The methylotrophic yeast Hansenula polymorpha (syn. Pichia angusta) is one of the most important industrially applied non-conventional yeasts [1, 2]. H.polymorpha is a ubiquitous yeast species occurring naturally in spoiled orange juice, maize meal, in the gut of various insect species and in soil. It grows as white to cream colonies and does not form filaments [3]. H.polymorpha isolates are homothallic and reproduction occurs vegetatively by budding. Methods of classic and molecular genetics are well developed for this species [4, 5]

H.polymorpha is a popular system for basic research, i.e. studying methanol metabolism, peroxisome biogenesis and degradation, biochemistry of nitrate assimilation, resistance to heavy metals and oxidative stress, as well as production of recombinant proteins that include commercially available pharmaceuticals [2, 5].

Furthermore, H.polymorpha is a thermo-tolerant microorganism with some strains growing at temperatures up to 50°C and more. The H.polymorpha strain NCYC 495 leu1.1 is capable to ferment xylose, cellobiose and glucose to ethanol at high temperatures (45° - 50° C) [6,7]. This is so far the maximal known temperature for yeast growth and eukaryotic alcoholic fermentation. Despite the ethanol yield from xylose of engineered H.polymorpha strain still is rather low, the yeast defines it as a good candidate for use in efficient process of simultaneous saccharification and fermentation.

1.Gellissen, G. (2000) Heterologous protein production in methylotrophic yeasts. Appl. Microbiol. Biotechnol. 54, 741-750.

2.Gellissen, G. (Ed.) (2002) Hansenula polymorpha - Biology and Applications. Wiley-VCH, Weinheim.

3.Barnett, J.A., Payne, R.W. and Yarrow, D. (2000) Yeasts: Characteristics and Identification, 3rd edn. Cambridge University Press, Cambridge

4.Lahtchev, K.L., Semenova, V.D., Tolstorukov, I.I., van der Klei, I., Veenhuis, M. (2002) Arch. Microbiol., 177, 150-158.

5.Krasovska, O.S., Stasyk, O.V., Nahorny, V.O., Stasyk, O.V., Granovski N., Kordium, V.A., Vozianov, O.F., Sibirny, A.A. (2007) Glucose-induced production of recombinant proteins in Hansenula polymorpha mutants deficient in catabolite repression. Biotechnol. Bioeng. 97, 858-870.

6.Ryabova, O.B., Chmil, O.M. and Sibirny, A.A. (2003) Xylose and cellobiose fermentation to ethanol by the thermotolerant methylotrophic yeast Hansenula polymorpha. FEMS Yeast Res. 4, 157?164.

7.Ishchuk, O.P., Voronovsky, A.Y., Abbas, C.A., Sibirny, A.A. (2009) Construction of Hansenula polymorpha strains with improved thermotolerance. Biotechnol. Bioeng. 104, 911-919.