Assessment of the diversity and abundance of bacterial population and its correlation with medium chain fatty acids production from fermentation of two leachate qualities

The potential of medium chain fatty acids (MCFA) production from two seasonal leachates along with their bacterial community structure were investigated using GC-FID and Illumina high-throughput sequencing during the acid chain elongation process. Significant amounts of MCFA (C6-10) were produced during the experiment, especially with rainy season leachate. The amounts ranged from 1646 mg/l to 22,000 mg/l for C6-C8 and reached 959.65 mg/l for C9 and C10, with optimum values obtained on day 21. Bacterial communities were also different among seasonal samples, with Bacteroidetes, Firmicutes, and Proteobacteria being the most abundant phyla. The relative abundance of Lactobacillus, Clostridium, and Pseudomonas increased during fermentation and showed positive correlations with MCFA with longer chains (C6-C10), demonstrating their probable involvement in the chain elongation process. This study enhances our understanding of the composition, structure and contribution of the bacterial community during the chain elongation process and gives value to leachate from solid waste in sub-Saharan countries.