Kinetic analysis of dihydroxyacetone production from crude glycerol by immobilized cells of Gluconobacter oxydans MTCC 904
Kinetic analysis of dihydroxyacetone production from crude glycerol by immobilized cells of Gluconobacter oxydans MTCC 904
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DOI：
10.1016/j.biortech.2016.06.042
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发表时间：
2016-09-01
影响因子：
11.4
通讯作者：
Moholkar, Vijayanand S.
中科院分区：
文献类型：
--
作者：
Dikshit, Pritam Kumar;Moholkar, Vijayanand S.
采用改进的Halcantine底物抑制模型，研究了固定化氧化葡萄糖酸杆菌细胞转化生物柴油中的粗甘油制备二羟基丙酮的动力学特征。将结果与游离细胞和纯甘油进行了比较。动力学参数K-S、K-I、V-max、n和X的相对变化表明，固定化G.以粗甘油为底物的oxydans细胞（在PU泡沫基底上）给出较高的抑制阶数（n）和较低的最大反应速度（V-max）。这些结果基本上暗示了底物跨固定化基质的运输限制，这导致基质中底物的保留和细胞可用底物（X）分数的减少。与游离细胞相比，这导致K-S（V-max/2时的底物浓度）和K-I（抑制常数）降低。对于固定化细胞，对于作为底物的纯甘油和粗甘油，对应于V-max的底物浓度（S-max）几乎相同。(C)2016爱思唯尔有限公司版权所有。
The present study has investigated kinetic features of bioconversion of biodiesel-derived crude glycerol to dihydroxyacetone with immobilized Gluconobacter oxydans cells using modified Haldane substrate-inhibition model. The results have been compared against free cells and pure glycerol. Relative variations in the kinetic parameters K-S, K-I, V-max, n and X reveal that immobilized G. oxydans cells (on PU foam substrate) with crude glycerol as substrate give higher order of inhibition (n) and lower maximum reaction velocities (V-max). These results are essentially implications of substrate transport restrictions across immobilization matrix, which causes retention of substrate in the matrix and reduction in fractional available substrate (X) for the cells. This causes reduction in both K-S (substrate concentration at V-max/2) and K-I (inhibition constant) as compared to free cells. For immobilized cells, substrate concentration (S-max) corresponding to V-max is practically same for both pure and crude glycerol as substrate. (C) 2016 Elsevier Ltd. All rights reserved.