TY - JOUR
T1 - Significant enhancement by casamino acids of caproate production via chain elongation
AU - Yang, Peixian
AU - Leng, Ling
AU - Zhuang, Huichuan
AU - Lee, Po Heng
N1 - Funding Information:
This work was supported by the Fundamental Research Funds for the Central Universities ( XJ2021000601 ).
Publisher Copyright:
© 2023
PY - 2023/4
Y1 - 2023/4
N2 - In this study, the effects of casamino acids, as the main component in yeast extract, on the bioproduction of caproate were evaluated. A dosage of 5 g/L casamino acids addition significantly promoted caproate production and shortened the lag phase for caproate production by 7.6-folds compared with the control. Both the net carbon and electron conversion efficiencies were enhanced. The addition of casamino acids shaped a dissimilar microbial community from that of the control and that of the inoculum. The caproate-producing Clostridium and Caproiciproducens, the proteolytic Proteiniphilum and Brassicibacter, and the saccharide-utilizing Hydrogenoanaerobacteriu were enriched, and their abundance were distinguished between with and without the addition of casamino acids as fermentation progressed. Further metagenomics analysis recovered genome bins of Clostridium kluyveri, Clostridium cochlearium, Caprobacter fermentans and Proteiniphilum acetatigenes, representing the majority of the functional bacteria with casamino acids addition. The complete reverse β-oxidation and amino acids (serine/glycine) metabolic pathway for caproate production and butyrate formation, respectively, were fully recovered. Furthermore, all the genes involved were highly expressed and metabolically active in meta-transcriptomics analysis. The finding proved that casamino acids was able to enhance caproate formation by promoting ethanol utilization and butyrate formation. In general, yeast extract could not only support microbial growth but also contribute to the formation of medium chain fatty acids, therefore promoting the efficiency of chain elongation process.
AB - In this study, the effects of casamino acids, as the main component in yeast extract, on the bioproduction of caproate were evaluated. A dosage of 5 g/L casamino acids addition significantly promoted caproate production and shortened the lag phase for caproate production by 7.6-folds compared with the control. Both the net carbon and electron conversion efficiencies were enhanced. The addition of casamino acids shaped a dissimilar microbial community from that of the control and that of the inoculum. The caproate-producing Clostridium and Caproiciproducens, the proteolytic Proteiniphilum and Brassicibacter, and the saccharide-utilizing Hydrogenoanaerobacteriu were enriched, and their abundance were distinguished between with and without the addition of casamino acids as fermentation progressed. Further metagenomics analysis recovered genome bins of Clostridium kluyveri, Clostridium cochlearium, Caprobacter fermentans and Proteiniphilum acetatigenes, representing the majority of the functional bacteria with casamino acids addition. The complete reverse β-oxidation and amino acids (serine/glycine) metabolic pathway for caproate production and butyrate formation, respectively, were fully recovered. Furthermore, all the genes involved were highly expressed and metabolically active in meta-transcriptomics analysis. The finding proved that casamino acids was able to enhance caproate formation by promoting ethanol utilization and butyrate formation. In general, yeast extract could not only support microbial growth but also contribute to the formation of medium chain fatty acids, therefore promoting the efficiency of chain elongation process.
KW - Anaerobic fermentation
KW - Caproate
KW - Casamino acids
KW - Chain elongation
KW - Yeast extract
UR - http://www.scopus.com/inward/record.url?scp=85149218634&partnerID=8YFLogxK
U2 - 10.1016/j.bej.2023.108879
DO - 10.1016/j.bej.2023.108879
M3 - Journal article
AN - SCOPUS:85149218634
SN - 1369-703X
VL - 193
JO - Biochemical Engineering Journal
JF - Biochemical Engineering Journal
M1 - 108879
ER -