Antarctic bacteria inhibit growth of food-borne microorganisms at low temperatures.
The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food preservation. Colonies (4496) were isolated from 12 Antarctic soil samples and tested against Listeria innocua, Pseudomonas fragi and Brochothrix thermosphacta. Thirteen bacteria were confirmed as being growth-inhibitor producers (detection rate 0.29%). When tested against a wider spectrum of eight target organisms, some of the isolates also inhibited the growth of L. monocytogenes and Staphylococcus aureus. Six inhibitor producers were psychrotrophic (growth optima between 18 and 24 degrees C), halotolerant (up to 10% NaCl) and catalase-positive; all but one were Gram-positive and oxidase-positive. The inhibitors produced by four bacteria were sensitive to proteases, suggesting a proteinaceous nature. Four of the inhibitor-producers were shown to be species of Arthrobacter, Planococcus and Pseudomonas on the basis of their 16S rRNA gene sequences and fatty acid compositions. It was concluded that Antarctic soils represent an untapped reservoir of novel, cold-active antimicrobial-producers.
O'Brien
Andrea
A
Microbiology Research Group, Faculty of Health and Human Sciences, Thames Valley University, 32-38 Uxbridge Road Ealing, London, UK.
Sharp
Richard
R
Russell
Nicholas J
NJ
Roller
Sibel
S
D000864:Antarctic Regions; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000494:pharmacology; D000898:Antibiosis; D001419:Bacteria / Q000737:chemistry / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D016000:Cluster Analysis; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D005516:Food Microbiology; D010088:Oxidoreductases / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; D002374:Catalase