ANALYSIS OF MICROBIAL COMMUNITIES IN VARIOUS FULL-SCALE ANAEROBIC WASTEWATER TREATMENT PLANTS

Anaerobic digestion (AD) has received more attention worldwide as an alternative technology for wastewater treatment and bioenergy production. AD process involves a complex consortium of microorganisms converting organic compounds into biogas. However, various anaerobic digesters have suffered from being periodically unstable of biogas production due to limited understanding of microbial community structures and functions. As different sludge sources contain various habitant microorganisms, revealing microbial profiles would provide insights to monitor and control the systems. This study investigated microbial communities from different anaerobic wastewater treatment plants of domestic (Domestic), fruit juice (FruitJuice), palm oil mill effluent (PalmOil), pig manure (PigManure), seafood (Seafood), and starch (Starch) industries using 16S rRNA gene sequencing and bioinformatics analysis. The microbiome of Domestic and Seafood showed the highest and lowest alpha diversity, respectively. Common and specific microbes among the investigated microbiome sources were revealed. For instance, the phenol degrading bacteria Cryptanaerobacter (5.30%), fermentative bacteria Saccharofermentans (2.07%), and hydrogenotrophic methanogen Methanospirillum (3.49%) were found uniquely in Domestic, FruitJuice and Seafood samples, respectively. Common dominant syntrophic bacteria and methanogens were revealed with average relative abundance in all sludge sources including Acidaminobacter (3.02%), Anaerolineaceae (2.94%), Methanobacterium (9.44%), Methanolinea (3.06%), Methanosaeta (10.71%), Peptoclostridium (6.33%), Smithella (4.61%) and Synergistaceae (2.84%). These microbes show wide-range abilities to degrade various types of wastewater. The FruitJuice and PigManure microbiome showed higher abundance of methanogenesis pathway compared to others. We identified common and unique microbes in AD full-scale wastewater treatment plants, leading better understanding of microbiome structures and functions involving biogas production.