Fermented beverages such as wine, cider and beer are normally fermented with Saccharomyces yeasts due to their well-known fermentative behavior. These yeasts have been extensively investigated and are used in commercial processes. On the other hand, non-Saccharomyces yeasts were always considered contaminants in winemaking and brewing. Most researchers in the past argued that these yeasts produce several compounds that may alter the sensory quality of wine and beers. However, recent studies have demonstrated that their fermentative metabolism can be regulated and addressed to the production of compounds of sensory importance. Currently, some non-Saccharomyces yeasts belonging to the genera Kloeckera, Candida, Hanseniaspora are getting importance due to their high potentiality to be used in the production of fermented beverages such as special wines and craft beers. The emergence of new consumption patterns and market niches demanding products with new sensory characteristics has catapulted the exploitation of these yeasts.

ResumenSe ha estudiado la actividad fermentativa de Hansenula anomala RIVE 7-1-5 con el objetivo de evaluar la producción de compuestos químicos de importancia sensorial. Los resultados mostraron que fermenta bien monosacáridos y también sucrosa y maltosa. Su actividad fermentativa es inhibida a concentraciones de 100,0mg/L de metabisulfito de sodio en el medio. Además, es capaz de producir 5,81±0,1 % v/v de etanol. La agitación del medio de cultivo incrementa la producción de alcoholes superiores (679,2 mg/L) y etil acetato (206,0±8,0 mg/L), por el contrario disminuye la producción de ácido acético (196,0±7,0 mg/L). La producción de glicerol fue similiar tanto en cultivo estático (sin agitación) como agitado. Durante el cultivo batch en biorreactor a condiciones aireadas la tasa de crecimiento (µ) alcanzó el valor de 0,13 h -1 y se observó la producción de ácido acético hasta 4,2±0,3 g/L. La concentración de oxígeno en el medio afecta su metabolismo, así cantidades insuficientes de oxígeno provocaría un metabolismo respirofermentativo con la producción de etanol, alcoholes superiores, ésteres y ácido acético. El control de la aireación al medio de fermentación es una herramienta útil para controlar el balance entre la actividad respiratoria y fermentativa y así la síntesis de compuestos de importancia sensorial en la producción de bebidas fermentadas no tradicionales. Palabras clave:Hansenula anomala, fermentación alcohólica, alcoholes superiores, etil acetato, cultivo por lote. AbstractThe 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.