Single-cell proteins(SCPs)derived from hydrogen-oxidizing bacteria(HOB)are a promising strategy to address global food challenges.As versatile microorganisms with rich carbon metabolism,they also have the potential to...Single-cell proteins(SCPs)derived from hydrogen-oxidizing bacteria(HOB)are a promising strategy to address global food challenges.As versatile microorganisms with rich carbon metabolism,they also have the potential to address environmental emission issues.HOB efficiently utilize carbon through the Calvin-Benson-Bassham(CBB)cycle under autotrophic conditions,introducing an innovative approach to industrial exhaust treatment.In heterotrophic environments,HOB rapidly degrade organic pollutants,including organic carbon,to meet emis-sion standards.Their nitrogen-fixing capacity further supports the production of sustainable nitrogen fertilizers and enables greener agricultural practices.This study systematically reviews the key metabolic pathways of HOB and summarizes their applications in waste gas treatment,organic pollutant purification,and ammonia pro-duction.The potential of HOB as drivers of sustainable carbon and nitrogen cycling has been confirmed,offering broader solutions to various environmental and food issues.展开更多
Bacteria are key denitrifiers in the reduction of nitrate(NO_(3)^(-)N),which is a contaminant in wastewater treatment plants(WWTPs).They can also produce carbon dioxide(CO_(2))and nitrous oxide(N2O).In this study,the ...Bacteria are key denitrifiers in the reduction of nitrate(NO_(3)^(-)N),which is a contaminant in wastewater treatment plants(WWTPs).They can also produce carbon dioxide(CO_(2))and nitrous oxide(N2O).In this study,the autotrophic hydrogen-oxidizing bacterium Rhodoblastus sp.TH_(2)0 was isolated for sustainable treatment of NO_(3)^(-)N in wastewater.Efficient removal of NO_(3)^(-)N and recovery of biomass nitrogen were achieved.Up to 99%of NO_(3)^(-)N was removed without accumulation of nitrite and N2O,consuming CO_(2)of 3.25 mol for each mole of NO_(3)^(-)N removed.The overall removal rate of NO_(3)^(-)N reached 1.1 mg L^(-1)h^(-1)with a biomass content of approximately 0.71 g L^(-1)within 72 h.TH20 participated in NO_(3)^(-)N assimilation and aerobic denitrification.Results from 15N-labeled-nitrate test indicated that removed NO_(3)^(-)N was assimilated into organic nitrogen,showing an assimilation efficiency of 58%.Seventeen amino acids were detected,accounting for 43%of the biomass.Nitrogen loss through aerobic denitrification was only approximately 42%of total nitrogen.This study suggests that TH_(2)0 can be applied in WWTP facilities for water purification and production of valuable biomass to mitigate CO_(2)and N_(2)O emissions。展开更多
Coupling water electrolysis with hydrogen-oxidizing bacteria(HOB)fermentation is a promising approach for single-cell protein(SCP)production.However,this inorganic-biological hybrid system is hindered by low efficienc...Coupling water electrolysis with hydrogen-oxidizing bacteria(HOB)fermentation is a promising approach for single-cell protein(SCP)production.However,this inorganic-biological hybrid system is hindered by low efficiency,primarily due to the inhibition of electrochemical reactions on microbial activities and low hydrogen utilization.Here,we report an electrolytic gas lift reactor designed to improve the efficiency of this hybrid system for HOB-SCP production.By integrating the cathode of the electrolyzer with a gas lift reactor,the setup mitigated the inhibition of anodic reactive oxygen species on HOB and enhanced hydrogen utilization efficiency.By gradually increasing the current(1-2-4-6 A),the reactor achieved a maximum biomass yield of 0.20 g cell dry weight/L/d,a protein content of 58.3%,and a hydrogen utilization efficiency of 100%.The microbial community was dominated by HOB such as Ancylobacter(74.4%)and Xanthobacter(8.2%).These results indicated that the innovative reactor design effectively improved the performance of HOB-SCP production by inorganic-biological hybrid systems.The electrolytic gas lift reactor demonstrates substantial potential for scaling up and practical applications.展开更多
基金supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2024QB128)the Natural Science Foundation of Qingdao(Grant No.24-4-4-zrjj-187-jch)+1 种基金the Special Project on High-tech Industrialization of Scientific and Technological Cooperation between Jilin Province and the Chinese Academy of Sciences(Grant No.2024SYHZ0002)the Taishan Scholars Program(Grant No.tsqn202312268).
文摘Single-cell proteins(SCPs)derived from hydrogen-oxidizing bacteria(HOB)are a promising strategy to address global food challenges.As versatile microorganisms with rich carbon metabolism,they also have the potential to address environmental emission issues.HOB efficiently utilize carbon through the Calvin-Benson-Bassham(CBB)cycle under autotrophic conditions,introducing an innovative approach to industrial exhaust treatment.In heterotrophic environments,HOB rapidly degrade organic pollutants,including organic carbon,to meet emis-sion standards.Their nitrogen-fixing capacity further supports the production of sustainable nitrogen fertilizers and enables greener agricultural practices.This study systematically reviews the key metabolic pathways of HOB and summarizes their applications in waste gas treatment,organic pollutant purification,and ammonia pro-duction.The potential of HOB as drivers of sustainable carbon and nitrogen cycling has been confirmed,offering broader solutions to various environmental and food issues.
基金the Shenzhen Fundamental Research Programs(JCYJ20180503182122539,JCYJ20180503182130795,and GXWD20201231165807007-20200810165349001)the National Natural Science Foundation of China(51939009).
文摘Bacteria are key denitrifiers in the reduction of nitrate(NO_(3)^(-)N),which is a contaminant in wastewater treatment plants(WWTPs).They can also produce carbon dioxide(CO_(2))and nitrous oxide(N2O).In this study,the autotrophic hydrogen-oxidizing bacterium Rhodoblastus sp.TH_(2)0 was isolated for sustainable treatment of NO_(3)^(-)N in wastewater.Efficient removal of NO_(3)^(-)N and recovery of biomass nitrogen were achieved.Up to 99%of NO_(3)^(-)N was removed without accumulation of nitrite and N2O,consuming CO_(2)of 3.25 mol for each mole of NO_(3)^(-)N removed.The overall removal rate of NO_(3)^(-)N reached 1.1 mg L^(-1)h^(-1)with a biomass content of approximately 0.71 g L^(-1)within 72 h.TH20 participated in NO_(3)^(-)N assimilation and aerobic denitrification.Results from 15N-labeled-nitrate test indicated that removed NO_(3)^(-)N was assimilated into organic nitrogen,showing an assimilation efficiency of 58%.Seventeen amino acids were detected,accounting for 43%of the biomass.Nitrogen loss through aerobic denitrification was only approximately 42%of total nitrogen.This study suggests that TH_(2)0 can be applied in WWTP facilities for water purification and production of valuable biomass to mitigate CO_(2)and N_(2)O emissions。
基金supported by the National Natural Science Foundation of China(No.52204043 and No.32300101)The“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2024C03111)+2 种基金The Capability Program Support of Shaanxi(No.2023-CX-TD-31)China Postdoctoral Science Foundation General Project(No.2024M762609)the Open Fund from the Xi’an Key Labora〓〓tory of C1 Compound Bioconversion Technology.
文摘Coupling water electrolysis with hydrogen-oxidizing bacteria(HOB)fermentation is a promising approach for single-cell protein(SCP)production.However,this inorganic-biological hybrid system is hindered by low efficiency,primarily due to the inhibition of electrochemical reactions on microbial activities and low hydrogen utilization.Here,we report an electrolytic gas lift reactor designed to improve the efficiency of this hybrid system for HOB-SCP production.By integrating the cathode of the electrolyzer with a gas lift reactor,the setup mitigated the inhibition of anodic reactive oxygen species on HOB and enhanced hydrogen utilization efficiency.By gradually increasing the current(1-2-4-6 A),the reactor achieved a maximum biomass yield of 0.20 g cell dry weight/L/d,a protein content of 58.3%,and a hydrogen utilization efficiency of 100%.The microbial community was dominated by HOB such as Ancylobacter(74.4%)and Xanthobacter(8.2%).These results indicated that the innovative reactor design effectively improved the performance of HOB-SCP production by inorganic-biological hybrid systems.The electrolytic gas lift reactor demonstrates substantial potential for scaling up and practical applications.
