The bacterial diversity of raw Moroccon camel milk

Int J Food Microbiol. 2021 Mar 2:341:109050. doi: 10.1016/j.ijfoodmicro.2021.109050. Epub 2021 Jan 20.

Abstract

Dromedary camel milk is generally considered a valuable and marketable commodity but its production suffers from poor hygienic conditions that result in low microbiological quality and the presence of various pathogens. The objective of the present study was to provide a detailed report of the bacterial species level composition of Moroccan raw camel milk samples that can serve as a starting point for the selection of starter cultures to facilitate a change in manufacturing practices to an improved and safer production system. The composition of the bacterial community in four freshly collected raw camel milk samples was analyzed by performing a large-scale isolation campaign combined with 16S rRNA gene amplicon sequencing. A total of 806 isolates were obtained from four raw camel milk samples using ten combinations of growth media and incubation conditions. Subsequent isolate dereplication using MALDI-TOF mass spectrometry and identification of representative isolates through sequence analysis of protein encoding and 16S rRNA genes revealed the presence of established and novel dairy lactic acid bacteria, as well as bacteria that are considered indicators of poor hygienic conditions and psychrotrophic spoilage organisms. The large numbers of Lactococcus and Enterococcus isolates obtained present an interesting resource for starter culture selection.

Keywords: 16S rRNA amplicon sequencing; Lactic acid bacteria; MALDI-TOF mass spectrometry; Microbiota; Raw camel milk.

MeSH terms

  • Animals
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification*
  • Camelus / physiology*
  • Enterococcus / genetics
  • Enterococcus / isolation & purification*
  • Food Microbiology
  • Lactobacillales / genetics
  • Lactobacillales / isolation & purification
  • Milk / microbiology*
  • Morocco
  • RNA, Ribosomal, 16S / genetics
  • Raw Foods / microbiology*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • RNA, Ribosomal, 16S