通过纤维小体产生菌Clostridium thermocellum ATCC 27405与产溶剂菌Clostridium beijerinckii NCIMB 8052的偶联培养,直接从木质纤维原料厌氧发酵生产丁醇。首先考察C.thermocellum在60℃下对玉米棒芯的降解情况,初始玉米棒芯浓度为50 ...通过纤维小体产生菌Clostridium thermocellum ATCC 27405与产溶剂菌Clostridium beijerinckii NCIMB 8052的偶联培养,直接从木质纤维原料厌氧发酵生产丁醇。首先考察C.thermocellum在60℃下对玉米棒芯的降解情况,初始玉米棒芯浓度为50 g L-1。分阶段控制发酵pH,并在指数生长期内间歇补给55 g L-1玉米棒芯,C.thermocellum 120h内降解94.3 g L-1玉米棒芯,发酵上清液经稀硫酸水解后,测得总还原糖含量为37.4 g L-1,其中戊糖含量24.8 g L-1,葡萄糖含量5.28 g L-1。进一步研究C.thermocellum和C.beijerinckii偶联发酵,利用玉米棒芯生产总溶剂(丙酮、丁醇、乙醇)浓度达16.0 g L-1,其中丁醇产量高达8.75 g L-1。研究结果表明:该偶联发酵体系无须添加外源纤维素酶,并能同时发酵己糖和戊糖,具有实现生物燃料低成本生产的潜力。展开更多
Microbial utilization and conversion of organic one-carbon compounds,such as formate and methanol that can be easily produced from CO_(2),has emerged as an attractive approach for biorefinery.In this study,we discover...Microbial utilization and conversion of organic one-carbon compounds,such as formate and methanol that can be easily produced from CO_(2),has emerged as an attractive approach for biorefinery.In this study,we discovered Clostridium beijerinckii NCIMB 8052,a typical solventogenic Clostridium strain,to be a native formate-utilizing bacterium.^(13)C isotope analysis showed that formate could be metabolized via both assimilation and dissimi-lation pathways in C.beijerinckii NCIMB 8052.Notably,the use of formate as the supplementary substrate by this strain could significantly enhance its glucose consumption and ABE(acetone-butanol-ethanol)production,largely due to the up-regulation of genes responsible for glycolysis and glucose transport under formate stress.Based on these findings,we further improved formate tolerance of C.beijerinckii NCIMB 8052 by adaptive lab-oratory evolution,generating an evolved strain Cbei-FA01.The Cbei-FA01 strain could produce 23.0 g/L of ABE solvents using glucose and formate as dual substrates,~50%higher than that of the wild-type strain under the same condition.Moreover,such a promotion effect of formate on ABE production by Cbei-FA01 was also observed in fermenting a glucose-xylose mixture.This work reveals a previously unreported role of formate in biological ABE production,providing a new approach to utilize this one-carbon source.展开更多
1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opport...1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L^(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.展开更多
文摘通过纤维小体产生菌Clostridium thermocellum ATCC 27405与产溶剂菌Clostridium beijerinckii NCIMB 8052的偶联培养,直接从木质纤维原料厌氧发酵生产丁醇。首先考察C.thermocellum在60℃下对玉米棒芯的降解情况,初始玉米棒芯浓度为50 g L-1。分阶段控制发酵pH,并在指数生长期内间歇补给55 g L-1玉米棒芯,C.thermocellum 120h内降解94.3 g L-1玉米棒芯,发酵上清液经稀硫酸水解后,测得总还原糖含量为37.4 g L-1,其中戊糖含量24.8 g L-1,葡萄糖含量5.28 g L-1。进一步研究C.thermocellum和C.beijerinckii偶联发酵,利用玉米棒芯生产总溶剂(丙酮、丁醇、乙醇)浓度达16.0 g L-1,其中丁醇产量高达8.75 g L-1。研究结果表明:该偶联发酵体系无须添加外源纤维素酶,并能同时发酵己糖和戊糖,具有实现生物燃料低成本生产的潜力。
基金supported by the National Key R&D Program of China(2018YFA0901500,2021YFC2103500)Science and Technology Commission of Shanghai Municipality(21DZ1209100)+1 种基金DNL Coopera-tion Fund,CAS(DNL202013)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-016).
文摘Microbial utilization and conversion of organic one-carbon compounds,such as formate and methanol that can be easily produced from CO_(2),has emerged as an attractive approach for biorefinery.In this study,we discovered Clostridium beijerinckii NCIMB 8052,a typical solventogenic Clostridium strain,to be a native formate-utilizing bacterium.^(13)C isotope analysis showed that formate could be metabolized via both assimilation and dissimi-lation pathways in C.beijerinckii NCIMB 8052.Notably,the use of formate as the supplementary substrate by this strain could significantly enhance its glucose consumption and ABE(acetone-butanol-ethanol)production,largely due to the up-regulation of genes responsible for glycolysis and glucose transport under formate stress.Based on these findings,we further improved formate tolerance of C.beijerinckii NCIMB 8052 by adaptive lab-oratory evolution,generating an evolved strain Cbei-FA01.The Cbei-FA01 strain could produce 23.0 g/L of ABE solvents using glucose and formate as dual substrates,~50%higher than that of the wild-type strain under the same condition.Moreover,such a promotion effect of formate on ABE production by Cbei-FA01 was also observed in fermenting a glucose-xylose mixture.This work reveals a previously unreported role of formate in biological ABE production,providing a new approach to utilize this one-carbon source.
基金CNPq,FAPERJ and CAPES through the PDSE and Program and Human Resources Program 13 of the National Petroleum Agency (ANP-PRH 13)
文摘1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L^(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.
