Metagenomic analysis and characterization of acidogenic microbiome and effect of pH on organic acid production
Organic acid production including lactate and acetate is an economically attractive technology that has gained momentum worldwide over the past years. These series of action need to be performed by an esoteric and complex microbial community, in which different members have distinct roles in the establishment of a collective organization. In this study, we analyzed the bioma from bioreactors with various pH conditions of 4.0, 5.0 and 6.0 (R1, R2 and R3), respectively, involved in acidogenic digestion for stable production of various organic acids by means of high-throughput Illumina sequencing, disclosing thousands of genes and extracting more than 53 microbial genomes. At pH 5.0, the hydrolysis reaction was enhanced and thus the lactic acid fermentation was stably improved to 45.96 mm/L and acetic acid to 73.77 mm/L. R2 was found with the most suitable pH condition for stable organic acids production as Lactobacilli and Bifidobacteria were the major members. Both the members have the key roles in heterofermentation and produce higher transcripts of key encoding enzymes involved in the dominant heterofermentation pathways.
KeywordsCSTR Acidogenic fermentation Metagenomics Microbial community structure KEGG analysis
This work was supported by Major Science and Technology Program for Water Pollution Control and Treatment of China (Grant No. 2017ZX07102-004), and National Natural Science Foundation of China (Grant No. 21206084). We are grateful to University of Chinese Academy of Sciences, China for additional support.
Compliance with ethical standards
Conflict of interest
The authors declare that there is no conflict of interest. All the authors read and approved the final manuscript.
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