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

Abstract

Trichoderma 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 T. asperellum 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 in vitro growth of Colletotrichum sp. (about 95%) and Sclerotium rolfsii (about 97%). In peanut plants, 20 U/mL of chitinase significantly reduced the incidence of S. rolfsii 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 T. asperellum PQ34 can also prevent anthracnose that is caused by Colletotrichum sp. on both mango and chilli fruits up to 72 h after enzyme pretreatment 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.

A Broad-Specificity Chitinase from Penicillium oxalicum k10 Exhibits Antifungal Activity and Biodegradation Properties of Chitin

“…The activity of the enzyme remained above 90% for 60 min of incubation at 40 °C but decreased to 70% at 50 °C for 60 min and to 35% at 60 °C for 10 min ( Figure 4 B). The optimal temperature was similar to other chitinases from T. asperellum PQ34 [ 21 ], T. viride [ 24 ], Chitinibacter Tainanensis CT01 [ 29 ], and Bacillus subtilis [ 30 ].…”

“…Chitinases from Acremonium sp. YS2-2 [ 8 ], Trichoderma asperellum PQ34 [ 21 ], Myxococcus fulvus UM01 [ 22 ], and Achromobacter xylosoxidans [ 23 ] were induced in response to 1% colloidal chitin. The maximum chitinase yield of Trichoderma viride [ 24 ], Streptomyces pratensis KLSL55 [ 25 ], and Hydrogenophilus hirschii B-DZ44 [ 26 ] were obtained at 1.4%, 1.5%, and 2% of colloidal chitin, respectively.…”

Research Progress on Phytopathogenic Fungi and Their Role as Biocontrol Agents

“…Mechanisms in Trichoderma that are antagonistic to plant pathogens include heavy parasitism, antibiosis, and competition (Costa et al, 2019;Zhao et al, 2020). The application of phytopathogenic fungi in the field of biological control has shown great developmental prospects, but if they are to become an important disease management tool for crops, a large number of reliable and efficient biological agents must be produced (Antweiler et al, 2017;Garrigues et al, 2018;Loc et al, 2019;Vitorino et al, 2020). Trichoderma produce a variety of cell wall-degrading enzymes during the parasitism process to dissolve the cell walls of pathogenic fungi and achieve biocontrol effects.…”

Phylogeny and Optimization of Trichoderma harzianum for Chitinase Production: Evaluation of Their Antifungal Behaviour against the Prominent Soil Borne Phyto-Pathogens of Temperate India

“…It is a prominently abundant polysaccharide in major fungi cell walls viz., ascomycetes, chitridiomycetes, basidiomycetes and deuteromycetes, insect exoskeleton and crustacean shells [ 9 ]. Various types of microorganisms, viz., fungi, bacteria, yeast, etc., produce chitinase enzymes for catalyzing the biological hydrolysis of chitin to its monomer N-acetyl-D-glucosamine [ 10 , 11 ]. The chitinase enzyme produced by different biological entities digest chitin and utilizes it as carbon and energy sources [ 12 ].…”