(191ag) Optimization of Pleuran Production By Pleurotus Ostreatus Using Batch and Fed-Batch Cultivation System

Pleurotus mushrooms are known for producing β-glucans which have medicinal properties as a constituent in the cellular cell wall of the fruiting body or the mycelium. This mushroom is rich with protein, fibre, carbohydrates, vitamins and minerals. Several bioactive compounds have been identified in P. Ostreatus showing strong anti-cancer activities such as polysaccharides, mainly β-D-glucans, proteoglycans, lectins, fibres, terpenoids, steroids, nucleic acids and others. Pleuran is an exopolysaccharide (β-(1,3/1,6)-D-glucan) produce by P. Ostreatus. This exopolysaccharide has molecular formula of (C₆H₁₀O₅)_n while the molecular weight is varied depending on the length of molecular structure repetition. The main objective of this research is to develop a new process for maximal production of pleuran by P. Ostreatus in submerged fermentation both in shake flask and bioreactor. In media screening, highest pleuran production of 2.13 g L^-1 obtained in selected medium which consist of (in g L^-1): glucose, 60.0; yeast extract, 3.0; (NH₄)₂SO₄, 2.0; K₂HPO₄, 1.0 and MgSO₄.7H₂O, 0.2. The medium component was then optimized using One-Factor-at-a-Time and statistical method. The optimized medium using OFAT which composed of (in g L^-1): glucose, 100.0; yeast extract, 3.0; (NH₄)₂SO₄, 2.0; K₂HPO₄, 1.0; MgSO₄.7H₂O, 0.2 was able to produced 3.33 g L^-1 plueran. The OFAT optimization was done to provide better understanding on suitable parameter range during statistical optimization. For semi industrial scale production, statistical optimized medium was used in 16-L bioreactor fermentation. The batch cultivation was conducted in order to understand the growth pattern of P. Ostreatus and to design the cultivation strategies for fed-batch cultivation. The batch cultivation of P. Ostreatus was studied under controlled pH condition. Following that, fed-batch cultivation was carried out using constant feeding strategy of 0.4 g L^-1 h^-1 substrate. The substrate tested were either by using mono-glucose or full medium composition. It was found that feeding with full medium composition provide better result compared to feeding with mono-glucose. Feeding using full medium produced 4.5 g L^-1 pleuran while feeding with mono-glucose produced only 3.8 g L^-1 pleuran. In conclusion, this study offers a promising and comprehensive strategy for development of new process for maximal pleuran production by P. Osteratus in submerged fermentation in both shake flask and scale-up in 16-L bioreactor.