Kluyveromyces marxianus
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Kluyveromyces marxianus colonies in petri dish |
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| ( ECHansen ) Van der Walt |
Kluyveromyces marxianus is a species of yeast in the genus Kluyveromyces . K. marxianus is used commercially to produce lactase enzymes similar to that used with other fungi such as the Aspergillus genus.
features
Microscopic features
On yeast-malt agar the cells are spherical, ellipsoidal or cylindrical, measure 2-6x3-11 µm and grow individually, in pairs or in short chains. The colony grows buttery, shiny, cream-colored to brown, rarely also pink due to the production of pulcherrimine . On glucose-yeast extract medium , the species forms a ring and sometimes a thin membrane. The formation of tubes takes place either through the previous conjugation of haploid cells or offspring parent cells, or also directly from diploid cells. Sporulating cultures are homothallic . 1-4, spherical, ellipsoidal or kidney-shaped ascospores are formed in the asci , which are released soon after their formation and tend to clump together. Most strains sporulate well after 2–5 days at 17 ° to 25 ° C on 1% malt extract agar.
Physiological / biochemical characteristics
Few sugars like raffinose and other carbon sources are assimilated . Unlike other yeasts and related genera, nitrate is not used as a source of nitrogen. The coenzyme Q6 is formed. The diazonium blue B reaction is negative. Growth to 0.01% cycloheximide is possible. The species grows well at 37 ° C. It is the only Kluyveromyces species that can assimilate inulin , but not methyl- α-D- glucoside
ecology
Kluyveromyces marxianus was isolated from various foods and beverages, especially dairy products. They can also be found on rotting plant waste and insects associated with it.
Use and meaning
Due to its ability to ferment lactose, Kluyveromyces marxianus is used in the dairy industry to produce yeast proteins and ethanol , as well as ethanol from whey . The production of endo-polygalacturonase is used to eliminate the cloudiness of apple juice caused by pectin . It is also produced as a nutritional yeast and binding agent for animal feed and as a raw material for ribonucleic acid in the pharmaceutical sector. Kluyveromyces marxianus can also have negative properties for humans. So it can cause rot in the onion . It is of clinical importance as an opportunistic pathogen in immunocompromised patients.
Systematics
Kluyveromyces marxianus is the type species of the genus Kluyveromyces . The secondary crop form ( anamorphic ) was previously called Candida kefyr , but is only a synonym . The species was first scientifically described in 1888 by the Danish mycologist Emil Christian Hansen , who isolated it from wort . He named them after the zymologist Louis Marx from Marseille , who first isolated these mushrooms from grapes. In 1956 the species was transferred by Johannes P. van der Walt to the genus Kluyveromyces , which he had newly described . Another synonym is K. fragilis . The closest relative of K. marxianus is the yeast K. lactis , which is mainly used in the dairy industry. Both the genus Kluyveromyces and Saccharomyces are considered part of the " Sacchromyces complex", a subclade of the Saccharomycetes . Using 18S rRNA gene sequencing, it was assumed that K. marxianus , K. aestuarii , K. dobzhanskii , K. lactic , K. wickerhamii , K. Blattae , K. thermotolerans, and K. waltii are a common kin within the genus Kluyveromyces represent.
Individual evidence
- ↑ I. Seyis and N. Aksoz: Production of lactase by Trichoderma sp, Food Technol.. Biotechnol. 42 (2) 121-124 (2004) Free text.
- ↑ a b c d e f g Marc-André Lachance: Chapter 35: Kluyveromyces van der Walt, in: Cletus Kurtzman, JW Fell, Teun Boekhout (ed.): " The Yeasts: A Taxonomic Study, Volume 1 "; Elsevier, BV 2010: p. 478 ff .; ISBN 978-0-444-52149-1 . On-line
- ↑ a b Marc-André Lachance: Chapter 35: Kluyveromyces van der Walt, in: Cletus Kurtzman, JW Fell, Teun Boekhout (eds.): “ The Yeasts A Taxonomic Study, Volume 1 ”; Elsevier, BV 2010: p. 471 ff .; ISBN 978-0-444-52149-1 . On-line
- ↑ Archived copy ( Memento of the original from July 18, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ A b Gustavo Graciano Fonseca, Elmar Heinzle, Christoph Wittmann, Andreas K. Gombert: The yeast Kluyveromyces marxianus and its biotechnological potential . In: Applied Microbiology and Biotechnology . 79, No. 3, April 22, 2008, pp. 339-354. doi : 10.1007 / s00253-008-1458-6 . PMID 18427804 .
- ↑ NCBI: Kluyveromyces marxianus
- ↑ Melanie M. Lane, Niall Burke, Rob Karreman, Kenneth H. Wolfe, Conor P. O'Byrne, John P. Morrissey: Physiological and metabolic diversity in the yeast Kluyveromyces marxianus . In: Antonie van Leeuwenhoek . 100, No. 4, June 15, 2011, pp. 507-519. doi : 10.1007 / s10482-011-9606-x . PMID 21674230 .
- ↑ Melanie M. Lane, John P. Morrissey: Kluyveromyces marxianus: A yeast emerging from its sister's shadow . In: Fungal Biology Reviews . 24, No. 1-2, February 2010, pp. 17-26. doi : 10.1016 / j.fbr.2010.01.001 .
- ^ Saul Nitsche Rocha, José Abrahão-Neto, Andreas Karoly Gombert: Physiological diversity within the kluyveromyces marxianus species . In: Antonie van Leeuwenhoek . 100, No. 4, July 6, 2011, pp. 619-630. doi : 10.1007 / s10482-011-9617-7 . PMID 21732033 .
