title: Review of the enzymatic machinery of Halothermothrix orenii with special reference to industrial applications.
abstract: Over the past few decades the extremes at which life thrives has continued to challenge our understanding of physiology, biochemistry, microbial ecology and evolution. Innovative culturing approaches, environmental genome sequencing, and whole genome sequencing have provided new opportunities for the biotechnological exploration of extremophiles. The whole genome sequencing of H. orenii has provided valuable insights not only into the survival and adaptation strategies of thermohalophiles but has also led to the identification of genes encoding biotechnologically relevant enzymes. The present review focuses on the purified and characterized enzymes from H. orenii including amylases, β-glucosidase, fructokinase, and ribokinase--along with uncharacterized but industrially important enzymes encoded by the genes identified in the genome such as β-galactosidases, mannosidases, pullulanases, chitinases, α-L-arabinofuranosidases and other glycosyl hydrolases of commercial interest. This review highlights the importance of the enzymes and their applications in different sectors and why future research for exploring the enzymatic machinery of H. orenii should focus on the expression, purification, and characterization of the novel proteins in H. orenii and their feasible application to pertinent industrial sectors. H. orenii is an anaerobe; genome sequencing studies have also revealed the presence of enzymes for gluconeogenesis and fermentation to ethanol and acetate, making H. orenii an attractive strain for the conversion of starch into bioethanol.
authors.affiliation: Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa. Electronic address: B.Pletschke@ru.ac.za.
authors.forename: Brett I
authors.initials: BI
authors.lastname: Pletschke
mesh_terms: D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D001426:Bacterial Proteins / Q000378:metabolism; D005285:Fermentation; D005544:Forecasting; D006358:Hot Temperature; D006867:Hydrolases / Q000378:metabolism; D006868:Hydrolysis; D007218:Industrial Microbiology / Q000379:methods*; D060106:Lakes; D012997:Solvents / Q000494:pharmacology; D013213:Starch / Q000378:metabolism; D014416:Tunisia; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D012997:Solvents; D013213:Starch; D006867:Hydrolases
keywords: Extremophile; Extremozymes; Glycosyl hydrolases; Halothermothrix orenii