Lu Fengning, Ren Yanna, Ding Lulu, Lu Jian, Zhou Xiangshan, Liu Haifeng, Wang Nengfei, Cai Menghao
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
China Resources Biopharmaceutical Co., Ltd, Unit 601, Building No. 2, YESUN Intelligent Community III, Guanlan Street, Shenzhen, China.
Bioresour Bioprocess. 2022 Nov 4;9(1):118. doi: 10.1186/s40643-022-00604-5.
The polar psychrotrophic fungus Geomyces sp. WNF-15A can produce high-quality natural red pigment for the potential use as edible pigment. However, it shows low-temperature-dependent synthesis of red pigment, which limits its large-scale industrial applications due to the difficult and high-cost bioprocess control. This study aims to develop transposon-mediated mutagenesis methods to generate mutants that are able to synthesize red pigment at normal temperature. Four transposable systems, including single and dual transposable systems, were established in this fungus based on the Minos from Drosophila hydei and the Restless from Tolypocladium inflatum. A total of 23 production-dominant mutants and 12 growth-dominant mutants were thus obtained by constructed transposable systems. At 14 °C and 20 °C, the MPS1 mutant strain achieved the highest level of red pigment (OD of 43.3 and 29.7, respectively), which was increased by 78.4% and 128.7% compared to the wild-type, respectively. Of note, 4 mutants (MPS1, MPS3, MPS4 and MPD1) successfully synthesized red pigment (OD of 5.0, 5.3, 4.7 and 4.9, respectively) at 25 °C, which broke the limit of the wild-type production under normal temperature. Generally, the dual transposable systems of Minos and Restless were more efficient than their single transposable systems for mutagenesis in this fungus. However, the positive mutation ratios were similar between the dual and single transposable systems for either Minos or Restless. This study provides alternative tools for genetic mutagenesis breeding of fungi from extreme environments.
极地嗜冷真菌嗜冷地霉属Geomyces sp. WNF-15A能够产生高质量的天然红色素，具有作为食用色素的潜在用途。然而，它表现出红色素合成依赖低温，由于生物过程控制困难且成本高，限制了其大规模工业应用。本研究旨在开发转座子介导的诱变方法，以产生能够在常温下合成红色素的突变体。基于来自海德氏果蝇的Minos和来自inflatum拟青霉的Restless，在该真菌中建立了四种转座系统，包括单转座系统和双转座系统。通过构建的转座系统共获得了23个产量优势突变体和12个生长优势突变体。在14℃和20℃下，MPS1突变菌株的红色素水平最高（OD分别为43.3和29.7），分别比野生型增加了78.4%和128.7%。值得注意的是，4个突变体（MPS1、MPS3、MPS4和MPD1）在25℃时成功合成了红色素（OD分别为5.0、5.3、4.7和4.9），突破了野生型在常温下的产量限制。总体而言，在该真菌中，Minos和Restless的双转座系统比单转座系统诱变效率更高。然而，对于Minos或Restless，双转座系统和单转座系统的正向突变率相似。本研究为极端环境真菌的遗传诱变育种提供了替代工具。
