丝孢酵母TX1降酚动力学研究及过程优化

Biodegradation kinetics study and process optimization on removal of phenol with Trichosporon sp. strain TX1

针对自行分离筛选出的高效降酚丝孢酵母菌株TX1,通过不同初始浓度苯酚分批培养系列实验结果和分析,建立其降酚动力学模型,并在此基础上进行过程优化。结果表明,体系的生长动力学可以用Haldane方程描述,其参数分别为μm ax=0.667 h-1,KS=51.14 mg/L,Ki=271.7 mg/L。参数说明TX1能较快地降解苯酚,而且具有较高的耐酚浓度。体系的底物消耗符合P irt模型,真得率系数YG和维持能系数m值分别为2.268 mg/mg和0.195 h-1,进而获得了降解动力学方程。采用最佳底物浓度作为分批补料培养操作参数,反应器的平均容积负荷提高至39 g/(m3.h),优化了苯酚降解过程。

An effective phenol-degrading yeast strain,named TX1,was isolated and identified as genus Trichosporon sp.With the data obtained in batch culture of strain TX1 under a series of initial phenol concentrations,the kinetics of cell growth and phenol degradation were investigated to optimize the process.Growth kinetics model of culture system could be fitted with Haldane equation.The parameters of μmax,KS,Ki were 0.667 h-1,51.14 mg/L,271.7 mg/L,respectively,which demonstrated that TX1 can degrade phenol rapidly and has a high phenol-tolerance.The variation of observed yield coefficient（YX） with specific growth rate（μg） could be fitted with Pirt model.The maintenance energy coefficient（m） and true growth yield coefficient（YG） were found to be 0.195 h-1 and 2.268 mg/mg,respectively.And then the degradation kinetics equation of phenol was established.Adopted the optimal substrate concentration from analysis above as the operational parameters of the fed-batch reactor,phenol degradation process was optimized with the average volumetric loading increasing to 39 g/（m3·h）.