Effects of the method of acid hydrolysis combining with biotransformation on tigogenin production efficiency in sisal
Using the residue from decorticated sisal as a material,the bacterial strains with degradation capabilities were identified,and the fermentation conditions of the strains were optimized to establish a procedure of an acid hydrolysis combined with microbial fermentation method to improve the extraction rate of tigogenin.The results showed that 14 strains were isolated from sisal residue,among which Aspergillus niger,Trichoderma harzianum,and Trichoderma reesei had a higher biotransformation ability for tigogenin.Single-factor experiments on the fermentation conditions of the above three strains found that the tigogenin extraction rates reached 42.56,61.70,and 73.53 mg/g,respectively when the fermentation time was 3 days,the initial pH was 6,the fermentation temperature was 30 ℃ and with 0.1％Tween-80 addition.With addition of Fe2+1.0 mmol/L,the tigogenin extraction rates of Aspergillus niger and Trichoderma reesei reached 55.14 and 89.45 mg/g,respectively.And,with the addition of 0.5 mmol/L Fe2+,the tigogenin extraction rate of Trichoderma harzianum reached 78.64 mg/g.Separate acid hydrolysis experiments showed that the extraction rate of tigogenin reached 92.249 mg/g with the condition of 4.5 mol/L hrdrohlorie acid and 60 minutes.Using 1.5 mol/L hydrochloric acid combined with the fermentation of Aspergillus niger,Trichoderma harzianum,and Trichoderma reesei,the extraction rates of tigogenin of the three strains were 78.70,95.40,and 107.3 mg/g,respectively.In summary,the acid hydrolysis combined with microbial fermentation method for extracting tigogenin reduced the acid consumption by 2/3.and increases the extraction rate of tigogenin.
万方数据
维普
