Presence of glucose, xylose, and glycerol fermenting bacteria in the deep biosphere of the former Homestake gold mine, South Dakota

Frontiers in Microbiology

Kenneth eBischoff¹  Ramon eGonzalez²  Sudhir eKumar³  Stephen eHughes³  Aditya eBhalla⁴  Raghunandan eGurram⁴  Rajesh Kumar Sani⁴  Gurdeep eRastogi⁴ 

[1] Biomolecular Engineering and Bioengineering, Rice University;;Departments of Chemical &National Center for Agricultural Utilization Research, U.S. Department of Agriculture;South Dakota School of Mines and Technology;

关键词: Fermentation;    bioenergy;    bioethanol;    Gold mine;    Biofules;    1 3 propandiol;   

DOI  :  10.3389/fmicb.2013.00018

来源: DOAJ

【 摘 要 】

Eight fermentative bacterial strains were isolated from mixed enrichment cultures of a composite soil sample collected at 1.34 km depth from the former Homestake gold mine in Lead, SD, USA.Phylogenetic analysis of their 16S rRNA gene sequences revealed that these isolates were affiliated with the phylum Firmicutes belonging to genera Bacillus and Clostridium.Batch fermentation studies demonstrated that isolates had the ability to ferment glucose, xylose, or glycerol to industrially valuable products such as ethanol and 1,3-propanediol (PDO).Batch fermentation studies on selected seven bacterial strains demonstrated that these have the ability to ferment glucose, xylose, or glycerol to industrially valuable products such as ethanol and 1,3-propanediol (PDO).Ethanol was detected as the major fermentation end product in glucose-fermenting cultures at pH 10 with yields of 0.206 - 0.304 g of ethanol/g of glucose.While a xylose-fermenting strain yielded 0.189 g of ethanol/g of xylose and 0.585 g of acetic acid/g of xylose at the end of fermentation.At pH 7, glycerol-fermenting isolates produced PDO (0.323 - 0.458 g of PDO/g of glycerol) and ethanol (0.284 - 0.350 g of ethanol/g of glycerol) as major end products while acetic acid and succinic acid were identified as minor by-products in fermentation broths.These results suggest that the deep biosphere of the former Homestake gold mine harbors bacterial strains which could be used in bio-based production of ethanol and PDO.

【 授权许可】

Unknown