Anaerobic Fermentation Hydrogen Production Reactor Continuous Operation And The Study Of Proteomics

The anaerobic fermentation hydrogen production technology is a bio-hydrogen production technology that scientists pay more attention to it in recent years.This technology is used to effectively combine high-concentration organic wastewater with hydrogen production,and gradually develops an anaerobic fermentation hydrogen reactor with high hydrogen production efficiency,stable operation,and suitable for industrial production.The research on anaerobic fermentation hydrogen production reactor and hydrogen-producing bacterial proteomics provides important information for further improving the hydrogen production efficiency of anaerobic fermentation hydrogen production reactor.In this study,the continuous operation of continuous flow stirred tank anaerobic fermentation reactor?CSTR?was used to treat high-concentration molasses wastewater and domesticate activated sludge.The high-throughput sequencing technology of Illumina Mi Seq platform was used to compare and analyze the dominant microbial composition in different stages of start-up operation,and the high-efficiency hydrogen-producing strain was screened.Furthermore,using the quantitative proteomics technology based on iTRAQ labeling,the abundance difference protein in the hydrogen production process of the strain was analyzed.The results showed that the domestication of anaerobic activated sludge was well completed according to twice start-up operation of CSTRs with different initial sludge loads.The reactor effluent p H value is stable between 4.7⁴.9,and the domesticated sludge has good sedimentation performance.The total amount of liquid fermentation products during two reactor operation were 1,298mg?L^-1and 1,934 mg?L^-1,Among them,the acetic acid and butyric acid in total mass of the fermentation product accounted for 73.1% and 70.8%,so twice reactors start-up operation are all butyric acid type fermentation.The dominant bacterial flora analysis showed that,Ethanoligenes,Megasphaera and Clostridium IV were formed by activated sludgedomestication during the first reactor start-up operation.During the second reactor start-up operation,the dominant bacteria group mainly consists of Megasphaera and Ethanoligenens through activated sludge domestication.After twice reactor start-up operations activated sludge domestication,the strains related to the hydrogen production account for more than 40% of the microorganisms' total amount in the sludge.It is proved that the twice reactors are started-up well,the purpose of sludge domestication is achieved,and the target strain is obtained.Through the separation and screening of acclimated activated sludge,8 strains of hydrogen-producing strains were screened out,and further batch experiments were carried out to select the best strains for hydrogen production.The strain WJY-29 had the highest hydrogen production capacity,cumulative gas production and cumulative hydrogen production were 3,464mL/L-culture and 2,004mL/L-culture.16 Sr DNA analysis showed that the strain WJY-29 and the Clostridium beijerinckii NRRL B-598 gene sequence homology was 99%.Quantitative proteomics analysis based on i TRAQ labeling was performed on Clostridium beijerinckii cultured at p H 6.5 for 10h,15h and 30h culture time.Three biological replicates identified 757 abundance difference proteins,of which 378 proteins abundance increased,339 protein abundance decreased.The protein abundance of glucose-phosphate isomerase,enolase,aldehyde dehydrogenase,and fructose-diphosphate aldolase protein abundance increased significantly at different culture times of Clostridium beijerinckii WJY-29.In addition,the protein abundance of ferredoxin [Fe Fe]-hydrogenase,formatted dehydrogenase,and pyruvate oxidoreductase increased significantly in different culture time of Clostridium beijerinckii WJY-29.From this,it can be inferred that the hydrogen production pathway of Clostridium beijerinckii WJY-29 is that in the strict anaerobic medium,it ferments glucose,and decomposes glucose into pyruvic acid,decarboxylation of pyruvate under the action of pyruvate dehydrogenase,hydroxyethyl combined with the enzyme thiamine pyrophosphate to form acetyl-Co A,acetyl-Co A is dehydrogenated to reduce ferredoxin,and further,under the action of hydrogenase,ferredoxin is reoxidized by ferredoxin hydrogenase and releases H₂.