Prospecting Potential Filamentous Fungi that Produce Cellulase for Production of 2G Ethanol

Abstract The production of second-generation ethanol has been recognized as a promising alternative for reducing greenhouse gas emissions. To achieve this, the hydrolysis of lignocellulosic residues by cellulases and hemicellulases is required, facilitating the release of monosaccharides that are subsequently fermented for ethanol production. In this study, the prospecting and macroscopic characterization of filamentous fungi were conducted, along with the evaluation of potential cellulase producers. Four distinct samples were collected and filamentous fungi were isolated using three different methods. Macromorphological characteristics were assessed in two solid culture media, CMC and oat flour, under incubation at 30 °C. Qualitative cellulase production was analyzed in CMC medium, with enzymatic halos visualized through Congo red staining. To determine the effect of temperature on fungal growth, the growth rates of the isolates were measured at 30 °C, 35 °C, and 40 °C in CMC containing medium. A total of nineteen filamentous fungi were successfully isolated. Limited macromorphological variation was observed in CMC containing medium; however, greater morphological diversity was noted when isolates were cultivated in oat flour medium. The highest growth rates were recorded for B.D.1.3.A at 30 °C, B.D.1.4.B and B.I.3.8.2 at 35 °C, and B.I.3.8.2 at 40 °C. Additionally, the isolates B.D.1.1, B.D.1.4.B, B.I.3.8.2, V.D.7.1, and V.I.2.7.1 exhibited the highest cellulolytic activity. The findings of this study contribute to the identification of potential cellulase producing filamentous fungi, improving the understanding of their biotechnological potential and supporting the development of sustainable technologies.