Cultivation Conditions Of Two Kinds Of Perylenequinones Produced By Solid-state Fermentation Of Bamboo Yellow

Hypocrellin A(HA)and elsinochrome A(EA)were produced by Shiraia bambusicola which could act as natural photosensitizers for photodynamic therapy(PDT).To explore and reveal the roles of light on HA and EA production during solid-state fermentation of Shiraia bambusicola,the strain S4201 was used as the material,the effects of light conditions(all dark,12h light/12h dark,24h light/24h dark,48h light/48h dark,all light)on HA and EA yields were studied.Secondly,on the basis of the optimal light conditions,the effect of nutrients(carbon source and nitrogen source)on the production of HA and EA of the S.bambusicola S4201 strain in the Shiraia bambusicola solid state fermentation was studied.Finally,the optimal carbon and nitrogen source additional concentrations were optimized by response surface methodology,and the optimal carbon to nitrogen ratio of solid-state fermentation medium was obtained.The results showed that 12h light/12h darkness had a better effect than other light conditions.The difference was significant(P<0.05).After 16 days of culture at 28?,HA presented in 572.77±37.88 mg/Kg.RNA of the S.bambusicola S4201 strain treated with different light durations for 5 d was extracted using the method of Trizol,Seven genes involved in the synthesis of HA(genes encoded by FAD/FMN dependent oxidoreductases?Hydroxylases?Zinc fingertranscription factor?O-methyltransferases?Major cotransporter superfamilies?O-methyltransferases/FAD dependent monooxygenases?Polyketide synthases)were investigated by real-time PCR analysis.Effect of expression volume.Our results showed that the expression of seven related genes synthesizing HA was significantly greater under the solid-state fermentation conditions of 12h light/12h dark than under the conditions of full darkness,24h light/24h dark,48h light/48h dark and full illumination.Secondly,on the basis of the optimal light conditions,namely 12h light/12h dark,the effect of nutrients(carbon source and nitrogen source)on the HA production of S.bambusicola S4201 strain in solid fermentation was studied.The single-factor experiment results showed that among the 6 carbon sources and 5 nitrogen sources tested.Sucrose and(NH₄)₂SO₄were the best carbon and nitrogen sources to increase HA production,respectively.In order to determine the ratio of the carbon source of nitrogen source in solid-state fermentation medium,the optimal carbon source and nitrogen source supplementation concentration were optimized by response surface methodology.The results showed that under 12h light/12h dark,add 2.75 g with 100 g sucrose and 0.38g/100g(NH₄)₂SO₄,the yield of HA reached 2869.31±58.04 mg/Kg.S.bambusicola S4201 solid-state fermentation of EA under 12h light/12h dark conditions is better than other light conditions,and the difference is significant(P<0.05).After 16 days of culture at 28°C,the yield of EA is 977.88±32.68 mg/Kg.The Trizol method was used to extract RNA from the S.bambusicola S4201 strain treated with different light durations for 5 d,and the 5 related genes(RDT1,Ef PKS1,PRF1,Ef HP1and TSF1)of the light duration for the synthesis of EA were explored by real-time quantitative PCR technology.The influence of the amount of expression.The results showed that under the conditions of 12h light/12h dark solid state fermentation,the expression levels of the five related genes of synthetic EA were significantly greater than the four types of solid state fermentation under full darkness,24h light/24h darkness,48h light/48h darkness,and full light.On the basis of the optimal light conditions,namely 12h light/12h dark,the effect of nutrients(carbon source and nitrogen source)on the EA production of bamboo yellow S.bambusicola S4201 strain in Shiraia bambusicola solid fermentation was studied.The single factor experiment results showed that among the 6carbon sources and 5 nitrogen sources tested,sucrose and NH₄Cl were the best thing carbon and nitrogen sources to increase the yield of EA,respectively.In order to determine the ratio of the carbon source of nitrogen source in solid-state fermentation medium,the optimal carbon source and nitrogen source supplemental concentration were optimized by response surface methodology.The results showed that under 12h light/12h dark,3.44 g with 100g sucrose and 0.45 g/100g NH₄Cl,the yield of EA reached 3412.57±39.39mg/Kg.The research results laid the foundation for the production of HA and EA for solid fermentation of Shiraia bambusicola.The research results laid the foundation for the production of HA and EA for solid fermentation of Shiraia bambusicola.We speculate that the change of light duration in the solid-state fermentation conditions of bamboo yellow S.bambusicola S4201 leads to the increase in the production of HA and EA,which may be due to the increase in the expression of the synthetic genes related to Shiraia bambusicola HA and EA,thereby promoting the second generation High-level metabolic activities and the optimization of the culture medium laid the foundation for the production of HA and EA by solid fermentation of Shiraia bambusicola.