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Microbial community dynamics during the early stages of plant polymer breakdown in paddy soil
Author(s) -
Wegner CarlEric,
Liesack Werner
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12815
Subject(s) - biology , firmicutes , methanogen , lachnospiraceae , hemicellulose , methanogenesis , euryarchaeota , acidobacteria , population , botany , microbiology and biotechnology , bacteria , 16s ribosomal rna , cellulose , biochemistry , gene , genetics , demography , sociology
Summary We used paddy soil slurries amended with rice straw to identify the microbial populations involved in the methanogenic breakdown of plant polymers. Rice straw greatly stimulated microbial activity over the 28‐day incubation period. On day 7, the transient peak concentration of acetate (24 m M ) coincided with the onset of increased methane production. Microbial 16 S rRNA transcript numbers increased by one to two orders of magnitude, but not the 16 S rRNA gene copy numbers. Using metatranscriptomic rRNA , C lostridiaceae , L achnospiraceae , R uminococcaceae , V eillonellaceae and P seudomonadaceae were identified to be the most abundant and the most dynamic bacterial groups. Changes in methanogen rRNA and mRNA abundances corresponded well with methanogenic activity. Acetate determined the abundance ratio between M ethanosarcinaceae and M ethanosaetaceae . M ethanocellaceae dominated hydrogenotrophic methanogenesis. Transcript levels of mRNA families involved in plant polymer breakdown increased slightly with time. Glycosyl hydrolase ( GH ) transcripts involved in cellulose and chitin breakdown were predominantly expressed by the F irmicutes , whereas those involved in hemicellulose breakdown exhibited more diverse taxonomic sources, including A cidobacteria , B acteriodetes and C hloroflexi . Taken together, we observed strong population dynamics and the expression of taxonomically diverse GH families, suggesting that not only F irmicutes , but also less abundant groups play a major functional role in the decomposition of rice straw.