Strategies and Challenges for the Development of Industrial Enzymes Using Fungal Cell Factories
Strategies and Challenges for the Development of Industrial Enzymes Using Fungal Cell Factories
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DOI：
10.1007/978-3-030-29541-7_7
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发表时间：
2019-09-27
期刊：
影响因子：
--
通讯作者：
Hjort CM
中科院分区：
文献类型：
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作者：
Arnau J;Yaver D;Hjort CM
从微生物生产工业酶已经有世纪多的历史。今天，很大一部分酶产品是使用重组微生物生产的。本章重点介绍了属于子囊菌纲的主要工业真菌种类，如黑曲霉、黑曲霉、黑曲霉和黑曲霉。和里氏木霉（Trichoderma reesei）。许多可商购的重组酶是使用真菌制造的。描述了用于食品中的真菌酶的实例。酶行业在很大程度上是成本驱动的，因此酶产品需要满足严格的COGS（商品销售成本）目标。因此，细胞工厂必须非常有效地以高滴度生产酶并有效地利用原材料。其次，它必须被设计为一个强大的和通用的发酵过程。当开发用于酶生产的真菌宿主时，需要考虑与细胞工厂的效率、产物的纯度以及细胞工厂和产物两者的安全性有关的系统的若干性质。纯度通过细胞工厂的工程化来保证，并且与安全性相关的特性也必须被工程化到真菌宿主中。用于菌株改良的方法正在不断开发以提高产量，并在本文中进行了描述。使用精确工具进行基因组修饰的更多自动化（即，CRISPR）和低成本测序极大地扩展了可能性，并实现了快速菌株开发。使用系统生物学方法，现在可以更好地了解细胞过程，从而实现真菌细胞工厂的先进工程。令人惊讶的是，对该领域创新的调查显示，近年来专利申请数量有所减少。最后，在过去几年中，对酶的批准要求，特别是在食品和饲料中，在世界范围内显著增加。包括对食品和饲料监管环境及其挑战的描述。
Industrial enzymes have been produced from microorganisms for more than a century. Today, a large share of enzyme products is manufactured using recombinant microorganisms. This chapter focuses on major industrial fungal species belonging to the ascomycetes like Aspergillus niger, A. oryzae, and Trichoderma reesei. Many of the commercially available recombinant enzymes are manufactured using fungi. Examples of fungal enzymes used in food products are described. The enzyme industry is to a large extent cost-driven, so the enzyme product needs to meet strict COGS (cost of goods sold) targets. Therefore, the cell factory must be very efficient to produce the enzyme in high titers and efficiently utilize raw materials. Secondly, it must be designed for a robust and generic fermentation process. When developing fungal hosts for enzyme production, several properties of the system need to be considered relating to efficiency of the cell factory, purity of the product, and safety of both the cell factory and the product. Purity is secured by engineering of the cell factory, and properties related to safety must also be engineered into the fungal host. The methods used for strain improvement are continuously being developed to increase yields and are described herein. More automation using precision tools for modification of the genome (i.e., CRISPR) and low-cost sequencing have vastly expanded the possibilities and enabled fast strain development. Using systems biology approaches, better understanding of cellular processes is now possible enabling advanced engineering of fungal cell factories. Surprisingly, a survey of innovation in the field revealed a decrease in the number of patent applications in recent years. Finally, the requirements for enzyme approval, especially in food and feed, have increased significantly worldwide in the last few years. A description of the regulatory landscape and its challenges in food and feed is included.