Biomolecules and Biocatalysis Laboratory, Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, 603203, Kancheepuram District, Tamil Nadu, India.
Biomolecules and Biocatalysis Laboratory, Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, 603203, Kancheepuram District, Tamil Nadu, India.
J Environ Manage. 2018 Aug 15;220:87-95. doi: 10.1016/j.jenvman.2018.04.120. Epub 2018 May 15.
Petroleum hydrocarbon removal from tank bottom oil sludge is a major issue due to its properties. Conventional physicochemical treatment techniques are less effective. Though the bioremediation is considered for the hydrocarbon removal from tank bottom oil sludge, the efficiency is low and time taking due to the low yield of biocatalysts and biosurfactants. The focal theme of the present investigation is to modify the process by introducing the intermittent inoculation for the enhanced biodegradation of hydrocarbons in the tank bottom oil sludge by maintaining a constant level of biocatalysts such as oxidoreductase, catalase, and lipase as well as biosurfactants. In addition, the heavy metal removal was also addressed. The microbial consortia comprising Shewanalla chilikensis, Bacillus firmus, and Halomonas hamiltonii was used for the biodegradation of oil sludge. One variable at a time approach was used for the optimum of culture conditions. The bacterial consortia degraded the oil sludge by producing biocatalysts such as lipase (80 U/ml), catalase (46 U/ml), oxidoreductase (68 U/ml) along with the production of lipoprotein biosurfactant (152 mg/g of oil sludge) constantly and achieved 96% reduction of total petroleum hydrocarbon. The crude enzymes were characterized by FT-IR and the biosurfactant was characterized by surface tension reduction, emulsification index, FT-IR, TLC, and SDS-PAGE. GC-MS and NMR also revealed that the hydrocarbons present in the oil sludge were effectively degraded by the microbial consortia. The ICP-OES result indicated that the microbial consortium is also effective in removing the heavy metals. Hence, bioremediation using the hydrocarbonoclastic microbial consortium can be considered as an environmentally friendly process for disposal of tank bottom oil sludge from petroleum oil refining industry.
从罐底油泥中去除石油烃是一个主要问题，因为其性质所致。传统的物理化学处理技术效果较差。尽管生物修复被认为是从罐底油泥中去除烃类的一种方法，但由于生物催化剂和生物表面活性剂的产量低，效率低且耗时。本研究的重点是通过间歇接种来修改该过程，以提高罐底油泥中烃类的生物降解效率，同时保持氧化还原酶、过氧化氢酶和脂肪酶等生物催化剂以及生物表面活性剂的恒定水平。此外，还解决了重金属去除问题。使用 Shewanalla chilikensis、Bacillus firmus 和 Halomonas hamiltonii 组成的微生物群落来生物降解油泥。采用单因素变量法优化培养条件。该细菌群落通过产生生物催化剂（如脂肪酶（80 U/ml）、过氧化氢酶（46 U/ml）和氧化还原酶（68 U/ml））来降解油泥，同时不断产生脂蛋白生物表面活性剂（152mg/g 油泥），实现了总石油烃的 96%去除率。粗酶通过傅里叶变换红外光谱（FT-IR）进行了表征，生物表面活性剂通过表面张力降低、乳化指数、FT-IR、薄层色谱（TLC）和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）进行了表征。GC-MS 和 NMR 也表明，微生物群落有效地降解了油泥中的烃类。电感耦合等离子体-原子发射光谱（ICP-OES）的结果表明，微生物群落也能有效地去除重金属。因此，使用烃类降解微生物群落进行生物修复可以被视为一种处理石油精炼厂罐底油泥的环保方法。
