Prajapati Vimalkumar S, Mehta Vaibhavkumar N, Patel Swati K
Division of Microbial and Environmental Biotechnology, ASPEE SHAKILAM Biotechnology Institute (ASBI), Navsari Agricultural University, Surat, Gujarat, India.
Center of Excellent in Nano Agri-Biotechnology, ASPEE SHAKILAM Biotechnology Institute (ASBI), Navsari Agricultural University, Surat, Gujarat, India.
Front Bioeng Biotechnol. 2025 Jun 3;13:1569902. doi: 10.3389/fbioe.2025.1569902. eCollection 2025.
In recent years, gold nanoparticles (Au-NPs) have garnered popularity for their remarkable and promising applications in various areas. Here, we report the synthesis of Au-NPs using extracellular amylase produced by VSP4 under solid-state fermentation (SSF) through the reduction of AuCl with retention of enzymatic activity in the complex. Accordingly, VSP4 was exploited to enhance α-amylase production under SSF using the Plackett-Burman design, followed by the central composite design (CCD) of response surface methodology (RSM). According to our analysis, the most significant components in the medium are starch, yeast extract, and CaCl (significance >95%, ANOVA), which prominently enhance enzyme production. The optimum levels of these three selected variables were evaluated using CCD-RSM (20 runs), and it was confirmed that 0.05 g of starch, 0.1 g of yeast extract, and 5 mM of CaCl per 5 g of wheat bran under SSF produced the maximum α-amylase yield (169.72 U/gds). The -value of the quadratic model (18.36) implies that the model is significant, while the -value of the lack of fit (3.17) indicates that the lack of fit is not significant, meaning that the model has good fit. The coefficient of variance was found to be 0.369, which denotes that the experiments performed herein are reliable (R = 0.94) (multiple correlation coefficient), and the standard deviation for the quadratic model was found to be 4.72. We also performed separate validation experiments to confirm the adequacy of the quadratic model. The present work highlights α-amylase production by VSP4 under SSF, which was prominently enhanced by adopting a statistical experimental design, leading to the formation of Au-NPs of average size 5.17 ± 0.85 nm showing a surface plasmon resonance peak at 528 nm.
近年来，金纳米颗粒（Au-NPs）因其在各个领域的卓越且有前景的应用而受到广泛关注。在此，我们报道了利用VSP4在固态发酵（SSF）条件下产生的胞外淀粉酶，通过还原AuCl来合成Au-NPs，且复合物中酶活性得以保留。相应地，利用Plackett-Burman设计，随后采用响应面法（RSM）的中心复合设计（CCD），在固态发酵条件下利用VSP4提高α-淀粉酶的产量。根据我们的分析，培养基中最重要的成分是淀粉、酵母提取物和CaCl（显著性>95%，方差分析），它们显著提高了酶的产量。使用CCD-RSM（20次运行）评估了这三个选定变量的最佳水平，证实了在固态发酵条件下，每5g麦麸中含有0.05g淀粉、0.1g酵母提取物和5mM CaCl时，α-淀粉酶产量最高（169.72 U/gds）。二次模型的F值（18.36）表明该模型具有显著性，而失拟F值（3.17）表明失拟不显著，这意味着模型拟合良好。变异系数为0.369，这表明本文所进行的实验是可靠的（R = 0.94）（多重相关系数），二次模型的标准差为4.72。我们还进行了单独的验证实验以确认二次模型的充分性。本研究突出了VSP4在固态发酵条件下产生α-淀粉酶的情况，通过采用统计实验设计显著提高了产量，导致形成平均尺寸为5.17±0.85nm的Au-NPs，在528nm处呈现表面等离子体共振峰。
