Singh Kritika, Srivastava Garima, Talat Mahe, Srivastava Onkar Nath, Kayastha Arvind Mohan
School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
Nanoscience and Nanotechnology Unit, Department of Physics, Banaras Hindu University, Varanasi 221005, India.
Biochem Biophys Rep. 2015 Jul 14;3:18-25. doi: 10.1016/j.bbrep.2015.07.002. eCollection 2015 Sep.
α-Amylase is imperative for starch and its deriviatized industries. Functionalized graphene sheets were tailored and optimized as scaffold for α-amylase immobilization using Response Surface Methodology based on Box-Behnken design, with an overall immobilization efficiency of 85.16%. Analysis of variance provided adequacy to the mathematical model for further studies. Native and immobilized functionalized graphene were characterized using transmission and scanning electron microscopy, followed by Fourier transform infrared (FTIR) spectroscopy. Wheat α-amylase conjugated with functionalized graphene sheets were visually evident on transmission and scanning micrographs while the FTIR spectra showed interplay of various chemical interactions and bonding, during and after immobilization. Optimum pH and optimum temperature for immobilized enzyme though remained unchanged but showed broader range whereas showed a slight decrease (1.32 mg/mL). It also showed enhanced thermal and storage stability and retained 73% residual activity after 10 uses. These ensemble of properties and non-toxic nature of functionalized graphene, makes it viable to be absorbed commercially in starch processing industries.
α-淀粉酶对淀粉及其衍生行业至关重要。基于Box-Behnken设计的响应面法对功能化石墨烯片进行了定制和优化，将其作为α-淀粉酶固定化的支架，总体固定化效率为85.16%。方差分析表明该数学模型适用于进一步研究。使用透射电子显微镜和扫描电子显微镜对天然和固定化的功能化石墨烯进行了表征，随后进行了傅里叶变换红外（FTIR）光谱分析。在透射和扫描显微照片上可以直观地看到与功能化石墨烯片结合的小麦α-淀粉酶，而FTIR光谱显示了固定化过程中和固定化后各种化学相互作用和键合的相互作用。固定化酶的最适pH和最适温度虽然保持不变，但范围变宽，而其活性略有下降（1.32 mg/mL）。它还表现出增强的热稳定性和储存稳定性，在重复使用10次后仍保留73%的残余活性。功能化石墨烯的这些综合性能和无毒性质使其在淀粉加工行业具有商业应用的可行性。
