Influence of Environmental and Productive Factors on the Biodiversity of Lactic Acid Bacteria Population from Sheep Milk

Abstract

Milk is a typical and satisfactory medium for the growth of lactic acid bacteria (LAB). These microorganisms are of vital importance in the quality of the milk since they contribute to its preservation and give differential organoleptic properties to the final product. Furthermore, LABs can act as biocontrol agents in the dairy industry by inhibiting the growth of undesirable bacteria present in milk and by improving the quality of dairy products such as cheese. In this context, knowing the transfer routes used by LABs from the livestock environment to the milk is of great importance within the dairy industry. Therefore, the objectives of the present study were to expand the knowledge of the LAB population present in the milk of Manchego ewe by means of DNA sequencing techniques and to evaluate the possible transfers of LAB species based on the management of each dairy farm. Samples of bulk tank milk, air (from the milking parlour and from the livestock housing), animal feed and teat surface (taken from 10 sheep per farm) were collected in 12 traditional livestock farms in Castilla-La Mancha (Spain), where each farm presented differences regarding their farming practices. A mixed-effects model was used to evaluate the effects of livestock practices on the distribution of LAB species. Results showed that the vast majority of species identified in the milk had an isolate that was also found in other matrices, which could indicate a microbial transference via the livestock environment to the milk. In addition, the mixed model showed that the factors that positively influence the LAB count were the low-line milking system and the daily use of acid detergent in cleaning the milking machine.

Microbial Ecology of Artisanal Feta and Kefalograviera Cheeses, Part I: Bacterial Community and Its Functional Characteristics with Focus on Lactic Acid Bacteria as Determined by Culture-Dependent Methods and Phenotype Microarrays

“…The frequent occurrence of Lp. plantarum in raw sheep's milk has been reported by Medina et al [34], Patil et al [35] and Quintana et al [36]. In addition, the presence of W. paramesenteroides, Ln.…”

“…plantarum-group), and Lt. curvatus has also been reported [34,36]. The frequent presence of P. pentosaceus and E. faecium may be attributed to their omnipresence in the livestock environment [36], especially regarding the latter. It may also indicate a hygienically compromised milking environment [34].…”

Air Quality, Management Practices and Calf Health in Italian Dairy Cattle Farms

“…Regarding yeast, some authors [ 6 ] stated that they may be allergenic to certain individuals when present in sufficient concentrations and can affect both animal and human health. Recent studies highlighted that some farm practices can have significant effects on the type of microorganisms in the sheep barn and revealed positive correlations between the concentrations of lactic bacteria and yeast in the barn air and their concentrations in the milk [ 47 , 48 ]. These studies underline the importance of deepening our knowledge about the microbiological quality of the barn air.…”

Isolation, characterization, and probiotic profiling of amylolytic lactic acid bacteria from Sonadi sheep milk

“…Milk of various species like cow, buffalo, goat, and sheep is consumed worldwide. Sheep milk stands out for its high digestibility, nutritional richness, low allergenicity, and potential nutraceutical attributes [5,21]. Sheep milk consumption is about 1.9% of total milk produced worldwide from different sources [18].…”

“…These microorganisms, originating from breast milk, possess the advantage of direct vertical transmission, warranting further comprehensive investigation. Sheep milk contains prebiotic bers and probiotic LAB, which may be a potential source for exploring bene cial probiotic strains [5,21,28]. The Sonadi sheep breed is well-adapted to the arid and semi-arid climates of Rajasthan, India, making them resilient to hot and dry conditions.…”