Biodegradation of lignocellulosic wastes by thermotolerant cellulolytic actinomycetal consortium isolated from Uhud Mountain, Madinah, Saudi Arabia

The actinomycetal consortium plays a key role in lignocellulose degradation and offers promising applications in sustainable biomass conversion and biotechnology. A thermotolerant lignocellulolytic actinobacterial consortium, composed of strains A5 (Streptomyces cavourensis strain QT227), C13 (Streptomyces parvus 5-94 gene), and C17 (Streptomyces cavourensis strain SIF3) isolated from an arid region in Madinah, Saudi Arabia, demonstrates significant potential in sustainable biomass conversion and biotechnology. This consortium effectively degrades various cellulosic substrates, including bagasse (SB), corncob (CC), and palm leaves (PL), making it suitable for biorefinery processes. Specifically, the consortium achieved saccharification percentages of 159% for CC, 96.2% for SB, and 37.02% for PL. Correspondingly, the utilization percentages for these substrates were 37% for CC, 11% for SB, and 17% for PL. The consortium's crude extract exhibited total cellulase activities of 1.34 U/mL on CC, 1.51 U/mL on SB, and 0.42 U/mL on PL. The kinetic parameters of CMCase activity were determined for individual strains A5, C13, and C17, with affinity (K_m) values of 3.64, 1.28, and 1.56 mM, respectively. Therefore, these strains represent promising candidates for industrial applications, offering the production of thermostable cellulases and efficient lignocellulosic biomass conversion without the need for costly and environmentally impactful chemical or thermal pretreatments.