Study of the fermentative activity of Hansenula anomala and production of chemical compounds of sensory importance

Abstract

The fermentative behaviour of Hansenula anomala RIVE 7-1-5 was studied in order to evaluate the production of chemical compounds of sensory importance. The results demonstrated that the strain ferments very well monosaccharides and also sucrose and maltose. Its fermentative activity was inhibited at concentrations of 100 mg/L of sodium metabisulphite in the medium. Furthermore, it was able to produce 5,81±0,1% (v/v) of ethanol. Agitation of the culture medium increases the production of higher alcohols (679,2 mg/L) and ethyl acetate (206,0±8,0 mg/L), but on the contrary affects the production of acetic acid (196,0±7,0mg/L). Glycerol production was similar in static (without agitation) and shaken cultivation. During batch cultivation carried out in biorreactor under aerated conditions the growth rate (μ) reached value of 0,13 h-1 and, it was also observed production of acetic acid at levels of 4,2±0,3 g/L. The oxygen concentration in the medium affects its metabolism, thus insufficient amounts of oxygen would provoke a respirofermentative metabolism with production of ethanol, higher alcohols, esters and acetic acid. The control of aeration during fermentation is a useful tool to control the balance between the respiratory and fermentative activity and thus; synthesis of compounds of sensory importance in the production of non-traditional fermented beverages.