Labortaory of Applied Microbiology, Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, India.
Labortaory of Applied Microbiology, Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, India.
Ecotoxicol Environ Saf. 2021 Jan 15;208:111621. doi: 10.1016/j.ecoenv.2020.111621. Epub 2020 Nov 10.
The study explored the polycyclic aromatic hydrocarbon tolerance of indigenous biosurfactant producing microorganisms. Three bacterial species were isolated from crude oil contaminated sites of Haldia, West Bengal. The three species were screened for biosurfactant production and identified by 16S rRNA sequencing as Brevundimonas sp. IITISM 11, Pseudomonas sp. IITISM 19 and Pseudomonas sp. IITISM 24. The strains showed emulsification activities of 51%, 57% and 63%, respectively. The purified biosurfactants were characterised using FT-IR, GC-MS and NMR spectroscopy and found to have structural similarities to glycolipopeptides, cyclic lipopeptides and glycolipids. The biosurfactants produced were found to be stable under a wide range of temperature (0-100 °C), pH (4-12) and salinity (up to 20% NaCl). Moreover, the strains displayed tolerance to high concentrations (275 mg/L) of anthracene and fluorene and showed a good amount of cell surface hydrophobicity with different hydrocarbons. The study reports the production and characterisation of biosurfactant by Brevundimonas sp. for the first time. Additionally, the kinetic parameters of the bacterial strains grown on up to 300 mg/L concentration of anthracene and fluorene, ranged between 0.0131 and 0.0156 µ (h), while the K(mg/L) ranged between 59.28 and 102.66 for Monod's Model. For Haldane-Andrew's model, µ (h) varied between 0.0168 and 0.0198. The inhibition constant was highest for Pseudomonas sp. IITISM 19 on anthracene and Brevundimonas sp. IITISM 11 on fluorene. The findings of the study suggest that indigenous biosurfactant producing strains have tolerance to high PAH concentrations and can be exploited for bioremediation purposes.
该研究探讨了土著生物表面活性剂产生微生物对多环芳烃的耐受性。从西孟加拉邦哈尔迪亚受原油污染的地点分离出三种细菌。通过 16S rRNA 测序，这三种细菌被筛选为 Brevundimonas sp. IITISM 11、Pseudomonas sp. IITISM 19 和 Pseudomonas sp. IITISM 24。这些菌株的乳化活性分别为 51%、57%和 63%。纯化的生物表面活性剂通过傅里叶变换红外光谱、气相色谱-质谱和核磁共振波谱进行了表征，发现它们的结构与糖脂肽、环状脂肽和糖脂相似。生物表面活性剂在很宽的温度（0-100°C）、pH（4-12）和盐度（高达 20%NaCl）范围内都很稳定。此外，这些菌株对高浓度（275mg/L）的蒽和芴显示出耐受性，并表现出不同烃类的良好细胞表面疏水性。该研究首次报道了 Brevundimonas sp. 产生生物表面活性剂及其特性。此外，在高达 300mg/L 浓度的蒽和芴上生长的细菌菌株的动力学参数在 0.0131 和 0.0156µ（h）之间，而 Monod 模型的 K（mg/L）在 59.28 和 102.66 之间。对于 Haldane-Andrew 模型，µ（h）在 0.0168 和 0.0198 之间变化。在蒽上，Pseudomonas sp. IITISM 19 的抑制常数最高，在芴上，Brevundimonas sp. IITISM 11 的抑制常数最高。该研究的结果表明，土著生物表面活性剂产生菌株对高浓度 PAH 具有耐受性，可以用于生物修复目的。
