Functional patterns and temperature response of cellulose-fermenting microbial cultures containing different methanogenic communities

Citation
Xl. Wu et al., Functional patterns and temperature response of cellulose-fermenting microbial cultures containing different methanogenic communities, APPL MICR B, 56(1-2), 2001, pp. 212-219
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biotecnology & Applied Microbiology",Microbiology
Journal title
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
ISSN journal
0175-7598 → ACNP
Volume
56
Issue
1-2
Year of publication
2001
Pages
212 - 219
Database
ISI
SICI code
0175-7598(200107)56:1-2<212:FPATRO>2.0.ZU;2-9
Abstract
The effect of microbial composition on the methanogenic degradation of cell ulose was studied using two lines of anaerobic cellulose-fermenting methano genic microbial cultures at two different temperatures: that at 15 degreesC being dominated by Methanosaeta and that at 30 degreesC by Methanosarcina. In both cultures, CH4 production and acetate consumption were completely i nhibited by either 2-bromoethanesulfonate or chloroform, whereas H-2 consum ption was only inhibited by chloroform, suggesting that homoacetogens utili zed H-2 concomitantly with methanogens. Hydrogen was the intermediate that was consumed first, while acetate continued to accumulate. At 15 degreesC, acetoclastic methanogenesis smoothly followed H-2-dependent CH4 production. Fluorescence in situ hybridization showed that populations of Methanosaeta steadily increased with time from 5 to 25% of total cell counts. At 30 deg reesC, two phases of CH4 production were obtained, with acetate consumed af ter the abrupt increase of Methanosarcina from 0 to 45% of total cell count s. Whereas populations of Methanosaeta were able to adapt after transfer fr om 15 to 30 degreesC, those of Methanosarcina were not, irrespective of dur ing which phase the cultures were transferred from 30 degreesC to 15 degree sC. Our results thus show that the community structure of methanogens indee d affects the function of a cellulose-fermenting community with respect to temperature response.