Characteristics of Newly Isolated Geobacillus sp. ZY-10 Degrading Hydrocarbons in Crude Oil
Yumei Sun, Zhanguo Ning, Fan Yang, Xianzhen Li Pol J Microbiol 2015; 64 (3): ICID: 1170464 Article type: Original article IC™ Value: 10.00
Abstract provided by Publisher
An obligately thermophilic strain ZY-10 capable of degrading heavy crude oil was isolated from the crude oil in a high-temperature oilfield. Phenotypic and phylogenetic analyses demonstrated that the strain ZY-10 should be grouped in the genus Geobacillus. The 16S rDNA sequence of strain ZY-10 exhibited the highest similarity (99%) to that of the type strain Geobacillus stearothermophilus (former named Bacillus stearothermophilus). The major cellular fatty acid iso-15:0(28.55%), iso-16:0(24.93%), iso-17:0(23.53%) and the characteristics including indole production, tolerance to NaN3 and carbohydrate fermentation indicated that the strain ZY-10 is different from the recognized species in the genus Geobacillus. Strain ZY-10 could grow in the crude oil supplemented with inorganic salts and trace yeast extract. When tridecane, hexadecane, octacosane or hexatridecane was used as sole carbon source, the contents of the tested alkanes in the medium decreased, and the utilization rate of long-chain alkanes was less than that of short-chain alkanes. Strain ZY-10 could utilize the tested alkanes for growth, and grew best on hexadecane as sole carbon source. Strain ZY-10 growing on the heavy crude oil with higher concentration of long-chain alkanes could significantly increase the content of short-chain alkane and decreased the long-chain alkanes at low concentration of oxygen, which indicated that the strain ZY-10 could convert the larger hydrocarbon components in crude oil into shorter-chain alkanes. Strain ZY-10 is a potential and valuable microbe improving the mobility of crude oil and upgrading heavy crude oil in situ.