The. Sophorolipid A Bacterium And Its Sophorolipid Antibacterial And Anti-tumor Role

It is well-known that surfactants can be used in pharmaceutic, energetic, cosmetic industries, etc. Biosurfactants are the metabolic products of some microorganisms and have many advantages including low toxicity, biodegradability and biocompatibility compared with synthetic surfactants by chemical methods. Therefore, biosurfactants have promising applications in petroleum, environment, food, pharmaceutical industries.Sophorolipids are the most important and promising ones of many kinds of biosurfactants due to their biodegradability, low toxicity, effectiveness and high yields.In the past decades, the optimization of fermentation yields and applications of sophorolipids were studied extensively. Only a few of papers were related to the pharmacological function of sophorolipids, Very little information was available concerning mechanism of antitumor activities of sophorolipids. The main research aspects and results are as following:1. A new strain producing sophorolipids was isolated from oil-containing wastewater. First, using rapeseed oil as sole carbon source, more than 200 strains were isolated from soil and wastewater samples by enrichment culture and plate streaking. Second, these strains were cultured in fermentation media, 5 strains producing biosurfactant were isolated by measuring the oil film-collapsing activity and surface tension of the culture broth. Finally, it is demonstrated that the yeast strain Y_2A can produce sophorolipids by some spectral methods, including TLC, IR, HPLC, NMR and MS. The surface tension of Y_2A culture broth was decreased to 37.3 mN/m. The product is a mixture containing more than six glycolipids. After HPLC analysis, there are three main products, compound Ⅰ , compound Ⅱ and compound Ⅲ, occurring at retention time 33.28, 34.62 and 38.15min. Compound Ⅲ was 17-L-( [2 '-O-β-D-glucopyranosyl-1"-β-D-glucopyranosyl]-oxy)-octadecanoic acid 1, 4"-lactone 6', 6"-diacetate, that is lactonic diacetyl-sophorolipid.By using BIOLOG system and conventional methods for yeast identification,...