Institute of Himalayan Bioresource Technology (CSIR), Palampur (HP)-176061, India.
J Basic Microbiol. 2010 Apr;50(2):150-9. doi: 10.1002/jobm.200800400.
The diversity of proteolytic bacteria associated with a glacier and cold environment soils from three different locations in Lahaul and Spiti, India was investigated. Two hundred seventeen bacterial strains were isolated in pure culture. Subsequently these strains were screened for protease-production and one hundred nine showed protease production. From these protease producing psychrotrophic bacteria twenty showing high enzyme production at low temperature and alkaline pH were characterized and identified. The 16S rRNA phylogenetic analysis revealed that none of the strains showed 100% identity with the validly published species of various genera. Isolates belonged to three classes i.e. Actinobacteria, Gammaproteobacteria and Alphaproteobacteria, and were affiliated with the genera Acinetobacter, Arthrobacter, Mycoplana, Pseudomonas, Pseudoxanthomonas, Serratia and Stenotrophomonas. The optimal growth temperature ranged from 10 to 28 degrees C and interestingly, high levels of enzyme productions were measured at growth temperatures between 15 and 25 degrees C, for most of the isolates in plate assay. Most of the isolates were found to produce at least two other hydrolytic enzymes along with protease. The crude protease from one strain was active over broad range of temperature and pH with optima at 30 degrees C and 7.5, respectively. The protease activity was enhanced by Ca(2+), dithiothreitol and beta-mercaptoethanol. While Na(+), Hg(2+), Zn(2+), Mn(2+), phenylmethanesulfonyl fluoride and ethylenediaminetetraacetic acid did not showed much effect on protease activity. The results enrich our knowledge on the psychrotrophic bacterial diversity and biogeographic distribution of enzyme producing bacteria in western Himalaya.
对来自印度拉胡尔和斯皮提的三个不同地点的冰川和冷环境土壤中与蛋白酶相关的细菌多样性进行了研究。分离出 217 株纯培养细菌。随后，对这些菌株进行了蛋白酶产生筛选，其中 109 株显示出蛋白酶产生。从这些产蛋白酶的嗜冷菌中，有 20 株在低温和碱性 pH 值下表现出高酶产量，对其进行了特征描述和鉴定。16S rRNA 系统发育分析显示，没有一株与各种属的有效公布种显示出 100%的同一性。分离物属于 3 个纲，即放线菌、γ-变形菌和α-变形菌，与不动杆菌属、节杆菌属、微菌属、假单胞菌属、假黄单胞菌属、沙雷氏菌属和寡养单胞菌属有关。最佳生长温度范围为 10 至 28 度，有趣的是，在平板测定中，大多数分离物在 15 至 25 度的生长温度下测量到高酶产量。大多数分离物除了蛋白酶外，还至少产生两种其他水解酶。来自一株菌的粗蛋白酶在较宽的温度和 pH 值范围内具有活性，最适温度分别为 30 度和 7.5。蛋白酶活性可通过 Ca(2+)、二硫苏糖醇和β-巯基乙醇增强。而 Na(+)、Hg(2+)、Zn(2+)、Mn(2+)、苯甲磺酰氟和乙二胺四乙酸对蛋白酶活性没有太大影响。这些结果丰富了我们对喜冷细菌多样性和西喜马拉雅酶产生细菌生物地理分布的知识。
