Screening of a fungus of Aspergillus fumigatus strain F7 and determination of mechanisms related to cellulose degradation and temperature adaptation [一株烟曲霉菌株F7的筛选及其纤维素降解与温度适应相关机制]

作者：Yang T.; Jia X.; Qin X.; Zhao Y.; Tian X.; Deng R.; Huang J.^*

来源：Chinese Journal of Applied and Environmental Biology, 2022, 28(1): 190-200.

DOI：10.19675/j.cnki.1006-687x.2021.03001

• Aspergillus fumigatus
• cellulose degradation
• genome sketch
• high temperature resistance
• low temperature adaptation

In winter, low temperatures could inhibit the growth and metabolism of microorganisms and prevent heaps of compost from heating up, leading to failed start-ups of aerobic composting of cellulosic biomass waste. At the same time, low lignocellulose degradation efficiency would result in a long composting cycle and high production cost. Therefore, it is of great importance to screen microorganisms with low-temperature resistance and efficient cellulose-degrading ability to ensure the successful start of aerobic composting of cellulosic biomass waste under low temperature conditions. A highly efficient cellulose-degrading fungus, Aspergillus fumigatus strain F7, was screened and characterized in this study. It grew on sodium carboxymethyl cellulose (CMC-Na) and Congo red plates over a wide temperature (15-50 ℃) and formed hydrolytic transparent circles. The cellulase activities of A. fumigatus strain F7 were detected on substrates of CMC-Na, microcrystalline cellulose, and filter paper, indicating that A. fumigatus strain F7 had a complete cellulolytic enzyme system. In addition, the analysis of the genome sketch of A. fumigatus strain F7 showed that there were 12 types of genes related to cellulose degradation, which encoded enzymes degrading hemicellulose, cellulose, and lignin. Moreover, there were 20 types of genes related to low-temperature adaptation, which could primarily improve cell membrane fluidity and produce compounds that could protect cells at low temperatures. There were 15 types of genes related to high temperature tolerance, encoding heat shock proteins, superoxide dismutase, and enzymes involved in trehalose metabolism. Most of the three types of predicted genes showed differences at the transcription level under different substrates and temperature conditions, further indicating that the prediction of functional potential was credible through the draft genome. These genes may be involved in the degradation of lignocellulose and temperature adaptation. Therefore, A. fumigatus strain F7 showed good application potential in the aerobic composting of cellulose waste owing to the characteristics described above.

• 单位
  四川大学; 中国科学院; 中国科学院大学