Importance of inoculum source and initial community structure

The overall aim of the present study was to investigate the importance of inoculum source for efficient degradation of lignocellulose rich material and biogas production in a continuously operated process and to specifically study the initial community structure and how this was affected by the used substrates and operating parameters. We hypothesize that choosing a suitable inoculum could give an early advantage on biogas production and degradation of lignocellulose. Inoculums were taken from three different industrial-scale biogas plants in Sweden showing differences in degradation of straw and cellulose and a manure-grass mixture was used as substrate to operate lab-scale CSTR reactors initiated with the different inoculums. The processes were monitored by analysis of different chemical parameters and the microbial community structure was analysed by illumina sequencing targeting the 16sRNA genes and by T-RFLP analysis targeting glycoside hydrolase families 5 and 48. The degradation and biogas production of the substrate was furthermore evaluated during batch cultivation, stated with the different initial inoculums and with inoculums from the lab-scale CSTR reactors at the end of the experiment.