Crude biosurfactant from thermophilic Alcaligenes faecalis: Feasibility in petro-spill bioremediation
Crude biosurfactant from thermophilic Alcaligenes faecalis: Feasibility in petro-spill bioremediation
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DOI：
10.1016/j.ibiod.2011.04.001
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发表时间：
2011-08-01
影响因子：
4.8
通讯作者：
Thakur, A. J.
中科院分区：
文献类型：
--
作者：
Bharali, P.;Das, S.;Thakur, A. J.
从印度上阿萨姆邦原油污染土壤中分离的嗜热细菌粪化碱性杆菌。首先对分离的细菌进行了生产生物表面活性剂的能力筛选。菌株在42℃条件下生长，在添加2% （v/v）柴油作为唯一碳源和能源的培养基中，可以产生较高数量的生物表面活性剂。生化表征包括FT-IR和MS研究表明生物表面活性剂为糖脂。张力学研究表明，菌株在碳氢化合物表面生长96 h后，可将空气-水界面表面张力（sigma）从71.6降低到32.3 mNm(-1)，临界胶束浓度（CMC）值较低，约为38 mgl(-1)，具有较高的表面活性。在不同pH（2-12）、温度（100℃和121℃）和盐度（1-6% NaCl, w/v）条件下，含该生物表面活性剂的培养上清液功能稳定。培养液和无细胞上清液对不同的烃类和原油组分均表现出较高的乳化活性。菌株的细胞表面疏水性和糖脂产量的增加表明生物表面活性剂的存在增强了碳氢化合物的界面吸收。此外，部分纯化的生物表面活性剂通过抑制几种细菌和真菌的生长而表现出抗菌活性。该菌株代表了一类新的生物表面活性剂生产者，可能是生产糖脂类生物表面活性剂的潜在候选菌株，可用于各种生物技术和工业过程，特别是石油工业。(C) 2011 Elsevier Ltd.版权所有。
The thermophilic bacterium Alcaligenes faecalis isolated from the crude oil contaminated soil of Upper Assam, India. The isolated bacterium was first screened for the ability to produce biosurfactant. The strain growing at 42 degrees C could produce higher amount of biosurfactant in medium supplemented with 2% (v/v) diesel as sole source of carbon and energy. Biochemical characterizations including FT-IR and MS studies suggested the biosurfactant to be glycolipid. Tensiometric studies revealed that the biosurfactant produced by the bacterial strain could decrease the surface tension (sigma) at air-water interface from 71.6 to 32.3 mNm(-1) after 96 h of growth on hydrocarbon and possessed a low critical micelle concentration (CMC) value of approximately 38 mgl(-1), indicating high surface activity. The culture supernatant containing the biosurfactant was found to be functionally stable at varying pH (2-12), temperature (100 and 121 degrees C) and salinity (1-6% NaCl, w/v) conditions. Both the culture broth and the cell free supernatant exhibited high emulsifying activity against the different hydrocarbons and the crude oil components. The increase in cell surface hydrophobicity and glycolipid production by the strain suggested the existence of biosurfactant enhanced interfacial uptake of the hydrocarbons. Moreover, the partially purified biosurfactant exhibited antimicrobial activity by inhibiting the growth of several bacterial and fungal species. The strain represented a new class of biosurfactant producers and could be a potential candidate for the production of glycolipid biosurfactant which could be useful in a variety of biotechnological and industrial processes, particularly in the oil industry. (C) 2011 Elsevier Ltd. All rights reserved.