| Halomonas meridiana | |
|---|---|
Scientific classification  | |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Gammaproteobacteria |
| Order: | Oceanospirillales |
| Family: | Halomonadaceae |
| Genus: | Halomonas |
| Species: | H. meridiana |
| Binomial name | |
| Halomonas meridiana James et al. 1990 [1] | |
Halomonas meridiana (H. meridiana) is a bacterial species discovered in 1990 in the hypersaline lakes of Vestfold Hills, Antarctica. [2]
Halomonas meridiana is a Gram-negative microorganism of the family Halomonadaceae. [2] There are several known strains of this microbe including DSM 5425, ACAM 246, ATCC 49692, and CIP 104043. [3] It shares many characteristics with other species in the same genus. H. meridiana was placed in this genus due to its halophillic nature as well as its close genomic relation to others in the same taxa. [2] This species shares a close relationship with the known species Halomonas elongate, Halomonas halmophila, and Halomonas subglaciescola [2] .
Halomonas meridiana is a Gram-negative halophilic organism found in the lakes of Antarctica. [4] It is a rod-shaped cell with rounded ends, and it has peritrichous, all over the surface, flagella. It is between 2 and 3 micrometers in length and 1 micrometer wide. [2] [5] This organism has an average genome currently sized 3.8 mega base pairs (Mbp) containing 56.96% GC's, or guanine and cytosine content. [6] It has 3,864 genes of which 3,696 of those genes are protein coding. [7] H. meridiana is a commensal marine bacteria that is found living on reef-building corals as part of their surface microbiome. [3] It is not known to be pathogenic. Halomonas meridiana is a heterotrophic organism capable of anaerobic growth with the aid of glucose when nitrogen is not present. [4]
In 1997, James et al. published a paper describing an organism they had discovered. It was found in the Vestfold Hills, Antarctica salt lakes, which contained many undescribed microbes including this organism. [2] Water from the lake was placed on agar plates and incubated. [2] After allowing time for growth, single cells were removed from colonies and grown on new agar places. [2] After 2–4 weeks of incubation, colonies were transferred to a basal media designed to simulate an organic lake. [2] Many species of microorganisms and several strains of what would later be identified as Halomonas meridiana were found and tested for physical and chemical characteristics using quantitative phylogenetic techniques. [2] James et al. mapped the results of DNA base composition, salt tolerance, and temperature tolerance tests against those of other known organisms of the same family. [2] After careful study, they determined that the organism they had found was different from the rest. [2] They placed the organism in the genus Halomonas . [2] In addition to Antarctica, Halomonas meridiana was also isolated from the host of organisms found living in and on coral, Acropora, across the world. [7] The found organism was identified as Halomonas meridiana using sequences of parts of the 16S rRNA gene. [7] The word Halomonas comes from the Greek word halos meaning "salt" and monas meaning "unit" and The word meridiana comes from the word meridian meaning “of or belonging to the south". [2]
This species helps expand our knowledge of the importance of heterotrophic bacteria that live in a symbiotic relationship with other organisms. This organism is a symbiont that lives on the surface of coral reefs. [7] Halomonas meridiana was discovered living on the surface of the species Acropora , which are reef building coral. [7] Halomonas meridiana also produces proteases. [7] These metalloproteases specific to marine bacteria are important for cleavage of connective tissues as well as adhesion of detachment to mucus. [7] The alkaline proteases are important aspects of the processes involving detergents, leather, food, and silk for consumer consumption. [7]
Halomonas meridiana was an important organism used in defining the new term, haloversatile. [2] H. meridiana exhibits properties of both halotolerant and slightly halophilic bacteria, and as a result a new term, haloversatile, describes the salinity tolerance of this organism better than the traditional terms. [2] Halotolerant and halophilic bacteria, like H. meridiana can also provide valuable information about species that have been adapted to the salt lakes in cold temperatures as well as retaining the ability to live in symbiosis with other organisms. [2]
A halophile is an extremophile that thrives in high salt concentrations. In chemical terms, halophile refers to a Lewis acidic species that has some ability to extract halides from other chemical species.
Halotolerance is the adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles are organisms that live in highly saline environments, and require the salinity to survive, while halotolerant organisms can grow under saline conditions, but do not require elevated concentrations of salt for growth. Halophytes are salt-tolerant higher plants. Halotolerant microorganisms are of considerable biotechnological interest.
Psychrophiles or cryophiles are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C (−4 °F) to 20 °C (68 °F). They are found in places that are permanently cold, such as the polar regions and the deep sea. They can be contrasted with thermophiles, which are organisms that thrive at unusually high temperatures, and mesophiles at intermediate temperatures. Psychrophile is Greek for 'cold-loving', from Ancient Greek ψυχρός (psukhrós) 'cold, frozen'.
Lactobacillus acidophilus is a rod-shaped, Gram-positive, homofermentative, anaerobic microbe first isolated from infant feces in the year 1900. The species is commonly found in humans, specifically the gastrointestinal tract and oral cavity as well as some speciality fermented foods such as fermented milk or yogurt, though it is not the most common species for this. The species most readily grows at low pH levels, and has an optimum growth temperature of 37 °C. Certain strains of L. acidophilus show strong probiotic effects, and are commercially used in dairy production. The genome of L. acidophilus has been sequenced.
Halobacterium is a genus in the family Halobacteriaceae.
Oral microbiology is the study of the microorganisms (microbiota) of the oral cavity and their interactions between oral microorganisms or with the host. The environment present in the human mouth is suited to the growth of characteristic microorganisms found there. It provides a source of water and nutrients, as well as a moderate temperature. Resident microbes of the mouth adhere to the teeth and gums to resist mechanical flushing from the mouth to stomach where acid-sensitive microbes are destroyed by hydrochloric acid.
Blood Falls is an outflow of an iron(III) oxide–tainted plume of saltwater, flowing from the tongue of Taylor Glacier onto the ice-covered surface of West Lake Bonney in the Taylor Valley of the McMurdo Dry Valleys in Victoria Land, East Antarctica.
Halomonas titanicae is a gram-negative, halophilic species of bacteria which was isolated in 2010 from rusticles recovered from the wreck of the RMS Titanic. It has been estimated by Henrietta Mann, one of the researchers that first isolated it, that the action of microbes like H. titanicae may bring about the total deterioration of the Titanic by 2030. While the bacteria have been identified as a potential danger to oil rigs and other man-made objects in the deep sea, they also have the potential to be used in bioremediation to accelerate the decomposition of shipwrecks littering the ocean floor.
Soil microbiology is the study of microorganisms in soil, their functions, and how they affect soil properties. It is believed that between two and four billion years ago, the first ancient bacteria and microorganisms came about on Earth's oceans. These bacteria could fix nitrogen, in time multiplied, and as a result released oxygen into the atmosphere. This led to more advanced microorganisms, which are important because they affect soil structure and fertility. Soil microorganisms can be classified as bacteria, actinomycetes, fungi, algae and protozoa. Each of these groups has characteristics that define them and their functions in soil.
The hologenome theory of evolution recasts the individual animal or plant as a community or a "holobiont" – the host plus all of its symbiotic microbes. Consequently, the collective genomes of the holobiont form a "hologenome". Holobionts and hologenomes are structural entities that replace misnomers in the context of host-microbiota symbioses such as superorganism, organ, and metagenome. Variation in the hologenome may encode phenotypic plasticity of the holobiont and can be subject to evolutionary changes caused by selection and drift, if portions of the hologenome are transmitted between generations with reasonable fidelity. One of the important outcomes of recasting the individual as a holobiont subject to evolutionary forces is that genetic variation in the hologenome can be brought about by changes in the host genome and also by changes in the microbiome, including new acquisitions of microbes, horizontal gene transfers, and changes in microbial abundance within hosts. Although there is a rich literature on binary host–microbe symbioses, the hologenome concept distinguishes itself by including the vast symbiotic complexity inherent in many multicellular hosts.
Halomonas subglaciescola is a Gram-negative halophilic bacterium. It was first isolated from an Antarctic, hypersaline, meromictic lake, but has since been found in other environments, such as fermenting seafood. It has a largely oxidative mode of metabolism and it is motile through peritrichous flagellation. This species doesn't utilise glucose, and its type strain is ACAM 12.
Halobacterium noricense is a halophilic, rod-shaped microorganism that thrives in environments with salt levels near saturation. Despite the implication of the name, Halobacterium is actually a genus of archaea, not bacteria. H. noricense can be isolated from environments with high salinity such as the Dead Sea and the Great Salt Lake in Utah. Members of the Halobacterium genus are excellent model organisms for DNA replication and transcription due to the stability of their proteins and polymerases when exposed to high temperatures. To be classified in the genus Halobacterium, a microorganism must exhibit a membrane composition consisting of ether-linked phosphoglycerides and glycolipids.
A microbiome is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps et al. as "a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity". In 2020, an international panel of experts published the outcome of their discussions on the definition of the microbiome. They proposed a definition of the microbiome based on a revival of the "compact, clear, and comprehensive description of the term" as originally provided by Whipps et al., but supplemented with two explanatory paragraphs, the first pronouncing the dynamic character of the microbiome, and the second clearly separating the term microbiota from the term microbiome.
A holobiont is an assemblage of a host and the many other species living in or around it, which together form a discrete ecological unit through symbiosis, though there is controversy over this discreteness. The components of a holobiont are individual species or bionts, while the combined genome of all bionts is the hologenome. The holobiont concept was initially introduced by the German theoretical biologist Adolf Meyer-Abich in 1943, and then apparently independently by Dr. Lynn Margulis in her 1991 book Symbiosis as a Source of Evolutionary Innovation. The concept has evolved since the original formulations. Holobionts include the host, virome, microbiome, and any other organisms which contribute in some way to the functioning of the whole. Well-studied holobionts include reef-building corals and humans.
Endozoicomonas is a genus of Gram-negative, aerobic or facultatively anaerobic, chemoorganotrophic, rod-shaped, marine bacteria from the family of Endozoicomonadaceae. Endozoicomonas are symbionts of marine animals.
Endozoicomonas gorgoniicola is a Gram-negative and facultative anaerobic bacterium from the genus of Endozoicomonas. Individual cells are motile and rod-shaped. Bacteria in this genus are symbionts of coral. E. gorgoniicola live specifically with soft coral and were originally isolated from a species of Plexaura, an octocoral, off the coast of Bimini in the Bahamas. The presence of this bacterium in a coral microbiome is associated with coral health.
Halomonas elongata is considered the type species of the genus Halomonas. It is a chemoorganotrophic, halophilic bacterium first isolated from a solar salt facility located in Bonaire, Netherlands Antilles.
All animals on Earth form associations with microorganisms, including protists, bacteria, archaea, fungi, and viruses. In the ocean, animal–microbial relationships were historically explored in single host–symbiont systems. However, new explorations into the diversity of marine microorganisms associating with diverse marine animal hosts is moving the field into studies that address interactions between the animal host and a more multi-member microbiome. The potential for microbiomes to influence the health, physiology, behavior, and ecology of marine animals could alter current understandings of how marine animals adapt to change, and especially the growing climate-related and anthropogenic-induced changes already impacting the ocean environment.
Kimberly B. Ritchie is an American marine biologist. She is an Associate Professor in the Department of Natural Sciences at the University of South Carolina Beaufort. Her research is focused on marine microbiology and how microbes affect animal health in hosts such as corals and sharks.
Carol Ann Darlene Litchfield was an American microbiologist whose research focused on halophile organisms. Litchfield joined George Mason University's biology department in 1993, serving as a research professor between 2005 and 2010 in the Department of Environmental Science and Policy.