SIMULTANEOUS PRODUCTION OF BIOSURFACTANTS AND LIPASES FROM Aspergillus niger AND OPTIMIZATION BY RESPONSE SURFACE METHODOLOGY AND DESIRABILITY FUNCTIONS

Abstract Microbial conversion for the synthesis of high added-value compounds, such as biosurfactants and lipases, is one of the most promising fields within the biotechnology industry, given its current development. In this study the simultaneous production of biosurfactants and lipases by Aspergillus niger in a submerged bioprocess was analyzed. Full Factorial Design (23) was conducted to assess the influence of the malt extract (g·L-1; 25, 50, 75) and soybean oil concentrations (% v/v; 0.0, 1.25, 2.5) and agitation rates (rpm; 0.0, 100, 200) on biosurfactant and lipase production. Higher levels of the factors favored microbial growth, while their lower levels favored the production of biosurfactants and lipases. The variables were optimized through the response surface methodology and desirability functions, obtaining simultaneous maximized values of 0.48 g·L-1 (biomass); 42.03% (EAw/o);2.17 UE (EAw/o) and 3.28 U (LA). This indicates the possibility of combined biosurfactant and lipase production.

摘要：微生物转化法合成生物表面活性剂、脂肪酶等高附加值化合物，是当前生物技术产业中极具发展前景的方向之一。本研究针对黑曲霉（Aspergillus niger）在浸没式生物工艺中同步生产生物表面活性剂与脂肪酶的过程展开分析。实验采用全因子设计（Full Factorial Design，2³），考察麦芽提取物浓度（单位：g·L⁻¹，取值25、50、75）、大豆油浓度（体积百分比，% v/v，取值0.0、1.25、2.5）及搅拌速率（单位：rpm，取值0.0、100、200）对生物表面活性剂与脂肪酶产量的影响。结果表明，各因素的高水平更利于微生物生长，而低水平则更有助于生物表面活性剂和脂肪酶的合成。本研究通过响应面法（response surface methodology）与期望函数法对变量进行优化，最终获得同步最大化的各项指标：生物量0.48 g·L⁻¹、EAw/o为42.03%、EAw/o对应2.17 UE以及LA对应3.28 U。这证实了同步生产生物表面活性剂与脂肪酶的可行性。