Metagenomics profiling of bacterial communities of distillery sludge

Sugarcane molasses-based distilleries generates huge amounts of distillery sludge after anaerbic digestion of raw distillery effluent, commonly known as spent wash. Distillery sludge contains a high concentration of recalcitrant organic pollutants including nitrogenous heterocyclic Maillard Reaction Products, melanoidin-like products, and complex organic matter along with metallic and non-metallic ions. A continuous disposal of such sludge into the natural environment can result in environmental degradation as well as negative effect on human health. Saccharum arundinaceum, commonly known as hardy sugar cane, is a native perennial grassgrass species to India and has been found actively growing in several distillery sludge disposal sites. Thus, exploring the rhizospheric bacterial communities of S. arundinaceum can connect and correlate how bacterial species are involved in in situ phytoremediation of hazardous organometallic waste. Samples of non-rhizospheric and rhizospheric distillery sludge were taken according to a simple randomized schematic strategy. The sequence analysis of small rRNA hypervariable region with Illumina MiSeq platform showed the major phyla detected in rhizospheric sludge sample was Proteobacteria. The dominant three genera were detected as Rheinheimera. The results suggested that rhizospheric bacterial communities associated with S. arundinaceum were substantially different in richness, diversity, and relative abundance of taxa compared to non-rhizospheric sludge. The results of this study will be helpful in understanding the role of rhizospheric bacterial communities responsible for degradation and detoxification of complex organometallic waste and, thus, can help in designing appropriate phytoremediation studies for eco-restoration of polluted sites. (This work was done at the Department of Environmental Microbiology at Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh India)