Author(s)

Rahayu Ahmad, Najeeb Kaid Nasser Al-Shorgani, Aidil Abdul Hamid, Wan Mohtar Wan Yusoff, Fauzi Daud

School of Bioscience and Biotechnology, Faculty Science and Technology, National University of Malaysia, Bangi, Selangor, Malaysia.
School of Bioscience and Biotechnology, Faculty Science and Technology, National University of Malaysia, Bangi, Selangor, Malaysia; Department of Applied Microbiology, Faculty of Applied Sciences, Taiz University, Taiz, Yemen.

The interaction between sucrose, yeast extract and initial pH was investigated to optimize critical medium components for mycelium biomass and production of exopolysaccharide (EPS) of Lentinus squarrosulus using Response Surface Methodology (RSM). A central composite design (CCD) was applied and a polynomial regression model with quadratic term was used to analyse the experimental data using analysis of variance (ANOVA). ANOVA analysis showed that the model was very significant (p < 0.0001) for both mycelium biomass and EPS production. The yeast extract concentrations and initial pH showed the strongest effect (p < 0.001) meanwhile sucrose concentrations showed significant value at p < 0.005 for mycelium biomass. For EPS production, only sucrose and yeast extract concentrations gave significant value with p < 0.001 and p < 0.005 respectively. The model was validated by applying the optimized conditions and 25.8 ± 0.9 g/L of mycelium biomass, and 5.7 ± 0.4 mg/mL EPS concentration was obtained. The estimated optimum conditions of the variables for the production of mycelium biomass and EPS production by Lentinus squarrosulus are as follows: sucrose concentration 114.61 g/L, yeast extract 1.62 g/L and initial pH of 5.81; sucrose concentration 115.8 g/L, yeast extract of 3.39 g/L and initial pH of 6.44 respectively.

Lentinus squarrosulus; Response Surface Methodology (RSM); Exopolysaccharide; Submerged Culture; Central Composite Design (CCD)

Ahmad, R. , Al-Shorgani, N. , Hamid, A. , Wan Yusoff, W. and Daud, F. (2013) Optimization of medium components using response surface methodology (RSM) for mycelium biomass and exopolysaccharide production by Lentinus squarrosulus. Advances in Bioscience and Biotechnology, 4, 1079-1085. doi: 10.4236/abb.2013.412144.