Taxonomic Investigation and Growth Characteristics of Citrinin Free Monascus Pilosus C₁ Strain

ABSTRACT

Monascus sp. C¹ strain was isolated from cellulose as a natural pigment citrinin-free producing strain. Taxonomical investigation of the new strain was carried out on the recommended media and the results were compared with those of the referent strains—Monascus pilosus CBS 289.34, Monascus ruber CBS 291.34, Monascus purpureus CBS 285.34. The new strain was morphologically closer to the strain Monascus pilosus CBS 289.34. We did not observe any sexual structures of Monascus sp. C₁ strain but there are not significant differences between both strains in their asexual reproduction. Monascus sp. C₁strain is a prototrophic one, which utilizes quite well both ammonium and nitrate nitrogen sources. Assimilation and fermentation abilities of the experimental strain were studied too. It was found that both the tested and referent strains utilized quite well glucose and possess a high specific growth rate on media containing this sugar. The synthesis of citrinin was found only in the referent strain Monascus pilosus CBS 289.34. In anaerobic conditions both microorganisms can transform glucose to ethanol with high values of Y_Et/C—0.315 (for Monascus pilosus CBS 289.34) and 0.317 (for Monascus sp. C₁) respectively. According to the morphological and physiological similarity between the referent strain Monascus pilosus CBS 289. 34 and the new one, Monascus sp.C₁ is described as belonging to the species Monascus pilosus.