Manure microbial community dynamics and activity during adaptation to psychrophilic methanisation

Psychrophilic methanisation is limited by the long start-up and acclimation period of processes and microbial communities. To better understand these crucial steps we monitored the microbial community acclimation of four different manures and one digestate to anaerobic digestion at 13°C. The psychrophilic adapted microbial community was then submitted to brutal temperature changes by incubation at 35, 25, 15 and 5°C to assess its adaptive potential. Methane production was measured continuously. Bacterial and Archaeal communities dynamics were monitored by 16S rDNA targeted qPCR, CE-SSCP and pyrosequencin the isolates were identified as Serratia sp. JHT01, Serratia liquefacien PT01, Pseudomonas chlororaphis PT02, Stenotrophomonas sp. PT03 and Mesorhizobium sp. PT04. The Mesorhizobium sp. PT04 was isolated from under water environment. All isolates showed significant growth on water-extractive-free lignin. Synthetic aromatic dyes were used to assess the presence of oxidative enzymes. Pseudomonas chlororaphis PT02 presented high potential in degradation of aromatic monomers and biphenyl. Mesorhizobium sp. PT04 being a facultative anaerobic strain, its degradation of lignin polymer might be executed by specific sets of enzymes. Novel lignin degradation bacterial consortium may be prepared by using these isolates for delignification of the lignocellulosic biomass.