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The Screening And Fermentation Performance Of Oenococcus Oeni From Ningxia Yinchuan Wine Product Region

Posted on:2019-06-09Degree:MasterType:Thesis
Country:ChinaCandidate:X XueFull Text:PDF
GTID:2371330569477736Subject:Fermentation engineering
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China is one of the major countries for wine consumption and production,but the malolactic fermentation?MLF?starter used in the wine industry mainly relies on imports.At present,there is no commercial wine lactic acid bacterias of our own.The screening of native lactic acid bacterias is important for developing lactic acid bacterias in China and commercial wine production and application.In this study,Oenococcus oeni was isolated and identified from wines of Ningxia Yinchuan wine product area.Strains were selected with better fermentation adaptability,higher?-D-glucosidase activity,and better antifreeze-drying characteristics.Finally,the deacidification rate of L-malic acid of MLF by the strain were tested,and the effect on the aroma of wine.The experimental results are as follows.1.Strains isolated from Ningxia Yinchuan red wines were analyzed by morphological identification,physiological and biochemical identification,and molecular biological identification.The analysis of 16S rRNA sequences,compared with the Genebank RNA data,shows the similarity of isolated strains and O.oeni NBRC 100497 was 99%,indicating that 22strains were O.oeni.2.There is a phylogenetic relationship between the strains screened in wines of different ages in the same production area.The 16S rRNA sequences of O.oeni strains isolated in 2009and 2017 from Yinchuan were compared respectively.By constructing a phylogenetic tree,a certain phylogenetic relationship between the strains was found.3.There are differences in the fermentation adaptability of different strains.The stronger the environmental stress,the worse the growth of strains.The ferementation suitability of the strains?alcohol,pH,and SO2?was studied.The results showed that the tolerance to wine environment of O.oeni 144-46,120-30,144-53,118-24,120-28,120-41 was better than other strains,even better than O.oeni NX-4b,isolated in 2009 from Yinchuan.4.Different strains have different resistance to freeze-drying.The strains with higher freeze-dried survival rates were obtained in O.oeni 120-28,144-53,118-24,144-46.5.Different strains have different?-D-glucosidase activities.The activity of?-D-glucosidase produced by strains in ATB medium and simulated grape juice medium was measured.The activity of?-D-glucosidase produced by selected strains was compared with that of Lactobacillus plantarum XJ-25,proven with higher?-D-glucosidase activity.The results showed that the activity of?-D-glucosidase produced by O.oeni 144-46 and 120-30was higher than L.plantarum XJ-25.6.O.oeni 144-46 screened in this study showed high deacidification rate of L-malic acid,good aroma-producing ability and excellent MLF performance.The GC-MS analysis of aromas produced by O.oeni 144-46 in wine displayed that the volatile aroma compounds were more abundant and with higher quality than other treatments.And fermented aromas were performed more prominently such as esters and higher alcohols,increasing the overall fragrance of the wine with fruit and flower odor characteristics.Over all,O.oeni 144-46 had the feasibility of commercial production applications.
Keywords/Search Tags:Oenococcus oeni, Malolactic fermentation, Wine, Glucosidase, Fermentation performance
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