High cellulolytic potential of the Ktedonobacteria lineage revealed by genome-wide analysis of CAZymes
| Autor: | Kei Nanatani, Keietsu Abe, Naoki Abe, Mayumi Maruoka, Masafumi Hidaka, Yu Zheng, Yasuteru Sakai, Jun Kaneko, Shuhei Yabe, Akira Yokota |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0301 basic medicine Glycoside Hydrolases Lineage (evolution) Bioengineering Cellulase Polysaccharide 01 natural sciences Applied Microbiology and Biotechnology Genome 03 medical and health sciences Polysaccharides 010608 biotechnology Cellulases Glycoside hydrolase Cellulose Thermostability chemistry.chemical_classification Bacteria Organisms Genetically Modified biology Thermophile Fungi Chromosome Mapping Chloroflexi Gene Expression Regulation Bacterial Plants biology.organism_classification 030104 developmental biology Chloroflexi (class) Metabolic Engineering chemistry Biochemistry biology.protein Carbohydrate Metabolism Genome Bacterial Biotechnology |
| Zdroj: | Journal of Bioscience and Bioengineering. 131:622-630 |
| ISSN: | 1389-1723 |
| Popis: | 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 of plant biomass. Noticeably, the Ktedonobacteria lineage (phylum Chloroflexi) with actinomycetes-like morphology was identified and exhibited diverse carbohydrate utilization or degradation abilities. In this study, we performed genome-wide profiling of carbohydrate-active enzymes (CAZymes) in the filamentous Ktedonobacteria lineage. Numerous CAZymes (153–290 CAZymes, representing 63–131 glycoside hydrolases (GHs) per genome), including complex mixtures of endo- and exo-cellulases, were predicted in 15 available Ktedonobacteria genomes. Of note, 4–28 CAZymes were predicted to be extracellular enzymes, whereas 3–29 CAZymes were appended with carbohydrate-binding modules (CBMs) that may promote their binding to insoluble carbohydrate substrates. This number far exceeded other Chloroflexi lineages and were comparable to the cellulolytic actinomycetes. Six multi-modular extracellular GHs were cloned from the thermophilic Thermosporothrix hazakensis SK20-1T strain and heterologously expressed. The putative endo-glucanases of ThazG5-1, ThazG9, and ThazG12 exhibited strong cellulolytic activity, whereas the putative exo-glucanases ThazG6 and ThazG48 formed weak but observable halos on carboxymethyl cellulose plates, indicating their potential biotechnological application. The purified recombinant ThazG12 had near-neutral pH (optimal 6.0), high thermostability (60°C), and broad specificity against soluble and insoluble polysaccharide substrates. It also represented described a novel thermostable bacterial β-1,4-glucanase in the GH12 family. Together, this research revealed the underestimated cellulolytic potential of the Ktedonobacteria lineage and highlighted its potential biotechnological utility as a promising microbial resource for the discovery of industrially useful cellulases. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect