Abstract

Crude glycerol, a by-product of biodiesel production, was employed as the carbon source to produce lipase using Pichia pastoris. Under identical fermentation conditions, cell growth and lipase activity were improved using crude glycerol instead of pure glycerol. The impacts of crude glycerol impurities (methyl ester, grease, glycerol, methanol, and metal ions Na⁺, Ca²⁺, and Fe³⁺) on lipase production were investigated. Impurities accelerated P. pastoris entering the stationary phase. Na⁺, Ca²⁺, and grease in waste crude glycerol were the main factors influencing higher lipase activity. Through response surface optimization of Ca²⁺, Na⁺, and grease concentrations, lipase activity reached 1437 U/mL (15,977 U/mg), which was 2.5 times that of the control. This study highlights the economical and highly efficient valorization of crude glycerol, demonstrating its possible utilization as a carbon source to produce lipase by P. pastoris without pretreatment.

摘要

生物柴油生产的副产物粗甘油被用作使用毕赤酵母生产脂肪酶的碳源。在相同的发酵条件下，使用粗甘油代替纯甘油可以改善细胞生长和脂肪酶活性。研究了粗制甘油杂质（甲酯，油脂，甘油，甲醇和金属离子Na ⁺，Ca ²⁺和Fe ³⁺）对脂肪酶生产的影响。杂质加速了巴斯德毕赤酵母进入稳定期。废粗甘油中的Na ⁺，Ca ²⁺和油脂是影响较高脂肪酶活性的主要因素。通过Ca ^2+的响应面优化，Na ⁺和油脂浓度，脂肪酶活性达到1437 U / mL（15,977 U / mg），是对照的2.5倍。这项研究突出了粗甘油的经济和高效的增值，证明了其可能被用作巴斯德毕赤酵母未经预处理而产生脂肪酶的碳源。