Studies on the relation between the agglutination of milk fat globule and the uneven distribution of bacteria in raw bovine milk

生牛乳中脂肪球凝集与细菌分布不均关系的研究

• 批准号: 06660342
• 负责人: MASUDA Tetsuya
• 金额: $ 0.96万
• 依托单位: NIHON UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660342/
• 关键词: Bacteria agglutination; Bovine IgM; Agglutination factor of bacteria; Starter bacteria; クリーミング; 細菌擬集; 免疫グロブリン; 脂肪球皮膜

We reconfirmed the agglutination of starter bacteria in cow's milk and tried to elucidate the mechanism of this agglutination.1. Skim milk culture of each strain (Lactococcus lactis subsp. cremoris) was added to fresh raw milk at the rate of 1 %. After the milk had stood still at 4flC for 17 hours, bacterial cell numbers of upper layr (cream layr), intermediate layr and bottom layr were determined. Bacterial cell number of bottom layr was higher than that of intermediate layr in all the test 11 strains.2. After washed bacterial cells were reacted with colostrum whey, we could find the band originated in IgM in the electrophoretic pattern of the bacterial cells and confirm that only this band reacted with anti-bovine IgM.We obtained some results that IgG was also suggested to adhere to bacterial cells.3. We confirmed that the agglutination abilities of IgM differed considerably among different strains. Moreover, about 250 times difference of maximum dilution rate was recognized between bovine serum IgM and IgG in case of certain strain. Additionally, there was not any effect of the existence of either 5% ethanol or 1 M-NaCl on the agglutination ability of the IgM.4. When the PVDF membrane transcribed polypeptides of bacterial cell was reacted with colostrum, we confirmed that some bands on the membrane reacted with anti-bovine IgM.As the reactivity of the band (M.W.= about 52,000) was especially high, this polypeptide was suggested to be a receptor of IgM.5. As we have confirmed the distribution of IgM in cow's milk became uneven a few hours after standing fresh raw milk, the present results gave positive evidence that uneven distribution of starter bacteria in cow's milk was promoted by the adhesion of IgM to bacteria cell.

我们再次确认了发酵剂细菌在牛奶中的凝集作用，并试图阐明这种凝集的机理。各菌株(乳酸乳球菌亚种)的脱脂乳培养。奶油)以1%的比例添加到新鲜的生奶中。牛奶在4flC静置17h后，测定上层(奶油层)、中间层和底层的细菌数量。11个供试菌株底层细菌数均高于中间层细菌数。洗涤后的细菌细胞与初乳乳清反应后，在细菌细胞的电泳图谱中可以发现该条带起源于IgM，并证实只有该条带与抗牛Ig M反应，得到了一些结果，即Ig G也被建议与细菌细胞黏附。我们证实不同菌株之间的IgM的凝集能力有很大的差异。此外，在某些菌株中，牛血清IgM和IgG的最大稀释率相差约250倍。此外，5%乙醇或1M-氯化钠的存在对IgM的凝集能力没有任何影响。当PVDF膜转录的细菌多肽与初乳反应时，我们证实了膜上的一些条带与抗牛IgM反应，由于该条带的反应性特别高(分子量约为52,000)，因此该多肽被认为是IgM.5的受体。由于我们已经证实，新鲜生奶放置几小时后，牛奶中IgM的分布变得不均匀，这一结果提供了积极的证据，表明IgM与细菌细胞的黏附促进了牛奶中发酵剂细菌的不均匀分布。

项目成果

Masuda T.: "Participation of IgM in uneven distribution of starter bacteria in cow's milk." The 8th AAAP Animal Science Congress Proceedings. Vol.2. 1022-1023 (1996)

Masuda T.：“IgM 参与了牛奶中发酵剂细菌的不均匀分布。”

T.Masuda: "Studies on the skim milk component participating in creaming phenomenon" 24th International Dairy Congress Brief Communication. 187 (1994)

T.Masuda：“脱脂乳成分参与乳化现象的研究”第24届国际乳业大会简短通讯。

T.Masuda: "Participation of IgM in uneven distribution of starter bacteria in cow's milk" The 8th AAAP Animal Science Congress Proceedings Vol.2. 1022-1023 (1996)

T.Masuda：“牛奶中发酵剂细菌分布不均匀中 IgM 的参与”第八届 AAAP 动物科学大会论文集第 2 卷。

Masuda T.: "Studies on the skim milk component participating in creaming phenomenon." 24th International Dairy Congress Brief Communications. 187 (1994)

Masuda T.：“脱脂牛奶成分参与乳化现象的研究。”