Isolation and characterization of a novel thermophilic Bacillus strain degrading long-chain n-alkanes

Abstract

A thermophilic Bacillus strain NG80-2 growing within the temperature range of 45-73 degrees C (optimum at 65 degrees C) was isolated from a deep subterranean oil-reservoir in northern China. The strain was able to utilize crude oil and liquid paraffin as the sole carbon sources for growth, and the growth with crude oil was accompanied by the production of an unknown emulsifying agent. Further examination showed that NG80-2 degraded and utilized only long-chain (C15-C36) n-alkanes, but not short-chain (C8-C14) n-alkanes and those longer than C40. Based on phenotypic and phylogenic analyses, NG80-2 was identified as Geobacillus thermodenitrificans. The strain NG80-2 may be potentially used for oily-waste treatment at elevated temperature, a condition which greatly accelerates the biodegradation rate, and for microbial enhancing oil recovery process.

Identification of Thermophilic Bacterial Strains Producing Thermotolerant Hydrolytic Enzymes from Manure Compost

“…These results are different from the strain Bacillus thermodentrificans DSM 465 T which metabolizes both lactose and arabinose [27]. Sugar metabolism profiles for CMB-A1, CMB-A2 and CMB-A7 were closer to that previously reported for G. thermodenitrificans NG80-2 [28,29] whereas CMB-A3 and CMB-A10 differed from NG80-2 in terms of utilization of arabinose. Furthermore, RFLP analysis revealed differences in the EcoRI/BamHI digestion pattern of the 16S-ITS-23S region within the G. thermodenitrificans isolates.…”

Enzyme-mediated biodegradation of long-chain n-alkanes (C32 and C40) by thermophilic bacteria

“…In this study, the MN6 was able to perform superior than other strains or mixed consortium in degradation of C 40 . Similarly, IR2 and IR4 were able to degrade 87-88% of C 40 into different intermediate compound such as eicosane, heneicosane and docosaneetc (Table 2) (Wang et al 2006;Zhang et al 2012b). The degradation of C 40 was found to be high and similar reports were not available in the literature yet.…”

“…The microbes play a key role in remediation of hydrocarbon (Wang et al 2006). In this study, we have compared the pure cultures and mixed culture for degradation of C 32 and C 40 , while the mixed consortium showed high BE % for C 32 , while pure strains showed better BE % for C 40 .…”

“…Residual C 32 and C 40 from each biodegradation flasks were extracted with n-hexane (Wang et al 2006). Finally the characterization of the n-alkanes fractions and changes in functional group were qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS) with the Elite column 30.0 m 9 0.25 mm, 250 lm (Perkin elmer, Clarus 680, USA).…”

“…While, Pseudomonas aeruginosa normally metabolize the alkanes through oxidation process and it has two alkane hydroxylases (alkB1 and alkB2), cytochrome P450 and other essential electron transfer proteins that allow it to metabolize long-chain alkanes (Gunasekera et al 2013). Similarly, G. stearothermophilus are reported to contain hydroxylase enzyme and gene-encoding alkane monooxygenase are responsible for degradation of long-chain alkanes (C 12 -C 31 ) (Sakai et al 1994;Wang et al 2006;Liu et al 2010;). Many microbial species were used by many researchers to degrade long-chain alkanes like B. stearothermophilus, Acinetobacter sp., B. thermoleovorans, G. kaustophilus, Dietzia sp., B. licheniformis, etc.…”