« Previous AbstractAcquisition of Volatile Compounds by Gas Chromatography-Mass Spectrometry (GC-MS)    Next AbstractHerbivore-Dependent Induced Volatiles in Pear Plants Cause Differential Attractive Response by Lacewing Larvae »

Antonie Van Leeuwenhoek

Title:		Fermentation of Agave tequilana juice by Kloeckera africana: influence of amino-acid supplementations
Author(s):		Valle-Rodriguez JO; Hernandez-Cortes G; Cordova J; Estarron-Espinosa M; Diaz-Montano DM;
Address:		"Area de Biotecnologia Industrial, CIATEJ Centro de Investigacion y Asistencia en Tecnologia y Diseno del Estado de Jalisco, Av. Normalistas 800, Col. Colinas de la Normal, 44270, Guadalajara, Jal, Mexico"
Journal Title:		Antonie Van Leeuwenhoek
Year:		2012
Volume:		20110715
Issue:		2
Page Number:		195 - 204
DOI:		10.1007/s10482-011-9622-x
ISSN/ISBN:		1572-9699 (Electronic) 0003-6072 (Linking)
Abstract:		"This study aimed to improve the fermentation efficiency of Kloeckera africana K1, in tequila fermentations. We investigated organic and inorganic nitrogen source requirements in continuous K. africana fermentations fed with Agave tequilana juice. The addition of a mixture of 20 amino-acids greatly improved the fermentation efficiency of this yeast, increasing the consumption of reducing sugars and production of ethanol, compared with fermentations supplemented with ammonium sulfate. The preference of K. africana for each of the 20 amino-acids was further determined in batch fermentations and we found that asparagine supplementation increased K. africana biomass production, reducing sugar consumption and ethanol production (by 30, 36.7 and 45%, respectively) over fermentations supplemented with ammonium sulfate. Therefore, asparagine appears to overcome K. africana nutritional limitation in Agave juice. Surprisingly, K. africana produced a high concentration of ethanol. This contrasts to poor ethanol productivities reported for other non-Saccharomyces yeasts indicating a relatively high ethanol tolerance for the K. africana K1 strain. Kloeckera spp. strains are known to synthesize a wide variety of volatile compounds and we have shown that amino-acid supplements influenced the synthesis by K. africana of important metabolites involved in the bouquet of tequila. The findings of this study have revealed important nutritional limitations of non-Saccharomyces yeasts fermenting Agave tequilana juice, and have highlighted the potential of K. africana in tequila production processes"
Keywords:		Agave/metabolism/*microbiology Alcoholic Beverages/analysis/*microbiology Amino Acids/*metabolism Ethanol/metabolism Fermentation Kloeckera/*metabolism;
Notes:		"MedlineValle-Rodriguez, Juan Octavio Hernandez-Cortes, Guillermo Cordova, Jesus Estarron-Espinosa, Mirna Diaz-Montano, Dulce Maria eng Research Support, Non-U.S. Gov't Netherlands 2011/07/16 Antonie Van Leeuwenhoek. 2012 Feb; 101(2):195-204. doi: 10.1007/s10482-011-9622-x. Epub 2011 Jul 15"