Study of microbial dynamics during optimization of hydrogen production from food waste by using LCFA-rich agent

In dark fermentation of food waste, changes in microbial community composition and dynamics were studied, after inoculum pre-treatment with waste frying oil (WFO). The microbial diversity in the raw sludge was the highest, considering that all genera with abundances higher than 0.1% contributed to only 37.42% of the total diversity. After inoculum pre-treatment with WFO, many genera were inhibited; however, no effect was observed on spore-forming fermentative bacteria. In addition, none-spore-forming H2 producers were enriched significantly after inoculum pre-treatment, while spore-forming H2 producing bacteria (e.g. Clostridium spp.) remained almost unchanged. The predominant OTUs after dark fermentation were Clostridium sp. (27.24%), Aeromonas sp. (13.43%) and Chromobacterium sp. (12.00%).