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Canadian Journal of Microbiology Jun 1977Slow-growing bacteria, isolated on nutrient-rich and nutrient-limited media, from Chesapeake Bay water and sediment samples, were examined for 119 biochemical, cultural,...
Slow-growing bacteria, isolated on nutrient-rich and nutrient-limited media, from Chesapeake Bay water and sediment samples, were examined for 119 biochemical, cultural, morphological, nutritional, and physiological characters. Those bacteria which grow on low nutrient media, termed oligotrophs, a total of 162 strains, were subjected to taxonomic analysis, as a preliminary step in determining their ecological significance. The data for all strains included in the study were examined by computer and the simple matching (S SM) and Jaccard (SJ) coefficients calculated. Clustering was achieved by the unweighted average-linkage method. From sorted similarity matrices and dendrograms, 148 strains, 90% of the total, were recovered in 24 phenetic groups defined at the 80 to 85% similarity level. Only 12 phena could be presumptively identified and these included representatives of Alcaligenes, Corynebacterium, Hyphomicrobium, Hyphomonas polymorpha, Listeria, Nocardia marina, Pedomicrobium, Planococcus citreus, Sphaerotilus, Streptothrix, and Streptomyces. Of the remaining organisms, 10% were unidentified sheathed bacteria. It is concluded that slow-growing bacteria are distributed throughout the estuarine environment and can account for a large proportion of the colonies observed on media after prolonged periods of incubation. The oligotrophic bacteria appear to predominate in areas where the concentration of available nutrients is low and are more characteristic of non-eutrophic aquatic systems.
Topics: Actinomycetales; Alcaligenes; Bacteria; Bacterial Physiological Phenomena; Computers; Corynebacterium; Culture Media; Ecology; Listeria; Maryland; Nocardia; Streptomyces; Water Microbiology
PubMed: 871972
DOI: 10.1139/m77-110 -
Systematic and Applied Microbiology Jun 1998Three facultative psychrophilic Gram-positive bacterial strains were isolated from brine samples from the sea ice community in Antarctica. All strains were coccoid to...
Three facultative psychrophilic Gram-positive bacterial strains were isolated from brine samples from the sea ice community in Antarctica. All strains were coccoid to rod-shaped and exhibited broad salinity and temperature ranges for growth. The three strains were subjected to 16S rDNA sequencing and subsequent phylogenetic analysis. All possess unique 16S rDNA sequences indicating they are new, previously unreported organisms. Phylogenetic analyses coupled with phenotypic characterization indicated that one of the strains is most closely related to the low mol% G + C genus Planococcus for which a new species, P. mcmeekinii, is proposed. The two other strains are members of the high mol% G + C Gram-positive bacteria and most closely related to the genera Arthrobacter and Brachybacterium. This study reports the first phylogenetic evidence that Gram-positive bacteria reside in the marine sea ice brine.
Topics: Actinomycetales; Antarctic Regions; Arthrobacter; DNA, Ribosomal; Fatty Acids; Ice; Micrococcaceae; Microscopy, Phase-Contrast; Molecular Sequence Data; Phenotype; Phylogeny; Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S; Seawater; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid
PubMed: 9704115
DOI: 10.1016/S0723-2020(98)80038-6 -
World Journal of Microbiology &... Jan 2015To study culturable bacterial diversity under subzero temperature conditions and their possible functional annotation, soil and water samples from Leh Ladakh region were...
To study culturable bacterial diversity under subzero temperature conditions and their possible functional annotation, soil and water samples from Leh Ladakh region were analysed. Ten different nutrient combinations were used to isolate the maximum possible culturable morphotypes. A total of 325 bacterial isolates were characterized employing 16S rDNA-Amplified Ribosomal DNA Restriction Analysis with three restriction endonucleases AluI, MspI and HaeIII, which led to formation of 23-40 groups for the different sites at 75 % similarity index, adding up to 175 groups. Phylogenetic analysis based on 16S rRNA gene sequencing led to the identification of 175 bacteria, grouped in four phyla, Firmicutes (54 %), Proteobacteria (28 %), Actinobacteria (16 %) and Bacteroidetes (3 %), and included 29 different genera with 57 distinct species. Overall 39 % of the total morphotypes belonged to the Bacillus and Bacillus derived genera (BBDG) followed by Pseudomonas (14 %), Arthrobacter (9 %), Exiguobacterium (8 %), Alishewanella (4 %), Brachybacterium, Providencia, Planococcus (3 %), Janthinobacterium, Sphingobacterium, Kocuria (2 %) and Aurantimonas, Citricoccus, Cellulosimicrobium, Brevundimonas, Desemzia, Flavobacterium, Klebsiella, Paracoccus, Psychrobacter, Sporosarcina, Staphylococcus, Sinobaca, Stenotrophomonas, Sanguibacter, Vibrio (1 %). The representative isolates from each cluster were screened for their plant growth promoting characteristics at low temperature (5-15 °C). Variations were observed among strains for production of ammonia, hydrogen cyanide, indole-3-acetic acid and siderophore, solubilisation of phosphate, 1-aminocyclopropane-1-carboxylate deaminase activity and biocontrol activity against Rhizoctonia solani and Macrophomina phaseolina. Cold adapted microbes may have application as inoculants and biocontrol agents in crops growing at high altitudes under cold climate condition.
Topics: Animals; Antibiosis; Bacteria; Biota; Cluster Analysis; Cold Temperature; DNA, Bacterial; DNA, Ribosomal; Desert Climate; Environmental Microbiology; India; Molecular Sequence Data; Molecular Typing; Phylogeny; Plant Growth Regulators; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 25371316
DOI: 10.1007/s11274-014-1768-z -
Applied and Environmental Microbiology Aug 1997The bacterial populations associated with sea ice sampled from Antarctic coastal areas were investigated by use of a phenotypic approach and a phylogenetic approach...
The bacterial populations associated with sea ice sampled from Antarctic coastal areas were investigated by use of a phenotypic approach and a phylogenetic approach based on genes encoding 16S rRNA (16S rDNA). The diversity of bacteria associated with sea ice was also compared with the bacterial diversity of seawater underlying sea ice. Psychrophilic (optimal growth temperature, < or = 15 degrees C; no growth occurring at 20 degrees C) bacterial diversity was found to be significantly enriched in sea ice samples possessing platelet and bottom ice diatom assemblages, with 2 to 9 distinct (average, 5.6 +/- 1.8) psychrophilic taxa isolated per sample. Substantially fewer psychrophilic isolates were recovered from ice cores with a low or negligible population of ice diatoms or from under-ice seawater samples (less than one distinct taxon isolated per sample). In addition, psychrophilic taxa that were isolated from under-ice seawater samples were in general phylogenetically distinct from psychrophilic taxa isolated from sea ice cores. The taxonomic distributions of psychrotrophic bacterial isolates (optimal growth temperature, > 20 degrees C; growth can occur at approximately 4 degrees C) isolated from sea ice cores and under-ice seawater were quite similar. Overall, bacterial isolates from Antarctic sea ice were found to belong to four phylogenetic groups, the alpha and gamma subdivisions of the Proteobacteria, the gram-positive branch, and the Flexibacter-Bacteroides-Cytophaga phylum. Most of the sea ice strains examined appeared to be novel taxa based on phylogenetic comparisons, with 45% of the strains being psychrophilic. 16S rDNA sequence analysis revealed that psychrophilic strains belonged to the genera Colwellia, Shewanella, Marinobacter, Planococcus, and novel phylogenetic lineages adjacent to Colwellia and Alteromonas and within the Flexibacter-Bacteroides-Cytophaga phylum. Psychrotrophic strains were found to be members of the genera Pseudoalteromonas, Psychrobacter, Halomonas, Pseudomonas, Hyphomonas, Sphingomonas, Arthrobacter, Planococcus, and Halobacillus. From this survey, it is proposed that ice diatom assemblages provide niches conducive to the proliferation of a diverse array of psychrophilic bacterial species.
Topics: Antarctic Regions; Bacteria; Gram-Negative Bacteria; Gram-Positive Bacteria; Ice; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Seawater; Sequence Analysis, DNA; Water Microbiology
PubMed: 9251193
DOI: 10.1128/aem.63.8.3068-3078.1997 -
Applied and Environmental Microbiology Jun 2000We isolated a gram-positive, halotolerant psychrophile from a hypersaline pond located on the McMurdo Ice Shelf in Antarctica. A phylogenetic analysis of the 16S rRNA...
We isolated a gram-positive, halotolerant psychrophile from a hypersaline pond located on the McMurdo Ice Shelf in Antarctica. A phylogenetic analysis of the 16S rRNA gene sequence of this organism showed that it is a member of the genus Planococcus. This assignment is consistent with the morphology and physiological characteristics of the organism. A gene encoding a beta-galactosidase in this isolate was cloned in an Escherichia coli host. Sequence analysis of this gene placed it in glycosidase family 42 most closely related to an enzyme from Bacillus circulans. Even though an increasing number of family 42 glycosidase sequences are appearing in databases, little information about the biochemical features of these enzymes is available. Therefore, we purified and characterized this enzyme. The purified enzyme did not appear to have any metal requirement, had an optimum pH of 6.5 and an optimum temperature of activity at 42 degrees C, and was irreversibly inactivated within 10 min when it was incubated at 55 degrees C. The enzyme had an apparent K(m) of 4.9 micromol of o-nitrophenyl-beta-D-galactopyranoside, and the V(max) was 467 micromol of o-nitrophenol produced/min/mg of protein at 39 degrees C. Of special interest was the finding that the enzyme remained active at high salt concentrations, which makes it a possible reporter enzyme for halotolerant and halophilic organisms.
Topics: Antarctic Regions; Genes, Bacterial; Genes, rRNA; Gram-Positive Bacteria; Hydrogen-Ion Concentration; Kinetics; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Sodium Chloride; Substrate Specificity; Temperature; Water Microbiology; beta-Galactosidase
PubMed: 10831422
DOI: 10.1128/AEM.66.6.2438-2444.2000 -
TheScientificWorldJournal 2014Catechol 2,3-dioxygenases (C23Os, E.C.1.13.12.2) are two domain enzymes that catalyze degradation of monoaromatic hydrocarbons. The catalytically active C-domain of all...
Catechol 2,3-dioxygenases (C23Os, E.C.1.13.12.2) are two domain enzymes that catalyze degradation of monoaromatic hydrocarbons. The catalytically active C-domain of all known C23Os comprises ferrous ion ligands as well as residues forming active site pocket. The aim of this work was to examine and discuss the effect of nonsense mutation at position 289 on the activity of catechol 2,3-dioxygenase from Planococcus strain. Although the mutant C23O showed the same optimal temperature for activity as the wild-type protein (35 °C), it exhibited activity slightly more tolerant to alkaline pH. Mutant enzyme exhibited also higher affinity to catechol as a substrate. Its K(m) (66.17 µM) was approximately 30% lower than that of wild-type enzyme. Interestingly, removal of the C-terminal residues resulted in 1.5- to 1.8-fold (P < 0.05) increase in the activity of C23OB61 against 4-methylcatechol and 4-chlorocatechol, respectively, while towards catechol the activity of the protein dropped to about 80% of that of the wild-type enzyme. The results obtained may facilitate the engineering of the C23O for application in the bioremediation of polluted areas.
Topics: Carbon Dioxide; Catechol 2,3-Dioxygenase; Enzyme Activation; Enzyme Stability; Hydrocarbons, Aromatic; Planococcus Bacteria; Species Specificity; Structure-Activity Relationship; Substrate Specificity
PubMed: 24693238
DOI: 10.1155/2014/598518 -
Extremophiles : Life Under Extreme... May 2015Planococcus halocryophilus OR1 is a bacterial isolate capable of growth at temperatures ranging from -15 to +37 °C. During sub-zero (cryophilic) growth, nodular...
Planococcus halocryophilus OR1 is a bacterial isolate capable of growth at temperatures ranging from -15 to +37 °C. During sub-zero (cryophilic) growth, nodular features appear on its cell surface; however, the biochemical compositions of these features as well as any cold-adaptive benefits they may offer are not understood. This study aimed to identify differences in the cell surface proteome (surfaceome) of P. halocryophilus cells grown under optimal (24 °C, no added salt), low- and mid-salt (5 and 12 % NaCl, respectively) at 24 °C, and low- and mid-salt sub-zero (5 % NaCl at -5 °C and 12 % NaCl at -10 °C) culture conditions, for the purpose of gaining insight into cold-adapted proteomic traits at the cell surface. Mid-log cells were harvested, treated briefly with trypsin and the resultant peptides were purified followed by identification by LC-MS/MS analysis. One hundred and forty-four proteins were subsequently identified in at least one culture condition. Statistically significant differences in amino acid usage, a known indicator of cold adaptation, were identified through in silico analysis. Two proteins with roles in peptidoglycan (PG) metabolism, an N-acetyl-L-alanine amidase and a multimodular transpeptidase-transglycosylase, were detected, though each was only detected under optimal conditions, indicating that high-salt and high-cold stress each affect PG metabolism. Two iron transport-binding proteins, associated with two different iron transport strategies, were identified, indicating that P. halocryophilus uses a different iron acquisition strategy at very low temperatures. Here we present the first set of data that describes bacterial adaptations at the cellular surface that occur as a cryophilic bacterium is transitioned from optimal to near-inhibitory sub-zero culture conditions.
Topics: Adaptation, Physiological; Cold Temperature; Membrane Proteins; Planococcus Bacteria; Proteome
PubMed: 25832669
DOI: 10.1007/s00792-015-0743-4 -
Biochimica Et Biophysica Acta Sep 2003As part of a study to identify novel lipids with immune adjuvant activity, a structural comparison was made between the polar lipids from two halophiles, an archaeon...
As part of a study to identify novel lipids with immune adjuvant activity, a structural comparison was made between the polar lipids from two halophiles, an archaeon Haloferax volcanii and a eubacterium Planococcus H8. H. volcanii polar lipid extracts consisted of 44% archaetidylglycerol methylphosphate, 35% archaetidylglycerol, 4.7% of archaeal cardiolipin, 2.5% archaetidic acid, and 14% sulfated glycolipids 1 and 2. Nuclear magnetic resonance (NMR) and Fast atom bombardment mass spectrometry (FAB MS) data determined the glycolipids to be 6-HSO(3)-D-Man(p)-alpha1-2-D-Glc(p)-alpha1,1-[sn-2,3-di-O-phytanylglycerol] and a novel glycocardiolipin 6'-HSO(3)-D-Man(p)-alpha1-2-D-Glc(p)-alpha1,1-[sn-2,3-di-O-phytanylglycerol]-6-[phospho-sn-2,3-di-O-phytanylglycerol]. The polar lipids of Planococcus H8 consisted of 49% saturated phosphatidylglycerol and cardiolipin (9:1, w/w), and surprisingly 51% of the photosynthetic membrane lipid sulfoquinovosyldiacylglycerol (SQDG). This study documents archaeal cardiolipin and a novel glycocardiolipin in H. volcanii (lacking purple membrane), and is the first report of SQDG in a non-photosynthetic, halophilic bacterium.
Topics: Bacteria; Carbohydrates; Cardiolipins; Haloferax; Lipids; Liposomes; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Sodium Chloride; Spectrometry, Mass, Fast Atom Bombardment; Stereoisomerism
PubMed: 14499737
DOI: 10.1016/j.bbalip.2003.08.001 -
Astrobiology Oct 2022The search for life elsewhere in the Universe goes together with the search for liquid water. Life as we know it requires water; however, it is possible for microbial...
The search for life elsewhere in the Universe goes together with the search for liquid water. Life as we know it requires water; however, it is possible for microbial life to exist under hyperarid conditions with a minimal amount of water. We report on the ability of two typical terrestrial bacteria ( and sp) and two extremophiles (-20201027-1 sp and ) to grow and survive in three martian soil (regolith) simulants (Mohave Mars Simulant-1 [MMS-1] F, Mars Global Simulant-1 [MGS-1], and JSC Mars-1A [JSC]). Survival and growth were assessed over a 21-day period under terrestrial conditions and with water:soil (vol:wt) ratios that varied from 0.25:1 to 5:1. We found that and sp grew best in the simulants MMS and JSC, respectively, while growth rates were better in the JSC simulant. As expected, did not show significant growth. Our results indicate that these martian simulants and thus martian regolith, with minimal or no added nutrients or water, can support the growth of extremophiles such as and . Similar extremophiles on early Mars may have survived to the present in near-surface ecological niches analogous to those where these organisms exist on Earth.
Topics: Cyanobacteria; Escherichia coli; Extraterrestrial Environment; Extremophiles; Mars; Soil; Water
PubMed: 36000998
DOI: 10.1089/ast.2022.0022 -
The ISME Journal Jun 2013Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at -15 °C, the lowest temperature demonstrated to date, and is...
Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at -15 °C, the lowest temperature demonstrated to date, and is metabolically active at -25 °C in frozen permafrost microcosms. To understand how P. halocryophilus Or1 remains active under the subzero and osmotically dynamic conditions that characterize its native permafrost habitat, we investigated the genome, cell physiology and transcriptomes of growth at -15 °C and 18% NaCl compared with optimal (25 °C) temperatures. Subzero growth coincides with unusual cell envelope features of encrustations surrounding cells, while the cytoplasmic membrane is significantly remodeled favouring a higher ratio of saturated to branched fatty acids. Analyses of the 3.4 Mbp genome revealed that a suite of cold and osmotic-specific adaptive mechanisms are present as well as an amino acid distribution favouring increased flexibility of proteins. Genomic redundancy within 17% of the genome could enable P. halocryophilus Or1 to exploit isozyme exchange to maintain growth under stress, including multiple copies of osmolyte uptake genes (Opu and Pro genes). Isozyme exchange was observed between the transcriptome data sets, with selective upregulation of multi-copy genes involved in cell division, fatty acid synthesis, solute binding, oxidative stress response and transcriptional regulation. The combination of protein flexibility, resource efficiency, genomic plasticity and synergistic adaptation likely compensate against osmotic and cold stresses. These results suggest that non-spore forming P. halocryophilus Or1 is specifically suited for active growth in its Arctic permafrost habitat (ambient temp. ∼-16 °C), indicating that such cryoenvironments harbor a more active microbial ecosystem than previously thought.
Topics: Acclimatization; Arctic Regions; Cell Membrane; Cold Temperature; Ecosystem; Freezing; Gene Expression Regulation, Bacterial; Genome, Bacterial; Molecular Sequence Data; Osmotic Pressure; Planococcus Bacteria
PubMed: 23389107
DOI: 10.1038/ismej.2013.8