TY - JOUR
T1 - Phylogenetic diversity of Fe(III)-reducing microorganisms in rice paddy soil
T2 - Enrichment cultures with different short-chain fatty acids as electron donors
AU - Li, Huijuan
AU - Peng, Jingjing
AU - Weber, Karrie A.
AU - Zhu, Yongguan
N1 - Funding Information:
Acknowledgments We thank Max M. Häggblom for discussion and critical reading of the manuscript. This study was financially supported by the Natural Science Foundation of China (grant no. 41090282).
PY - 2011/10
Y1 - 2011/10
N2 - Purpose: Microbial ferric iron reduction is an important biogeochemical process in nonsulfidogenic anoxic environments, yet the structure of microbial communities involved is poorly understood because of the lack of a functional gene marker. Here, with ferrihydrite as the iron source, we characterized the potential Fe(III)-reducing bacteria from the paddy soil in the presence of different short-chain fatty acids, formate, acetate, propionate, pyruvate, succinate, and citrate. Materials and methods: Enrichment culture was used to characterize the potential Fe(III)-reducing bacteria in the present study. Clone library and terminal restriction fragment length polymorphism (T-RFLP) analyses of bacterial 16S rRNA gene sequence fragments were conducted to reveal the bacterial community structure. Results and discussion: T-RFLP and cloning/sequence analysis showed that Firmicutes were the predominant phylotype in all the enrichment cultures (more than 81% of total peak height, more than 75% of all clones), whereas Geobacter spp. represented a small fraction of the bacterial community. Specifically, distinct bacterial families in the phylum Firmicutes were enriched depending on the short-chain fatty acid amended. Clostridium spp. were the predominant microorganisms in pyruvate treatment, while both Bacillus and Clostridium were enriched in formate, acetate, and propionate treatments. Sequences related to Veillonellaceae and Alkaliphilus were predominant in succinate and citrate treatment, respectively. Conclusions: The results indicated Fe(III)-reducing microorganisms in rice paddy soil are phylogenetically diverse. Besides the well-known Geobacter species, Firmicutes-related Fe(III)-reducing bacteria might also be an important group of Fe(III) reducers in paddy soil. To confirm the populations which play an important role in situ, further studies with culture-independent mRNA-based analysis are needed.
AB - Purpose: Microbial ferric iron reduction is an important biogeochemical process in nonsulfidogenic anoxic environments, yet the structure of microbial communities involved is poorly understood because of the lack of a functional gene marker. Here, with ferrihydrite as the iron source, we characterized the potential Fe(III)-reducing bacteria from the paddy soil in the presence of different short-chain fatty acids, formate, acetate, propionate, pyruvate, succinate, and citrate. Materials and methods: Enrichment culture was used to characterize the potential Fe(III)-reducing bacteria in the present study. Clone library and terminal restriction fragment length polymorphism (T-RFLP) analyses of bacterial 16S rRNA gene sequence fragments were conducted to reveal the bacterial community structure. Results and discussion: T-RFLP and cloning/sequence analysis showed that Firmicutes were the predominant phylotype in all the enrichment cultures (more than 81% of total peak height, more than 75% of all clones), whereas Geobacter spp. represented a small fraction of the bacterial community. Specifically, distinct bacterial families in the phylum Firmicutes were enriched depending on the short-chain fatty acid amended. Clostridium spp. were the predominant microorganisms in pyruvate treatment, while both Bacillus and Clostridium were enriched in formate, acetate, and propionate treatments. Sequences related to Veillonellaceae and Alkaliphilus were predominant in succinate and citrate treatment, respectively. Conclusions: The results indicated Fe(III)-reducing microorganisms in rice paddy soil are phylogenetically diverse. Besides the well-known Geobacter species, Firmicutes-related Fe(III)-reducing bacteria might also be an important group of Fe(III) reducers in paddy soil. To confirm the populations which play an important role in situ, further studies with culture-independent mRNA-based analysis are needed.
KW - Enrichment culture
KW - Fe(III)-reducing bacteria
KW - Paddy soil
KW - Terminal restriction fragment length polymorphism (T-RFLP)
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U2 - 10.1007/s11368-011-0371-2
DO - 10.1007/s11368-011-0371-2
M3 - Article
AN - SCOPUS:80052643947
VL - 11
SP - 1234
EP - 1242
JO - Journal of Soils and Sediments
JF - Journal of Soils and Sediments
SN - 1439-0108
IS - 7
ER -