A Chauhan1, K R Reddy, A V Ogram. 1. Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290, USA.
Abstract
AIMS: Evaluation of the composition, distribution and activities of syntrophic bacteria and methanogens in soils from eutrophic and low nutrient regions of a freshwater marsh, and to compare these results with those obtained from a similar study in the Florida Everglades. METHODS AND RESULTS: Culture dependent and independent approaches were employed to study consortia of syntrophs and methanogens in a freshwater marsh. Methanogenesis from butyrate oxidation was fourfold higher in microcosms containing soil from eutrophic regions of the marsh than from low nutrient regions. Propionate was oxidized in eutrophic microcosms at lower rates than butyrate and with lower yields of methane. Sequence analysis of 16S rRNA gene clone libraries from DNA extracted from microcosms and soils revealed differences such that the dominant restriction fragment length polymorphism (RFLP) phylotypes (representing 82-88% of clone libraries) from eutrophic soils clustered with fatty acid oxidizing Syntrophomonas spp. The four dominant RFLP phylotypes (representing 11-24%) from microcosms containing soils from low nutrient regions were sequenced, and clustered with micro-organisms having the potential for fermentative and syntrophic metabolism. Archaeal 16S rRNA sequence analysis showed that methanogens from eutrophic regions were from diverse families, including Methanomicrobiaceae, Methanosarcinaceae, and Methanocorpusculaceae, but clone libraries from low nutrient soils revealed only members of Methanosarcinaceae. CONCLUSIONS: These findings indicate that syntroph-methanogen consortia differed with nutrient levels in a freshwater marsh. SIGNIFICANCE AND IMPACT OF THE STUDY: This is one of few studies addressing the distribution of fatty acid consuming-hydrogen producing bacteria (syntrophs) and their methanogenic partners in wetland soils, and the effects of eutrophication on the ecology these groups.
AIMS: Evaluation of the composition, distribution and activities of syntrophic bacteria and methanogens in soils from eutrophic and low nutrient regions of a freshwater marsh, and to compare these results with those obtained from a similar study in the Florida Everglades. METHODS AND RESULTS: Culture dependent and independent approaches were employed to study consortia of syntrophs and methanogens in a freshwater marsh. Methanogenesis from butyrate oxidation was fourfold higher in microcosms containing soil from eutrophic regions of the marsh than from low nutrient regions. Propionate was oxidized in eutrophic microcosms at lower rates than butyrate and with lower yields of methane. Sequence analysis of 16S rRNA gene clone libraries from DNA extracted from microcosms and soils revealed differences such that the dominant restriction fragment length polymorphism (RFLP) phylotypes (representing 82-88% of clone libraries) from eutrophic soils clustered with fatty acid oxidizing Syntrophomonas spp. The four dominant RFLP phylotypes (representing 11-24%) from microcosms containing soils from low nutrient regions were sequenced, and clustered with micro-organisms having the potential for fermentative and syntrophic metabolism. Archaeal 16S rRNA sequence analysis showed that methanogens from eutrophic regions were from diverse families, including Methanomicrobiaceae, Methanosarcinaceae, and Methanocorpusculaceae, but clone libraries from low nutrient soils revealed only members of Methanosarcinaceae. CONCLUSIONS: These findings indicate that syntroph-methanogen consortia differed with nutrient levels in a freshwater marsh. SIGNIFICANCE AND IMPACT OF THE STUDY: This is one of few studies addressing the distribution of fatty acid consuming-hydrogen producing bacteria (syntrophs) and their methanogenic partners in wetland soils, and the effects of eutrophication on the ecology these groups.
Authors: Dawn E Lewis; Ashvini Chauhan; John R White; Will Overholt; Stefan J Green; Puja Jasrotia; Denis Wafula; Charles Jagoe Journal: Microb Ecol Date: 2012-03-04 Impact factor: 4.552
Authors: Dawn E Lewis; John R White; Denis Wafula; Rana Athar; Tamar Dickerson; Henry N Williams; Ashvini Chauhan Journal: Microb Ecol Date: 2009-12-18 Impact factor: 4.552
Authors: Jin Zhou; Mindy L Richlen; Taylor R Sehein; David M Kulis; Donald M Anderson; Zhonghua Cai Journal: Front Microbiol Date: 2018-06-06 Impact factor: 5.640