The components of waste cooking oil (WCO) are complex and contain toxic substances, which are difficult to treat biologically. Pseudomonas aeruginosa WO2 was isolated from oily sludge by an anaerobic enrichment–aerobic screening method, which could efficiently utilize WCO and produce rhamnolipid. The effects of nutrients and culture conditions on bacterial growth and lipase activity were investigated to optimize the fermentation of WCO. The results showed that strain WO2 utilized 92.25% of WCO and produced 3.03 g/L of rhamnolipid at 120 h. Compared with inorganic sources, the organic nitrogen source stabilized the pH of fermentation medium, improved lipase activity (up to 19.98 U/mL), and promoted the utilization of WCO. Furthermore, the WO2 strain exhibited inferior utilization ability of the soluble starch contained in food waste, but superior salt stress up to 60 g/L. These unique characteristics demonstrate the potential of Pseudomonas aeruginosa WO2 for the utilization of high-salinity oily organic waste or wastewater.

Temperature affected ethanol fermentation of energy beet greatly.This study showed that yeast HADY was tolerant to high temperature and when the fermentation temperature was 45°C,the translation rate of ethanol was higher.The three main factors were screened out from nine factors related fermentation by Plackett-Burman design and response surface methodology, such as substrate concentration, ratio of solvent to material, added HADY amount,nutrient salts, phosphorus addition amount, pH value, rotational speed, fermentation temperature and fermentation time. The three main factors included substrate concentration, fermentation temperature and phosphorus addition amount.The optimized technological parameters of HADY were as follows:substrate concentration12%, ratio of solvent to material 1:1, added HADY15%,nutrient salts 0.5,added phosphorus 0.9%, pH 5.0,rotation speed 130r/min, fermentation temperature 37°C and fermentation time 44 hours.At the time, the result showed that the translation rate of ethanol was 89.43%.

In order to meet the needs of industrial mass production,people began to explore the effect on different modes to ethanol fermentation.Ethanol fermentation with energy beet was done by using batch fermentation and continuous fermentation.Results showed that batch fermentation was better than continuous mode,but its technology was cockamamie.The residual glucose content in fermenting mash was high when fermentation was continuous.And the fermentation was halfway.But continuous fermentation was convenient for industrialization producing.Although the residual glucose content in continuous fermentation mode was high through 0.06 h-1 sugar concentration,the last translation rate of ethanol was high.