The Solid-state Fermentation Process Of Gibberellin By Adding Enzymatic Hydrolysate Of Steam Explosion Corn Stalks

Gibberellin is widely used in agriculture,nursery,gardening,cultivation technology,tea garden and so on,which is one of the five major phytohormones.Gibberellin is a typical secondary metabolite for microorganisms,which is mainly produced by the way of fermentation.Compared with the liquid fermentation,the solid-state culture has the advantages as follows:(1)The fermented raw materials are generally agricultural products,which are easy obtained.(2)The downstream processes are easy and less pollution to environment with less water consumption.(3)Less investment and simpler process operation.(4)Low requirement for aseptic operation.This work mainly presented that the solid-state fermentation process of gibberellin by adding corn stalks.And this work explored a new solid-state fermentation process of gibberellin,which was produced by Fusarium moniliforme ZZU-FmS preserved in our laboratory.Investigations for gibberellin production when corn starch as carbon source and wheat bran as inert carrier and nitrogen source were carried out.The research contents and results were listed as follows:(1)Corn stalks after destroyed,steam explosion corn stalks,and steam explosion corn stalks after enzymolysis were added into the culture medium for solid-state fermentation.The results indicated that these three ways against producing the gibberellin.(2)In this work,we also investigate that the solid-state fermentation process for gibberellin by adding the enzymatic hydrolysate of steam explosion corn stalks during culture period.The results indicated that the yield of gibberellin was 9.48 g/kg dry basis when the enzyme solution was added into the substrate of 400 ml/kg dry basis in solid-state fermentation for the 60 th hour.(3)The culture conditions were studied by single factor during solid-state fermentation for gibberellin,and the medium was added 400 ml/kg dry basis in solid-state fermentation for the 60 th hour.The optimum conditions of fermentation process were obtained,that is,the seed age is 36 h,the inoculum concentration is 10%,the temperature is 30℃,the pH is 7.00,the mass ratio of solid to liquid is 1:1.1,and the maximum yield of gibberellin is 9.48 g/kg dry basis when the fermentation period is 168 hours.(4)The biomass was studied by single factor during the solid-state fermentation for gibberellin,and the medium was added 400 ml/kg dry basis in solid-state fermentation for the 60 th hour.The optimum conditions of fermentation process were obtained,which maximized the biomass,that is,the seed age is 36 h,the inoculum concentration is 14%,the temperature is 32℃,the pH is 6.00,the mass ratio of solid to liquid is 1:1.1,and the fermentation period is 96 hours.The results indicated that the peak biomass of Fusarium moniliforme was 100.23 g/kg basis when the seed age is 36 h,the mass ratio of solid to liquid is 1:1.1 or the fermentation period is 96 h.The gibberellin yield was 8.83 g/kg dry basis when the initial pH was 6.00.The gibberellin yield was 6.12 g/kg dry basis,when inoculation quantity was 14%.The gibberellin yield was 9.20 g/kg dry basis when the culture temperature was 32℃.The gibberellin yield was 6.94 g/kg dry basis in the 96 hours.It provides a new alternative way for the gibberellin production by the solid-state fermentation.In the same time,the application of the corn stalks is considered as well.