鼠李糖脂产生菌的筛选及其发酵条件的优化

采用富集培养,蓝色凝胶平板法,排油圈法分离筛选到1株产生物表面活性剂的菌株铜绿假单胞菌（Pseudomonas aeruginosa）LJ-3,并通过单因素试验和L9（43）正交试验对该菌株产表面活性剂的影响因素和发酵条件进行了优化,结果表明：菌株LJ-3产鼠李糖脂的条件为：餐厨废弃油脂50 g/L,硝酸钠3.0 g/L,磷酸二氢钾0.437 550 g/L,磷酸氢二钾0.562 550 g/L,硫酸镁1.550 g/L,硫酸锰0.06 g/L,硫酸亚铁0.025 0 g/L,酵母膏15 g/L,接种量75 mL/L,pH值为7,于37℃,150 r/min条件下,恒温振荡培养72 h,通过排油圈法测得的直径为6.8 cm,表面张力降低到29 mN/m。

Screening and Fermentation Condition Optimization of Rhamnolipid-producing Strains

Pseudomonas aeruginosa LJ-3 strains for producing surfactants were isolated and screened by enrichment culture, blue agar plate and oil spreading methods. Influencing factors of producing surfactants and fermentation conditions of the strains were optimized by single factor test and L9（43） orthogonal test. The results show that, the rhamnolipid production conditions of strains LJ-3 are as follows： dining kitchen waste oil 50 g/L,sodium nitrate 3.0 g/L,potassium dihydrogen phosphate 0.437 550 g/L,dipotassium hydrogen phosphate 0.562 550 g/L, magnesium sulfate 1.550 g/L, manganese sulfate 0.06 g/L, ferrous sulfate 0.0250 g /L, yeast extract 15 g/L, inoculum 75 mL/L, pH value 7, temperature 37 ℃, stirring speed 150 r/min,constant temperature shaking 72h; the diameter of oil spreading is 6.8 cm, the surface tension is reduced to 29 mN / m.