Kurthia

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Kurthia
Systematics
Domain : Bacteria (bacteria)
Department : Firmicutes
Class : Bacilli
Order : Bacillales
Family : Planococcaceae
Genre : Kurthia
Scientific name
Kurthia
Trevisan , 1885

Kurthia is a genus of bacteria . The gram test is positive, it is one of the firmicutes . The genus is named in honor of Heinrich Kurth , a German microbiologist. The type species is Kurthia zopfii .

Appearance

The cells are rod-shaped with rounded ends. The cells often appear in chains. These chains are often arranged parallel to one another. The diameter is approximately 0.6 to 1.2 μm, the length varies between 2 and 5 μm depending on the growth time. These mostly form filaments. In older cultures (3–7 days), cocci-shaped cells can arise in some species through division of the rod-shaped cells; in stationary cultures , very short rods usually predominate. Spores are not formed. The cells are usually mobile due to a perithric flagellation , but non-mobile trunks also appear.

metabolism

Kurthia is heterotrophic . The species are strictly aerobic , meaning they rely on oxygen.

Systematics

The genus Kurthia in the family Planococcaceae is placed in the order Bacillales in the department of Firmicutes . In September 2019 the following species were known:

ecology

Some species of Kurthia are psychrophilic , for example the species Kurthia sibirica shows growth at 5–37 ° C, the optimal growth temperature is 20–25 ° C. Kurthia zopfii and Kurthia gibsonii prefer slightly warmer growing conditions of 25 to 30 ° C. Media with a neutral pH value are preferred .

Kurth isolated the type strain from the intestinal contents of chickens , which he spread on gelatine plates. They were later isolated on meat and meat products of all kinds, feces, sewage, milk and similar substrates.

According to studies of contaminated pork , about 10 percent of the bacterial flora were gram-positive, rod-shaped, non-spore-forming bacteria, which were assigned to the genus Kurthia . Species of the genus occurred in higher proportions only on meat at room temperature (16 ° C), not at cold store temperatures (2 ° C) or on frozen meat. Involvement in the spoilage of meat under aerobic conditions is assumed, but the importance of the species is considered to be minor. Despite being isolated from the feces of humans and wild and domestic animals, including some that have suffered from diarrhea , the genus is not considered to be pathogenic .

Kurthia sibirica has been described from a subfossil mammoth carcass preserved in the Siberian permafrost . Kurthia massiliensis was found in the feces of a healthy person. Kurthia huakuii was isolated from waste water from biogas production in China .

insulation

Similar to the first description, Kurthia is still isolated today mainly by smearing samples on gelatine or agar plates. The cultures are usually recognizable by a characteristic, feather-shaped growth pattern. As a rule, meat extract , yeast extract and table salt ( sodium chloride ) are added to the medium . They can be distinguished from Bacillus species with a similar growth pattern in that they are unable to dissolve the gelatine. The bacteria tolerate the administration of saline, but are not necessarily dependent on it.

Individual evidence

  1. ^ A b Paul Vos, George Garrity, Dorothy Jones, Noel R. Krieg, Wolfgang Ludwig, Fred A. Rainey, Karl-Heinz Schleifer, William B. Whitman: Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes . Springer-Verlag, New York 2009, ISBN 978-0-387-95041-9 .
  2. ^ Jean Euzéby, Aidan C. Parte: Genus Kurthia. In: List of Prokaryotic names with Standing in Nomenclature ( LPSN ). Retrieved September 2, 2019 .
  3. ^ A b c Erko Stackebrandt, Ronald M. Keddie, Dorothy Jones: The Genus Kurthia (Chapter 1.2.15) . In: Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (eds.): The Prokaryotes. A Handbook on the Biology of Bacteria, Volume 4: Bacteria: Firmicutes, Cyanobacteria . 3. Edition. Springer-Verlag, New York 2006, ISBN 0-387-25494-3 .
  4. ^ V. Roux, K. El Karkouri, JC Lagier, C. Robert, D. Raoult: Non-contiguous finished genome sequence and description of Kurthia massiliensis sp. nov. In: Standards in genomic sciences. Volume 7, Number 2, December 2012, pp. 221-232, ISSN  1944-3277 . doi : 10.4056 / sigs.3206554 . PMID 23407462 . PMC 3569394 (free full text).
  5. ↑ Z. Ruan, Y. Wang, J. Song, S. Jiang, H. Wang, Y. Li, B. Zhao, R. Jiang, B. Zhao: Kurthia huakuii sp. nov., a new member of the genus Kurthia isolated from biogas slurry in China, and emended description of the genus Kurthia. In: International journal of systematic and evolutionary microbiology. October 2013, ISSN  1466-5034 . doi : 10.1099 / ijs.0.056044-0 . PMID 24108326 .

literature

  • Paul Vos, George Garrity, Dorothy Jones, Noel R. Krieg, Wolfgang Ludwig, Fred A. Rainey, Karl-Heinz Schleifer , William B. Whitman: Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes . Springer-Verlag, New York 2009, ISBN 978-0-387-95041-9 .
  • Erko Stackebrandt, Ronald M. Keddie, Dorothy Jones: The Genus Kurthia (Chapter 1.2.15) . In: Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (eds.): The Prokaryotes. A Handbook on the Biology of Bacteria, Volume 4: Bacteria: Firmicutes, Cyanobacteria . 3. Edition. Springer-Verlag, New York 2006, ISBN 0-387-25494-3 , doi : 10.1007 / 0-387-30744-3 .