Statistical optimization of lovastatin production by Omphalotus olearius (DC.) singer in submerged fermentation.

In this study, culture conditions were optimized to improve lovastatin production by Omphalotus olearius, isolate OBCC 2002, using statistical experimental designs. The Plackett-Burman design was used to select important variables affecting lovastatin production. Accordingly, glucose, peptone, and agitation speed were determined as the variables that have influence on lovastatin production. In a further experiment, these variables were optimized with a Box-Behnken design and applied in a submerged process; this resulted in 12.51 mg/L lovastatin production on a medium containing glucose (10 g/L), peptone (5 g/L), thiamine (1 mg/L), and NaCl (0.4 g/L) under static conditions. This level of lovastatin production is eight times higher than that produced under unoptimized media and growth conditions by Omphalotus olearius. To the best of our knowledge, this is the first attempt to optimize submerged fermentation process for lovastatin production by Omphalotus olearius.

Enhanced production of lovastatin by Omphalotus olearius (DC.) Singer in solid state fermentation.

BACKGROUND: Although lovastatin production has been reported for different microorganism species, there is limited information about lovastatin production by basidiomycetes. AIMS: The optimization of culture parameters that enhances lovastatin production by Omphalotus olearius OBCC 2002 was investigated, using statistically based experimental designs under solid state fermentation. METHODS: The Plackett Burman design was used in the first step to test the relative importance of the variables affecting production of lovastatin. Amount and particle size of barley were identified as efficient variables. In the latter step, the interactive effects of selected efficient variables were studied with a full factorial design. RESULTS: A maximum lovastatin yield of 139.47mg/g substrate was achieved by the fermentation of 5g of barley, 1-2mm particle diam., at 28°C. CONCLUSIONS: This study showed that O. olearius OBCC 2002 has a high capacity for lovastatin production which could be enhanced by using solid state fermentation with novel and cost-effective substrates, such as barley.

Optimization of submerged fermentation conditions for lovastatin production by the culinary-medicinal oyster mushroom, Pleurotus ostreatus (Higher Basidiomycetes).

Statistical experimental designs were used to optimize lovastatin production by culinary-medicinal oyster mushroom Pleurotus ostreatus OBCC 1031 under submerged fermentation. The Plackett-Burman design was used to determine effective culture parameters, glucose, lactose, maltose, glycerol, peptone, yeast extract, NH4SO2, NaCl, thiamine, and agitation speed. Statistical analyses of data from the Plackett-Burman design show that glucose, yeast extract, and agitation speed are significant parameters. The interactive effects of these culture parameters on lovastatin production by P. ostreatus OBCC 1031 were further studied by a Box-Behnken design. Maximum lovastatin production (114.82 mg/L) was reached after 6 days of fermentation in optimized culture conditions (30 g/L glucose, 10 g/L yeast extract, 200 rpm, 28°C, and pH 6). This amount was found to be 50 times higher than that produced under unoptimized conditions in submerged fermentation by P. ostreatus.

Screening of medicinal higher Basidiomycetes mushrooms from Turkey for lovastatin production.

As a first attempt, a study was carried out to test for lovastatin production ability in local higher Basidiomycetes mushroom isolates from Turkey. An extended screening was performed for lovastatin production in yeast lactose agar medium, among a total of 136 macrofungi isolates from the Basidiomycetes Culture Collection of Eskisehir Osmangazi University. Lovastatin production was evaluated by disc diffusion method and was also confirmed by TLC and HPLC. Only six isolates were found to be lovastatin producers. The highest production of lovastatin was obtained from the extracts from Omphalotus olearius OBCC 2002 and Pleurotus ostreatus OBCC 1031. The lovastatin amount produced by commercial strains, Aspergillus terreus NRRL 255 (7.0 mg/L) and Penicillium citrinum NRRL 1841 (7.0 mg/L), was nearly comparable to the amount produced by Pleurotus ostreatus OBCC 1031 (5.8 mg/L) and Omphalotus olearius OBCC 2002 (4 mg/L).