Novel biosynthesis of MnO NPs using Mycoendophyte: industrial bioprocessing strategies and scaling-up production with its evaluation as anti-phytopathogenic agents

Abstract

Abstract This report provides the first description of the myco-synthesis of rod-shaped MnO NPs with an average crystallite size of ~ 35 nm, employing extracellular bioactive metabolites of endophytic Trichoderma virens strain EG92 as capping/reducing agents and MnCl2·4H2O as a parent component. The wheat bran medium was chosen to grow endophytic strain EG92, which produced a variety of bioactive metabolites in extracellular fraction, which increases the yield of MnO NPs to 9.53 g/l. The whole medium and fungal growth conditions that influenced biomass generation were optimized as successive statistical optimization approaches (Plackett–Burman and Box–Behnken designs). The production improvements were achieved at pH 5.5, WBE (35%), and inoculum size (10%), which increased Xmax to twelve-folds (89.63 g/l); thereby, Pmax increased to eight-folds (82.93 g/l). After 162 h, Xmax (145.63 g/l) and Pmax (99.52 g/l) on the side of µmax and YX/S were determined as 0.084 and 7.65, respectively. Via Taguchi experimental design, fungus-fabricated MnO NPs reaction was improved by adding 0.25 M of MnCl2·4H2O to 100% of fungal extract (reducing/capping agents) and adjusting the reaction pH adjusted to ~ 5. This reaction was incubated at 60 °C for 5 h before adding 20% fungal extract (stabilizing agent). Also, Pmax was raised 40-fold (395.36 g/l) over the BC. Our myco-synthesized MnO NPs exhibit faster and more precise antagonistic actions against phytopathogenic bacteria than fungi; they could be employed as an alternative and promised nano-bio-pesticide to manage a variety of different types of disease-pathogens in the future.