High cellulolytic potential of the Ktedonobacteria lineage revealed by genome-wide analysis of CAZymes

Traditionally, filamentous fungi and actinomycetes are well-known cellulolytic microorganisms that have been utilized in the commercial production of cellulase enzyme cocktails for industrial-scale degradation plant biomass. Noticeably, Ktedonobacteria lineage (phylum Chloroflexi) with actinomycetes-like morphology was identified exhibited diverse carbohydrate utilization or abilities. In this study, we performed genome-wide profiling carbohydrate-active enzymes (CAZymes) lineage. Numerous CAZymes (153–290 CAZymes, representing 63–131 glycoside hydrolases (GHs) per genome), including complex mixtures endo- exo-cellulases, were predicted 15 available genomes. Of note, 4–28 to be extracellular enzymes, whereas 3–29 appended carbohydrate-binding modules (CBMs) may promote their binding insoluble substrates. This number far exceeded other Chloroflexi lineages comparable actinomycetes. Six multi-modular GHs cloned from thermophilic Thermosporothrix hazakensis SK20-1T strain heterologously expressed. The putative endo-glucanases ThazG5-1, ThazG9, ThazG12 strong activity, exo-glucanases ThazG6 ThazG48 formed weak but observable halos on carboxymethyl cellulose plates, indicating potential biotechnological application. purified recombinant had near-neutral pH (optimal 6.0), high thermostability (60°C), broad specificity against soluble polysaccharide It also represented described a novel thermostable bacterial β-1,4-glucanase GH12 family. Together, research revealed underestimated highlighted its utility as promising microbial resource discovery industrially useful cellulases.