果胶酶产生菌的分离及其产酶条件研究

Separation of Pectinase Producer and Study on Its Pectinase-producing Condition

[目的]从自然界寻求高效的果胶酶生产菌株,减少生产成本,使发酵产生的果胶酶直接应用于果汁、果酒等的澄清中。[方法]从富含果胶质的土壤及腐烂水果中采集样品,筛选出2株产酶活性相对较高的菌株,并对其最佳培养时间、培养温度、最适pH以及最适接种量等酶学性质进行初步研究。[结果]确定了2个菌株的最佳培养条件:A1在28℃,pH7.0,接种量20%,发酵周期48h时产酶最高,具有较强的分解果胶质的能力;A2在31℃,pH7.0,接种量30%,发酵周期60h时产酶最高,具有较强的分解果胶质的能力。[结论]菌株A1生长繁殖周期较短,具快速的生长期,同时生长的外界环境易于获得,但产酶效益较低,酶学曲线波动较大,稳定性差;A2具长的生长期,所需培养温度也较高,培养条件有些难度,但产酶效益较高,总体酶学曲线稳定性较好,具长的稳定期。

[ Objective ] The purpose was to find efficient pectinase producer from the nature world, reduce production cost and make the pec- finase produced from fermentation be applied to clarify fruit juice and fruit wine directly. [Method] The samples were collected from soil rich in pectic substance and rotten fruit, 2 strains with relatively higher enzyme-producing activity were screened out and their zymulngic properties of optimum culture time, culture temperature, optimum pH and optimum innoculation amount were studied preliminarily. [ Result] The opti- mum culture conditions for the 2 strains were as follows： culture temperature of 28 ~C, pH value of 7.0 and innoculation amount of 20% were optimum for A1, its enzyme-producing activity was highest when its fermentation period was 48 h and it possessed higher ability of degrading pectic substance; culture temperature of 31 ~C, pH value of 7.0 and iunoculation amount of 30% were optimum for A2, its enzyme-producing activity was highest when its fermentation period was 60 h and it possessed higher ability of degrading pectic substance. [ Conclusion ] The growth and prolmgation period of the strain A1 was shorter and it had fast-growing period as well as that its growth environment was easily avail- able, but its enzyme-producing efficiency was lower, the wave of its enzymologie curve was larger and its stability was poorer. The growth peri- od of the strain A2 was longer and its culture temperature was higher. Its culture condition was some difficult to satisfy, hut its enzyme-predu- cing efficiency was higher, the stability of whole enzymologic curve was better and it possessed longer stable period.