A Production Of Beta-carotene, Red Yeast Mutation Breeding And Fermentation Conditions

In this paper,we study the red yeast strain ns-1 isolated in our laboratory. The protoplast formation, regeneration of Rhodotorula ns-1 which produces carotenoid was studied. The mutagenization breeding of ns-1 was researched further.In the mutation strains,we compared the content of carotenoid via picking-up the pigments and the methods of HPLC.At last, a carotenoid hyproducing mutagenized strain was obtained. Then the optimum fermentation conditions and the conditions in cheaper substitute was researched.The logarithm phase cell of Rhodotorula ns-1 was dealed with by 1.5% β-glucuronidase, 1.5% lysing enzyme and 1.5% lyticase in series in the high sucrose pervasion solution.The protoplast formation ratio is 72.5 % .After the protoplasts was irradiated with ultraviolet radiation , the biggish and preferable strains from all of the strains was chose.we continuted to mutate on the mutagenized strains,at last the hyproducing P-carotene strain UVss was obtained which can be handed on stably, biomasses and carotenoid yields was increased more 67.6% and 54.1% than the original strain.The composition of pigments in strain UVss was analyzed by HPLC. The result showed that P-carotene was in the majority of total extraction and it comprised 89.4% of the total pigment mixture.The P-carotene yields was 5.71mg/L.The courses of fermentation and optimum fermentation conditions were studied in the strain UVss. The most suitable temperture was 28℃.The constant pH was helpful to growth and carotenoid accumulation of strain UVss. The best carbon source and nitrogen source was maltose and pepton respectively. The corn starch and bean cake lysised with amylase could be the good substitute for carbon source and nitrogen source.The ratio of corn starch and bean cake is 3:1. The optimum fermentation conditions for carotenoid production were as follows: pH is controlled about 6.0,inoculum volume 60mL/L, shake frequency 450 r/min,aeration volume 6L/min and culture time 5 days at 28℃. Its cell biomasses, carotenoid content and carotenoid yields could reach 9.48g/L, 1147.6ug/g, 10.88mg/L.