Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
Lett Appl Microbiol. 2013 Aug;57(2):102-7. doi: 10.1111/lam.12078. Epub 2013 May 22.
Ruminal organic acid production, especially lactic acid, can be modified by feeding cattle highly concentrated diets, which have been shown to adversely affect dairy cattle health. Therefore, the use of lactic acid-utilizing organisms is considered to be a potential method for controlling lactic acid levels. This study was conducted to isolate and identify lactic acid-utilizing yeasts from the ruminal fluid of dairy cattle and to determine the specific growth rate and generation time when using lactic acid as a carbon source instead of glucose. Seventeen yeast isolates were examined in this study. Yeasts isolated from dairy cattle that were fed a high cassava pulp diet (HCP) had higher specific growth rates and shorter generation times than yeasts isolated from dairy cattle that were fed a high-concentrate diet (HC) and a mixed diet (M). The three most effective yeasts in terms of specific growth rate and generation time were Pichia kudriavzevii, Candida rugosa and Kodamaea ohmeri, with 99, 100 and 99% nucleotide identities, respectively. These three isolates could be used as potential probiotics in dairy cattle diets.
This study demonstrates that yeasts isolated from the ruminal fluid of dairy cattle can utilize lactic acid as a carbon and energy source for growth. The isolated yeasts can be used as probiotic supplements for dairy cattle that are fed highly concentrated diets to reduce ruminal lactic acid production.
瘤胃有机酸的产生，尤其是乳酸，可以通过给牛喂食高浓度的饲料来改变，这已被证明会对奶牛的健康产生不利影响。因此，利用乳酸利用生物被认为是控制乳酸水平的一种潜在方法。本研究旨在从奶牛瘤胃液中分离和鉴定利用乳酸的酵母，并确定以乳酸代替葡萄糖作为碳源时的特定生长率和世代时间。本研究共检查了 17 株酵母分离株。从喂食高木薯浆日粮（HCP）的奶牛中分离出的酵母比从喂食高浓缩日粮（HC）和混合日粮（M）的奶牛中分离出的酵母具有更高的特定生长率和更短的世代时间。在特定生长率和世代时间方面，最有效的三种酵母是毕赤酵母、皱褶假丝酵母和奥默毕赤酵母，它们的核苷酸同一性分别为 99%、100%和 99%。这三种分离株可以用作奶牛日粮中的潜在益生菌。
本研究表明，从奶牛瘤胃液中分离出的酵母可以利用乳酸作为碳源和能源进行生长。分离出的酵母可作为奶牛的益生菌补充剂，用于喂食高浓度日粮，以减少瘤胃中乳酸的产生。
