期刊
JOURNAL OF MICROBIOLOGICAL METHODS
卷 59, 期 3, 页码 381-393出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.mimet.2004.08.002
关键词
biofilm activity; heterotrophic CO2 metabolism; P. putida; drinking water; activated sludge; benzalkonium chloride
We have examined whether assimilation of CO2 can be used as a measure of metabolic activity in planktonic and sessile heterotrophic bacteria. CO2 assimilation by environmental samples and pure cultures of heterotrophic bacteria was studied using (CO2)-C-14 and (CO2)-C-13 as tracers. Heterotrophic growth on complex organic Substrates resulted in assimilation of CO2 into cell biomass by activated sludge, drinking water biofilm, and pure cultures of Escherichia coli ATCC 25922, Es. coli ATCC 13706, Rhodococcus ruber, Burkholderia sp., Bacillus circulans, Pseudomonas putida, Pseudomonas stutzeri, and Pseudomonas aeruginosa. Analysis of C-13-labelled phospholipid fatty acids (PLFAs) confirmed that heterotrophic bacteria may assimilate (CO2)-C-13 into cell macromolecules such as membrane lipids. All major PLFAs extracted from activated sludge and drinking water biofilm samples were enriched in C-13 after incubation with CO2. Between 1.4% and 6.5% of the biomass produced by cultures of P. putida and a drinking water biofilm during growth in complex media was apparently derived from assimilation of CO2. Resting cells assimilated less CO2 compared to actively growing cells, and CO2 assimilation activity correlated with the amount of biomass produced during heterotrophic growth. The (CO2)-C-14 assimilation assay was evaluated as a tool to examine inhibitory effects of biocides on planktonic and sessile heterotrophs (biofilms). On the basis of (CO2)-C-14 assimilation activity, the minimum inhibitory concentration (MIC) of benzalkonium chloride was estimated to 21.1 and 127.2 mg l(-1) for planktonic and biofilm samples, respectively. The results indicate that assimilation of isotopically labelled CO2 can be used as a relatively simple measure of metabolic activity in heterotrophic bacteria. CO2 assimilation assays may be used to study the effects of antimicrobial agents on growth and survival of planktonic and sessile heterotrophic organisms. (C) 2004 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据