Variation of the microbial community in thermophilic anaerobic digestion of pig manure mixed with different ratios of rice straw

• Published in: Journal of bioscience and bioengineering 2016-09, Vol.122 (3), p.334-340
• Main Authors: Zhou, Sheng, Nikolausz, Marcell, Zhang, Jining, Riya, Shohei, Terada, Akihiko, Hosomi, Masaaki
• Format: Article
• Language: English
• Subjects: Ammonia; Ammonia - metabolism; Anaerobiosis; Animals; Bacterial community; Bioreactors - microbiology; Carbon - metabolism; Firmicutes - metabolism; Hydrogen - metabolism; Hydrogen-Ion Concentration; Hydrogenotrophic methanogen; Manure - analysis; Manure - microbiology; Methane - biosynthesis; Methane - metabolism; Methanobacteriaceae - metabolism; Methanosarcina - metabolism; Nitrogen - metabolism; Oryza - chemistry; Swine; Temperature; Terminal restriction fragment-length polymorphisms; Thermophilic
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/j.jbiosc.2016.02.012

The effect of pig manure mixed with rice straw on methane yield and the microbial community involved in a thermophilic (55°C) anaerobic digestion process was investigated. Three substrates composed of mixed pig manure and rice straw at different ratios (95:5; 78:22 and 65:35 w/w, which resulted in C/N ratios of 10:1, 20:1 and 30:1) were used for the experiment. The substrate type had a major influence on the total bacterial community, while the methanogens were less affected. The members of the class Clostridia (phylum Firmicutes) were predominant regardless of mixture ratio (C/N ratio), but at species level there was a major difference between the low and high C/N ratio samples. The hydrogenotrophic methanogenic genus of Methanothermobacter was predominant in all samples but higher C/N ratio sequences affiliated to the genus Methanosarcina were also detected. The appearance of Methanosarcina sp. is most likely due to the less inhibition of ammonia during the anaerobic digestion.