Microbial diversity of marine shrimp pond sediment and its variability due to the effect of immobilized media in biohydrogen and biohythane production

Abstract

Immobilization of microorganism on material is one of the effective methods to improve the production of bio-products including biofuel such as biohydrogen and biohythane (H2 + CH4). In this work, the effect of immobilizing media was studied including clay/activated carbon (CAC), clay/zeolite (CZ) and clay/mixed activated carbon and zeolite (CACZ) on microbial attachment and biogas production including biohydrogen and biohythane using shrimp pond sediment as organic resource and microbial consortium. The result showed that CAC was the most appropriate material for microbial attachment among the other materials. CAC digesters demonstrated higher H2 concentration than control reactors. Interestingly, the control reactors of using only shrimp pond sediment without CAC showed the ability of biohythane production. From 454-pyrosequencing results, it found that Alcaligenaceae family, Tissierella Soehngenia sp. and Planomicrobium sp. were the predominant species in shrimp pond sediment. Meanwhile, the study of microbial species on CAC after digestion process by Illumina MiSeq platform represented Clostridium cellobioparum, Tolumonas auensis and Microbacter margulisiae for bacteria and Methanobacterium aggregans for archaea as predominant species. It was shown that the immobilized media (CAC) favored some types of microbes mainly hydrogen producing microbes and hydrogenotrophic methanogen. This research suggests the CAC as an alternative immobilizing media for bioenergy production especially biohydrogen and biohythane.