【摘要】 采用响应面分析法对影响粘红酵母细胞固定化的4个主要因素——单体浓度、交联剂浓度、包埋量、包埋时间进行了优化.首先用Plackett-Burman法设计实验对以上4个影响因素进行了评价,并筛选出显著影响因素——单体浓度和包埋量;第2步用最陡爬坡实验逼近以上两因素最优水平;最后由中心复合实验及响应面分析确定主要影响因素的最佳条件.固定化粘红酵母细胞的最优包埋条件为:单体浓度16.7%,包埋量43%,交联剂浓度2.0%,包埋时间45min.在此条件下得到的固定化细胞与游离细胞相比,酶活保留率可达63%,较优化前提高了31%.实验室制备试验中L-苯丙氨酸(L-Phe)积累浓度可达53.3g/L,与该菌株的中试游离整细胞一次批式转化产L-Phe浓度30g/L比较,产率提高了1.8倍.图3表9参15更多还原

【Abstract】 Placked-Burman (PB) design,path of steepest ascent (PSA),and central composite design (CCD) were used to select and optimize four factors,i.e.,monomer concentration,crosslinking agent concentration,embedded amount in the media and embedding time for the conditions of bio-production of L-phenylalanine (L-Phe) by the immobilized cells of Rhodotorula glutinis CIBAS 06112-8-3 used as biocatalysts.Firstly,two key factors,the monomer concentration and embedded amount in the media,were found significant via PB method.Secondly,according to the following statistic analysis of the yield and activity of the immobilized cells of the strain,PSA was adopted to approach the optimal region.Finally,CCD design and response surface analysis were to determine the optimal levels of the main factors.Therefore,there were the optimal conditions for the immobilized cells,including monomer concentration of 16.7%,embedded amount in the media of 43%,crosslinking agent concentration of 2.0% and embedded time of 45 min,and the recovery of the immobilized cells’ activity reached at 63% and increased by 31%,compared with control treatment.In addition,the yield of L-Phe increased 1.8 times with a general whole cells,i.e.,a total amount of L-Phe accumulated in several batches of reactive media,reached 53.3 g/L in laboratory scale as compared with 30 g/L in pilot scale.Fig 3,Tab 9,Ref 15更多还原