Spatial Variations of Bacterial Communities of an Anaerobic Lagoon-Type Biodigester Fed with Dairy Manure


Marleny García-Lozano1, Inty Omar Hernández-De Lira1, David H. Huber2 and Nagamani Balagurusamy1*

1Laboratorio de Biorremediación, Facultad de Ciencias Biológicas, Universidad Autonoma de Coahuila, Torreon 27000, Mexico

2 Department of Biology and Gus R. Douglas Institute, West Virginia State University, Institute, WV 25112, USA

* Correspondence:

Anaerobic digestion technology is being widely employed for sustainable management of organic wastes generated in animal farms, industries, etc. Nevertheless, biodigester microbiome is still considered a “black box” because it is regulated by dierent physico-chemical and operational factors. In this study, the bacterial diversity and composition in different sites of a full-scale lagoon type biodigester (23,000 m3) fed with dairy manure, viz., the influent, beginning, middle, final and effluent were analyzed. The biodigester registered a total of 1445 OTUs, which demonstrated the complex microbial ecosystem in it. Of them, only six OTUs were shared among all the different sampling points. The most abundant phyla belonged to Firmicutes, Proteobacteria, Latescibacteria and Thermotogae. The Simpson and Shannon index showed that the highest microbial diversity was observed in the beginning point of the biodigester, meanwhile, the lowest diversity was recorded in the middle. Based on the UniFrac distances, microbial communities with high similarity were recorded in the middle and final of the biodigester. It can be clearly observed that bacterial communities varied at the different points of the biodigester. However, based on metagenome predictions using PICRUSt, it was found that independent of the dierences in taxonomy and location, bacterial communities maintained similar metabolic functions.

Bacterial diversity-spatial-anaerobic biodigestor