Micrococcus luteus

Micrococcus luteus
Micrococcus luteus (scanning electron microscope image)
Systematics
Department : Actinobacteria Order : Actinomycetales Subordination : Micrococcineae Family : Micrococcaceae Genre : Micrococcus Type : Micrococcus luteus
Scientific name
Micrococcus luteus
( Schröter 1872) Cohn 1872 emend. Wieser et al. 2002

Micrococcus luteus is a gram-positive bacterium from the genus Micrococcus . The name of the genus is also written in Germanized micrococcus . Its cells are aerobic , so they can only multiply when oxygen is present. It ispresentin the air as a so-called “air germ”,but it is also part of the normalhuman skin flora and is not considered to be pathogenic. Itgrows as a yellow colony on nutrient media . As early as1921, Alexander Fleming examined the effect of the lysozyme he discoveredon the bacterium.

The species includes numerous phyla . The genome of the strain Micrococcus luteus NCTC 2665 was completely sequenced in 2007 , followed by further genome analyzes of other strains. The classification of the species, as well as the genus, has been updated several times since the end of the 1990s. The strains assigned to the species Micrococcus luteus in 2013 differ in an extraordinarily large number of characteristics. M. luteus is important in food microbiology when determining the germ content and as an indicator when checking antibiotics .

features

Appearance

Microscopic picture of M. luteus after Gram staining , tetrads can be seen.

The cell shape of the bacterium is round to oval, it is cocci . Their typical appearance in the light microscope image is due to a peculiarity of cell division : the cells do not separate completely after each division, but rather stick together with the cell wall. This creates packages of four connected cocci, so-called tetrads. In addition, packets of two cocci (diplococci) also occur. A single cell is about 0.5-3.5 µm in diameter . In the Gram stain , M. luteus is gram-positive, i.e. it is stained blue by the dyes used. This is caused by a thick layer of murein in the cell wall . It has no flagella for active movement, cannot form persistent forms such as endospores , and the bacterial cell wall is not surrounded by a capsule .

Colonies of M. luteus on TSA agar (contains peptone from soy ).

In pure culture , it forms sulfur-yellow to golden-yellow colonies on solid, glucose- containing nutrient media . If there is no carbohydrate but only peptone , the colonies are light yellow to cream-colored. This pigmentation - also noted in his name - is due to the presence of yellow-colored carotenoids .

Growth and metabolism

Micrococcus luteus is strictly aerobic , so it needs oxygen to grow, this serves as a distinguishing feature to members of the Staphylococcaceae family , who also metabolize glucose anaerobically in a fermentation with acid formation. The bacterium is catalase- positive and oxidase- positive. The temperatures usually used for cultivation are in the range of 25-37 ° C, the temperature optimum is 28 ° C, so the bacterium is one of the mesophilic organisms. The optimal pH value for growth is the neutral value pH 7.0, whereby alkaline pH values ​​up to pH 10.0 are also tolerated. M. luteus is relatively insensitive to drought and high salt concentrations, it still grows in nutrient media with 10% sodium chloride (table salt), while with a proportion of 15% no growth occurs.

Its aerobic metabolism is characteristic , it absorbs oxidizable substrates , which it oxidizes with the help of oxygen - this happens with the help of the respiratory chain - and uses the energy released in the process. This process is also known as breathing in bacteria . Furthermore, his metabolism can be characterized as chemoorganotrophic and heterotrophic , he uses organic compounds as an energy source and also to build up cellular substances. For example, glucose as an organic substrate is broken down by oxidation with oxygen to carbon dioxide and water:

Reaction equation

Glucose + oxygen react to form carbon dioxide + water

${\displaystyle \mathrm {C_{6}H_{12}O_{6}+6\ O_{2}\longrightarrow 6\ CO_{2}+6\ H_{2}O} }$

Carbohydrates that are metabolized in this way include D- glucose, D - mannose and sucrose . The bacterium can store glycogen - a polysaccharide made up of glucose units - as a reserve substance in the cell so that it can be broken down into glucose for energy production if necessary.

M. luteus has a number of enzymes that are used in the metabolism to break down certain substrates and the evidence of which is used for identification in the context of a " colorful series ". It has the enzyme nitrate reductase (NADH) ( EC 1.7.1.1) and can thus reduce nitrate (NO ₃ ^- ) to nitrite (NO ₂ ^- ). The enzyme urease to break down urea is not present in all strains . In addition, it has proteolytic enzymes with which it can break down proteins.

The bacterium is very sensitive to lysozyme, an antibacterial enzyme that is found in egg white, tear fluid and nasal mucus. In 1921, Alexander Fleming examined the effect of lysozyme on the bacterium and observed rapid lysis ("dissolution") of the cells in a liquid medium . The reason lies in the structure of the cell wall : In gram-positive bacteria such as M. luteus , this consists of many murein layers , the cross-linking of the glucose-like building blocks is split by lysozyme and thus the cell wall is destroyed. Already 1 µg / ml ( micrograms per milliliter ) of lysozyme is effective in M. luteus , while in the likewise gram-positive Bacillus megaterium a concentration of 50 µg / ml is necessary for the lysis. Fleming named the examined bacterium as Micrococcus lysodeikticus in 1929 , according to the current classification it is the strain Micrococcus luteus DSM 20030 (also called Micrococcus luteus Fleming NCTC 2665).

Sarcinaxanthin, a xanthophyll produced by M. luteus .

Combination of structural formula and skeletal formula

Skeletal formula

The mostly yellow color of its colonies is a typical feature and can be attributed to the presence of sarcinaxanthin, a yellow dye from the group of xanthophylls , which belong to the carotenoids . The structure of the dye is similar to zeaxanthin (yellow dye in maize). The pigmentation of "airborne germs", ie microorganisms that can be found in the air, can often be observed. The dyes act as protection against UV rays and the rays of visible light . The pigmented bacteria have an advantage in locations that are heavily exposed to light over colorless bacteria, which are killed off more quickly. The pigments in the cell membrane protect against photo-oxidation . B. the cytochromes , important proteins in the respiratory chain, are destroyed.

This antioxidant effect of sarcinaxanthin and compounds derived from it was confirmed by a study from 2010. Sarcinaxanthin is one of the C ₅₀ carotenoids, they contain 50 carbon atoms in the molecule. Such compounds are rare as natural coloring agents, most of the carotenoids isolated from natural sources are C ₄₀ carotenoids. The biosynthesis of the C ₅₀ -carotinoid sarcinaxanthin takes place from two molecules of farnesyl diphosphate (C ₂₀ ) as a precursor, and includes lycopene (C ₄₀ ), nonaflavuxanthin (C ₄₅ ), and flavuxanthin (C ₅₀ ) as intermediates.

genetics

The genome of the strain Micrococcus luteus Fleming NCTC 2665 was completely sequenced in 2007 , and in 2009 it was reported in the Journal of Bacteriology . The bacterial strain used for the study can be traced back to the bacterial strain that Alexander Fleming called Micrococcus lysodeikticus in 1929 . The genome has a size of 2501 kilobase pairs (kb), which is about half the size of the genome of Escherichia coli . 2236 proteins are annotated . In 2010 the genome of another strain - Micrococcus luteus SK58 - was sequenced and this strain was isolated from human skin. At 2623 kb, the genome size is somewhat larger than that of the strain examined first; 2489 proteins are annotated. At the end of 2012, the genome of the strain Micrococcus luteus modasa was sequenced, which was isolated from soil contaminated with hydrocarbons in the Indian city of Modasa . The variability of the M. luteus strains is currently (2019) being researched in numerous genome projects.

The results of the sequencing show a strikingly high GC content (the proportion of the nucleobases guanine and cytosine ) in the bacterial DNA , at around 73 mol percent. This proves that M. luteus is not related to Sarcina species, which are characterized by a particularly low GC content in the genome. Because of the similarity in microscopic appearance, the bacterium was previously called Sarcina lutea . Further genetic studies on M. luteus include e.g. B. the gene cluster that codes for the enzymes for sarcinaxanthin biosynthesis . This gene cluster was transferred "piece by piece" into an E. coli host, thus clarifying the individual steps of biosynthesis. In addition, the gene was also fully expressed , so that the host bacterium produced sarcinaxanthin.

A plasmid of the bacterium is also used as an object of investigation. Known as pMEC2 plasmid has a genome size of 4.2 kb on - that is, compared to the bacterial chromosome very small - and gives M. luteus a resistance against macrolide antibiotics such as erythromycin , as well as against lincomycin . The macrolide resistance is an inducible characteristic of the bacterium: Only if the nutrient medium contains extremely small amounts (about 0.02-0.05  µg / ml ) erythromycin, which are not yet sufficient to inhibit bacterial growth, does this act as an inducer and the corresponding gene product is formed, which gives M. luteus the resistance. A plasmid-bound, inducible resistance in the non- pathogenic bacteria that are part of the normal skin flora raises the question of the extent to which they are involved in the spread of antibiotic resistance .

Pathogenicity

M. luteus is normally not pathogenic, it is  assigned to risk group 1 by the Biological Agents Ordinance in conjunction with TRBA 466 . However, isolated cases have been observed in which it caused skin infections in patients with a weakened immune system (for example from infection with HIV ).

proof

An “air trap”, a Petri dish with nutrient medium , is exposed to air for a few minutes, the microorganisms multiply until visible colonies develop after a few days , many of which are pigmented .

The bacterium can be cultivated well in liquid or on solid nutrient media that contain peptone and meat extract. A selective medium is not available, but may be a selective enrichment occur when the medium has a high salt content (7.5% sodium chloride having) and aerobically at about 30 ° C incubated is. The pigmentation of the colonies is also an indication of M. luteus , as well as the typical cell aggregates in the microscopic image in the form of four connected cells (tetrads). It can be differentiated from the facultative anaerobic staphylococci, which presumably also grew on the nutrient medium, by means of an oxidation-fermentation test (OF test), since these form acid from glucose both aerobically and anaerobically, while micrococci can only metabolize glucose with oxygen. Further biochemical tests for identification include the catalase and oxidase test , as well as typical tests from a " colorful series ", which examine, among other things, the usability of various carbohydrates and other substrates. M. luteus behaves positively in nitrate reduction , negative in indole formation, positive in the Voges-Proskauer reaction and is urease- variable. A rapid determination system based on this in miniature format ( Analytical Profile Index ) for the determination of bacteria from the Staphylococcaceae family is commercially available and also includes the detection of Micrococcus species. The results for M. luteus can be viewed in the freely accessible database BacDive of the DSMZ ( German Collection of Microorganisms and Cell Cultures ).

Occurrence

House dust on a keyboard, presumably with M. luteus

Micrococcus luteus is known as a so-called "air germ" (colloquially it is also called "yellow air coccus"), as it often grows on nutrient media in Petri dishes that are used to collect air germs . It is ubiquitous, so it can be found almost everywhere, in addition to room air e.g. B. on dust particles , objects and in the upper soil layer . It is also part of the natural human skin flora. There it is mainly detectable on the rather unclothed parts of the body. It was spread via humans or the air to other habitats , such as sea and fresh water, plants, as well as meat and dairy products.

Documented, for example, the isolation of M. luteus strains from the soil, sludge from a waste water treatment plant , sea water , from a piece of coral , the human skin, medieval wall painting , indoor air , from cheese and rotten meat .

Systematics

External system

→ Main article : Micrococcus

Micrococcus luteus was described by Ferdinand Cohn in 1872 after preliminary work by Joseph Schröter . Cohn had grown the bacteria on a potato culture medium. In the same work, Cohn first developed a Darwin- based classification scheme for bacteria with generic and species names. It was not until 1955 that a reliable distinction between Micrococcus and Staphylococcus species was achieved. As a result, at the beginning of the 21st century, staphylococci and other genera were classified in the newly described family of the Staphylococcaceae , while they were previously combined with the genus Micrococcus in the family of the Micrococcaceae . At the end of the 20th century, the genus Micrococcus was re-described by Stackebrandt et al. a. - with assignment of previous Micrococcus species to other genera. Investigations at the beginning of the 21st century led to a further improved description of the genus Micrococcus , as well as the species M. luteus and M. lylae by Wieser et al. a. Micrococcus luteus is a type of the genus.

Internal system

The morphologically oriented systematics in microbiology in earlier times means that M. luteus is known by numerous synonyms . These are the names already mentioned Micrococcus lysodeikticus (Fleming's experiments with lysozyme) and Sarcina lutea (because of the microscopic appearance), but also Sarcina citrea and Sarcina flava . Schröter originally called the bacterium Bacteridium luteum in 1872 .

In 2019, phylogenetic studies by Taiwanese scientists showed that the three Microcoocus species M. aloeverae , M. yunnanensis and M. luteus are so genetically similar that they belong to one species. They therefore suggested classifying the first two species as later described heterotypic synonyms of M. luteus .

Studies from the years 1999 to 2002 show an astonishing diversity of the species Micrococcus luteus , namely with regard to chemotaxonomic characteristics and biochemical or metabolic physiological properties. To elucidate the tribal history - and the relationship between the organisms - one examines the DNA sequences and, in the case of bacteria, the 16S rRNA, a typical representative of ribosomal RNA for prokaryotes . Genetic investigations of the DNA sequences by means of DNA-DNA hybridization and the analysis of the 16S rRNA sequences indicate a close relationship of the strains investigated in M. luteus , so that they all remain or are reassigned to the species. A distinction is made between the following strains (as of 2019):

• Micrococcus luteus NCTC 2665 is the species typical strain. Synonyms for this are Micrococcus luteus NCIB  9278, Micrococcus luteus CCM  169, Micrococcus luteus ATCC 4698 (corresponds to ATCC 15307), Micrococcus luteus DSM 20030, Micrococcus luteus CN 3475, Micrococcus luteus Fleming NCTC 2665. Identical names are Micrococcus lute strain 2665 and Micrococcus luteus str. NCTC 2665. This is the "Fleming strain", the genome is sequenced (Biovar I).
• Micrococcus luteus SK58. Identical names are Micrococcus luteus strain (strain) SK58 and Micrococcus luteus str. SK58. It has been isolated from human skin and the genome has been sequenced.
• Micrococcus luteus str. modasa. It was isolated from contaminated soil in India , the genome has been sequenced.
• Micrococcus luteus MU201. It was isolated from cheese, the genome has been sequenced.
• Micrococcus luteus CD1_FAA_NB_1. This strain is being studied as part of the Human Microbiome Project (HMP). The HMP was initiated in 2008 by the US National Institutes of Health and aims to further characterize the human microbiome . Genome sequencing of this strain of M. luteus is incomplete.
• Micrococcus luteus J28. The genome is sequenced.
• Micrococcus luteus DSM 14234, synonym Micrococcus luteus CCM 4959. It was isolated from a medieval wall painting in Austria and was designated strain D7 (Biovar II) during the investigation.
• Micrococcus luteus DSM 14235, synonym Micrococcus luteus CCM 4960. He was from activated sludge from a wastewater treatment plant in Ballarat isolated (Australia) and was during the investigation as a strain called Ballarat (biovar III).

The assignment to three biovars is the result of the investigations mentioned above. There was no division into subspecies (subspecies), instead a more formal separation into biovars was made. The term “biovar” is based on the biological variability of the organisms examined.

In the case of M. luteus this concerns v. a. Chemotaxonomic characteristics, the menaquinones present in bacteria were investigated ; these quinones have an important function in the respiratory chain , similar to ubiquinones in the respiratory chain in humans. With regard to the structure of the bacterial cell wall , the polar lipids and diamino acids were examined in order to characterize the type of peptidoglycans (murein). Further research includes the breakdown of carbohydrates and other substrates . The following table gives an overview of the test results and thus of the properties of the three biovars.

features	Biovar I M. luteus NCTC 2665	Biovar II M. luteus DSM 14234	Biovar III M. luteus DSM 14235
Similarities	Degradation of D - glucose , D - mannose and sucrose ; Hydrolysis of p-nitrophenyl, α-glucopyranoside and L -alanine-p -nitroanilide; (weak) growth at 45 ° C, at pH  10.0 and with a content of 10% sodium chloride .
PH value	no growth at pH 6.0	Growth variable at pH 6.0	no growth at pH 6.0
Urease	Urease positive	Urease variable	Urease positive
Recovery of	Maltitol , L - aspartate and propionate	D - maltose , D - trehalose , acetate , propionate , DL -3-hydroxybutyrate , DL - lactate , pyruvate , L - histidine , L - phenylalanine , L - serine and phenyl acetate	D - maltose , D - trehalose , 4-aminobutyrate , fumarate , DL -3-hydroxybutyrate , DL - lactate , oxoglutarate , pyruvate , L - histidine and L - proline
Peptidoglycan type	A2	A2	A4α
Predominant menaquinone	MK-8 and MK-8 (H 2 )	MK-8 (H 2 )	MK-8 (H 2 )

Usually the bacterial strains of one species show greater similarities in phenotypic characteristics. Such clear variations within a species have not yet been observed. However, it must be remembered that an organism type is not a static unit, but changes over a long period of time. One possible interpretation of these results is that they only show a “ snapshot ” in the course of evolution.

etymology

The genus name can be traced back to the appearance of the cells ( mikros from ancient Greek means “small”, kokkos is ancient Greek for “berry”), the species name refers to the appearance of the colonies ( luteus from Latin means “golden yellow”).

meaning

An antibiogram that tests the effects of the antibiotic neomycin on various bacteria . An inhibitory effect on a bacterium is shown by the fact that it does not quite grow onto the antibiotic (middle), as is the case with M. luteus (below).

The carotenoid sarcinaxanthin produced by M. luteus offers the potential for economic use. Carotenoids act as antioxidants ("radical scavengers"), which are already marketed for this purpose as food additives or food supplements . Use as a food coloring - similar to beta-carotene - is also conceivable.

The bacterium is already important as an indicator when checking antibiotics. M. luteus is not only sensitive to lysozyme, but is also affected by several antibiotics, e.g. B. chloramphenicol , erythromycin , neomycin and streptomycin are inhibited in growth. In a so-called antibiogram it is determined whether a microorganism (usually a pathogen ) reacts sensitively to a certain antibiotic or is resistant to it; ideally, the antibiotic therapy is based on the result. Conversely, you can also investigate which microorganisms a certain antibiotic acts on by placing a plate with a defined amount of an antibiotic in the middle of the nutrient medium in a Petri dish and spreading different types of bacteria radially to it (see illustration). If the bacterium does not react sensitively to the active ingredient, it grows up to the platelet, otherwise the antibiotic that has diffused into the nutrient medium inhibits its growth. When checking an antibiotic, M. luteus is included as a positive control if it is known beforehand that it is sensitive.

An ecologically and economically interesting application of certain M. luteus strains in the future lies in their ability to bind metal ions as complexing agents . Studies show that this is possible with ores containing gold and strontium in low contents, so that the metals can be enriched with the help of the bacterium. A microbiological remediation of contaminated soils is also conceivable - through the strain M. luteus str. modasa - which is able to break down hydrocarbons and thus can potentially be used to remove petroleum residues in the soil.

From the perspective of food microbiology is M. luteus important. Since it is not pathogenic, there are no direct limit or guide values. However, its growth on food can spoil it because it feeds on the organic ingredients. The presence of bacteria consequently leads to an accumulation of metabolic products in the food and also to the loss of the ingredients. The proteolytic enzymes of M. luteus are important here, with which it can break down proteins. This leads to the spoilage of many protein-containing foods (e.g. meat products) without causing food poisoning .

In order to prevent this, hygienic measures must be applied in the production and packaging of food, and limit or guide values ​​are also specified for groups of bacteria. This is in particular the “aerobic mesophilic colony count”, including all bacteria from the food that grow with oxygen at medium temperatures (20–40 ° C) on a complex nutrient medium, ie form colonies. Since M. luteus is aerobic and mesophilic and also very widespread, it is an important representative in this group. Guideline values ​​for the aerobic mesophilic colony count are published by the German Society for Hygiene and Microbiology , for example:

• 1 • 10 ⁵ CFU ( colony-forming units ) per gram for ice cream for bulk delivery to the consumer and for instant products that are mixed cold (mousse, pudding, desserts);
• 1 • 10 ⁶ CFU per gram for delicatessen salads ; moist, packaged pasta (e.g. spaetzle ); Smoked salmon and freshwater fish ;
• 5 • 10 ⁶ CFU per gram for minced meat , raw pork and raw poultry .

swell

literature

• Michael T. Madigan, John M. Martinko, Jack Parker: Brock Microbiology. German translation edited by Werner Goebel. 1st edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2000, ISBN 3-8274-0566-1 .
• Hans G. Schlegel, Christiane Zaborosch: General microbiology . 7th edition. Thieme Verlag, Stuttgart / New York 1992, ISBN 3-13-444607-3 .
• Microorganisms in class . In: Horst Bayrhuber, Eckhard R. Lucius (ed.): Handbook of practical microbiology and biotechnology . 1st edition. tape 3 . Metzler-Schulbuchverlag, Hannover 1992, ISBN 3-8156-3351-6 , p. 63-64 .
• M. Wieser, EB Denner u. a .: Emended descriptions of the genus Micrococcus, Micrococcus luteus (Cohn 1872) and Micrococcus lylae (Kloos et al. 1974) . In: International journal of systematic and evolutionary microbiology . tape 52 , no. 2 , 2002, p. 629–637 , doi : 10.1099 / ijs.0.01901-0 ( PDF, 326kB [accessed on March 23, 2013]).

Individual evidence

1. ↑ ^{a b c d e f g} Michael T. Madigan, John M. Martinko, Jack Parker: Brock Mikrobiologie. German translation edited by Werner Goebel. 1st edition. Spektrum Akademischer Verlag GmbH, Heidelberg / Berlin 2000, ISBN 3-8274-0566-1 .
2. ↑ ^{a b c d e f g} Hans G. Schlegel, Christiane Zaborosch: General microbiology . 7th edition. Thieme Verlag, Stuttgart / New York 1992, ISBN 3-13-444607-3 .
3. ↑ ^{a b c d e f g} Taxonomy Browser Micrococcus luteus. In: National Center for Biotechnology Information (NCBI) website . Retrieved December 27, 2019 . 
4. ↑ ^{a b c} Micrococcus luteus NCTC 2665. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
5. ↑ ^{a b c d e f g h i j k l m} M. Wieser, EB Denner u. a .: Emended descriptions of the genus Micrococcus, Micrococcus luteus (Cohn 1872) and Micrococcus lylae (Kloos et al. 1974). In: International journal of systematic and evolutionary microbiology. Volume 52, Number 2, March 2002, pp. 629-637, ISSN  1466-5026 . PMID 11931177 .
6. ↑ ^{a b c d e f g} E. Stackebrandt, C. Koch, O. Gvozdiak, P. Schumann: Taxonomic dissection of the genus Micrococcus: Kocuria gen. Nov., Nesterenkonia gen. Nov., Kytococcus gen. Nov., Dermacoccus gen. nov., and Micrococcus Cohn 1872 gen. emend. In: International journal of systematic bacteriology. Volume 45, Number 4, October 1995, pp. 682-692, ISSN  0020-7713 . PMID 7547287 .
7. ↑ ^{a b} Micrococcus luteus str. modasa genome sequencing. In: BioProject website of the National Center for Biotechnology Information (NCBI). Retrieved December 27, 2019 . 
8. ↑ ^{a b c d e f g h i j k l} Microorganisms in class . In: Horst Bayrhuber, Eckhard R. Lucius (ed.): Handbook of practical microbiology and biotechnology . 1st edition. tape 3 . Metzler-Schulbuchverlag, Hannover 1992, ISBN 3-8156-3351-6 , p. 63-64 .
9. ↑ ^{a b c} Joachim M. Wink: Micrococcus luteus DSM 20030. (PDF; 150 kB) In: Compendium of Actinobacteria from Dr. Joachim M. Wink, University of Braunschweig - available from the DSMZ . Retrieved March 26, 2013 . 
10. ^ A. Fleming: Lysozyme: President's Address. In: Proceedings of the Royal Society of Medicine. Volume 26, Number 2, December 1932, pp. 71-84, ISSN  0035-9157 . PMID 19989057 . PMC 2204285 (free full text).
11. ↑ A. Fleming: Lysozyme: a bacteriolytic ferment found normally in tissues and secretions. In: The Lancet . Volume 213, number 5501, February 2, 1929, pp. 217-220, doi : 10.1016 / S0140-6736 (00) 97556-1 .
12. ↑ ^{a b c d e f} Catalog of microorganisms. In: Website of the Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH . Retrieved December 27, 2019 . 
13. ↑ ^{a b c d e} R. Netzer, MH Stafsnes u. a .: Biosynthetic pathway for γ-cyclic sarcinaxanthin in Micrococcus luteus: heterologous expression and evidence for diverse and multiple catalytic functions of C (50) carotenoid cyclases. In: Journal of bacteriology. Volume 192, Number 21, November 2010, pp. 5688-5699, ISSN  1098-5530 . doi : 10.1128 / JB.00724-10 . PMID 20802040 . PMC 2953688 (free full text).
14. ↑ ^{a b} A. Osawa, Y. Ishii et al. a .: Characterization and antioxidative activities of rare C (50) carotenoids-sarcinaxanthin, sarcinaxanthin monoglucoside, and sarcinaxanthin diglucoside-obtained from Micrococcus yunnanensis. In: Journal of Oleo Science . Volume 59, Number 12, December 2010, pp. 653-659, ISSN  1347-3352 . PMID 21099143 .
15. ↑ M. Young, V. Artsatbanov u. a .: Genome sequence of the Fleming strain of Micrococcus luteus, a simple free-living actinobacterium. In: Journal of Bacteriology . Volume 192, number 3, February 2010, online publication November 2009, pp. 841-860, doi : 10.1128 / JB.01254-09 , PMID 19948807 , PMC 2812450 (free full text).
16. ↑ ^{a b c d} Micrococcus luteus. In: National Center for Biotechnology Information (NCBI) Genome website . Retrieved December 27, 2019 . 
17. ↑ Micrococcus luteus SK58. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
18. ↑ ^{a b c} A. Ghosh, SA Chaudhary et al. a .: Whole-Genome Sequencing of Micrococcus luteus Strain Modasa, of Indian Origin. In: Genome announcements. Volume 1, Number 2, 2013 Mar-Apr, p. E0007613, ISSN  2169-8287 . doi : 10.1128 / genomeA.00076-13 . PMID 23516205 . PMC 3593314 (free full text).
19. ↑ Micrococcus luteus modasa. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
20. ^ W. Liebl, WE Kloos, W. Ludwig: Plasmid-borne macrolide resistance in Micrococcus luteus. In: Microbiology. Volume 148, Number 8, August 2002, pp. 2479-2487, ISSN  1350-0872 . PMID 12177341 .
21. ↑ TRBA (Technical Rules for Biological Agents) 466: Classification of prokaryotes (Bacteria and Archaea) into risk groups. In: Website of the Federal Institute for Occupational Safety and Health (BAuA). August 25, 2015, p. 266 , accessed on December 27, 2019 (last change on August 14, 2019). 
22. ↑ KJ Smith, R. Neafie, J. Yeager, HG Skelton: Micrococcus folliculitis in HIV-1 disease. In: The British journal of dermatology. Volume 141, Number 3, September 1999, pp. 558-561, ISSN  0007-0963 . PMID 10583069 .
23. ↑ API® ID test strips. In: website of bioMérieux Germany. Retrieved December 27, 2019 . 
24. ^ German collection of microorganisms and cell cultures (DSMZ): Micrococcus luteus, Type Strain. In: Website BacDive . Retrieved December 27, 2019 . 
25. ↑ Micrococcus luteus SK58. In: BioProject website of the National Center for Biotechnology Information (NCBI). Retrieved December 27, 2019 . 
26. ↑ ^{a b} Micrococcus luteus MU201 genome sequence. In: BioProject website of the National Center for Biotechnology Information (NCBI). Retrieved December 27, 2019 . 
27. ^ Daniel V. Lim: Microbiology . 2nd Edition. Mc Graw-Hill, Boston 1998, ISBN 0-697-26186-7 , pp. 614 f .
28. ^ ^{A b} Ferdinand Cohn: Investigations on Bacteria . In: Contributions to the biology of plants . Vol. 1, No. 2, 1872, pp. 127-234, here p. 153.
29. ^ Ferdinand Cohn: Investigations on Bacteria . In: Contributions to the biology of plants . Vol. 1, No. 2, 1872, pp. 127-234.
30. ↑ Chien-Hsun Huang, Chun-Lin Wang and a .: Reclassification of Micrococcus aloeverae and Micrococcus yunnanensis as later heterotypic synonyms of Micrococcus luteus. In: International Journal of Systematic and Evolutionary Microbiology . Volume 69, November 2019, pp. 3512-3518, doi : 10.1099 / ijsem.0.003654 .
31. ↑ Micrococcus luteus MU201. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
32. ↑ Micrococcus luteus CD1_FAA_NB_1 Human Microbiome Project (HMP) reference genome. In: BioProject website of the National Center for Biotechnology Information (NCBI). Retrieved December 27, 2019 . 
33. ↑ Micrococcus luteus CD1_FAA_NB_1. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
34. ↑ Micrococcus luteus J28. In: Website Genomes OnLine Database (GOLD). Retrieved December 27, 2019 . 
35. ↑ Micrococcus luteus NCTC 2665 - Bioremediation strain capable of sequestering metals. In: BioProject website of the National Center for Biotechnology Information (NCBI). Retrieved December 27, 2019 . 
36. ↑ Specialist group for food microbiology and hygiene, working group for microbiological guidelines and warning values ​​of the DGHM eV: Microbiological guidelines and warning values ​​for the assessment of food (as of May 2012). (No longer available online.) In: Website of the German Society for Hygiene and Microbiology (DGHM) . Archived from the original on February 11, 2013 ; Retrieved March 24, 2013 . 

Web links

Commons : Micrococcus luteus  - collection of images, videos and audio files

• Jean Euzéby, Aidan C. Part: Genus Micrococcus. In: List of Prokaryotic names with Standing in Nomenclature, Systematics of Bacteria (LPSN) . Retrieved December 27, 2019 . 
• Entry to the genus Micrococcus. In: MicrobeWiki - Curated pages are reviewed and updated by microbiologists at Kenyon College . August 6, 2010, accessed March 26, 2013 . 

This article was added to the list of excellent articles on November 2, 2013 in this version .