RESUMO
A psychrotolerant marine bacterial strain, designated JUB59(T), was isolated from Antarctic surface seawater and classified as a new species of the genus Bizionia. Here, we present the first draft genome sequence for this genus, which suggests interesting features such as UV resistance, hydrolytic exoenzymes, and nitrogen metabolism.
Assuntos
Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Genoma Bacteriano , Água do Mar/microbiologia , Regiões Antárticas , Sequência de Bases , Flavobacteriaceae/classificação , Dados de Sequência Molecular , FilogeniaRESUMO
We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica, which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (G+C content 41.24%). This strain harbors several mobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution.
RESUMO
Extracellular proteases from 8 Antarctic psychrotolerant Pseudomonas sp. strains were purified and characterised. All of them are neutral metalloproteases, have an apparent molecular mass of 45kDa, optimal activity at 40 degrees C and pH 7-9, retaining significant activity at pH 5-11. With the exception of P96-18, which is less stable, all retain more than 50% activity after 3 h of incubation at pH 5-9 and show low thermal stability (their half-life times range from 20 to 60 min at 40 degrees C and less than 5 min at 50 degrees C). These proteases can be used in commercial processes carried out at neutral pH and moderate temperatures, and are of special interest for their application in mixtures of enzymes where final thermal selective inactivation is needed. Results also highlight the relevance of Antarctic biotopes for the isolation of protease-producing enzymes active at low temperatures.
Assuntos
Temperatura Baixa , Endopeptidases/metabolismo , Pseudomonas/enzimologia , Regiões Antárticas , Endopeptidases/isolamento & purificação , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Pseudomonas/crescimento & desenvolvimento , TemperaturaRESUMO
Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.
Assuntos
Azospirillum brasilense/isolamento & purificação , Bacillus/isolamento & purificação , Endófitos/isolamento & purificação , Hordeum/microbiologia , Fixação de Nitrogênio , Pseudomonas/isolamento & purificação , Sementes/microbiologia , Antibiose , Azospirillum brasilense/classificação , Azospirillum brasilense/genética , Azospirillum brasilense/metabolismo , Bacillus/classificação , Bacillus/genética , Bacillus/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Endófitos/classificação , Endófitos/genética , Endófitos/metabolismo , Ácidos Indolacéticos/metabolismo , Tipagem Molecular , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/metabolismo , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNARESUMO
BA42 is a protein belonging to the psychrophilic bacteria Bizionia argentinensis sp. nov. Bioinformatics analysis showed that it presents significant sequence identity with a Pfam A family, DUF 477, found both in eukarya and eubacteria but of unknown function in all these organisms. Here, we report the NMR spectra assignment of this 145 amino acid protein. These data will allow performing NMR structural studies with the aim of using the three-dimensional structure as relevant information in order to determine the function of this family of proteins.
Assuntos
Proteínas de Bactérias/química , Flavobacteriaceae/metabolismo , Ressonância Magnética Nuclear Biomolecular , Prótons , Sequência de Aminoácidos , Isótopos de Carbono , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Isótopos de Nitrogênio , Estrutura Secundária de ProteínaRESUMO
A marine bacterial strain, designated strain JUB59(T), was isolated from surface seawater in Antarctica and subsequently characterized. Cells were found to be Gram-negative, non-motile rods forming butyrous, shiny, yellowish orange colonies on marine agar. Growth occurred at 2-28 degrees C (optimally at 22-25 degrees C) but not at 30 degrees C; Na+ ions were required, but 9 % NaCl (w/v) was not tolerated. Phylogenetic analysis, based on comparisons of the complete 16S rRNA gene sequence of the novel isolate with the sequences of closely related strains, showed that strain JUB59(T) belonged to the family Flavobacteriaceae, representing a novel species of the genus Bizionia. The highest levels of sequence similarity were found with respect to Bizionia myxarmorum ADA-4(T) (97.4 %) and Bizionia algoritergicola APA-1(T) (97.1 %). However, the DNA-DNA relatedness of strain JUB59(T) with respect to these two strains was low (15.9-17.3 and 19.3-22.1 %, respectively). The predominant fatty acids of strain JUB59(T) were iso-15 : 1omega10c (18.1 %), iso-15 : 0 (17.3 %), anteiso-15 : 0 (13.9 %), iso-17 : 0 3-OH (9.2 %), 15 : 0 (6.0 %) and iso-16 : 0 3-OH (5.3 %). The main polar lipids were phosphatidylethanolamine, an aminolipid, an amino-positive phospholipid and two unidentified lipids. MK-6 was the major respiratory quinone (>90 %) and the DNA G+C content was 34 mol%. On the basis of the data obtained, strain JUB59(T) represents a novel species of the genus Bizionia, for which the name Bizionia argentinensis sp. nov. is proposed. The type strain is JUB59(T) (=DSM 19628(T)=CCM-A-29 1259(T)).