The Screening,Identification And Mutation Breeding Of High Pigment Produce Monascus Strain

Monascus pigment is ancient natural edible red pigment. In China, the use of red yeast rice has a long history in brewing, traditional Chinese medicine and food. The red yeast rice is a special resource in Fujian, how to fully develop and make good use of local specialty products are the major significance to the rapid development of the economy. However, the chromogenic ability of wild strains is lower and higher production costs limit it widely used in food. So, obtain produce higher pigment Monascus is important.In this paper, different methods of separation were used to abtain Monascus from red yeast rice in Fujian.Finally, thirteen plant Monascus are isolated and named M-1 to M-13 respectly. Screening by liquid fermentation, solid-state fermentation rescreening (1kg certain varieties of rice), gain produce higher pigment Monascus M-3, the color value is 8320 U/g,and obtained red rice rate is 60%.Then it was identified by identified by ITS (Internal Transcribed Spacer) sequencing analysis. Monascus M-3 is Monascus purpures, belonging to Mycobionta,Ascomycete subphylum, Ascomycetes, true Ascomycetes subclass, Aspergillus Division, Monascus genus.Monascus M-3 is used to make protoplast,under 1.0 mol/L sorbitol (pH 8.0) as a high permeability stabilized solution,0.3%cellulase and 0.3% snailase as the cleavage enzyme, single factor enzymatic tests showed that the ideal formation number of protoplasts and regeneration rate is enzymatic time 1.5 h,pH value 6, the temperature 30 ? from Monascus mycelium. Orthogonal test showed when enzymatic time is 2 h, the pH value is 6, the temperature is 32 ?, the protoplast regeneration obtained the largest number of colonies,that is 5.799 X 105.So,we Determined that this condition is the protoplast preparation conditions.Monascus M-3 protoplasts ultraviolet and lithium chloride combined mutagenesis, the determine joint mutagenesis by UV irradiation time is 35 sed, lithium chloride concentration is 0.3 mg/mL.After mutagenesis,we get a mutant M-3-7 with its color value is 9468 U/g,and obtained red rice rate is 59%. Mutant has stable chromogenic capability through six passaged culture. At the end of the 12 days, Mutant M-3-7 color value reached 6400 U/g which is 15.9% higher compare to the original Monascus M-3 in the plant experiment, while the obtained red rice rate is 43.6% and 44% respectively.In the research,we also gain the result that when Mutant M-3-7 from the laboratory, a small amount of culture 1 kg to factory mass production of culture 6t, its color value from 9468 U/g down to 6400 U/g, a decrease of 32.4%, the obtained red rice rate from 59% down to 43.6%, a decrease of 15.4%after 12 days. This is a different between small amount of culture in laboratory and batch culture in factory, closely related to environment as ventilation, temperature and humidity control and so on.