Department of Microbiology, Shivaji University, Kolhapur, India.
J Basic Microbiol. 2011 Aug;51(4):385-96. doi: 10.1002/jobm.201000364. Epub 2011 Mar 24.
The biosurfactant produced by Pseudomonas desmolyticum NCIM 2112 (Pd 2112) was confirmed as rhamnolipid based on the formation of dark blue halos around the colonies in CTAB-methylene blue agar plates and the content of rhamnose sugar. The average yield of rhamnolipid was 0.398 g/l/day when grown on hexadecane as sole carbon source. Pd 2112 emulsification potential associated with cell free culture broth was stable for 72 h using various hydrocarbons and vegetable oils. Chemical structure of the biosurfactant was identified as mono-rhamnolipid (Rha-C(6) -C(8) ) using HPTLC, fourier transform infrared spectroscopy, (1) H and (13) C NMR and gas chromatography-mass spectroscopy analysis. Pd 2112 mono-rhamnolipid (1 mg/ml) had increased permeabilization of Bacillus sp VUS NCIM 5342 and increased decolorization rate of textile dye Brown 3REL by 50%. Extracellular activities of lignin peroxidase and veratryl alcohol oxidase, enzymes involved in dye degradation, were significantly increased in the presence of mono-rhamnolipid by 324.52% and 100% respectively. Scanning electron micro-scopy observations revealed that rhamnolipid did not exert any disruptive action on Bacillus cells as compared to Tween 80. The mono-rhamnolipid of Pd 2112 has potential for its application in biodegradation of textile dyes.
从 CTAB-美蓝琼脂平板上菌落周围形成的深蓝色晕圈和鼠李糖含量可以确定解淀粉假单胞菌 NCIM 2112（Pd 2112）产生的生物表面活性剂为鼠李糖脂。以十六烷为唯一碳源时，鼠李糖脂的平均产量为 0.398 g/l/天。Pd 2112 细胞游离培养物的乳化活性在使用各种碳氢化合物和植物油的情况下可稳定 72 小时。使用 HPTLC、傅里叶变换红外光谱、(1)H 和 (13)C NMR 和气相色谱-质谱分析，确定生物表面活性剂的化学结构为单鼠李糖脂（Rha-C(6)-C(8)）。Pd 2112 单鼠李糖脂（1 mg/ml）可增加芽孢杆菌 VUS NCIM 5342 的通透性，并使纺织染料棕 3REL 的脱色率提高 50%。在单鼠李糖脂存在的情况下，木质素过氧化物酶和藜芦醇氧化酶的胞外活性分别显著提高了 324.52%和 100%。这两种酶都参与染料的降解。扫描电子显微镜观察表明，与吐温 80 相比，鼠李糖脂对芽孢杆菌细胞没有任何破坏作用。Pd 2112 的单鼠李糖脂具有在纺织染料生物降解中应用的潜力。
