scholarly journals Snapshot of Cyprus Raw Goat Milk Bacterial Diversity via 16S rDNA High-Throughput Sequencing; Impact of Cold Storage Conditions

Fermentation ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 100
Author(s):  
Eleni Kamilari ◽  
Dimitrios A. Anagnostopoulos ◽  
Photis Papademas ◽  
Marina Efthymiou ◽  
Svitlana Tretiak ◽  
...  

In general, it is a common practice among dairy producers to store the milk in the refrigerator directly after milking, in order to preserve it and prevent the development of spoilage microbes. However, the impact of keeping the milk in the refrigerator overnight on milk microbial diversity has been poorly investigated. This study aimed to provide a snapshot of the bacterial composition of goat milk after direct storage at −80 °C and after being kept overnight at 4 °C and then in storage at −80 °, using high-throughput sequencing (HTS). Goat milk samples from four different farms were analyzed, to reveal that milk bacterial diversity differed between the two different storage conditions. Goat milk directly stored at −80 °C was characterized by the presence of the Gram-negative contaminants Pseudomonas and Acinetobacter, in addition to the genera Corynebacterium, Chryseobacterium, Bacteroides and Clostridium. Milk samples that were kept overnight at 4 °C were characterized by a reduction in their bacterial biodiversity and the predominance of the Gram-negative, aerobic Phyllobacterium. Overall, HTS methodologies provide an in-depth identification and characterization of the goat raw milk microbiome. Further, they offer a better understanding of the contribution of cold storage conditions to milk microbiota formation. This study may assist dairy producers in improving raw milk and raw milk cheeses quality and guaranteeing consumers’ safety.

2019 ◽  
Author(s):  
Feng Huang ◽  
Siqi Liu ◽  
Xiaokang Zhou ◽  
Pengfei Wang ◽  
Rengchun He ◽  
...  

AbstractThe aim of this study was to evaluate the microbial composition of both raw and pasteurized goat milk using high-throughput DNA sequencing. This analysis revealed that the dominant phylum found in the raw milk was Proteobacteria, and the dominant genus was Kluyvera; Proteobacteria and Kluyvera constituted up to 67.66% and 28.85% of the total bacteria population, respectively. The microorganisms in goat milk predominantly consist of Gram-negative bacteria. Notably, Akkermansia and Faecalibacterium were identified in goat milk for the first time. In addition, the results also indicate that some bacteria in pasteurized goat milk may exist in a viable but nonculturable (VBNC) state. This study provides a theoretical basis that may aid the community in better understanding bacterial diversity in goat milk. The results of this study will help us to improve the quality and safety of goat milk.ImportanceThe microbial diversity in goat milk and pasteurized goat milk at different refrigeration stages was described. Several bacterial species that have not previously been reported in goat milk were identified, including many VBNC bacteria. The findings provided the necessary microbial information for quality and safety of goat milk and dairy products.


2018 ◽  
Vol 38 (8) ◽  
pp. 1577-1583 ◽  
Author(s):  
José C. Ribeiro Júnior ◽  
Pedro I. Teider Junior ◽  
André L.M. Oliveira ◽  
Edson A. Rios ◽  
Ronaldo Tamanini ◽  
...  

ABSTRACT: Pseudomonas, the main genus of gram-negative microorganisms isolated from milk, is psychrotrophic, biofilm-forming, and thermo-resistant deteriorating enzyme producers. The aim of this study was to quantify Pseudomonas spp. in goat’s and cow’s milk produced in the Paraná state, Brazil, to evaluate the deteriorating activity of the isolates at mesophilic and psychrotrophic conditions and to identify, at the species level, the isolates with alkaline metalloprotease (aprX gene) production potential. Microbiological, biochemical and molecular methods were used for isolating, confirming and identifying of isolates. The mean counts were 1.6 (±6.3)x104 and 0.89(±3)x102 CFU/mL for goat and bovine milk samples, respectively, immediately after milking. Of the Pseudomonas colonies isolated from goat milk (n=60), 91.7% showed proteolytic potential when incubated at 35°C/48 h and 80% at 7°C/10 days, and lipolytic potential was observed in 95% of the isolates incubated in mesophilic and 78.3% at refrigeration conditions. From the isolates of bovine milk (n=20), 35% showed proteolytic activity only when incubated at 35°C/48 h, and lipolytic potential was observed in 25% of the isolates incubated at 7°C/10d and 35°C/48h. It was observed that 83.3% and 25% of the isolates genetically confirmed as Pseudomonas spp. of goat and bovine milk showed the potential for alkaline metalloprotease production, with the species P. azotoformans, P. koreensis, P. gessardii, P. monteilii and P. lurida being the most frequent in goat milk and P. aeruginosa the only species identified in cow milk.


2020 ◽  
Vol 10 (7) ◽  
pp. 2314 ◽  
Author(s):  
Pasquale Russo ◽  
Daniela Fiocco ◽  
Marzia Albenzio ◽  
Giuseppe Spano ◽  
Vittorio Capozzi

Donkey milk is receiving increasing interest due to its attractive nutrient and functional properties (but also cosmetic), which make it a suitable food for sensitive consumers, such as infants with allergies, the immunocompromised, and elderly people. Our study aims to provide further information on the microbial variability of donkey milk under cold storage conditions. Therefore, we analysed by high-throughput sequencing the bacterial communities in unpasteurized donkey milk just milked, and after three days of conservation at 4 °C, respectively. Results showed that fresh donkey milk was characterized by a high incidence of spoilage Gram-negative bacteria mainly belonging to Pseudomonas spp. A composition lower than 5% of lactic acid bacteria was found in fresh milk samples, with Lactococcus spp. being the most abundant. The occurrence of microbial species belonging to risk group 2 was found in fresh milk. After three days of cold storage, the bacterial biodiversity of donkey milk was strongly reduced, since about 93% of the bacterial communities were identified as different species of psychrotrophic Pseudomonas. In conclusion, we report a preliminary description of the microbial diversity of donkey milk by using a metagenomic approach and encouraging a correct exploitation of this high-value niche product.


2016 ◽  
Vol 83 (2) ◽  
Author(s):  
Conor J. Doyle ◽  
David Gleeson ◽  
Paul W. O'Toole ◽  
Paul D. Cotter

ABSTRACT In pasture-based systems, changes in dairy herd habitat due to seasonality results in the exposure of animals to different environmental niches. These niches contain distinct microbial communities that may be transferred to raw milk, with potentially important food quality and safety implications for milk producers. It is postulated that the extent to which these microorganisms are transferred could be limited by the inclusion of a teat preparation step prior to milking. High-throughput sequencing on a variety of microbial niches on farms was used to study the patterns of microbial movement through the dairy production chain and, in the process, to investigate the impact of seasonal housing and the inclusion/exclusion of a teat preparation regime on the raw milk microbiota from the same herd over two sampling periods, i.e., indoor and outdoor. Beta diversity and network analyses showed that environmental and milk microbiotas separated depending on whether they were sourced from an indoor or outdoor environment. Within these respective habitats, similarities between the milk microbiota and that of teat swab samples and, to a lesser extent, fecal samples were apparent. Indeed, SourceTracker identified the teat surface as the most significant source of contamination, with herd feces being the next most prevalent source of contamination. In milk from cows grazing outdoors, teat prep significantly increased the numbers of total bacteria present. In summary, sequence-based microbiota analysis identified possible sources of raw milk contamination and highlighted the influence of environment and farm management practices on the raw milk microbiota. IMPORTANCE The composition of the raw milk microbiota is an important consideration from both a spoilage perspective and a food safety perspective and has implications for milk targeted for direct consumption and for downstream processing. Factors that influence contamination have been examined previously, primarily through the use of culture-based techniques. We describe here the extensive application of high-throughput DNA sequencing technologies to study the relationship between the milk production environment and the raw milk microbiota. The results show that the environment in which the herd was kept was the primary driver of the composition of the milk microbiota composition.


2013 ◽  
Vol 5 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Yue-Jian Hu ◽  
Qian Wang ◽  
Yun-Tao Jiang ◽  
Rui Ma ◽  
Wen-Wei Xia ◽  
...  

2014 ◽  
Vol 83 (10) ◽  
pp. S3-S8 ◽  
Author(s):  
Lenka Necidová ◽  
Šárka Bursová ◽  
Alena Skočková ◽  
Bohdana Janštová ◽  
Pavla Prachařová ◽  
...  

The aim of this study was to compare Bacillus cereus growth rates and diarrhoeal enterotoxin production in raw and pasteurized goat, sheep, and cow milk in terms of storage conditions. Milk samples were inoculated with B. cereus (CCM 2010), which produces diarrhoeal enterotoxins. Enterotoxin production was tested by ELISA (Enzyme-Linked Immunosorbent Assay), and the count of B. cereus was determined by the plate method. With raw cow milk, B. cereus growth and enterotoxin production can be completely suppressed; in raw goat and sheep milk, enterotoxin was produced at 22 °C. In pasteurized cow, goat, and sheep milk, the B. cereus count increased under all storage conditions, with more rapid growth being observed at 15 °C (sheep milk) and 22 °C (cow and goat milk). Enterotoxin presence was detected at 15 °C and 22 °C, and with pasteurized cow milk also at 8 °C. Our model experiments have determined that B. cereus multiplication and subsequent enterotoxin production depend on storage temperature and milk type.


PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0146015 ◽  
Author(s):  
Silvia Gschwendtner ◽  
Tapani Alatossava ◽  
Susanne Kublik ◽  
Mirna Mrkonjić Fuka ◽  
Michael Schloter ◽  
...  

2016 ◽  
Vol 32 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Denis Kucevic ◽  
Snezana Trivunovic ◽  
Vladan Bogdanovic ◽  
Ksenija Cobanovic ◽  
Dobrila Jankovic ◽  
...  

Possible differences between composition of raw milk due to dairy farming system (organic vs conventional) as well as seasonal variations were investigated. The samples were analysed during one year. A total of 6.782 samples of raw milk were collected (4.496 from organic farming). Dairy farms were located in the northern part of Republic of Serbia (Province of Vojvodina). The principle of analysis of raw milk samples was in accordance with the methodology by midinfrared spectrometry and flow cytometry. The fixed effect of system of farming and season (winter, spring, summer and fall) have shown a high statistical significance (P < 0.01) on all examined milk parameters except fat, total solids and somatic cell count, where the impact was slightly lower (P < 0.05). Significant difference wasn't found in number of bacterial colonies (P > 0.05). Composition of milk is also affected by a number of other factors, therefore it is recommended to involve factors such as nutrition of dairy cows, breed and farm management.


2021 ◽  
Author(s):  
Dongla Gao ◽  
Weihua Wang ◽  
Zhanjiang Han ◽  
Qian Xi ◽  
Ruicheng Guo ◽  
...  

Raw milk and fermented milk are rich in microbial resources, which are essential for the formation of texture, flavor and taste. In order to gain a deeper knowledge of the bacterial and fungal community diversity in local raw milk and home-made yogurts from Sayram town, Baicheng county, Akesu area, southern of Xinjiang, China,30 raw milk and 30 home-made yogurt samples were collected and experiment of high-throughput sequencing was implemented.The results of experiments revealed the species of fungi in raw milk was the most, and the species of bacteria in fermented milk was the least.Based on principal component analysis (PCA), it was found that the bacterial and fungal community structure differed in samples from two types of dairy products.And the presence of 15 bacterial and 12 fungal phyla, comprising 218 bacterial and 495 fungal genera respectively, among all samples. Firmicutes and Ascomycota,Lactobacillus and Candida were the predominant phyla and genera of bacteria and fungi, respectively. The results indicated that the microbial community of raw milk differs from home-made yogurts due to sampling location and manufacturing process. The study suggested that high-throughput sequencing could provide a better understanding of microbiological diversity as well as lay a theoretical foundation for selecting beneficial microbial resources from this natural yogurt.


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