Optimization of production of pectin lyase, exo pectinase and endo pectinase and pectinase by Pseudomonas fluorescens (NRLL B-2641) via response surface methodology

Optimization of Production of Pectin Lyase, Exo Pectinase and Endo Pectinase and Pectinase By Pseudomonas Fluorescens (NRRL B-2641) Via Response Surface Methodology In this study, production of pectin lyase, exo-pectinase and endo-pectinase was performed by Pseudomonas fluorescens in a batch system and the effects of different parameters on enzyme production were investigated and optimized by response surface method. Submerged culture fermentation and solid state fermentation methods were used in the experiments. In the first stage of the research, submerged culture fermentation experiments were performed and experimental conditions were determined using the response surface method. The effect of initial pectin concentration on enzyme production was examined at concentration of 0.17 % ( w/v) ammniumoum sulfate, pH 6.5 and 1.0 % pectin was determined as optimum pectin concentration. Ammniumoum sulfate was used as nitrogen sources and the highest pectin lyase, exo-pectinase and endo-pectinase activities were observed at 0.17 % (w/v) ammonium sulfate. Then the effects temperature and pH on the enzyme activities were tested. The optimum pH were found as 8, 10 and 9; optimum temperatures were found as 50, 40 and 40 oC for pectin lyase, exo and endo pectinase activities, respectively. In the response surface method, pH, pectin and ammniumoum sulfate concentrations were selected as independent variables. The second-order polynomial coefficients were calculated and the results were analyzed using statistical package Design Expert Software. Statistical analysis of the model was carried out using model of variance analysis (ANOVA). In the second stage of the research, solid state fermentation studies were performed, sugar beet pulp was selected as solid material, Experimental conditions were determined using the response surface method and sugar beet pulp, ammniumoum sulfate and yeast extract were chosen as independent variables. Firstly, effect of sugar beet pulp on enzyme activities was determined. The maximum pectin lyase, exo-pectinase and endo-pectinase activities were obtained at 4.25 % (w/v) sugar beet pulp. Then, the effect of ammniumoum sulfate on the enzyme activities was investigated and the maximum activities were predicted at concentration of 0.3 % (w/v) ammniumoum sulfate. Finally, effect of yeast extract was tested and the concentration of 0.3 % (w/v) was observed as optimum concentration. At the last stage of the research, solid state fermentation studies was optimized by the response surface method. Statistical analysis of the model was carried out using model of variance analysis (ANOVA). Key words: Pectinase, Pseudomonas fluorescens, Submerged Culture Fermentation, Solid State Fermentation, Reaction Surface Method