A Monascus pilosus MS-1 strain with high-yield monacolin K but no citrinin

Monacolin K (MK) produced by Monascus spp. is mostly used to regulate cholesterol level, while it can be contaminated by citrinin, a mycotoxin yielded by some Monascus strains. To develop production of citrinin-free MK, an M . sp. MS-1 strain, identified as M. pilosus by morphologies and internal transcribed spacer sequences analysis, was isolated from red fermented rice. After 14 days of fermentation, yields of citrinin-free MK could be up to 0.58 mg/mL and 16.45 mg/g in liquid- and solidstate fermentation products under optimal conditions, respectively. Further determination revealed that no citrinin biosynthesis related genes such as ctnA , pksCT , ctnE , and ctnR were detected. Thus, HPLC combined with citrinin-related gene analyses can be used for rapid screening of non-citrinin production Monascus strains.