Kluyveromyces marxianus

Genus/species (aliases): Kluyveromyces marxianus (Saccharomyces vanudenii, Kluyveromyces vanudenii)

Classification: Ascomycete;

Morphology:

  • Cell: Reproduce by budding; spheroidal, ovoid, ellipsoidal, occasionally cylindrical; Larger size, ~4-8 µm; occur singly, in pairs or small clusters or chains; pseudohyphae may be produced.
  • Colony: Malt agar: puffy, creamish-brown, flat, spreading, dull round colony.
  • Spore: smooth spores ranging from spheroidal to bean or crescent shaped; mature spores usually contain lipid globules.
  • Zygote: conjugation may immediately proceed sporulation.
  • Ascus: evanescent, one to four spores per ascus.
  • Liquid Growth: a sediment, ring and/or pellicle may be formed.
Kluyveromyces marxianus Kluyveromyces marxianus Kluyveromyces marxianus

Physiological Traits:

  • Fermentation: Glucose, Galactose, Sucrose, Raffinose; variable: Maltose, Lactose. Trehalose, Inulin.
  • Assimilation: Galactose, Sucrose, Cellobiose, Raffinose, Mannitol, Ethanol, Lactate, Succinate; variable use of: Ribose, Maltose, Melezitose, Trehalose, L-Arabinose, D-Xylose, Citrate, Salicin, Arbutin, Ribitol; No assimilation of nitrate; Uses ethylamine, cadaverine, lysine and variable use of tryptophan as sole N source; variable growth on vitamin-free medium, requires biotin and niacin.
  • Growth 37, 40, 42, and 45 oC: +
  • Growth Sensitivities: grows on 0.01 and 0.1% cycloheximide; variable growth on high glucose and 10% NaCl.
  • Chromosome bands: 4 to 18 bands reported
  • Also used commercially to produce the lactase enzyme and as a bonding agent for fodder and pet food, and as a source of ribonucleic acid in pharmaceuticals

Ecological Traits:

Found in grape juice but primarily in milk, cheese and other dairy products.

Distinguishing Features:

Able to withstand high temperatures, grows on NaCI-YM plates.

Role in wine:  

Kluyveromyces marxianus is able to ferment sugars in high temperature environments (up to 45°C) including grape juice. is also in some commercial preparations of yeast to contribute flavor complexity.

Sensitivities:

  • SO2: Yes
  • Sorbate­­­­­: Yes
  • DMDC: Yes
  • pH: Yes
  • Acids: Yes
  • Ethanol: No
  • Anaerobiosis:
  • Heat: No

References:

IMB3 yeast immobilized on delignified cellulosic material. 
Bioresouces Technology. Volume 82, Issue 2, April 2002, Pages 177-181

Tags

Yeast & Mold