Effect Of Microwave Irradiation On Detergent Enzymes

Detergent industry is the largest market of industrial enzymes, detergent enzymes (protease and lipase) can improve the detergency power in higher pH environment and reduce the amount of other ingredients. Microwave irradiation can change the conformation of the enzyme protein and enhance the activity of enzymes. In this experiment, we studied that whether the microwave irradiation can enhance detergent enzymes activity and their detergency power. Taking into account shelf time of the detergents, we also investigated the time course of the microwave effect on the detergent enzymes and the subsequent detergency. To verify the coincidence between the enzymes activity and their conformation before and after the irradiation, we investigated the UV absorption spectrum and fluorescence emission spectrum of the detergent enzymes. We also studied the effects of surfactants and detergent builder on the activity of Properase 1000E and Lipolase 100T before and after the irradiation. The main contents and research results are as follows:1. In this experiment, we used the microwave irradiation (1000W) to treat the detergent protease (Properase 1000E and Purafect 2000E). The results showed: after irradiating Properase 1000E and Purafect 2000E for 8s and 10s respectively; their activity increased by 11% and 16%, to the maximum, respectively; while the rate of the value of detergency of their formulated detergents did not change obviously. Two microwaved protease activity decreased slowly after storing at room temperature for two months. After irradiating Lipolase 100T and Lipex 100T for 5s respectively; their activity increased by 22% and 7%, to the maximum, respectively; while the rate of the value of detergency of their formulated detergents did not change obviously. Two microwaved lipases activity returned to the original state after storing at room temperature for four months. The above-mentioned two kinds of detergent enzymes activity were increased first and then decreased as the irradiation time went by.We also use low power microwave irradiation (microwave synthesizing instrument) to treat the liquid detergent enzymes: protease (Properase 1600L) and lipase (Lipolase 100L). The results showed that: after irradiating Properase 1600L and Lipolase 100L for 20min and 60min respectively; their activity increased by 7% and 11%, to the maximum, respectively; while the rate of the value of detergency of their formulated detergents did not change obviously. Two microwaved liquid activity returned to the original state after storing at room temperature for two months.In addition, the study also showed that: the standard laundry detergent by adding the enzymes before and after the irradiation, its surface tension and wetting force have no change; by adding Properase 1000E and Lipolase 100T, its emulsifying power was enhanced to a certain extent.2. In the spectrum experiments, the results shows that: after irradiating Properase 1000E and Lipolase 100T for 8s and 5s respectively, the peaks location of UV absorption spectrum and fluorescence emission spectrum of enzymes do not change; the peaks intensity of UV absorption spectrum increased by 6% and 12% respectively; the peaks intensity of fluorescence emission spectrum both increased by 5%. After storing Properase 1000E and Lipolase 100T at room temperature for 6 months and 12 months respectively, the peaks locations of enzymes spectrum do not change; the peaks intensity of UV absorption spectrum decreased by 11% and 17% respectively; the peaks intensity of fluorescence emission spectrum decreased by 8% and 6% respectively. The enzymes activity share the same change trend with its spectrum peaks intensity: the higher enzymes activity is, the higher peaks intensity is.3. Studied the effects of surfactants and detergent builder on the activity of Properase 1000E and Lipolase 100T, the results show that: Microwave irradiation can reduce the tolerance of Properase 1000E and Lipolase 100T in the LAS solution, but it did not change obviously in the AEO₉ solution. 0.1%(w/w) LAS and AEO₉ solution have activation effects on Properase 1000E and Lipolase 100T: their activity increased by 4% and 6% for LAS, increased by 10% and 22% for AEO₉ and increased by 2% and 12% for AEO₉ after the irradiation. AEO₉, APG_12～14, Tween-20, Tween-80 and 6501 have good stability for Properase 1000E and Lipolase 100T before and after the irradiation in the LAS solution. Lipolase 100T has very good anti-degradation property in the protease solution, it's very suitable for using with protease. AEO₉ and APG_12～14 have the good stability for Lipolase 100T before and after the irradiation in the protease solution, they can decrease the degradation effects of protease for Lipolase 100T. Microwave irradiation can reduce the tolerance of Properase 1000E and Lipolase 100T in the sodium perborate solution, but the enzymes activity did not change obviously in the sodium tripolyphosphate solution.