Objective The aim was to screen strain resources for efficient cellulose degradation and to promote rapid decomposition of straw at low temperature.

Method Low-temperature cellulose degrading fungi were screened by using low-temperature dilution plate coating method, Congo red characterization and quantification of endo-β-glucanase activities. The strains were identified based on morphological characteristics and rDNA-ITS sequence analysis, their enzyme production capacities at different temperatures were investigated, and preliminary studies on the enzymatic properties of crude enzyme extracts were conducted.

Result ① A cold-adapted fungus, namely ZY-50, was obtained and identified as Metapochonia-bulbillosa. There are no reports of cellulase production by this fungus. ② Metapochonia-bulbillosa ZY-50 could grow at low temperatures and has strong cellulase production ability. Its Endo β-glucanase activities were 76.03 U mL⁻¹, 128.34 U mL^−1, and 115.67 U mL⁻¹ at 28℃, 16℃ and 10℃ respectively, and the abilities of the fungus to produce Exo β-glucanase and β-Glucosidase were more stable at 16℃. The highest activities of them were 2.31 U mL⁻¹ and 2.43 U mL⁻¹. The synergistic effect of the three cellulases was stronger at 16℃, with the highest filter paper activity of 7.89 U mL⁻¹. ③ The endo-β-glucanase of the crude enzyme extract had an optimum action temperature of 60℃. The relative enzyme activity was 90% within 1.5 h at temperatures between 10 and 40℃. The optimum pH was 5.0, and its activity was promoted by 10 mmol L⁻¹ Co^{2 +} .

Conclusion Metapochonia-bulbillosa ZY-50 can grow at low temperature and has a strong cellulase production ability, which has a high potential to promote straw decomposition at low temperature.