Metagenomic insights into the microbial community and biogas production pattern during anaerobic digestion of cow dung and mixed food waste

Abstract

BACKGROUND: The uncontrolled overproduction of fruit and vegetable waste causes serious environmental challenges such as emission of greenhouse gases. Anaerobic digestion (AD) is becoming a widely adopted technology for treatment of food waste with the concomitant production of biogas. This study investigated the link between microbial community structure and biogas production when using cow dung and mixed fruit and vegetable waste (MFVW) as substrates.RESULTS: Semi-continuous stir tank reactors were used for AD of cow dung and MFVW over a period of 40 days. The highest accumulative methane yield (112.9 L) was obtained from co-digestion, intermediate yield (59.5 L) was obtained from cow dung and lowest yield (6.1 L) from MFVW at the end of the digestion experiment. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) revealed higher bacterial and archaeal diversity indices in co-digestion in comparison to mono-digestion of cow dung and MFVW. High-throughput sequence analyses showed that operational taxonomic units (OTUs) belonging to the phyla Bacteroidetes, followed by Firmicutes, Actinobacteria and Proteobacteria were dominant in all treatments. CONCLUSION:The results of the study demonstrated that the enhanced methane production in co-digestion could be attributed to the neutral pH and partial shift of archaea from Methanosaeta to Methanosarcina rich communities.

Effects of Short-Chain Fatty Acid Modulation on Potentially Diarrhea-Causing Pathogens in Yaks Through Metagenomic Sequencing

“…These SCFA act as ligands for G-protein coupled receptors by activating anti-inflammatory signaling ( Parada Venegas et al., 2019 ). Metagenomics sequencing is commonly utilized in microbial organisms, as it provides the accurate classification of microbiota species and annotation to the bacteria at a functional level rather than functional prediction ( Mukhuba et al., 2019 ; Luan et al., 2020 ; Tian et al., 2020 ).…”

Biogas potential determination and production optimisation through optimal substrate ratio feeding in co-digestion of water hyacinth, municipal solid waste and cow dung

“…Cow dung and other animal manures emit 55 − 65 % methane into the atmosphere and tis affects global warming 21 times more than CO 2 does [30]. Of all the substrates for biogas production, cow dung is the major source, however, mordern researches on its co-digestion with other wastes has shown increased ultimate biogas yields [31][32] [33]. WH and MSW are rich in nutrients for biogas production, however, their lignocellulosic recalcitrant nature renders them resistive to micro-bacterial degradation hence reduced gas yields.…”

Effects of Short Chain Fatty Acids (SCFAs) Modulation on Potentially Diarrhea Causing Pathogens in Yaks Through Metagenomics Sequencing

“…These SCFAs are also known for acting as ligands for G-protein coupled receptors by activating anti-in ammatory signaling [16]. Metagenomics sequencing is commonly utilized in microbial organisms, as it provides accurate classi cation of microbiota species and annotation to the bacteria at functional level rather than functional prediction [17][18][19].…”