米根霉全细胞脂肪酶在化学-酶法环氧化反应体系中的稳定性
Stability of Rhizopus oryzae whole-cell lipase in a chemo-enzymatic epoxidation reaction
许丽莉 1赵晴晴 2李青云 2唐爱星 2刘幽燕2
作者信息
- 1. 广西大学 化学化工学院,广西 南宁 530004;北部湾大学 海洋学院,广西 钦州 535011
- 2. 广西大学 化学化工学院,广西 南宁 530004
- 折叠
摘要
为了提高米根霉(Rhizopus oryzae CGMCC 3.5040)全细胞脂肪酶在化学-酶法环氧化反应体系中的稳定性,以α-蒎烯为模式底物,考察柠檬酸三钠用量、戊二醛交联细胞、过氧化氢(H2O2)用量和回用方式对催化剂稳定性的影响.结果表明:过氧有机酸会影响酶稳定性,添加 3.5 mmol柠檬酸三钠会与质量分数为 30%H2O2 水溶液形成高渗液,防止细胞涨破,同时能中和过量过氧酸,提高反应选择性与细胞的回用稳定性;经过戊二醛交联后,全细胞催化剂的热稳定性、储存稳定性和回用稳定性都显著提高;蒎烯环氧化的最适H2O2 用量为 5 mmol;可采用直接分离有机相,再加入新鲜有机相的方式进行回用.优化回用方式后,该全细胞催化剂第 7 次使用时,催化反应仍然有 77.3%的转化率.
Abstract
Effects of trisodium citrate dosage,glutaraldehyde cross-linking of cells,H2O2 dosage and recycling methods on catalyst stability were examined using α-pinene as the model substrate,in order to enhance the stability of Rhizopus oryzae CGMCC 3.5040 whole-cell lipase in a chemo-enzymatic epoxidation reaction system.The results indicate that peroxyacid could affect enzyme stability.Addition of 3.5 mmol trisodium citrate could form a hypertonic solution with a 30%H2O2 solution,which prevented cell swelling and neutralized excess peroxyacid,thereby improved reaction selectivity and cell recycling stability.The thermal stability,storage stability,and recycling stability of the whole-cell catalyst were significantly enhanced after glutaraldehyde cross-linking.The optimal H2O2 dosage for the α-pinene epoxidation was 5 mmol.Recycling could be achieved by directly separating the organic phase and adding fresh organic phase.After optimizing the recycling method,the catalyst retains a conversion rate of 77.3%even after the 7th usage.
关键词
米根霉/全细胞脂肪酶/化学-酶法环氧化/过氧有机酸/稳定性Key words
Rhizopus oryzae/whole-cell lipase/chemo-enzymatic epoxidation/peroxyacid/stability引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据