Factors Affecting the Survival of Exogenous Bacteria in Microbial Ecosystems: Existence of Indigenous Bacteria with Antagonistic Activity
Factors Affecting the Survival of Exogenous Bacteria in Microbial Ecosystems: Existence of Indigenous Bacteria with Antagonistic Activity
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影响微生物生态系统中外源细菌生存的因素：具有拮抗活性的本土细菌的存在
DOI：
10.4265/bio.3.63
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发表时间：
1998
影响因子：
1.2
通讯作者：
M. Fujita
中科院分区：
文献类型：
--
作者：
S. Soda;H. Watatani;M. Ike;M. Fujita
研究了大肠杆菌K-12和恶臭假单胞菌BH在淡水、海水、活性污泥和土壤微宇宙中的存活情况。3种微宇宙，命名为完整、无原生动物（用1.0μm过滤器过滤或加入2.0 g/l放线菌酮）和灭菌微宇宙（用0.22μm过滤器过滤或在120 ℃下高压灭菌2次，20 min），从每种环境样品中制备，并用于存活研究，以分别评估原生动物捕食、与土著细菌的相互作用和饥饿的一般影响。在所有完整的微观世界中，两种外源性细菌种群在7 d内迅速减少1至4个数量级。实验结果表明，与土著细菌的相互作用，特别是以拮抗或偏害的形式，是导致外源细菌种群下降的最重要因素，而原生动物捕食的影响要小得多。为了证明这种拮抗作用存在的证据，异养细菌土著每个完整的缩影进行了分离，并对引入的外源性细菌的拮抗活性进行了检查。约1.0-3.5%的分离菌株对大肠杆菌和放线菌有拮抗活性。coil K-12或P. putida BH.然而，大多数菌株所产生的拮抗活性被发现是不稳定的。
The survival of Escherichia coil K-12 and Pseudomonas putida BH inoculated into fresh water, sea water, activated sludge, and soil microcosms was studied. Three kinds of microcosms, named as intact, protozoa-free (filtered with 1.0μm filter or 2.0 g/l of cycloheximide added), and sterilized microcosms (filtered with 0.22μm filter or autoclaved twice at 120°C for 20 min.), were made from each kind of environmental sample, and used for the survival studies in order to separately evaluate the general effects of protozoan predation, interaction with indigenous bacteria, and starvation. In the all intact microcosms, both exogenous bacterial populations decreased rapidly by 1 to 4 orders of magnitude over 7 d. The experimental results indicated that the interaction with indigenous bacteria, especially in the form of antagonism or amensalism, was the most influential factor causing the decline of the exogenous bacterial populations, and that the protozoan predation was much less influential. To demonstrate evidence for the presence of such antagonism, heterotrophic bacteria indigenous to each intact microcosms were isolated, and their antagonistic activities against the introduced exogenous bacteria were examined. Approximately 1.0-3.5% of the isolated bacterial strains showed antagonistic activity against either E. coil K-12 or P. putida BH. However, the antagonistic activity exerted by most strains was found to be unstable.