Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan

Abstract

This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.

Assessment of the Effect of Easily-metabolised Carbon Supplements on Xylanase Production by Newly Isolated Trichoderma asperellum USM SD4 Cultivated on Oil Palm Empty Fruit Bunches

“…Xylanase activities reported in earlier studies were very poor in the range 14. U/gds (Marx et al 2013) and 162 U/mL (Asad et al 2015), which is the highest xylanase activity ever reported prior to this study. Finding in this study therefore suggested the potential of T. asperellum for enhanced xylanase production Growth rate and the corresponding xylanase productivity by T. asperellum USM SD4 were determined.…”

“…Of specific importance is the genus Trichoderma. Species of Trichoderma (e.g., T. reesei) have been well investigated for the production of several hydrolytic enzymes including xylanase and cellulases and are well studied as bio-control agents against plant fungal pathogens (Asad et al 2015). Notable among the species of Trichoderma is T. asperellum, which is identified as a prominent mycoparasite non-pathogenic symbiont of plants and is most commonly used to produce biocontrol agents against plant pathogens (Asad et al 2015).…”

“…Species of Trichoderma (e.g., T. reesei) have been well investigated for the production of several hydrolytic enzymes including xylanase and cellulases and are well studied as bio-control agents against plant fungal pathogens (Asad et al 2015). Notable among the species of Trichoderma is T. asperellum, which is identified as a prominent mycoparasite non-pathogenic symbiont of plants and is most commonly used to produce biocontrol agents against plant pathogens (Asad et al 2015). Notwithstanding that xylanase is a principal fraction of several cell-walls degrading enzymes by which it exerts its mycoparasitic property, most studies on T. asperellum have focused on its bio-control ability at the expense of other industrial uses.…”

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

“…(Lima et al 1999), T. virens (Baek et al 1999). However, studies in T. asperellum have only recently begun and only focused on chitinase coding genes, its characterisation and activity (Loc et al 2011(Loc et al , 2013Kumar et al 2012a;Nadarajah et al 2014;Asad et al 2015;Wu et al 2017;Pandian et al 2018;Liu et al 2019, etc. ).…”

Trichoderma: IMPORTANCIA AGRÍCOLA, BIOTECNOLÓGICA, Y SISTEMAS DE FERMENTACIÓN PARA PRODUCIR BIOMASA Y ENZIMAS DE INTERÉS INDUSTRIAL

“…Otros metabolitos secundarios de importancia agrícola sintetizados por especies de Trichoderma se relacionan con compuestos volátiles y no volátiles con actividad antimicrobiana y defensa vegetal, destacando diterpenos tetracíclicos (por ejemplo, harziandione), sesquiterpenos (por ejemplo, tricotecenos, tricodermin, y harzianum A), y el triterpeno viridin (Zeilinger et al, 2016), que confieren sus propiedades como agente de biocontrol hacia organismos fitopatógenos (Asad et al, 2015;Chen et al, 2016). El éxito de Trichoderma como biocontrolador se basa en su capacidad de sintetizar compuestos antagónicos (proteínas, enzimas y antibióticos), y sustancias promotoras de crecimiento (vitaminas y hormonas), beneficiando así a los cultivos agrícolas (Navaneetha et al, 2015).…”