...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of industrial microbiology & biotechnology >Isolation and characterization of cellulose-degrading bacteria from the deep subsurface of the Homestake gold mine, Lead, South Dakota, USA
【24h】

Isolation and characterization of cellulose-degrading bacteria from the deep subsurface of the Homestake gold mine, Lead, South Dakota, USA

机译：从美国南达科他州利德市霍姆斯特克金矿的深层地下分离和降解纤维素的细菌

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The present study investigated the cultivable mesophilic (37pC) and thermophilic (60pC) cellulose-degrading bacterial diversity in a weathered soil-like sample collected from the deep subsurface (1.5 km depth) of the Homestake gold mine in Lead, South Dakota, USA. Chemical characterization of the sample by X-ray fluorescence spectroscopy revealed a high amount of toxic heavy metals such as Cu, Cr, Pb, Ni, and Zn. Molecular community structures were determined by phylogenetic analysis of 16S rRNA gene sequences retrieved from enrichment cultures growing in presence of microcrystalline cellulose as the sole source of carbon. All phylotypes retrieved from enrichment cultures were affiliated to Firmicutes. Cellulose-degrading mesophilic and thermophilic pure cultures belonging to the genera Brevibacillus, Paenibacillus, Bacillus, and Geobacillus were isolated from enrichment cultures, and selected cultures were studied for enzyme activities. For a mesophilic isolate (DUSELG12), the optimum pH and temperature for carboxymethyl cellulase (CMCase) were 5.5 and 55pC, while for a thermophilic isolate (DUSELR7) they were 5.0 and 75pC, respectively. Furthermore, DUSELG12 retained about 40% CMCase activity after incubation at 60pC for 8 h. Most remarkably, thermophilic isolate, DUSELR7 retained 26% CMCase activity at 60pC up to a period of 300 h. Overall, the present work revealed the presence of different cellulose-degrading bacterial lineages in the unique deep subsurface environment of the mine. The results also have strong implications for biological conversion of cellulosic agricultural and forestry wastes to commodity chemicals including sugars.
机译：本研究调查了从美国南达科他州铅市霍姆斯特克金矿的深地下（1.5公里深度）收集的风化土壤样样品中可培养的嗜温（37pC）和嗜热性（60pC）纤维素降解细菌的多样性。通过X射线荧光光谱对样品进行化学表征，发现了大量有毒重金属，例如Cu，Cr，Pb，Ni和Zn。通过对16S rRNA基因序列的系统发育分析来确定分子群落结构，该序列从在微晶纤维素作为唯一碳源存在下生长的富集培养物中获得。从富集培养物中检索到的所有系统型均与Firmicutes相关。从富集培养物中分离出属于短杆菌属，芽孢杆菌属，芽孢杆菌属和土生芽孢杆菌属的降解纤维素的嗜温和嗜热纯培养物，并研究所选培养物的酶活性。对于嗜温分离株（DUSELG12），羧甲基纤维素酶（CMCase）的最佳pH和温度分别为5.5和55pC，而对于嗜热分离株（DUSELR7）的最适pH和温度分别为5.0和75pC。此外，DUSELG12在60pC孵育8小时后保留了约40％的CMCase活性。最引人注目的是，嗜热分离株DUSELR7在60pC直至300小时内仍保留26％的CMCase活性。总的来说，目前的工作揭示了矿山独特的深层地下环境中存在着不同的纤维素降解细菌谱系。该结果对于将纤维素的农业和林业废物生物转化为糖等商品化学品也具有重要意义。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号