Biodegradation of Variable-Chain-Length Alkanes at Low Temperatures by a Psychrotrophic Rhodococcussp
Biodegradation of Variable-Chain-Length Alkanes at Low Temperatures by a Psychrotrophic Rhodococcussp
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DOI：
10.1128/aem.64.7.2578-2584.1998
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发表时间：
1998-07
影响因子：
4.4
通讯作者：
L. Whyte;J. Hawari;E. Zhou;L. Bourbonnière;W. E. Inniss;C. Greer
中科院分区：
文献类型：
--
作者：
L. Whyte;J. Hawari;E. Zhou;L. Bourbonnière;W. E. Inniss;C. Greer
摘要嗜冷菌红球菌属。对菌株Q15在低温条件下降解正构烷烃和柴油的能力进行了检测，并利用生化和遗传技术对其烷烃分解途径进行了研究。在0℃和5℃时，Q15对短链烷烃十二烷和十六烷的矿化程度大于对长链烷烃二十八烷和十三烷的矿化程度。在5°C下，Q15利用了柴油中广泛存在的脂肪烃(C10到C21烷烃、支链烷烃和取代的环己烷)。在碳氢化合物污染和原始土壤微生态中，在5°C下，十六烷的矿化程度显著高于未接种对照土壤微生态。采用固相微萃取-气相色谱-质谱法对正十六烷和正十二烷代谢中间产物(1-十六醇和2-十六醇，1-十二醇和2-十二酮)的检测和潜在代谢中间产物的利用表明，Q15通过末端氧化途径和亚末端氧化途径氧化烷烃。基因特征分析和核苷酸序列分析表明，Q15具有与红球菌THCA基因高度同源的脂肪醛脱氢酶基因。红球菌属菌株Q15具有两个大的质粒，大小约为90kb和115kb(表明介导对Cd的抗性)，这两个大质粒不是烷烃矿化所必需的，尽管90kb的质粒促进了一些烷烃的矿化和在5℃和25℃下在柴油上的生长。
ABSTRACT The psychrotroph Rhodococcus sp. strain Q15 was examined for its ability to degrade individual n-alkanes and diesel fuel at low temperatures, and its alkane catabolic pathway was investigated by biochemical and genetic techniques. At 0 and 5°C, Q15 mineralized the short-chain alkanes dodecane and hexadecane to a greater extent than that observed for the long-chain alkanes octacosane and dotriacontane. Q15 utilized a broad range of aliphatics (C10 to C21 alkanes, branched alkanes, and a substituted cyclohexane) present in diesel fuel at 5°C. Mineralization of hexadecane at 5°C was significantly greater in both hydrocarbon-contaminated and pristine soil microcosms seeded with Q15 cells than in uninoculated control soil microcosms. The detection of hexadecane and dodecane metabolic intermediates (1-hexadecanol and 2-hexadecanol and 1-dodecanol and 2-dodecanone, respectively) by solid-phase microextraction–gas chromatography-mass spectrometry and the utilization of potential metabolic intermediates indicated that Q15 oxidizes alkanes by both the terminal oxidation pathway and the subterminal oxidation pathway. Genetic characterization by PCR and nucleotide sequence analysis indicated that Q15 possesses an aliphatic aldehyde dehydrogenase gene highly homologous to the Rhodococcus erythropolis thcA gene. Rhodococcus sp. strain Q15 possessed two large plasmids of approximately 90 and 115 kb (shown to mediate Cd resistance) which were not required for alkane mineralization, although the 90-kb plasmid enhanced mineralization of some alkanes and growth on diesel oil at both 5 and 25°C.