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ESTERASES OF BAKER'S YEAST. II. SUBSTRATE SPECIFICITIES TOWARDS ESTERS FORMED DURING SUGAR FERMENTATIONS
Author(s) -
Parkkinen Elke,
Suomalainen Heikki
Publication year - 1982
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1982.tb04067.x
Subject(s) - yeast , isoamyl acetate , hydrolysis , esterase , chemistry , ethyl acetate , substrate (aquarium) , fermentation , chromatography , ammonium acetate , biochemistry , organic chemistry , enzyme , biology , ecology , high performance liquid chromatography
Ethyl esters of fatty acids (C 2 –C 12 ), isoamyl acetate and 2‐phenethyl acetate were studied as substrates for yeast esterases and compared with the synthetic substrates, p ‐nitrophenyl esters and β‐naphthyl esters. Intact yeast, the 55% and 55–75% ammonium sulphate precipitate of centrifuged yeast homogenate, and partly purified esterases were used for the determination of the hydrolysation activity towards the esters. The results showed that the yeast esterases prefer to hydrolyse the ethyl esters with acyl chain length of C 5 to C 12 . The acetate esters, ethyl acetate, isoamyl acetate and 2‐phenethyl acetate are only very slowly hydrolysed or remain unaffected. The substrate specificity of different esterases varies and can be used for their characterisation. Investigating pH optimum curves using intact yeast and a crude esterase preparation and different substrates confirmed the earlier result that there are esterases on both sides of the plasma membrane. The specificity of intracellular and periplasmically located esterases is, however, different.