Optimization of cultivation conditions in banana wastes for production of extracellular β-glucosidase byTrichoderma harzianumRifai efficient forin vitroinhibition ofMacrophomina phaseolina

Abstract

The present study was carried out to optimize the physical and nutritional parameters for cultivation of Trichoderma harzianum Rifai for production of extracellular b-glucosidase, an alternative to chemcial fungicides to control Macrophomina phaseolina, which causes charcoal rot disease in crops. Response surface methodology by the Box-Behnken design (BBD) based on four factors (temperature, carbon sources, inoculum size and pH) was used for optimization of the cultivation conditions to produce b-glucosidase using agro-industrial banana wastes. The highest b-glucosidase activity (1483.27 U/mL) was attained under optimized cultivation conditions: »36 C and pH 7.3, using carbon source and inoculum size of 10% (w/v) and 5% (w/v), respectively. It is noteworthy that the low deviation values (0.09¡0.44%) in the verification experiments (R1, R2 and R3) inferred the generated model was accurate to predict optimal cultivation conditions of T. harzianum Rifai. Likewise, the obtained diameters of inhibition zones ranging from 58.00¡38.66 mm following treatment with b-glucosidase was found comparable to other in vitro tests using pure T. harzianum isolates and chemical fungicides. Hence, the findings indicated that it was feasible to use b-glucosidase as a greener alternative to chemical fungicides for control of M. phaseolina infection and consequently, for protection of crops against charcoal rot disease.

In silico approach of receptor-ligand binding and interaction: Established phytoligands from Tagetes errecta Linn. against bacterial β-glucosidase receptor

“…It is well-known that inhibition of βglucosidase activity of fungus prevent fungal pathogenicity in host plants. 13,[21][22][23] Several experimental studies revealed that leaf volatile oil of T. errecta has potent antifungal activities, 5,24 but the prediction of lead compound(s) is an important task to know the design of fungistatic compound. Although, the isolation of lead compound(s) followed by in vitro and in vivo study is suggesting in future research.…”

Assessments on the catalytic and kinetic properties of beta-glucosidase isolated from a highly efficient antagonistic fungus Trichoderma harzianum

“…It is known that among the well-described antagonistic mechanisms for the fungal isolate, T. harzianum (nutrient competition, antibiotic production and mycoparasitism) (KUBICEK et al, 2001;VITERBO et al, 2002;GAJERA et al, 2010;KHALILI et al, 2016), its mycoparasitic behaviour is particularly interesting. T. harzianum has evolved the capability to secrete a type of β-glucosidase that digests the ordered layers of amorphic β-1, 3-glucan (GAJERA et al, 2010;KHALILI et al, 2017) in M. phaseolina. The hydrolytic activity of this βglucosidase targets the sugar-based polymer that forms the filling material in the chitin-based cell wall of the pathogenic fungus (GAJERA et al, 2010;KHALILI et al, 2017).…”

“…T. harzianum has evolved the capability to secrete a type of β-glucosidase that digests the ordered layers of amorphic β-1, 3-glucan (GAJERA et al, 2010;KHALILI et al, 2017) in M. phaseolina. The hydrolytic activity of this βglucosidase targets the sugar-based polymer that forms the filling material in the chitin-based cell wall of the pathogenic fungus (GAJERA et al, 2010;KHALILI et al, 2017). Driven by this knowledge, we believe that the enzyme may prove useful as an alternative bioactive component in a fungicide to inhibit proliferation of M. phaseolina.…”

“…Moreover, manufacturing processes that use natural enzymes as catalysts are typically carried out under near ambient conditions i.e. (1 atm, 30-50 o C, pH 6-8) (KARBOUNE et al, 2008;MARZUKI et al, 2015a;MARZUKI et al, 2015b;MOHAMAD et al, 2015b;MARZUKI et al, 2015c;MANAN et al, 2016;KHALILI et al, 2017), similar to conditions under agricultural settings. For these reasons, an enzyme-based fungicide i.e.…”