Institute for Applied Microbiology, University of Tennessee-Knoxville, Oak Ridge, Tennessee 37831, and Departments of Biology and Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061.
Appl Environ Microbiol. 1986 Dec;52(6):1236-41. doi: 10.1128/aem.52.6.1236-1241.1986.
We sought to determine factors relating to the survival of heterotrophic microorganisms from the high-dissolved-oxygen (HDO) waters of Lake Hoare, Antarctica. This lake contains perpetual HDO about three times that of normal saturation (40 to 50 mg liter). Five isolates, one yeast and four bacteria, were selected from Lake Hoare waters by growth with the membrane filter technique with oxygen added to yield dissolved concentrations 14 times that in situ, 175 mg liter. One bacterial isolate was obtained from the microbial mat beneath the HDO waters. This organism was isolated at normal atmospheric oxygen saturation. The bacteria were gram-negative rods, motile, oxidase positive, catalase positive, and superoxide dismutase positive; they contained carotenoids. The planktonic isolates grew in media containing 10 mg of Trypticase soy (BBL Microbiology Systems)-peptone (2:1) liter but not at 10 g liter. Under low-nutrient levels simulating Lake Hoare waters (10 mg liter), two of the planktonic isolates tested were not inhibited by HDO. Growth inhibition by HDO increased as nutrient concentration was increased. A carotenoid-negative mutant of one isolate demonstrated a decreased growth rate, maximal cell density, and increased cell lysis in the death phase under HDO compared with the parent strain. The specific activity of superoxide dismutase was increased by HDO in four of the five bacterial isolates. The superoxide dismutase was of the manganese type on the basis of inhibition and electrophoretic studies. The bacterial isolates from Lake Hoare possess several adaptations which may aid their survival in the HDO waters, as well as protection due to the oligotrophic nature of the lake.
我们试图确定与南极洲豪尔湖高溶解氧（HDO）水域中异养微生物生存有关的因素。该湖含有持续的 HDO，约为正常饱和度的三倍（40 至 50 毫克/升）。通过在添加氧气的膜过滤器技术中生长，从豪尔湖水中选择了五个分离株，一个酵母和四个细菌，使其溶解浓度增加到原位的 14 倍，即 175 毫克/升。从 HDO 水域下方的微生物席中获得了一个细菌分离物。该生物是在正常大气氧气饱和度下分离出来的。细菌是革兰氏阴性杆菌，可运动，氧化酶阳性，过氧化氢酶阳性，超氧化物歧化酶阳性；它们含有类胡萝卜素。浮游分离物在含有 10 毫克胰蛋白酶大豆（BBL 微生物系统）-蛋白胨（2：1）升的培养基中生长，但不能在 10 克/升中生长。在模拟豪尔湖水域的低营养水平下（10 毫克/升），测试的两个浮游分离物在 HDO 下不受抑制。随着营养浓度的增加，HDO 对生长的抑制作用增加。与亲株相比，一个分离株的类胡萝卜素阴性突变体在 HDO 下表现出生长速率降低、最大细胞密度降低和死亡阶段细胞裂解增加。在五个细菌分离物中，有四个细菌分离物的超氧化物歧化酶活性因 HDO 而增加。根据抑制和电泳研究，超氧化物歧化酶属于锰型。豪尔湖的细菌分离物具有几种适应能力，这可能有助于它们在 HDO 水域中的生存，以及由于湖泊的贫营养性质而提供的保护。
