title: Characterization of the indigenous microflora in raw and pasteurized buffalo milk during storage at refrigeration temperature by high-throughput sequencing.
abstract: The effect of refrigeration on bacterial communities within raw and pasteurized buffalo milk was studied using high-throughput sequencing. High-quality samples of raw buffalo milk were obtained from 3 dairy farms in the Guangxi province in southern China. Five liters of each milk sample were pasteurized (72°C; 15 s); and both raw and pasteurized milks were stored at refrigeration temperature (1-4°C) for various times with their microbial communities characterized using the Illumina Miseq platform (Novogene, Beijing, China). Results showed that both raw and pasteurized milks contained a diverse microbial population and that the populations changed over time during storage. In raw buffalo milk, Lactococcus and Streptococcus dominated the population within the first 24h; however, when stored for up to 72h the dominant bacteria were members of the Pseudomonas and Acinetobacter genera, totaling more than 60% of the community. In pasteurized buffalo milk, the microbial population shifted from a Lactococcus-dominated community (7d), to one containing more than 84% Paenibacillus by 21d of storage. To increase the shelf-life of buffalo milk and its products, raw milk needs to be refrigerated immediately after milking and throughout transport, and should be monitored for the presence of Paenibacillus. Results from this study suggest pasteurization should be performed within 24h of raw milk collection, when the number of psychrotrophic bacteria are low; however, as Paenibacillus spores are resistant to pasteurization, additional antimicrobial treatments may be required to extend shelf-life. The findings from this study are expected to aid in improving the quality and safety of raw and pasteurized buffalo milk.
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Dairy and Functional Foods Research Unit, Eastern Regional Research Center (ERRC), Agricultural Research Service (ARS), Wyndmoor, PA 19038.
authors.forename: John A
authors.initials: JA
authors.lastname: Renye
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Feng
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China. Electronic address: zqk456@163.com.
authors.forename: Qingkun
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.affiliation: Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310029, P. R. China.
authors.forename: Daxi
authors.initials: D
authors.lastname: Ren
authors.affiliation: Buffalo Research Institute, Chinese Academy of Agricultural Science, Nanning, Guangxi 530002, P. R. China.
authors.forename: Pan
authors.initials: P
authors.lastname: Yang
mesh_terms: D000818:Animals; D002020:Buffaloes; D002681:China; D005516:Food Microbiology; D008892:Milk / Q000382:microbiology*; D012034:Refrigeration; D013696:Temperature
keywords: buffalo milk; high-throughput DNA sequencing; indigenous microflora; refrigeration storage