Hansenula mrakii

Kido T, K Sida, K Asada (1978b) Properties of 2-nitropropane dioxygenase of Hansenula mrakii. J Biol Chem 253 226-232. 

The enzyme purified to homogeneity from Hansenula mrakii (1FO 0895) has a molecular weight of approximately 62,000 and consists of two subunits non-identical in molecular weight (39,000 and 25,000). The enzyme exhibits absorption... 

Esters also constitute a group of important flavour compounds. They are the main aroma components found in fruits (apples, pears,. ..). For example, bananas contain 12-18 ppm acetates. The price of the pure flavour compounds, when isolated from fruit, can range between 10,000 and 100,000 US /kg In the past, research has been carried out by our group about the microbial production of fruity esters by the yeast Hansenula mrakii and the fungus Geotrichum penicillatum [10]. A fermentation was developed whereby fusel oil was continuously converted into a mixture of 3-methylbutyl acetate (isoamyl acetate) and 2-methylbutyl acetate, the character impact compounds of banana flavour. 

The oxidation of 2-nitropropane by the yeast Hansenula mrakii is carried out by a flavoenzyme and produces 2 mol of acetone from 2 mol of substrate and one molecule of 02 that is activated by conversion to superoxide (Kido et al. 1978b Figure 4.50). A similar enzyme has been purified and characterized from the heterothallic ascomycete Neurospora crassa (Gorlatova et al. 1998) 2-nitropropane is the optimal substrate. 

Nitropropane is oxidized by Hansenula mrakii and the enzyme has been purified this is a flavodioxygenase that converts two molecules of the substrate to two molecules of acetone with the elimination of nitrite (Kido and Soda 1976) (Figure 6.119), and a similar enzyme has been isolated frm Neurospora crassa (Gorlatova... 

Kido, T. and K. Soda. 1976. A new oxygenase, 2-nitropropane dioxygenase of Hansenula mrakii. Enzymologic and spectrophotometric properties. ]. Biol. Chem. 251 6994-7000. 

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