Molecular Biology and Microbial Biotechnology Laboratory, Life Sciences Division, Institute of Advanced Study in Science and Technology (IASST), Guwahati, Assam, India.
Department of Molecular Biology and Biotechnology, Life Sciences Division, Cotton University, Guwahati, Assam, India.
World J Microbiol Biotechnol. 2019 Jun 24;35(7):102. doi: 10.1007/s11274-019-2677-y.
Preparation of curd vary worldwide due to which its taste, texture and impact on human health also differ. In Assam, curd prepared from raw milk (RMC) is preferred over curd prepared from boiled milk (BMC), a tradition believed to have originated from the Mongoloid customs. Microbial diversity of raw milk (RM), boiled milk (BM), RMC and BMC collected from three farms were investigated by culture dependent and independent techniques. Additionally, metabolite profiles of RMC and BMC were studied by gas chromatography and mass spectroscopy. A total of 59 bacterial isolates were identified from the four different dairy products. In RM, lactic acid bacteria such as Lactococcus, Enterococcus, Lactobacillus and Leuconostoc were obtained along with the environmental bacteria like Bacillus, Staphylococcus, Acetobacter, Chryseobacterium, Streptococcus, Acinetobacter, Kocuria, Klebsiella and Macrococcus. Additionally, Prevotella, Oscillospira, Phascolarctobacterium and Akkermansia were also detected in BM by culture independent technique. In RMC and BMC, Lactococcus, Leuconostoc and Lactobacillus were prevalent. RM and RMC shared Enterococcus, Lactococcus, Streptococcus and Acinetobacter as common bacterial genera. However, no bacterial genus was common in BM and BMC. The correlation analysis revealed that Lactobacillus was negatively correlated to other bacterial genera. Oligotyping analysis revealed that Lactobacillus brevis and L.fermentum were abundant in RMC and BMC, respectively. In metabolomic study, ascorbic acid, dodecanoic acid and hexadecanoic acid were found to be significantly higher in RMC. Presence of different types of probiotics in these curds samples opens a new avenue to understand their effects on human health.
由于制备凝乳的方法在世界范围内有所不同，因此其口感、质地和对人类健康的影响也有所不同。在阿萨姆邦，人们更喜欢用生奶（RMC）而不是煮过的奶（BMC）来制作凝乳，这种传统被认为起源于蒙古习俗。本研究采用培养依赖和独立技术研究了来自三个农场的生奶（RM）、煮过的奶（BM）、RMC 和 BMC 的微生物多样性。此外，还通过气相色谱和质谱研究了 RMC 和 BMC 的代谢物谱。从四种不同的乳制品中总共鉴定出 59 株细菌分离株。在 RM 中，获得了乳酸细菌，如乳球菌、肠球菌、乳杆菌和明串珠菌，以及环境细菌，如芽孢杆菌、葡萄球菌、醋杆菌、黄杆菌、链球菌、不动杆菌、科库利亚菌、克雷伯氏菌和巨球菌。此外，通过非培养技术还在 BM 中检测到普雷沃特菌、卵形螺旋菌、粪杆菌和阿克曼氏菌。在 RMC 和 BMC 中，乳球菌、肠球菌和乳杆菌普遍存在。RM 和 RMC 共享肠球菌、乳球菌、链球菌和不动杆菌作为常见的细菌属。然而，BM 和 BMC 中没有共同的细菌属。相关性分析表明，乳杆菌与其他细菌属呈负相关。寡型分析表明，短乳杆菌和发酵乳杆菌在 RMC 和 BMC 中分别丰富。在代谢组学研究中，发现 RMC 中的抗坏血酸、十二烷酸和十六烷酸含量显著较高。这些凝乳样品中存在不同类型的益生菌为了解它们对人类健康的影响开辟了新的途径。
