Srinivasaraghavan K, Sarma P M, Lal B
Center of Bioresources and Biotechnology, TERI school of Advanced Studies, New Delhi, India.
Lett Appl Microbiol. 2006 May;42(5):483-9. doi: 10.1111/j.1472-765X.2006.01842.x.
To compare few phenotypic and genotypic characteristics of two desulfurizing bacterial strains, Mycobacterium phlei SM120-1 and Mycobacterium phlei GTIS10.
In the present study, dibenzothiophene (DBT) desulfurizing activity, composition of fatty acids of cell membranes, DBT sulfone monoxygenase gene (bdsA) and the selection pressure applied during the growth and enrichment of the bacterial strains M. phlei SM120-1 and M. phlei GTIS10 were compared in our laboratory. The DBT desulfurization activity of M. phlei SM120-1 was found to be 0.17 +/- 0.02 micromol 2-HBP min(-1) (gram dry cell weight)(-1) and that of the bacterial strain M. phlei GTIS10 was 1.09 +/- 0.05 micromol 2-HBP min(-1) (gram dry cell weight)(-1). Fatty acid methyl ester analysis of cell membranes of these two bacterial strains in the presence of light gas oil showed that both the strains had different fatty acid profiles in their cell membranes. Comparison of the full gene sequences of the desulfurization gene bdsA in the two bacterial strains showed significant difference in the bdsA gene sequences. There was a significant difference observed in the selection pressure applied during the growth and enrichment of the two bacterial strains.
The results of the comparative study of the bacterial strains, M. phlei SM120-1 and M. phlei GTIS10 showed that there were considerable differences in the phenotypic and genotypic characteristics of these two strains.
The present study would broaden the understanding of biodesulfurization trait at intra-species level.
比较两株脱硫细菌——草分枝杆菌SM120 - 1和草分枝杆菌GTIS10的一些表型和基因型特征。
在本研究中，我们实验室比较了草分枝杆菌SM120 - 1和草分枝杆菌GTIS10的二苯并噻吩（DBT）脱硫活性、细胞膜脂肪酸组成、DBT砜单加氧酶基因（bdsA）以及这两种菌株生长和富集过程中所施加的选择压力。发现草分枝杆菌SM120 - 1的DBT脱硫活性为0.17±0.02微摩尔2 - 羟基联苯每分钟（克干细胞重量）⁻¹，而草分枝杆菌GTIS10菌株的为1.09±0.05微摩尔2 - 羟基联苯每分钟（克干细胞重量）⁻¹。对这两种菌株在轻质瓦斯油存在下的细胞膜脂肪酸甲酯分析表明，两株菌细胞膜中的脂肪酸谱不同。比较这两种菌株脱硫基因bdsA的全基因序列发现，bdsA基因序列存在显著差异。在这两种菌株生长和富集过程中所施加的选择压力也存在显著差异。
草分枝杆菌SM120 - 1和草分枝杆菌GTISl0这两种菌株的比较研究结果表明，这两种菌株在表型和基因型特征上存在相当大的差异。
本研究将拓宽对种内生物脱硫特性的理解。
