基于高含油废水降解的产脂肪酶菌株的 筛选及发酵工艺优化

为了筛选高产脂肪酶菌株并探究其对高含油废水的降解能力，采用传统的微生物筛选法从餐厨废水中分离筛选菌株，考察菌株对高含油废水（油脂含量20 g/L）的油脂降解率和产脂肪酶酶活，并对产脂肪酶酶活较高的菌株进行鉴定。采用单因素实验和响应面实验对鉴定菌株发酵产脂肪酶的工艺条件进行优化。结果表明：从餐厨废水中筛选出3株细菌、2株酵母菌，其中2株细菌可在高含油废水中快速生长代谢，油脂降解率和产脂肪酶酶活均较高，经鉴定1株为解淀粉芽孢杆菌（Bi），1株为鲁氏不动杆菌（Bu）；Bi产脂肪酶最优发酵工艺条件为pH 6.69、氯化钠含量301 g/L、蛋白胨含量6.01 g/L；Bu产脂肪酶最优发酵工艺条件为pH 5.07、氯化钠含量6.10 g/L、蛋白胨含量9.38 g/L；在最优发酵工艺条件下，Bi和Bu产脂肪酶酶活分别为（222.83±0.91）U/mL和（231.50±2.28）U/mL，优化后的Bu产脂肪酶酶活甚至高于初始脂肪酶酶活更高的Bi。综上，2株细菌具有高含油废水降解能力，具备广阔的应用前景。

Screening of lipase-producing strains based on the degradation of highly oily wastewater and optimization of fermentation process

In order to screen high lipase-producing strains and explore the ability to degrade highly oily wastewater, the traditional microbial screening method was used to select the strains from the kitchen wastewater, and the oil degradation rate of highly oily wastewater (oil content 20 g/L) and the lipase activity of the selected strains were studied. Strains with higher lipase production activity were identified. Furthermore, single factor experiment and response surface methodology were employed to optimize the fermentation conditions for lipase production of the identified strains. The results indicated that three bacterial strains and two yeast strains were screened from kitchen wastewater, two bacteria grew and metabolized rapidly in highly oily wastewater, and the oil degradation rate and lipase activity were higher, which were identified as Bacillus amyloliquefaciens （Bi）and Acinetobacter lwoffii（Bu）, respectively. The optimal fermentation conditions for lipase production by Bi were pH 6.69, NaCl content 3.01 g/L, peptone content 6.01 g/L, and lipase activity was (222.83±0.91) U/mL, while that of Bu were pH 5.07, NaCl content 6.10 g/L, peptone content 9.38 g/L, and the lipase activity was (231.50±2.28) U/mL. The lipase activity of Bu after optimization even higher than that of Bi , which had a greater initial lipase activity. In conclusion, these two bacterial strains show a high biodegradation performance for highly oily wastewater, and they have a wide application prospect.