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作 者:朱凡[1] 吕忠良[1] 杨叶东 朱建忠 徐志南[1] 蔡谨[1] 岑沛霖[1]
机构地区:[1]浙江大学化学工程与生物工程学系,浙江杭州310027 [2]浙江德清汇宁生物科技有限公司,浙江德清313200
出 处:《化学工程》2013年第12期9-11,47,共4页Chemical Engineering(China)
基 金:国家高技术研究发展计划(863计划)(2011AA02A201,2011BAD23B04);浙江省社会发展公益计划(2012C22034)
摘 要:γ-聚谷氨酸(γ-PGA)是由多种杆菌产生的一种胞外多肽,发酵生产时由于黏度高导致菌液分离困难。文中优化了发酵液微滤除菌、超滤浓缩和醇析干燥的工艺参数。综合考虑渗透通量、压差和除菌率等参数,确定微滤最佳操作温度为40℃,最佳操作压差0.3-0.4 MPa,最佳稀释度为V(发酵液)∶V(水)=1∶2,除菌率最高可达92.47%,在此条件下可以保持较高的渗透通量和较快的浓缩液循环流速,使微滤过程更为高效,同时不会因压力过高而造成微滤膜过早堵塞。通过优化,选择超滤最佳的浓缩比为5,此时渗透通量为31.8 L/(m2·h),产物回收率为81.6%。对pH=3—10共9个梯度进行了考察,比较在不同pH值条件下醇析操作纯化γ-PGA的粗产量,最优pH=7可达到最好的沉淀效果。这一优化分离工艺具有应用于γ-聚谷氨酸生产的潜力。The separation and purification of poly-γ--glutamtic acid (γ-PGA) from broth is very difficult due to high viscosity. The operating parameters were optimized to improve the performance of PGA isolation process containing micro-filtration, uhrafiltration and ethanol precipitation. With regards to the three parameters (permeation flux, pressure and cell removal ratio) , the micro-filtration operating conditions were optimized as follows : temperature 40 ℃, pressure differential 0.3-0.4 MPa, the volume ratio of dilution between broth and water 1 : 2. Under the above optimal conditions, 92. 47% of cells were removed from T-PGA broth. The optimal concentration rate of uhrafiltration was 5 : 1, while the permeation flux was 31.8 L/(m2 · h) and 81.6% of T-PGA was retained. The effects of different pH were examined and the optimal pH was determined to be 7 for efficient PGA precipitate. The present work promised the potential large-scale production of PGA in the future
分 类 号:TQ920.6[轻工技术与工程—发酵工程]
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