Preparation of Bacillus pumilus loaded electrosprayed nanoparticles as a plant protective against postharvest fungal decay

Abstract

One of the major difficulties of many countries today is to supply food in sufficient quantities and quality to provide for an increasing population without damaging the soil or the ecosystem. In order to overcome the food losses and improve food production, biotechnological and nanotechnological advances come to the fore. In this study we present a comprehensive production process for a food/crop protective which acts as a microbial biofungicide, produced from a microorganism rich in antimicrobial bioactive substances. In this context, Bacillus pumilus was produced in a bioreactor and their spores were encapsulated in alginate/poly (vinyl alcohol) nanoparticles. In the first part of the study, a high quantify of spores was produced during a short incubation period, reaching 2.0 x 10(11) CFU/mL using 1% inoculum. In the second part, B. pumilus loaded nanoparticles with a size of 695 nm were produced by electrospinning. Finally, the effects of B. pumilus spores and their nanoparticles on mycelial growth of Colletotrichum gloeosporioides were investigated. After electrospinning, the viability of spores was found to be 2.0 x 10(6) CFU/mL, and nanoparticles showed 28% inhibition of mycelial growth against C. gloeosporioides. Moreover, in vivo studies of spores and nanoparticles also showed efficient fruit protection. As a result, the use and controlled release of nanoparticles loaded with Bacillus spores can be considered a natural and new technique to prevent postharvest fungal decay disease on the crops.