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Diversity of protease‐producing marine bacteria from sub‐antarctic environments
Author(s) -
Cristóbal Héctor Antonio,
López Maria Alejandra,
Kothe Erika,
Abate Carlos Mauricio
Publication year - 2011
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201000413
Subject(s) - pseudoalteromonas , alteromonas , biology , shewanella , microbiology and biotechnology , protease , bacteria , marine bacteriophage , psychrophile , seawater , proteobacteria , gammaproteobacteria , proteases , aeromonas , pseudomonas , food science , biochemistry , 16s ribosomal rna , enzyme , ecology , genetics
Abstract From seawater and the intestines of benthonic organisms collected from the Beagle Channel, Argentina, 230 marine bacteria were isolated. Cultivable bacteria were characterized and classified as psychrotolerant, whereas few isolates were psychrophiles. These isolates were capable of producing proteases at 4 and 15 °C under neutral (pH 7.0), alkaline (pH 10.0) and acidic (pH 4.5) conditions on different media, revealing 62, 33 and 22% producers at cold and 84, 47 and 33% producers at low temperatures, respectively. More protease‐producing strains (67%) were detected when isolated from benthic invertebrates as compared to seawater (33%), with protease production under neutral conditions resulting in milk protein hydrolysis halos between 27 and 30 ± 2 mm in diameter. Using sterile 0.22 μm membrane filters, 29 isolates exhibiting extracellular protease activity were detected. These were grouped into six operational taxonomic units by restriction analysis and identified based on 16S rDNA as γ‐proteobacteria of the genera Pseudoalteromonas , Pseudomonas , Shewanella , Alteromonas , Aeromonas , and Serratia . Plasmids were found to be harbored by eight strains, mainly within the isolates from benthonic organisms. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)