Evaluation of the Biodegradation Potential of Phytopathogenic Fungi in Sugar Cane (Saccharum officinarum) Waste from the Rural Sector of Milagro, Ecuador

Abstract

In Ecuador, sugarcane (Saccharum officinarum) is a grass of great socioeconomic impact due to the employment rate involved in its cultivation and its use as a raw material for obtaining sugar and other derivatives. The industrial processing of the usable sugarcane material generates an excessive amount of waste, including leaves, bagasse, molasses, and other types of organic residues. Waste treatment systems have demonstrated inefficiency in the degradation time with respect to the harmful effects they cause. In this study, the dynamics of two genera of phytopathogenic microorganisms (Colletotrichum spp. and Rhizopus spp.) in the decomposition of sugarcane organic wastes were tested by analyzing the proximate composition, biodegradation characteristics, microbial incidence, and amino acid content. The results showed that inoculation with a combination of 2.00 × 106 spores/mL of Colletotrichum spp. and 2.00 × 106 spores/mL of Rhizopus spp., corresponding to treatment T4, led to a higher degree of biodegradation of the residues and aspartic amino acid content, with an incidence of 14.11 mmol/100 g. The amount of amino acids was not closely related to the addition of microorganisms, since the wastes belonging to the control treatment were not recorded as the wastes with the lowest concentration. On the other hand, the different treatments induced variations in the quantification of microorganisms in each biodegraded waste, reporting an average of 5.43 × 104 CFU/g of mesophilic bacteria and 6.52 × 104 CFU/g of fungi with treatment T2. The amounts obtained highlighted the predominance of cycles of increase and decrease in the concentration of microorganisms in a compost according to the stage of compost maturation.