底物浓度对地霉属降解正己醇能力的影响

摘要

研究了正己醇初始浓度对2个能够降解正己醇的地霉属菌株S12和S13的菌体生长和正己醇降解率的影响.结果发现,2株菌生长量的增减趋势与培养基中正己醇降解率的增减趋势基本吻合,高浓度正己醇对菌种生长和正己醇降解率均有抑制作用.菌株S13对高浓度正己醇的耐受能力和降解能力均较高,菌株S12对低浓度正己醇的降解速度较快;环境中正己醇浓度低于0.7 g/L时,2株菌均能在1 d内使正己醇完全降解;菌株S12和S13完全降解0.5 g/L正己醇的时间分别为14 h和16 h;菌株S13在22 h内可使0.8 g/L正己醇降解完全,而菌株S12在24 h时对0.8 g/L正己醇的降解率为80%.总体而言,地霉属微生物对培养基中正己醇的降解作用和降解速度在不同菌株和不同正己醇浓度之间存在显著差异.结果为地霉属降解正己醇的机理研究和实际应用提供了理论基础和实际依据.%In this paper,we studied the effect of hexanol lnitial concentration on the cell growth and hexanol-degrading ability of two Geotrichum sp.strains S12 and S13.In the results,the two strains showed same trends during the cultivation in aspects of cell growth and hexanol degradation rate.High hexanol concentration inhibited the cell growth and reduced the hexanol degradation rate.Comparatively,the strain S13 was more tolerant and had higher hexanol degradation ratio at high hexanol concentration levels,while the strain S12 had higher haxanol degradation rate at lower hexanol concentration levels.The strains S12 and S13 degraded the hexanol completely within one day at initial hexanol concentration levels lower than 0.7 g/L,and within 14 and 16 hours,respectively,at initial hexanol concentration of 0.5 g/L.The strain S13 completely degraded 0.8 g/L hexanol within 22 hours,while the strain S12 y 80% after 24 hours.In conclusion,the hexanol degradation rate varied greatly along with the fungi strains and the hexanol concentration.The result provided essential theoretical and practical information on further research on the hexanol-degrading mechanism and practical application.