanol production at a pH below 4.8.The efficient cell design resulted in average cell voltages of 2.6e2.8 V and a remarkably low electric energy requirement of 34.6 kWhel kg1 of butyric acid produced,despite coulombic efficiencies being restricted to 45%due to the cross-over of O_(2)and H2 through the membrane.In conclusion,this study revealed the optimal operating conditions to achieve energy-efficient butyric acid production from CO_(2)and suggested a strategy to further upgrade it to valuable butanol.展开更多
基金funding from the National Basic Research Program of China (2013CB127603 and 2012CB124705)the National Natural Science Foundation of China (31572414 and 30901036)the Natural Science Foundation of Jiangsu Province, China (BK20130058)
文摘D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-utilizing bacteria from pig gut using the Hungate rol-tube method, and to investigate their metabolic characteristicsin vitro. Six different anaerobes were isolated from pig feces, which were identiifed as related toBacteroides fragilis, Bacteroides acidifaciens,Veilonela denticariosi, Veilonela caviae,Bacteroides uniformis, andMegasphaera elsdenibased on the 16S rRNA gene sequences. Al strains had a signiifcant ability to utilize D-lactate, which was concluded afterin vitro fermentation with 25 mmol L–1 D-lactate as the primary carbon source. Of al 6 strains,M. elsdeniJ6 showed the highest efifciency of D-lactate utilization and produced a higher ratio of butyrate in total short chain fatty acids （SCFAs）. Thus, thein vitro fermentation characteristics of this strain in D-, L-, and DL-lactate mixtures （D-lactate：L-lactate=1：1 or 1：2） were further studied. The results showed that M. elsdeni J6 preferred utilizing D-lactate, and produced more SCFA when using D-lactate as the primary carbon source. The ifndings suggest that the administration of D-lactate-utilizing bacteria such asM. elsdeni J6 may have a potential advantage in the aleviation of D-lactic acidosis in the animal gut.
基金funded by the National Key Research and Development Program of China(2022YFA1304201)the Beijing Natural Science Foundation(6222032)+2 种基金the Starting Grants Program for Young Talents at China Agricultural Universitythe 2115 Talent Development Program of China Agricultural UniversityChinese Universities Scientific Fund。
文摘Background Ginkgo biloba extract(GBE)is evidenced to be effective in the prevention and alleviation of metabolic disorders,including obesity,diabetes and fatty liver disease.However,the role of GBE in alleviating fatty liver hemorrhagic syndrome(FLHS)in laying hens and the underlying mechanisms remain to be elucidated.Here,we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.Results The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet(HFD)-induced FLHS laying hen model by decreasing the levels of TG,TC,ALT and ALP.The lipid accumulation and pathological score of liver were also relieved after GBE treatment.Moreover,GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH,SOD,T-AOC,GSH-PX and reducing MDA,and downregulated the expression of genes related to lipid synthesis(FAS,LXRα,GPAT1,PPARγand Ch REBP1)and inflammatory cytokines(TNF-α,IL-6,TLR4 and NF-κB)in the liver.Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota,particularly elevated the abundance of Megasphaera in the cecum.Meanwhile,targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs,acetate and propionate,which were positively correlated with the GBE-enriched gut microbiota.Finally,we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation(FMT).Conclusions We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota.Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.
基金supported by the National Natural Science Foundation of China(Grant Nos.41172310 and 41877299)。
文摘We present variation patterns of trace elements within different sequences of the Ediacaran Doushantuo Formation(DST,635-551 million years ago),and inside the cells of the earliest differentiated multicellular eukaryotic fossils of the Weng'an biota in the Weng'an County of Guizhou Province.The results showed that selenium is the most enriched and significantly varied trace element among the 22 trace elements throughout the DST,followed by arsenic.The highest selenium and arsenic content sequences are consistent with the first appeared sequence of the earliest differentiated multicellular eukaryotic fossils Megasphaera at the middle to upper parts of the DST.Nanoman secondary ion mass spectrometry analyses show that selenium and arsenic have an inhomogeneous and punctate distribution in the nucleus and cytoplasm.The nucleus has anomalously enriched levels of selenium and arsenic among the organelles.The selenium and arsenic concentrations exhibit a positive correlation with the diversity of fossilized Megasphaera.These new findings give us a clue that the anomalous enrichment of selenium and arsenic might contributes to the cell differentiation in Ediacaran Doushantuo period.
文摘Gram negative aerobic bacteria such as Acetic Acid Bacteria, which include Acetobacter and Gluconobacter, have historically caused significant problems to brewers. Although incidences of spoilage have recently reduced as a result of improvements in beer packaging, these bacteria are still a concern in dispense systems in pub breweries, public houses and cask conditioned beers. Gram negative facultative bacteria of the genus Zymomonas can spoil primed cask conditioned beer and cider. There is a wide range of Enterobacteraeceace which are found within brewery environments and they serve as indicator microorganisms for hygiene and sanitation. Gram negative strictly anaerobic bacteria such as Pectinatus and Megasphaera have recently emerged as a significant threat due to the improvement in reduction of oxygen levels in beer and an increase in production of unpasteurised beer. Pectinatus and Megasphaera are sensitive to routine cleaning agents used in breweries, but they can survive and proliferate in biofilms eventually causing spoilage of beer. This review focuses on Gram negative aerobic, facultative anaerobic and strictly anaerobic brewery related spoilage bacteria.
基金This research was carried out in the project“PANGEA-Process intensificAtioN for bioelectroCO2 recyclinG into carbon-nEutrAl products)funded by the Spanish Ministry of Innovation and Science(ref.PID2021-126240OB-I00)PD is supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement,project ATMESPHERE,No 101029266+2 种基金MR-C is grateful for the support of the Spanish Government(FPU20/01362)S.P.is a Serra Hunter Fellow(UdG-AG-575)and acknowledges the funding from the ICREA Academia award.LF-P is grateful for the Research Training grant from the Catalan Government(2021 FISDU 00132)LEQUIA and EcoAqua have been recognized by the Catalan Government(Ref 2021 SGR01352 and 2021 SGR01142).
文摘Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrically efficient MES cells with a low ohmic resistance of 15.7 mU m^(2)were operated galvanostatically in fed-batch mode,alternating periods of high CO_(2)and H2 availability.This promoted acetic acid and ethanol production,ultimately triggering selective(78%on a carbon basis)butyric acid production via chain elongation.An average production rate of 14.5 g m^(-2)d^(-1)was obtained at an applied current of 1.0 or 1.5 mA cm^(-2),being Megasphaera sp.the key chain elongating player.Inoculating a second cell with the catholyte containing the enriched community resulted in butyric acid production at the same rate as the previous cell,but the lag phase was reduced by 82%.Furthermore,interrupting the CO_(2)feeding and setting a constant pH2 of 1.7e1.8 atm in the cathode compartment triggered solventogenic butanol production at a pH below 4.8.The efficient cell design resulted in average cell voltages of 2.6e2.8 V and a remarkably low electric energy requirement of 34.6 kWhel kg1 of butyric acid produced,despite coulombic efficiencies being restricted to 45%due to the cross-over of O_(2)and H2 through the membrane.In conclusion,this study revealed the optimal operating conditions to achieve energy-efficient butyric acid production from CO_(2)and suggested a strategy to further upgrade it to valuable butanol.
