The Effect Of Different Factors On Malolactic Fermentation Of Oenococcus Oeni

Malolactic fermentatio(nMLF)is an indispensable process for modern wine making. The effect of ethanol, SO₂, pH value and inoculation amount on MLF has been clearly studied, but the effect of carbon sources, organic acids and phenolic compounds on MLF of Oenococcus oeni remains unclear. So this work was focused on the study of carbon sources, organic acids and phenolic compounds on MLF of Oenococcus oeni. The results were as follows:1. After four days, the rates of malic acid degradation in simulated A culture medium inoculated with Oenococcus oeni 31MBR and simulated B culture medium inoculated with Oenococcus oeni SD-2a were 90.75% and 94.32% respectively. HPLC analysis showed that the chromatograms of A and B culture medium with Oenococcus oeni 31MBR and SD-2a inoculation respectively, were good with high resolution. So A and B culture medium were chosen for Oenococcus oeni 31MBR and SD-2a MLF for further research, respectively.2. It was easy to start fermentation and performed good deacidificaton in simulated wine culture with 1g/L glucose and 1g/L fructose inoculated with Oenococcus oeni 31MBR, with the increase of glucose and fructose, there was no difference of growth between samples and contrast, but the MLF activities was inhibited in simulated wine culture with 6g/L glucose and 1g/L fructose, when glucose and fructose were existed at the same time, two types of carbon sources were used at one time; It was easy to start fermentation and performed good deacidificaton in simulated wine culture with 1g/L glucose or 1g/L fructose inoculated with Oenococcus oeni SD-2a, with the increase of glucose and fructose, there was no difference of growth between samples and contrast, when glucose and fructose were present at the same time, fructose was preferred by Oenococcus oeni SD-2a, when the concentration of fructose was above 4g/L in simulated wine culture, fructose could be transformed into glucose by Oenococcus oeni 31MBR and SD-2a.3. L-malic acid promoted the growth and MLF activities of Oenococcus oeni 31MBR and SD-2a, but tartaric acid could inhibit the growth of Oenococcus oeni 31MBR and SD-2a when its concentration was 5.5g/L.4. P-coumaric acid inhibited the growth and MLF activities of Oenococcus oeni 31MBR when the concentration was 500mg/L, but gallic acid, coffee acid, hydroxyl benzaldehyde had no obvious influence on the growth and MLF activities of Oenococcus oeni 31MBR; P-coumaric acid and coffee acid inhibited the growth and MLF activities of Oenococcus oeni SD-2a when the concentration was 500mg/L, gallic acid and hydroxyl benzaldehyde had no obvious influence on the growth and MLF activities of Oenococcus oeni SD-2a.