Isolation And Identification Of Microorganisms From Kazakhstan Koumiss And Their Application To Cow Milk

Koumiss is a kind of famous fermented mare milk and is considered as an important nutritious beverage in central Asian countries.Therapeutic and other beneficial properties such as regulate alimentary canal's activity,improve kidney function and reduce the blood cholesterol levels make the koumiss a famous beverage and the health benefits of mare milk have been appreciated mainly because it can be used to produce fermented alcoholic beverages.Koumiss is fermented by the symbiosis of at least two main distinct microorganisms such as Lactic Acid Bacteria(LAB)and yeast,such combinations of microorganisms influence the unique flavor,texture and acidity level,as well as health benefits of the product.The production of koumiss from mare's milk has been known for a long time,however,so far it has not acquired an industrial scale.In the present scenario,koumiss cannot meet people's needs because of the limitation of raw mare milk production.This is because they produce it only in areas of herd horse breeding,getting mare's milk is highly seasonal,and its cost is high.Therefore,for a long time,the attention of specialists has been attracted by the issue of using cow's milk for making koumiss.At the same time,mares milk is different from the milk of other animals,it has its specific features(this is albumin milk,with a high content of milk sugar,small sizes of fat globules,and a significant content of vitamin C).All previously proposed methods of cow milk koumiss technology not properly investigated these distinctive features.They are based mainly on the use of skim milk with the addition of sugar.The chemical composition and physical properties of such koumiss in terms of protein,fat,solids,and vitamins are not identical to koumiss from mare's milk.Therefore,these products are more likely to have an existence,as nutritious,healing,diet sour-milk drinks.To solve the problem of making really koumiss from cow's milk,it is most appropriate to approach by selecting suitable technological methods,make a drink similar to natural koumiss.In this study,Kazakhstan's traditional koumiss used as material and the source of strains.All the LAB and yeast strains were isolated and identified in the study.At the same time,the fermentable ability of all the identified strains was observed by applying them to cow milk for fermentation.The best combination of LAB and yeast was selected by applying to cow milk for fermenting and through the sensory evaluating the fermented products for its sensory qualities.By using the best LAB and yeast combinations the cow milk was fermented and the fermentation conditions were optimized by applying the Response Surface Methodology(RSM).After evaluating the quality of the fermented samples,they were compared with the traditional koumiss,results suggest that cow milk fermented by these two strains possessed a promising taste,flavor,physicochemical and rheological properties.1.In the present study,53 Lactic acid bacteria strains and 21 Yeast strains from traditional homemade Kazakhstan koumiss were isolated and identified,it was found that koumiss is a good source for isolating novel bacteria with biotechnology potential.2.The results of cow milk fermentation by single LAB species showed that the majority of the strains can ferment cow milk,gives good taste and texture.Compared to other LAB species the L.delbrueckii DSM 20074 = JCM 1012 showed a high sensory evaluation score at the end of the fermentation.When the Lactobacillus delbrueckii subsp.delbrueckii DSM 20074 = JCM 1012 used for fermenting cow milk it gives good taste and fresh smell like kefir.Rest of the LAB strains had less sensory evaluation score because some of them produce too much sour and bad taste,which is not acceptable by mouth tasting or don't make any good fresh smell according to panelist's evaluation.3.The results of the best strains combination selection showed that Kluyveromyces marxianus E4 and Lactobacillus delbrueckii subsp.delbrueckii DSM 20074 = JCM 1012 had the highest sensory evaluation score,respectively.All fermented products were sensory evaluated at the end of the fermentation by well-trained panelists.Fermented products by these two strain combinations had good taste(a little bit sour),white color similar to kefir,and very attractive fresh smell.4.As observed optimization of the fermentation parameters of cow milk koumiss by the mixture of two strains showed the ratio of the starter culture 2.4:1.6(v/v)% L.delbrueckii DSM 20074 = JCM 1012 to K.marxianus E4 and at 36 °C for 16 hours,that is optimal fermentation conditions.For other fermentation parameters,the sensory evaluation score was lower than the optimal selected one.3D and normal plots of the RSM methodology picture also provide optimal fermentation data.Traditional Kazakhstan koumiss compared with optimized cow milk koumiss,the results showed that acidity,ethanol content is more in traditional koumiss than in optimized cow milk koumiss.It can be indicated that mare milk contains more lactose than cow milk.Also,sample transportation affected by ethanol and acidity,because koumiss has less storage time due to the big diversity of yeasts presented in koumiss,the acidity and ethanol content can increase fast during storage,which is why it is higher than cow milk koumiss.Additionally,selected yeast strain has less ethanol-producing ability but positively influencing the flavor compound production and combined with selected LAB strain giving a good tasted and flavored cow milk koumiss.In flavor compounds,the similarity observed for both samples but their concentration varied from each other.They were a total of 41 Volatile Organic Compounds(VOC)quantified in our study,among them 13 VOCs found to be present in both samples.Microbiological biodiversity in traditional koumiss due to spontaneous fermentation could explain the high number of potential volatiles compounds in comparison to our samples obtained after the optimized fermentation of cow milk by the koumiss starter culture.Quality of the cow milk koumiss compared with the traditional koumiss,results suggest that cow milk fermented by these two strains possessed a promising taste,flavor,physicochemical and rheological properties.Cow milk fermented with a combination of L.delbrueckii DSM 20074 = JCM 1012 and K.marxianus E4 can be considered as a good alternative product for koumiss.Therefore,all the evidence indicated that the optimized cow milk koumiss is most likely similar to traditional Kazakhstan koumiss.