Prospection of Cellulolytic Fungi from Composted Samples of Saturated Horse Litter

Abstract

The treatment of saturated horse beds before they arrive at their final destination is necessary to avoid the risk of animal and environmental contamination. For this purpose, the composting process has great functionality due its to low cost, effectiveness, and operational ease. However, because of the nature of the materials used, this process can be long, and it is necessary to improve it to optimize composting cycles. This work aimed to isolate and identify fungi present in the compost piles of saturated equine bedding made with shavings and rice straw, identifying those with the greatest potential for cellulase production. Using specific cellulolytic media containing shavings or rice straw, seven strains were isolated. The total cellulase enzymatic activity of the isolates from the beds made with shavings was lower than that obtained from rice straw beds. Four strains showed high enzymatic potential for use in the shavings substrate (MA -6 2 f1, MA -6 2 f2, MA -7 9, and MA -7 10) and three for the rice straw substrate (PA -7 5, PA -7 7, and PA -7 10). The isolate PA -7 5 reached 0.376 IU mL−1, the best index among all the isolates. These isolates were identified as belonging to the Aspergillus fumigatus species.