高效利用秸秆糖产衣康酸菌种选育及发酵条件优化

Efficient Use of Straw Sugar to Produce Itaconic Acid Strain Breeding and Optimization of Fermentation Conditions

以土曲霉(Aspergillus terreus)ASP-046为出发菌株,采用紫外诱变及经平板菌落筛选、摇瓶发酵筛选及稳定性考察,得到1株利用碳源广谱,衣康酸产量显著提高的土曲霉菌株ASP-M-87,产酸量达43.28 g/L。通过单因素试验,研究了初始pH、培养温度、接种量、装液量、摇床转速、培养时间6个不同因素对衣康酸产量的影响。采用Plackett-Burman试验设计法,从6个影响因素中筛选出培养温度、摇床转速、接种量3个主要影响因素,通过最陡爬坡试验和Box-Behnken响应面法优化了土曲霉发酵培养条件,优化后的发酵培养条件为:培养基初始pH2.5、培养温度36℃、接种量9.8%(V/V)、装液量30/250 mL、摇床转速247 r/min、发酵6 d时,衣康酸产量达61.21 g/L,比优化前提高了41.43%。

Using Aspergillus Terreus ASP-046 as the starting strain,using UV mutagination,and after plate colony screening,flask fermentation screening and stability investigation,a Aspergillus terreus ASP-M-87 strain with carbon source wide spectrum and significantly increased itaconic acid yield was obtained,with an acid yield of 43.28 g/L.By single-factor experiments,the effects of initial pH,culture temperature,inoculating amount,liquid loading amount,shaking speed and culture time on the yield of itaconic acid were investigated.Three most significant factors were selected from six factors with Plackett-Burman experiment design method,which were culture temperature,shaking speed and inoculating amount.The fermentation culture conditions was optimized by steepest ascent experiments and Box-Behnken surface methodology.The optimized fermentation culture conditions were as follows:initial medium pH2.5,9.8% inoculum(V/V),fermentation temperature 36℃,liquid loading 30/250 mL,shaking speed 247 r/min and fermentation for 6 days,the yield of itaconic acid reached 61.21 g/L,which was 41.43% higher than before the optimization.