Antarctic bioprospecting: In pursuit of microorganisms producing new antimicrobials and enzymes

DANILOVICH, M.E; SANCHEZ L. A; ACOSTA, F.; DELGADO O.D.

POLAR BIOLOGY

SPRINGER

Año: 2017 vol. 41 p. 1417 - 1433

0722-4060

Intensive efforts are being made to find new compoundswith antimicrobial activity. The search for these novel bio-products insparsely explored environments may be the key to providing solutions for manyemerging problems. Antarctic environments are valuable locations for bioprospecting.In this study, 63 cold-adapted bacterial strains of 6,100 different colonymorphotypes were isolated from Antarctic seawater samples around South Shetlandand Deception islands. Strains were selected based on cold-active antimicrobialproduction and were grouped into 11 operationaltaxonomic units by internal spacer region-PCR and amplified ribosomal DNArestriction analysis. Isolates arbitrarily named 2D, 5D, and 6D were closelyrelated to Halomonas titanicae, with99.8%,98.9%, and 96.7% identity according to 16S rDNA sequencing, and 99.7%, 99.3%,and 98.3% according to gyrB regionsequence analysis, respectively. The isolate 18SH was closelyrelated to Candida sake (99.2%) basedon sequence analysis of the ITS1?5.8S rDNA?ITS2 and D1/D2 domain of 26S rDNA. Antimicrobials produced byisolates 2D, 5D, and 6D exhibited a low molecular weight (<6,000 Da) and stabilityin wide pH and temperature ranges. When tested against foodborne andphytopathogenic bacteria, selected isolates exhibited a wide spectrum of activity.This work reports the isolation and identification of cold-adaptedmicroorganisms with the ability to produce antimicrobial compounds withpotential application in the pharmaceutical or in cold-chain management in the foodindustry. The current results highlight the potential of the Antarcticenvironment as a valuable and underexploited source of new antimicrobialmolecules with exceptional properties for different biotechnological applications.