固载化木聚糖酶交联酶聚集体的制备及性质

The preparation and properties of the immobilized Xylanase by carrier-crosslinked enzyme aggregation

目的提高木聚糖酶YS1069的稳定性、重复利用率以及便于从反应体系中分离。方法本文将交联酶聚集体CLEAs技术与载体固定化技术相结合,用LKZ-128氨基型树脂对木聚糖酶CLEAs进行固定化,并对其性质进行初步研究。结果及结论采用单因素法和响应面法对影响固定化酶活性的因素进行分析和优化,获得最佳固定化条件为:pH 9.0的酶液,以2mL的异丙醇为沉淀剂,沉淀1h,以1.59g/L的京尼平为交联剂,交联2h,20℃的环境中固定化9.25h,加酶量为8mg时回收率最高,达到65.63%,加酶量为60mg时酶活性最高,达到190U/g。重复使用10次后,其相对酶活仍为42.3%,说明具有良好的批次操作稳定性。该酶经过固定化后热稳定性和pH稳定性均得到了提高。

Objective To enhance the stability,repeated utilization of Xylanase and easily separate from the reaction system.Methods In this study,the cross-linked enzyme aggregates（CLEAs）technology was combined with carrier immobilization technique.Using amino resin LKZ-128,Xylanase CLEAs were immobolized and its properties were studied.Results and ConclusionImmobilized conditions of Xylanase CLEAs were studied by using single factor experiment and the response surface design.The study indicated that the best immobilized conditions were：pH 9.0enzyme liquid precipitated by 2mL isopropyl,precipitation 1h,and cross-linked 2hwith the carrier LKZ-128 by 1.59g/L genipin,immobilized 9.25 hin the environment of 20℃.The recovery rate was up to 65.63% when the enzyme dosage was 8mg,and activity of enzyme was up to 190U/g when the enzyme dosage was 60 mg.After repeated 10 times,the relative activity of the enzyme was still 42.3%,showing good reusability.Thermal stability and pH stability of the enzyme were improved after immobilization.