Meng Shujuan, Yin Yao, Yu Liu
School of Space and Environment, Beihang University Beijing 100191 PR China
Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University 1 Cleantech Loop Singapore 637141
RSC Adv. 2019 Jul 25;9(40):22980-22986. doi: 10.1039/c9ra04530a. eCollection 2019 Jul 23.
This study was aimed at the exploration of high-efficiency and low-cost technique for glucoamylase (GA) production from food waste; moreover, the produced GA could be directly used in the hydrolysis of food waste. A mixture of food waste, rice waste and cake waste as a sole feedstock was investigated for the production of GA solid-state fermentation. The highest GA activity of 458.3 U g was obtained from the rice waste after 9 days of incubation. The cake waste also demonstrated a high GA production, achieving 406.5 U g dry substrate. However, the most practical substrate for GA production that could be integrated in the food waste treatment was the mixed food waste, which could effectively produce GA without any additives or adjustments using the technique developed in this study. The optimum conditions for GA production from the mixed food waste were determined through a response surface methodology: the temperature of 31.16 °C, the inoculum amount of 1.54 mL, and the time of fermentation of 7.81 days. The maximum GA activity of 180.59 U g could be achieved under these optimum conditions, which was actually much higher than those reported in the literature. This study showed that the mixed food waste could be an ideal feedstock for the on-site production of high-activity GA, and the produced GA could be directly applied in food waste hydrolysis, which significantly reduced the process cost.
本研究旨在探索一种从食物垃圾中生产糖化酶（GA）的高效低成本技术；此外，所生产的GA可直接用于食物垃圾的水解。研究了以食物垃圾、米糠和饼粕废料的混合物作为唯一原料通过固态发酵生产GA的情况。培养9天后，米糠废料中获得了最高的GA活性，为458.3 U/g。饼粕废料也表现出较高的GA产量，达到406.5 U/g干底物。然而，可纳入食物垃圾处理的GA生产最实用的底物是混合食物垃圾，使用本研究开发的技术，无需任何添加剂或调整即可有效生产GA。通过响应面法确定了混合食物垃圾生产GA的最佳条件：温度为31.16℃，接种量为1.54 mL，发酵时间为7.81天。在这些最佳条件下可实现的最大GA活性为180.59 U/g，这实际上远高于文献报道的值。本研究表明，混合食物垃圾可能是现场生产高活性GA的理想原料，所生产的GA可直接应用于食物垃圾水解，这显著降低了工艺成本。
