Department of Microbiology and Department of Soil Science, University of Minnesota, St. Paul, Minnesota 55108.
Appl Environ Microbiol. 1988 Jun;54(6):1536-40. doi: 10.1128/aem.54.6.1536-1540.1988.
Two physiologically and serologically distinct strains of chemoautotrophic nitrite-oxidizing bacteria were isolated as numerically predominant members of the nitrite-oxidizer population of an undisturbed forest soil with a pH range of 4.3 to 5.2. One isolate responded as a neutrophile, characteristic of the family Nitrobacteraceae, and cross-reacted strongly with fluorescent antibody to Nitrobacter strain Engel. The second isolate responded as an acidophile in pure culture, demonstrated maximal nitrite oxidation activity at pH 5.5, and had a pH tolerance range of pH 4.1 to 7.2. Nitrite oxidase in whole cells of the acidophile sustained activity to at least pH 3.5. Cell morphology of both strains typified the genus Nitrobacter in all respects when cultured at pH 7. However, under more acidic conditions the acidophile tended to elongate and at times appeared to branch. These data provide the first evidence for the existence of an acidophilic chemoautotrophic nitrifying bacterium. Isolation of the neutrophilic Nitrobacter strain reported here complements the earlier isolation of a neutrophilic Nitrosospira strain to provide further evidence of a prominent acid-intolerant population of chemoautotrophic nitrifiers in this acid forest soil.
两种在生理学和血清学上都不同的化能自养亚硝酸盐氧化细菌被分离出来，它们是未受干扰的森林土壤中亚硝酸盐氧化菌群体中的优势数量成员，这些土壤的 pH 值范围为 4.3 至 5.2。一个分离株表现为嗜中性，是硝化杆菌科的特征，与针对 Nitrobacter 菌株 Engel 的荧光抗体强烈交叉反应。第二个分离株在纯培养中表现为嗜酸，在 pH 5.5 时表现出最大的亚硝酸盐氧化活性，其 pH 耐受范围为 pH 4.1 至 7.2。嗜酸菌的完整细胞中的亚硝酸盐氧化酶在至少 pH 3.5 时保持活性。当在 pH 7 下培养时，两种菌株的细胞形态在所有方面都典型地代表了硝化杆菌属。然而，在更酸性的条件下，嗜酸菌往往会拉长，有时似乎会分枝。这些数据首次提供了存在一种嗜酸化能自养硝化细菌的证据。这里报道的嗜中性 Nitrobacter 菌株的分离补充了早期分离的嗜中性 Nitrosospira 菌株，为这种酸性森林土壤中化能自养硝化菌的一个突出的耐酸种群提供了进一步的证据。
