School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia.
Food Chem. 2013 Dec 1;141(3):1673-80. doi: 10.1016/j.foodchem.2013.03.087. Epub 2013 Apr 13.
Previous work has shown that Oenococcus oeni produces esterases that are capable of hydrolysing artificial substrates. Using SPME-GCMS, this study provides evidence that purified O. oeni esterases have the ability to both synthesise and hydrolyse esters. Two purified esterases (EstA2 and EstB28) synthesised ethyl butanoate and ethyl hexanoate to varying degrees. Both purified esterases hydrolysed ethyl butanoate, ethyl hexanoate and ethyl octanoate. Once this dual activity was confirmed, malolactic fermentation (MLF) trials were conducted in wine with O. oeni strains that had been previously observed to have either high or low esterase activity against artificial substrates. Strain specific differences were observed and strains with low esterase hydrolysis activity against artificial substrates had a higher level of total esters measured after MLF. The results demonstrate the impact that O. oeni has on wine aroma and relates this to the ester hydrolysis and synthesis abilities of O. oeni strains.
先前的工作表明，酒香酵母能够产生酯酶，这些酯酶能够水解人工底物。本研究使用 SPME-GCMS 提供了证据，证明纯化的酒香酵母酯酶具有同时合成和水解酯的能力。两种纯化的酯酶（EstA2 和 EstB28）不同程度地合成了丁酸乙酯和己酸乙酯。两种纯化的酯酶都能水解丁酸乙酯、己酸乙酯和辛酸乙酯。在确认了这种双重活性后，用先前观察到对人工底物具有高或低酯酶活性的酒香酵母菌株进行了苹果酸-乳酸发酵（MLF）试验。观察到菌株特异性差异，并且对人工底物的酯酶水解活性低的菌株在 MLF 后测量的总酯水平更高。结果表明了酒香酵母对葡萄酒香气的影响，并将其与酒香酵母菌株的酯水解和合成能力联系起来。
