Characterisation and antifungal activity of extracellular chitinase from a biocontrol fungus, PQ34.

Journal: Mycology
Published Date:

Abstract

species were known as biological control agents against phytopathogenic fungi because they produce a variety of chitinases. Chitinases are hydrolytic enzymes that break down glycosidic bonds in chitin, a major component of the cell walls of fungi. The present study shows that extracellular chitinase activity reached a maximum value of approximately 22 U/mL after 96 h of PQ34 strain culture. The optimal temperature and pH of enzyme are 40°C and 7, respectively, whereas the thermal and pH stability range from 25°C to 50°C and 4 to 10, respectively. Chitinase at 60 U/mL inhibited nearly completely growth of sp. (about 95%) and (about 97%). In peanut plants, 20 U/mL of chitinase significantly reduced the incidence of infection compared to controls. The fungal infection incidence of seeds before germination and 30 days after germination was only 2.22% and 2.38%, while the control was 13.33% and 17.95%. Besides, chitinase from PQ34 can also prevent anthracnose that is caused by sp. on both mango and chilli fruits up to 72 h after enzyme pre-treatment at 40 U/mL. In mango and chilli fruits infected with anthracnose, 40 U/mL dose of chitinase inhibited the growth of fungi after 96 h of treatment, the diameter of lesion was only 0.88 cm for mango and 1.45 cm for chilli, while the control was 1.67 cm and 2.85 cm, respectively.

Authors

  • Nguyen Hoang Loc
    Institute of Bioactive Compounds and Department of Biotechnology, University of Sciences, Hue University, Hue, Vietnam.
  • Nguyen Duc Huy
    Department of Applied Biology and Biotechnology, Institute of Biotechnology, Hue University, Hue, Vietnam.
  • Hoang Tan Quang
    Department of Applied Biology and Biotechnology, Institute of Biotechnology, Hue University, Hue, Vietnam.
  • Tran Thuy Lan
    Department of Applied Biology and Biotechnology, Institute of Biotechnology, Hue University, Hue, Vietnam.
  • Tran Thi Thu Ha
    Department of Plant Protection, University of Agriculture and Forestry, Hue University, Hue, Vietnam.

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