南极拟酵母脂肪酶对聚丁二酸丁二酯薄膜的降解研究

Study on Biodegradation of PBS Film by Pseudozyma Antarctica Lipase

以聚丁二酸丁二酯(PBS)薄膜为降解底物,利用南极拟酵母脂肪酶(Lipozyme CALB)对其进行降解研究;考察了pH值、温度、酶浓度以及降解时间对Lipozyme CALB降解PBS薄膜的影响,并通过扫描电子显微镜、差示扫描量热仪、热重分析仪及质谱分析仪等对PBS薄膜以及PBS的降解产物进行了表征分析。结果表明,在酶浓度为20U/mL,反应温度为50℃,pH值为7.0的条件下,经24h的降解,PBS薄膜(3cm×1cm×0.5cm)的降解率可达90%以上;随着降解时间的延长,薄膜表面明显发生了降解并形成孔洞,且PBS的相对结晶度呈现上升趋势,PBS薄膜的热稳性逐渐上升;PBS的降解产物为1,4-丁二酸和丁二酸-丁二醇二聚体。

This paper reported a study on the biodegradation of poly（butylene succinate）（PBS）film as degraded substrate,the degradation behavior of PBS film by a Pseudozyma Antarctica Lipase,Lipozyme CALB.The effects of acidity,temperature,enzymatic concentration and degradation time on the degradation of PBS film were investigated,and then the post-degraded films were characterized by scanning electron microscopy,thermogravimetric analysis and differential scanning calorimetry. The degradation products were also analyzed by mass spectrometry.The results indicated that the optimum conditions for the degradation of PBS film by Lipozyme CALB were obtained at an acidity of pH 7,a temperature of 50 ℃ and an enzymatic concentration of 20 U/mL,and a weight loss of 90 wt% was achieved for the PBS film degraded for 24 hat these conditions.The morphologic observation indicated that the surface of PBS film became more and more rough,and some holes appeared with increasing degradation time.The thermal analysis results demonstrated that the crystallinity of the degraded film was found to increase with the increase of degradation time,but their thermal stability trended to increase gradually.The mass spectrometric analysis indicated that the PBS film was degraded into 1,4-succinate and succinate-butanediol,but no 1,4-butanediol was found.