Cold-active microbial enzymes and their biotechnological applications.

Microorganisms known as psychrophiles/psychrotrophs, which survive in cold climates, constitute majority of the biosphere on Earth. Their capability to produce cold-active enzymes along with other distinguishing characteristics allows them to survive in the cold environments. Due to the relative ease of large-scale production compared to enzymes from plants and animals, commercial uses of microbial enzyme are alluring. The ocean depths, polar, and alpine regions, which make up over 85% of the planet, are inhabited to cold ecosystems. Microbes living in these regions are important for their metabolic contribution to the ecosphere as well as for their enzymes, which may have potential industrial applications. Cold-adapted microorganisms are a possible source of cold-active enzymes that have high catalytic efficacy at low and moderate temperatures at which homologous mesophilic enzymes are not active. Cold-active enzymes can be used in a variety of biotechnological processes, including food processing, additives in the detergent and food industries, textile industry, waste-water treatment, biopulping, environmental bioremediation in cold climates, biotransformation, and molecular biology applications with great potential for energy savings. Genetically manipulated strains that are suitable for producing a particular cold-active enzyme would be crucial in a variety of industrial and biotechnological applications. The potential advantage of cold-adapted enzymes will probably lead to a greater annual market than for thermo-stable enzymes in the near future. This review includes latest updates on various microbial source of cold-active enzymes and their biotechnological applications.

Taxonomic Characterizations of Soil Streptomyces cavourensis DW102 and Its Activity against Fungal Pathogens.

BACKGROUND: Streptomyces spp. are soil bacteria that have commercial value from which numerous secondary metabolites such as antifungal compounds have been derived. There is growing concern that antifungal resistance is on the rise, and soil Streptomyces from various geographical places might produce novel antifungal molecules. The aim of this study was to characterize and identify the actinomycetes strain namely Streptomyces isolate DW102, and to evaluate its antimicrobial activity against nosocomial fungal pathogens. MATERIALS AND METHODS: Streptomyces isolate DW102 was identified based on morphological, cultural, physiological, and biochemical properties, together with 16S rRNA sequence. Its antifungal activity was determined by agar well-diffusion assays. RESULTS: The isolate DW102 phenotypic and molecular characterization was identified as Streptomyces cavourensis DW102 and sequencing results were deposited in GenBank under accession number MK508855. Furthermore, the fermented broth of Streptomyces isolate DW102 inhibited the growth of Aspergillus niger and Candida albicans in vitro. CONCLUSIONS: Phenotypic, molecular, and phylogenetic analysis of DW102 identified the strain to be S. cavourensis. The antifungal assay showed that DW102 fermentation broth was active against both C. albicans and A. niger in vitro. Further studies are required to use the Streptomyces isolate DW102 as a promising source for the development of antifungal drugs.