Application of local available resources in the biogas production of waste products from the bioethanol/sugar industry: Assessment of diversity and dynamics of microbial communities on different inoculation strategies and digestion set-ups

The start-up and proper inoculation of anaerobic systems is an influencing factor for the process stability on a long term. The waste products from the Brazilian bioethanol industry have shown potential for the biogas production, but proper inocula from already operating biogas systems are rarely available in Brazil. As alternative, the extensively accessible cow manure presented favourable characteristics for the set-up of anaerobic system fed with the bioethanol waste products. Two parallel biogas reactors with cow manure as inoculum were compared with two other parallel ones with mixed inoculum digestate originating from various reactors with diverse feeding configuration. All four mesophilic laboratory-scale continuous stirred tank reactors had the same substrate feeding consisting of the combination of filter cake (70%) and bagasse (30%). In order to study in detail the use of different inocula in the anaerobic system, the changes of microbial communities were observed through 454-Pyrosequencing.