BACKGROUND Gallic acid has received a significant amount of interest for its biological properties. Thus, there have been recent attempts to apply this substance in various industries and in particular the feed industry. As opposed to yeasts, fungi and bacteria and their tannases have been well documented for their potential bioconversion and specifically for the biotransformation of tannic acid to gallic acid. In this research, Sporidiobolus ruineniae A45.2 is introduced as a newly pigment-producing and tannase-producing yeast that has gained great interest for its use as an additive in animal feed. However, there is a lack of information on the efficacy of gallic acid production from tannic acid and the relevant tannase properties. The objective of this research study is to optimize the medium composition and conditions for the co-production of gallic acid from tannic acid and tannase with a focus on developing an integrated production strategy for its application as a feed additive. RESULTS Tannase produced by S. ruineniae A45.2 has been classified as a cell-associated tannase (CAT). Co-production of gallic acid obtained from tannic acid and CAT by S. ruineniae A45.2 was optimized using response surface methodology and then validated with the synthesis of 11.2 g/L gallic acid from 12.3 g/L tannic acid and the production of 31.1 mU/mL CAT after 48 h of cultivation in a 1-L stirred tank fermenter. Tannase was isolated from the cell wall, purified and characterized in comparison with its native form (CAT). The purified enzyme (PT) revealed the same range of pH and temperature optima (pH 7) as CAT but was distinctively less stable. Specifically, CAT was stable at up to 70 °C for 60 min, and active under its optimal conditions (40 °C) at up to 8 runs. CONCLUSION Co-production of gallic acid and CAT is considered an integrated and green production strategy. S. ruineniae biomass could be promoted as an alternative source of carotenoids and tannase. Thus, the biomass, in combination with gallic acid that was formed in the fermentation medium, could be directly used as a feed additive. On the other hand, gallic acid could be isolated and purified for food and pharmaceutical applications. This paper is the first of its kind to report that the CAT obtained from yeast can be resistant to high temperatures of up to 70 °C.

中文翻译：

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由产色素酵母 Sporidiobolus rusheniae A45.2 共同生产没食子酸和一种新型细胞相关单宁酶。


背景技术没食子酸因其生物特性而受到广泛关注。因此，最近已经尝试将该物质应用于各种工业，特别是饲料工业。与酵母相反，真菌和细菌及其单宁酶的潜在生物转化作用，特别是单宁酸向没食子酸的生物转化作用，已得到充分证明。在这项研究中，Sporidiobolus rusheniae A45.2 被引入作为一种新的产生色素和产生鞣酸酶的酵母，该酵母因其作为动物饲料添加剂的用途而引起了极大的兴趣。然而，缺乏关于从单宁酸生产没食子酸的功效和相关单宁酶特性的信息。本研究的目的是优化单宁酸和单宁酶联产没食子酸的培养基成分和条件，重点是为其作为饲料添加剂的应用开发综合生产策略。结果 S.rueniae A45.2 产生的鞣酸酶已被归类为细胞相关鞣酸酶 (CAT)。使用响应面方法优化了由 S.rueniae A45.2 从单宁酸和 CAT 获得的没食子酸的联产，然后通过从 12.3 g/L 单宁酸合成 11.2 g/L 没食子酸以及生产 31.1 进行验证。在 1 L 搅拌罐发酵罐中培养 48 小时后的 mU/mL CAT。从细胞壁中分离、纯化鞣酸酶并与其天然形式 (CAT) 进行比较。纯化酶 (PT) 显示与 CAT 相同的 pH 值和最适温度范围 (pH 7)，但稳定性明显较差。具体而言，CAT 在高达 70 °C 的温度下稳定 60 分钟，并在最佳条件 (40 °C) 下运行最多 8 次后保持活性。 结论没食子酸和CAT联产被认为是一种一体化的绿色生产策略。 S.rueniae生物质可以作为类胡萝卜素和单宁酶的替代来源进行推广。因此，生物质与发酵培养基中形成的没食子酸结合可以直接用作饲料添加剂。另一方面，没食子酸可以被分离和纯化用于食品和制药应用。该论文首次报道从酵母中获得的 CAT 可以耐受高达 70 °C 的高温。