Pigments and Anti-Cholesterol Agent Production by Monascus kaoliang KB9 and Its Color Mutants in Rice Solid Cultures

Abstract

A comparative study of four Monascus strains, (a red-pigment-producing Monascus kaoliang KB9 strain and its three color mutants of red, yellow and white) on various agar media revealed different colony and pigment characteristics. Three agar media: MYS, GYP and PDA gave clear cultural
characteristics. Upon varying medium formulas, the wild type and the red mutant showed red pigmentation, while the yellow and white mutants showed deep orange and white pigmentation, respectively. All strains were grown on rice solid culture and examined for the production of pigment
and anti-cholesterol agent using a spectrophotometer and a modified HPLC method, respectively. The results showed that the wild-type strain (KB9) and its red mutant (KB10M16) could produce substantial amounts of anti-cholesterol agent compared with the yellow and white mutants (KB20M10.2 and KB20M1). Due to its good growth and production of the greatest amount of anti-cholesterol agent, the wild-type KB9 strain was selected for a study on the optimization of anti-cholesterol agent fermentation. Under favorable conditions of 64% relative humidity at room temperature (28-30°C) for 5 weeks incubation, production of the anti-cholesterol agent and red pigment was high, with 17,892 mg/kg and 4,640 Unit (OD500) and 4,834 Unit (OD400) per gram dried weight, respectively.