Assessment of double screening programmes via solid substrate fermentation (SSF) in a flask system and identification of lovastatin potential producer

Assessment of double screening programmes via solid substrate fermentation (SSF) in a flask system and identification of lovastatin potential producer

1Syarifah Ab Rashid, 1Darah Ibrahim, and 2I Nyoman Pugeg Aryantha

1Industrial Biotechnology Research Laboratory (IBRL), School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Penang Malaysia.2School of Life Sciences and Technology, Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung, Indonesia 40132

Abstract

Local economical substrates namely rice bran and unprocessed brown rice was applied into fermentation condition to produce a potent secondary metabolite compound, lovastatin. A basis condition of fermentation viz. 70% (v/w) of moisture content (adjusted to pH 6.0), 1×107 spore/ml of inoculum size, mixture of 1:1 substrates and 7 days of incubation period, was applied into SSF system. During a preliminary test, all of 72 fungi disclosed positive dark spot onto the thin layer chromatography plate (TLC). In order to verify the existence of lovastatin, the secondary screening which involving high performance liquid chromatography (HPLC) was conducted. Out of 72, only 71 fungi were detected as lovastatin producers and the highest production was stated from SAR I isolate with 68.72±0.84 mg lovastatin/g dry substrate and 0.87±0.03 mg glucosamine/g dry substrate of fungal growth. SAR I isolate was identified via colony and microscopic morphologies. Through the observations, SAR I isolate was identical to Aspergillus niger.

Keywords: lovastatin, HPLC, solid substrate fermentation, screening, thin layer chromatography, identification, Aspergillus niger