Mahmoud Yehia A-G, Alamin Nisrin S, Mohamed Tarek M, El-Zawawy Nesma A, Salem Maha M
Botany and Microbiology Department, Faculty of Science, Tanta University, Tanta, 31257, Egypt.
Biochemistry Division, Chemistry Department, Faculty of Science, Tanta University, Tanta, 31257, Egypt.
Microb Cell Fact. 2025 Sep 9;24(1):201. doi: 10.1186/s12934-025-02832-8.
Synthetic dyes in the textile industry pose risks to human health and environmental safety. The current study aims to examine the efficacy of a novel esterase derived from an endophyte fungus in decolorizing diverse dyes, focusing on its production, purification, optimization, and characterization.
Trichoderma afroharzianum AUMC16433, a novel fungal endophyte with esterase-producing ability, was first detected from the cladodes of Opuntia ficus indica by ITS-rRNA sequencing. Furthermore, several fermentation variables that augment esterase production were improved by utilising the Plackett-Burman design and RSM. Ammonium sulphate precipitation at 60% and Sephacryl S300 HR gel filtration were employed to purify the isolated esterase to a specific activity of 1372.1 U/mg with a 2.29-fold increase and a recovery of 42.87%. The enzyme's molecular weight was ascertained to be 43 kDa via SDS-PAGE. The isolated esterase revealed peak activity at 40 °C and pH 8. The kinetic characteristics of esterase were Vmax = 2.717 U/mL and Km = 3.33 mM. The half-life time was 54.4% at 50 °C after 4 h, and the enzyme still retained 14.7% of its activity after 24 h at 50 °C. Esterase decolorized several synthetic dyes used industrially, with the highest decolorization rate in malachite green after 24 h with 66%, and successfully degraded both bromothymol blue and tartrazine with 65.5% and 65.3%, respectively, in the same time frame. Crystal violet and methyl red showed moderate decolorization, with decolorization rates of 57.1% and 43.1%, respectively.
The esterase enzyme isolated for the first time from the new endophytic Trichoderma afroharzianum has a high dyes decolorization potential, which offers it a sustainable strategy for addressing environmental contamination issues.
纺织工业中的合成染料对人类健康和环境安全构成风险。当前研究旨在考察一种源自内生真菌的新型酯酶对多种染料的脱色效果，重点关注其生产、纯化、优化及特性。
通过ITS-rRNA测序首次从印度榕仙人掌的茎片中检测到具有酯酶产生能力的新型真菌内生菌哈茨木霉AUMC16433。此外，利用Plackett-Burman设计和响应面法（RSM）改善了多个提高酯酶产量的发酵变量。采用60%硫酸铵沉淀和Sephacryl S300 HR凝胶过滤法对分离得到的酯酶进行纯化，比活性达到1372.1 U/mg，提高了2.29倍，回收率为42.87%。通过SDS-PAGE确定该酶的分子量为43 kDa。分离得到的酯酶在40℃和pH 8时显示出最高活性。酯酶的动力学特征为Vmax = 2.717 U/mL，Km = 3.33 mM。在50℃下4小时后半衰期为54.4%，在50℃下24小时后该酶仍保留14.7%的活性。酯酶对几种工业上使用过的合成染料进行了脱色，24小时后孔雀石绿的脱色率最高，为66%，同时在相同时间内分别成功降解溴百里酚蓝和柠檬黄，降解率分别为65.5%和65.3%。结晶紫和甲基红显示出中等程度的脱色，脱色率分别为57.1%和43.1%。
首次从新型内生哈茨木霉中分离得到的酯酶具有较高的染料脱色潜力，为解决环境污染问题提供了一种可持续策略。
