英语翻译6.Uptake of Hydrocarbons by BiosurfactantsBiosurfactants

英语翻译
6.Uptake of Hydrocarbons by Biosurfactants
Biosurfactants are heterogeneous group of surface active chemical compounds produced by a wide variety of microorganisms [57,58,60,81–83].Surfactants enhance solubilization and removal of contaminants [84,85].Biodegradation is also enhanced by surfactants due to increased bioavailability of pollutants [86].Bioremediation of oil sludge using biosurfactants has been reported by Cameotra and Singh [87].Microbial consortium consisting of two isolates of Pseudomonas aeruginosa and one isolate Rhodococcus erythropolis from soil contaminated with oily sludge was used in this study.The consortium was able to degrade 90% of hydrocarbons in 6 weeks in liquid culture.The ability of the consortium to degrade sludge hydrocarbons was tested in two separate field trials.In addition,the effect of two additives (a nutrient mixture and a crude biosurfactant preparation on the efficiency of the process was also assessed.The biosurfactant used was produced by a consortium member and was identified as being a mixture of 11 rhamnolipid congeners.The consortium degraded 91% of the hydrocarbon content of soil contaminated with 1% (v/v) crude oil sludge in 5 weeks.Separate use of any one additive along with the consortium brought about a 91–95% depletion of the hydrocarbon content in 4 weeks,with the crude biosurfactant preparation being a more effective enhancer of degradation.However,more than 98% hydrocarbon depletion was obtained when both additives were added together with the consortium.The data substantiated the use of a crude biosurfactant for hydrocarbon remediation.
Pseudomonads are the best known bacteria capable of utilizing hydrocarbons as carbon and energy sources and producing biosurfactants [37,87–89].Among Pseudomonads,P.aeruginosa is widely studied for the production of glycolipid type biosurfactants.However,glycolipid type biosurfactants are also reported from some other species like P.putida and P.chlororaphis.Biosurfactants increase the oil surface area and that amount of oil is actually available for bacteria to utilize it [90].Table 2 summarizes the recent reports on biosurfactant production by different microorganisms.Biosurfactants can act as emulsifying agents by decreasing the surface tension and forming micelles.The microdroplets encapsulated in the hydrophobic microbial cell surface are taken inside and degraded.Figure 4 demonstrates the involvement of biosurfactant (rhamnolipids) produced by Pseudomonas sp.and the mechanism of formation of micelles in the uptake of hydrocarbons [75].
Table 2:Biosurfactants produced by microorganisms.Figure 4:Involvement of biosurfactant (rhamnolipid) produced by Pseudomonas sp in the uptake of hydrocarbons.

6.吸收碳氢化合物的表面活性剂
表面活性剂是异质组表面活性化合物产生的各种各样的微生物[ 57,58,60,81–83 ].表面活性剂提高溶解和去除污染物[ 84,85 ].生物降解也增强了表面活性剂的生物利用度增加,污染物[ 86].生物修复石油污泥使用表面活性剂已报告的cameotra和辛格[ 87].微生物财团组成的2株铜绿假单胞菌和一个孤立的红平红球菌从土壤污染的含油污泥为研究.该财团能够降低90%的碳氢化合物在6周的培养液中.能力的财团降解污泥碳氢化合物进行了测试在不同的现场试验.此外,影响的添加剂（营养混合物和原油的生物表面活性剂的制备过程的效率进行评估.生物表面活性剂使用的是由一个财团的成员,被确定为11个混合鼠李糖脂同源.该财团降解91%的烃含量污染土壤与1%（体积比）原油污泥5周.单独使用任何一种添加剂随着联盟带来了91–95%枯竭的烃含量在4周,与原油生物表面活性剂的制备是一个更有效的增强的降解.然而,98%以上烃类耗尽时获得两种添加剂和财团.这些数据证实了利用原油生物表面活性剂的油补救.
假单胞菌是最有名的细菌能够利用碳氢化合物作为碳源和能源生产生物表面活性剂[ 37,87]–89.在假单胞菌,铜绿假单胞菌广泛研究生产糖脂类生物表面活性剂.然而,糖脂类生物表面活性剂也报告了一些其他物种一样的恶臭假单胞菌和绿脓chlororaphis.生物表面活性剂提高石油的表面面积和油量实际上可用于细菌利用[ 90].表2总结了最近的报告对生物表面活性剂生产不同的微生物.生物表面活性剂可作为乳化剂,通过降低表面张力和形成胶束.液滴封装在疏水性微生物细胞表面是内部和退化.图4显示了参与（鼠李糖脂生物表面活性剂）的假单胞菌.和机制的形成胶束的吸收碳氢化合物[ 75].
表2表面活性剂是由微生物产生的.图4：参与生物表面活性剂（鼠李糖脂）由假单胞菌在吸收碳氢化合物.