scholarly journals Staphylococcus sciuri Strain LCHXa is a Free-Living Lithium-Tolerant Bacterium Isolated from Salar de Atacama, Chile

2020 ◽  
Vol 8 (5) ◽  
pp. 668
Author(s):  
Camila Salazar-Ardiles ◽  
Tamara Caimanque ◽  
Alexandra Galetović ◽  
Claudia Vilo ◽  
Jorge E. Araya ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Specific Growth ◽  
Compatible Solutes ◽  
Luria Bertani ◽  
Coagulase Negative Staphylococcus ◽  
Northern Chile ◽  
Free Living ◽  
Bacterium Strain ◽  
Li Content ◽  
Motile Bacterium

In addition to the industrial and biomedical applications of lithium, information on the tolerance of microorganisms to high Li concentrations in natural biological systems is limited. Strain LCHXa is a novel free-living Gram-positive, non-motile bacterium strain isolated from water samples taken at Laguna Chaxa, a non-industrial water body with the highest soluble Li content (33 mM LiCl) within the Salar de Atacama basin in northern Chile. Enrichment was conducted in Luria-Bertani (LB) medium supplemented with 1 M LiCl. Strain LCHXa was a Novobiocin-resistant and coagulase negative Staphylococcus. Phylogenetically, strain LCHXa belongs to the species Staphylococcus sciuri. Strain LCHXa grew optimally in LB medium at pH 6–8 and 37 °C, and it was able to sustain growth at molar Li concentrations at 2 M LiCl, with a decrease in the specific growth rate of 85%. Osmoregulation in strain LCHXa partially involves glycine betaine and glycerol as compatible solutes.

Why can't a cell grow infinitely fast?

1988 ◽  
Vol 34 (4) ◽  
pp. 421-426 ◽  
Author(s):  
Arthur L. Koch
Keyword(s):  
Specific Growth ◽  
Living Organism ◽  
Free Living ◽  
Balanced Growth ◽  
Evolutionary Forces ◽  
A Cell ◽  
Effective Use ◽  
The Cost ◽  
Favorable Conditions

Living cells are esoteric physicochemical systems that have evolved to survive and reproduce in their natural environment. Under balanced conditions of growth, bacteria are probably systems as simple as any kind of free-living organism. Evolutionary forces, seemingly, should have driven prokaryotes to be very efficient. In part that is so; they make effective use of the machinery most expensive for the cell, i.e., the ribosomes and associated factors. But the evidence is that the efficiency with which they use the ribosomal machinery increases as the environment provides more favorable conditions for balanced growth. This article emphasizes the limitation to growth under optimal conditions. The role of fluctuations in the environment and the cost of accurate protein synthesis are discussed as reasons for the upper limit in obtainable specific growth rate.

Studies on a nudibranch that contains zooxanthellae. II. Contribution of zooxanthellae to animal respiration (CZAR) in Pteraeolidia ianthina with high and low densities of zooxanthellae

1986 ◽  
Vol 228 (1253) ◽  
pp. 511-521 ◽  
Keyword(s):  
Mitotic Index ◽  
Specific Growth ◽  
Symbiotic Association ◽  
Diel Pattern ◽  
Fixed Carbon ◽  
Free Living ◽  
Carbon Demand ◽  
Symbiotic Dinoflagellates ◽  
Specific Growth Rates ◽  
Relationship Of

Daily budgets of photosynthetically fixed carbon were constructed for Pteraeolidia ianthina with high and low densities of zooxanthellae, for irradiances typical of latitude 34° S in winter, spring and summer. Whereas nudibranchs with high densities of zooxanthellae were potentially phototrophic with respect to carbon, animals with densities of zooxanthellae less than 0.5 x 10 6 cells mg -1 protein were not. The proportion of dividing zooxanthellae (mitotic index) in P. ianthina was followed over 48 hours. The diel pattern of mitotic index was asynchronous; the indices were higher in animals with low densities of zooxanthellae (20.1±6.2%) than in animals with high densities of zooxanthellae (4.7±1.8%). Specific growth rates of zooxanthellae, calculated from mitotic indices, ranged between 0.100 and 0.399 d -1 , indicating that zooxanthellae in P . ianthina have the potential to grow at rates comparable to those found in free-living and other symbiotic dinoflagellates. Zooxanthellae in the host photosynthesized at similar rates, irrespective of their density in P . ianthina . Because of the greater amount of newly synthesized carbon dedicated to the population growth of zooxanthellae, low-density populations did not have excess organic carbon available for host respiration. High density populations, however, were able to supply 79% of the animal’s respiratory carbon demand in winter, 121% in spring and 173% in summer. These results demonstrate that the metabolic relationship of zooxanthellae and their invertebrate hosts may change during the establishment of a symbiotic association.

Utilization of the compatible solutes sucrose and trehalose by purple sulfur and nonsulfur bacteria

1998 ◽  
Vol 44 (10) ◽  
pp. 974-979
Author(s):  
David T Welsh ◽  
Remy Guyoneaud ◽  
Pierre Caumette
Keyword(s):  
Specific Growth ◽  
Coastal Lagoons ◽  
Compatible Solutes ◽  
Growth Yield ◽  
Sugar Uptake ◽  
Purple Sulfur Bacteria ◽  
Purple Nonsulfur Bacteria ◽  
Sugar Utilization ◽  
Sulfur Bacteria ◽  
Specific Growth Rates

Owing to their ubiquity as compatible solutes, sucrose and trehalose and their constituent monosaccharides, glucose and fructose, may represent a significant source of carbon for the growth of other bacteria. We investigated sugar utilization by 34 strains of purple sulfur and nonsulfur bacteria isolated from coastal lagoons. Amongst the purple nonsulfur bacteria, sugar utilization was common with almost all strains utilizing the tested monosaccharides and 70 and 50% of strains utilizing sucrose and trehalose, respectively. Sugar utilization was rarer amongst the purple sulfur bacteria, with none of the strains using glucose or trehalose. Fructose, was utilized by 50% of isolates and sucrose was utilized only by strains of Thiorhodococcus. Surprisingly, although unable to use glucose directly, Thiorhodococcus strains used both the glucose and fructose moieties of sucrose and utilized glucose slowly in the presence of fructose, indicating that these strains may be impaired in glucose transport, rather than glucose metabolism per se. Disaccharide metabolism was dependent on sugar uptake and none of the strains produced trehalases or sucrases. Efficacy of sugar utilization varied widely with specific growth yield between 0.09 and 0.78 g dry weight·g sugar-1, and was dependent upon both the sugar and the strain. Similarly, specific growth rates were highly variable with strain and the sugar present and ranged between 5.4 and 0.5 × 10-2·h-1.Overall, data indicate that in natural high salinity ecosystems, purple sulfur and particularly purple nonsulfur bacteria may be able to efficiently exploit compatible solutes released to the environment by other members of the bacterial community.Key words: Chromatiaceae, purple sulfur bacteria, purple nonsulfur bacteria, sugar utilization.

Physiological response of the moderately halophilic psychrotolerant strain Chromohalobacter sp. N1 to salinity change and low temperature

2021 ◽  
pp. 1-7
Author(s):  
Lyudmila N. Anan’ina ◽  
Aleksey A. Gorbunov ◽  
Anna A. Pyankova
Keyword(s):  
Growth Temperature ◽  
De Novo ◽  
Compatible Solutes ◽  
Optimal Growth ◽  
Intracellular Pool ◽  
Moderately Halophilic ◽  
Perm Krai ◽  
Psychrotolerant Bacterium ◽  
Bacterium Strain ◽  
Available Information

The available information on de novo synthesized compatible solutes in response to high medium salinity by bacteria of the Chromohalobacter genus is limited to studies of the mesophilic moderately halophilic strain Chromohalobacter salexigens DSM 3043T. Therefore, there is a need for studies of representatives of other species of the Chromohalobacter genus of the Halomonadaceae family. A moderately halophilic psychrotolerant bacterium, strain N1, closely related to the species Chromohalobacter japonicus was isolated from the salt crust of a rock salt waste pile in Berezniki, Perm Krai, Russia. An intracellular pool of compatible solutes of strain N1 was investigated by NMR spectroscopy. Cells grown in the presence of 5% NaCl at optimal growth temperature (28 °C) accumulated ectoine, glutamate, N(4)-acetyl-l-2,4-diaminobutyrate (NADA), alanine, trehalose, hydroxyectoine, and valine. Such a combination of compatible solutes is unique and distinguishes the strain from C. salexigens DSM 3043T. Hyperosmotic stress induced by 15% NaCl caused the accumulation of ectoine, NADA, and hydroxyectoine but led to a decrease in the amount of alanine, valine, and trehalose. The intracellular pool of glutamate was not significantly changed. A reduction of the growth temperature from 28 to 5 °C led to an increase in the amount of ectoine, NADA, trehalose, and hydroxyectoine. Ectoine was the major compatible solute.

scholarly journals Solirubrobacter soli sp. nov., isolated from soil of a ginseng field

2007 ◽  
Vol 57 (7) ◽  
pp. 1453-1455 ◽  
Author(s):  
Myung Kyum Kim ◽  
Ju-Ryun Na ◽  
Tae-Hoo Lee ◽  
Wan-Taek Im ◽  
Nak-Kyun Soung ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Type Strain ◽  
Novel Species ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Phenotypic Characteristics ◽  
Bacterium Strain ◽  
Motile Bacterium

A Gram-positive, non-spore-forming, rod-shaped and non-motile bacterium, strain Gsoil 355T, was isolated from soil of a ginseng field in South Korea. In phylogenetic analyses based on 16S rRNA gene sequences, strain Gsoil 355T showed the highest levels of sequence similarity with respect to Solirubrobacter pauli B33D1T (97.4 %), Conexibacter woesei DSM 14684T (94.2 %) and Patulibacter minatonensis KV-614T (91.8 %). The strain possesses menaquinone MK-7(H4) and contains C16 : 0 and C18 : 0 ω9c as the predominant fatty acids. The DNA G+C content is 71.5 mol%. On the basis of genotypic and phenotypic characteristics, strain Gsoil 355T represents a novel species of the genus Solirubrobacter, for which the name Solirubrobacter soli sp. nov. is proposed. The type strain is Gsoil 355T (=KCTC 12628T=LMG 23485T).

scholarly journals Bradyrhizobium diazoefficiens Requires Chemical Chaperones To Cope with Osmotic Stress during Soybean Infection

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Raphael Ledermann ◽  
Barbara Emmenegger ◽  
Jean-Malo Couzigou ◽  
Nicola Zamboni ◽  
Patrick Kiefer ◽  
...  
Keyword(s):  
Stress Response ◽  
Environmental Changes ◽  
Compatible Solutes ◽  
Nodule Development ◽  
Free Living ◽  
Chemical Chaperone ◽  
Content Type ◽  
General Stress Response ◽  
General Stress ◽  
Host Infection

ABSTRACT When engaging in symbiosis with legume hosts, rhizobia are confronted with environmental changes, including nutrient availability and stress exposure. Genetic circuits allow responding to these environmental stimuli to optimize physiological adaptations during the switch from the free-living to the symbiotic life style. A pivotal regulatory system of the nitrogen-fixing soybean endosymbiont Bradyrhizobium diazoefficiens for efficient symbiosis is the general stress response (GSR), which relies on the alternative sigma factor σEcfG. However, the GSR-controlled process required for symbiosis has not been identified. Here, we demonstrate that biosynthesis of trehalose is under GSR control, and mutants lacking the respective biosynthetic genes otsA and/or otsB phenocopy GSR-deficient mutants under symbiotic and selected free-living stress conditions. The role of trehalose as a cytoplasmic chemical chaperone and stress protectant can be functionally replaced in an otsA or otsB mutant by introducing heterologous genetic pathways for biosynthesis of the chemically unrelated compatible solutes glycine betaine and (hydroxy)ectoine. Alternatively, uptake of exogenously provided trehalose also restores efficient symbiosis and tolerance to hyperosmotic and hyperionic stress of otsA mutants. Hence, elevated cytoplasmic trehalose levels resulting from GSR-controlled biosynthesis are crucial for B. diazoefficiens cells to overcome adverse conditions during early stages of host infection and ensure synchronization with root nodule development. IMPORTANCE The Bradyrhizobium-soybean symbiosis is of great agricultural significance and serves as a model system for fundamental research in bacterium-plant interactions. While detailed molecular insight is available about mutual recognition and early nodule organogenesis, our understanding of the host-imposed conditions and the physiology of infecting rhizobia during the transition from a free-living state in the rhizosphere to endosymbiotic bacteroids is currently limited. In this study, we show that the requirement of the rhizobial general stress response (GSR) during host infection is attributable to GSR-controlled biosynthesis of trehalose. Specifically, trehalose is crucial for an efficient symbiosis by acting as a chemical chaperone to protect rhizobia from osmostress during host infection.

Applications of Scanning Microscopy in Biomedical Research

1968 ◽  
Vol 26 ◽  
pp. 354-355
Author(s):  
T. L. Hayes
Keyword(s):  
Information Content ◽  
Biomedical Research ◽  
Biomedical Applications ◽  
Three Dimensional ◽  
Dental Enamel ◽  
Resolving Power ◽  
Whole Mount ◽  
Two Parameters ◽  
Content Information ◽  
Sectioned Tissue

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.

Ultrastructure of neuromuscular relationships in the canine heartworm (dirofilaria immitis)

1986 ◽  
Vol 44 ◽  
pp. 278-279
Author(s):  
W. L. Steffens ◽  
Nancy B. Roberts ◽  
J. M. Bowen
Keyword(s):  
Dirofilaria Immitis ◽  
Domestic Dogs ◽  
Structural Description ◽  
Pharmacological Effects ◽  
Free Living ◽  
Canine Heartworm ◽  
The World ◽  
Synaptic Region ◽  
Muscle Innervation ◽  
Insight Into

The canine heartworm is a common and serious nematode parasite of domestic dogs in many parts of the world. Although nematode neuroanatomy is fairly well documented, the emphasis has been on sensory anatomy and primarily in free-living soil species and ascarids. Lee and Miller reported on the muscular anatomy in the heartworm, but provided little insight into the peripheral nervous system or myoneural relationships. The classical fine-structural description of nematode muscle innervation is Rosenbluth's earlier work in Ascaris. Since the pharmacological effects of some nematacides currently being developed are neuromuscular in nature, a better understanding of heartworm myoneural anatomy, particularly in reference to the synaptic region is warranted.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

Biomedical applications: Pitfalls in the practice

1994 ◽  
Vol 52 ◽  
pp. 378-379
Author(s):  
J. D. Shelburne ◽  
Peter Ingram ◽  
Victor L. Roggli ◽  
Ann LeFurgey
Keyword(s):  
Operating Room ◽  
Liquid Nitrogen ◽  
Lung Tissue ◽  
Biomedical Applications ◽  
Microprobe Analysis ◽  
Tissue Sample ◽  
Cellular Level ◽  
Tissue Samples ◽  
Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

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