Optimization of the ellagic acid synthesis process at the bioreactor level using non-conventional yeasts

Abstract Ellagic acid (EA) is a phenolic biomolecule. For its biosynthesis, a source of ellagitannins is required, such as strawberries and yeasts, as precursors of the tannase and β-glucosidase enzymes responsible for hydrolysis of ellagitannins. Two experimental mixture designs were applied., varying the yeast concentration and the number of ellagitannins in the culture medium, evaluating the enzymatic activity and ellagic acid biosynthesis. Aiming to find the optimal compositions of the non-conventional yeasts assessed in the research to biosynthesize ellagic acid feasibly and efficiently using a response surface performing the statistical analysis in the StatGraphics® program for obtaining a higher yield and optimizing the ellagic acid synthesis process, the results indicate that the strains Candida parapsilosis ITM LB33 and Debaryomyces hansenii ISA 1510 have a positive effect on the synthesis of ellagic acid, since as its concentration increases in the mixture the concentration of ellagic acid in the medium also increases; on the other hand, the addition of Candida utilis ITM LB02 causes a negative effect, resulting in the compositions of 0.516876, 0.483124 and 2.58687E-9 respectively, for a treatment under the same conditions, an optimal value of ellagic acid production would be obtained. With an approximate value of 7.33036 mg/mL.

摘要 鞣花酸（Ellagic acid, EA）是一种酚类生物分子。其生物合成需要鞣花单宁来源，例如草莓与酵母，二者作为负责水解鞣花单宁的鞣酸酶（tannase）与β-葡萄糖苷酶（β-glucosidase）的前体物质。本研究采用两种实验混料设计，通过改变培养基中的酵母浓度与鞣花单宁添加量，对酶活性及鞣花酸生物合成情况进行评估。本研究旨在通过响应面法筛选本研究中评估的非常规酵母的最优配比，以可行且高效地生物合成鞣花酸；实验借助StatGraphics®软件开展统计分析，以提升鞣花酸产率并优化其合成工艺。结果表明，副干酪假丝酵母（Candida parapsilosis）ITM LB33与汉森德巴利酵母（Debaryomyces hansenii）ISA 1510这两株菌对鞣花酸合成具有正向作用：当混合体系中二者浓度升高时，培养基内鞣花酸浓度亦随之上升；另一方面，产朊假丝酵母（Candida utilis）ITM LB02的添加则会产生负向影响。在相同实验条件下，当各组分配比分别为0.516876、0.483124与2.58687×10^-9时，可获得鞣花酸产量的最优值，约为7.33036 mg/mL。