Abstract

Responce surface methodology (RSM) was used to optimize  production of lovastatin from rice straw in solid state fermentation by Aspergillus terreus ATCC 74135. A four-factor-five-level central composite design (CCD) was used  to examine the combining effects of temprature, moisture, inoculum and pH on lovastatin production.  Results of the CCD study showed  that only temperature and moisture contents significantly affected (P<0.01) lovastatin production. The maximum lovastatin production from experimentation and predicted by the CCD were 351.54 and 357.54 mg/kgDM, respectively, under the optimal conditions of  51.19% moisture, 28.29°C incubation temperature, inoculum size of 10.26% and pH of 6.31. Results of the present study showed that lovastatin can be produced from rice straw in solid state fermentation and the lovastatin enriched rice straw has the potential to be used as feed ingredient for reduction of ruminal methanogenesis.

Key words: Lovastatin, solid state fermentation, Aspergillus terreus, rice straw, responce surface methodology.