Biobased volatile fatty acids (VFA) production via anaerobic acidogenesis of sugar processing industry effluent.

Rapid industrialization and unscientific disposal of industrial wastewaters have resulted in the pollution of water bodies and deterioration of water quality all over the globe. Valorization of industrial wastewaters will help in reducing the negative impact on the environment and will add value to the waste. The present study targets utilization of sugar processing industrial effluent for bio-based production of Volatile fatty acids (VFA) through anaerobic acidogenesis. Batch studies conducted to determine the VFA production potential of sugar processing industry effluent resulted in the VFA yield of 0.70 g/g COD utilized. Further continuous VFA production system was developed and optimization of Organic loading rate (OLR) (2-22 g COD/L·day) was carried out with constant Hydraulic retention time (HRT) of 1 day. The continuous reactors studies resulted in a maximum VFA yield of 0.72 g/g COD utilized and productivity of 11.04 g COD/L·day at OLR of 14 g COD/L·day and 22 g COD/L·day, respectively. The developed process will provide an environmentally safe and efficient method for the conversion of complex industrial wastes to valuable products such as VFA.

Microbial consortia adaptation to substrate changes in anaerobic digestion.

Renewable natural gas (RNG) produced from anaerobic digestion (AD) of agricultural residues is emerging a serious biofuel alternative. Complex nature of lignocellulosic biomass residues coupled with complex biochemical transformations involving a large spectrum of microbial communities make anaerobic digestion of biomass difficult to understand and control. The present work aims at studying adaptation of microbial consortia in AD to substrates changes and correlating these to biogas generation. The double edged study deals with (a) using a common starting culture inoculum on different fractions of pretreated lignocellulosic biomass (LBM) fractions; and (b) using different starter inocula for gas generation from simple glucose substrate. Taxonomic analysis using 16S amplicon sequencing is shown to highlight changes in microbial community structure and predominance, majorly in hydrolytic bacterial populations. Observed variations in the rate of digestion with different starter inocula could be related to differences in microbial community structure and relative abundance. Results with different treated biomass fractions as substrates indicated that AD performance could be related to abundance of substrate-specific microbial communities. The work is a step to a deeper understanding of AD processes that may lead to better control and operation of AD for super-scale production of RNG from biomass feedstocks.