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•Lactic acid bacteria from artisanal dairy products of the Western Balkan were tested.•White brined, fresh and hard cheeses, yogurt, cream and kajmak were analyzed.•Over 3000 isolates ...were characterized and 28 species were identified.•Many strains had one, two or more probiotic properties.
The aim of this review was to summarize the data regarding diversity of non-starter lactic acid bacteria (NSLAB) isolated from various artisanal dairy products manufactured in Western Balkan Countries. The dairy products examined were manufactured from raw cow's, sheep's or goat's milk or mixed milk, in the traditional way without the addition of commercial starter cultures. Dairy products such as white brined cheese, fresh cheese, hard cheese, yogurt, sour cream and kajmak were sampled in the households of Serbia, Croatia, Slovenia, Bosnia and Herzegovina, Montenegro, and North Macedonia. It has been established that the diversity of lactic acid bacteria (LAB) from raw milk artisanal dairy products is extensive. In the reviewed literature, 28 LAB species and a large number of strains belonging to the Lactobacillus, Lactococcus, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Weissella genera were isolated from various dairy products. Over 3000 LAB strains were obtained and characterized for their technological and probiotic properties including: acidification and coagulation of milk, production of aromatic compounds, proteolytic activity, bacteriocins production and competitive exclusion of pathogens, production of exopolysaccharides, aggregation ability and immunomodulatory effect. Results show that many of the isolated NSLAB strains had one, two or more of the properties mentioned. The data presented emphasize the importance of artisanal products as a valuable source of NSLAB with unique technological and probiotic features important both as a base for scientific research as well as for designing novel starter cultures for functional dairy food.
The goal of this study was the characterisation of indigenous lactic acid bacteria (LAB) and yeasts isolated from nine white pickled (BG) and nine fresh soft (ZG) artisanal cheeses collected in ...Serbia and Croatia. While LAB were present in all of the cheeses collected, yeasts were found in all BG cheeses but only in three ZG cheese samples. High LAB and yeast species diversity was determined (average H′L=0.4 and H′Y=0.8, respectively). The predominant LAB species in white pickled (BG) cheeses were Lactococcus lactis, Lactobacillus plantarum, and Leuconostoc mesenteroides, while in fresh soft (ZG) cheeses the most dominant LAB species were L. lactis, Enterococcus faecalis, and Leuconostoc pseudomesenteroides. Among the 20 yeast species found, Debaryomyces hansenii, Candida zeylanoides, and Torulaspora delbrueckii were found to be predominant in BG cheeses, while Yarrowia lipolytica was predominant in ZG cheeses. The characterisation of metabolic and technological potentials revealed that 53.4% of LAB isolates produced antimicrobial compounds, 44.3% of LAB strains showed proteolytic activity, while most of the yeast species possessed either lipolytic or proteolytic activity. In conclusion, the results obtained in this study showed that the composition of LAB and yeast populations in white pickled and fresh soft cheeses is region specific. The knowledge gained in this study could eventually be used to select region specific LAB and yeast strains for the production of white pickled and fresh soft artisanal cheeses with geographically specific origins under controlled conditions.
•Indigenous microbiota of 18 artisanal cheeses from Serbia and Croatia was determined.•LAB and yeast species were identified by using traditional and molecular methods.•High diversity of LAB and yeast populations were found.•Impact on starter culture development for traditional cheeses with defined properties•Implementation in controlled production of artisanal cheeses with geographical origin
In order to preserve the traditional manufacturing of white pickled (WPC) and fresh soft cheeses (FSC), well-characterized autochthonous lactic acid bacteria (LAB) with advantageous characteristics ...were applied for the production of the cheeses at small industrial scale under the controlled conditions. Selected LAB for design of defined mixed starter cultures belonged to Lactococcus lactis ZGBP5-9, Enterococcus faecium ZGPR1-54 and Lactobacillus plantarum ZGPR2-25 for FSC production and to Lc. lactis BGAL1-4, Lactobacillus brevis BGGO7-28 and Lb. plantarum BGGO7-29 for WPC production. A sensory evaluation indicated that the cheeses obtained by inoculation with selected autochthonous LAB are similar to the traditional cheese and received the best scores. Viable cell counts of LAB used for the production of both type chesses was high, over 106 cfu g−1. High viability of the surveyed strains was supported with PCR-DGGE, which confirm the retention of selected LAB strains as starter cultures in cheese production. Next, PFGE analysis showed that each single strains, selected in particular cheese mixed culture, revealed unique SmaI PFGE pattern that could enable efficient discrimination and monitoring of the strains in industrial process. As some of the selected LAB strains are attributed as potential probiotics, produced cheeses could be considered as functional food.
•Selection of wild LAB of technological and functional potential for industrial use.•Construction of the novel mixed starter cultures for production of industrial cheeses.•Industrial produced cheeses revealed high physicochemical and sensory properties.•Physicochemical and sensory properties are similar to that of traditional cheeses.•Comparison of sensory traits between traditional and industrial produced cheeses.
The aim of this study is to gain insight into the probiotic potential of autochthonous lactic acid bacteria (LAB) isolated from artisanal fresh soft and white pickled cheeses. Eleven out of 86 LAB ...isolates from traditionally produced artisanal fresh soft and white pickled cheeses which survived the most rigorous simulated gastrointestinal tract conditions and did not show resistance to antibiotics were subjected to further evaluation for functional probiotic properties. The ability of the examined strains to assimilate cholesterol in the presence of bile salts was strain dependent, with the highest percentage of cholesterol assimilated by strain Lactobacillus brevis BGGO7-28 possessing S-layer proteins on its cell surface. The growth of strains with mannitol or lactulose as the only carbon source was better than with fructooligosaccharides and inulin as prebiotic substrates, which should be considered in the production of synbiotics. This strain was the only one with the acidic cell surface, while other examined strains have the cell surfaces with electron donor and basic properties.
Microorganisms isolated from various traditionally fermented food products prepared in households without commercial starter cultures are designated as natural isolates. In addition, this term is ...also used for microorganisms collected from various natural habitats or products (silage, soil, manure, plant and animal material, etc.) that do not contain any commercial starters or bacterial formulations. They are characterized by unique traits that are the result of the selective pressure of environmental conditions, as well as interactions with other organisms. The synthesis of antimicrobial molecules, including bacteriocins, is an evolutionary advantage and an adaptive feature that sets them apart from other microorganisms from a common environment. This review aims to underline the knowledge of bacteriocins produced by natural isolates, with a particular emphasis on the most common location of their genes and operons, plasmids, and the importance of the relationship between the plasmidome and the adaptive potential of the isolate. Applications of bacteriocins, ranging from natural food preservatives to supplements and drugs in pharmacology and medicine, will also be addressed. The latest challenges faced by researchers in isolating new natural isolates with desired characteristics will be discussed, as well as the production of new antimicrobials, nearly one century since the first discovery of colicins in 1925.
Key points
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Natural bacterial isolates harbor unique properties shaped by diverse interactions.
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Horizontal gene transfer enables constant engineering of new antimicrobials.
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Fermented food products are important source of bacteriocin-producing natural isolates.
ABSTRACT
The genetic context of the
bla
NDM-1
gene in the genome of
Pseudomonas aeruginosa
MMA83 was investigated. Sequencing of the cosmid selected for the
bla
NDM-1
gene revealed the presence of ...two
bla
NDM-1
copies in the genome of
P. aeruginosa
MMA83 in a unique genetic environment. Additionally, mating assays, DNA-DNA hybridization, and an S1 nuclease assay strongly suggest that the
bla
NDM-1
gene in
P. aeruginosa
MMA83 is chromosome borne.
Screening of 203 Bacillus sp. natural isolates for antimicrobial activity against phytopathogenic bacteria showed that 127 tested strains inhibit at least one sensitive strain, which illustrates ...their potential use as biocontrol agents. Among them, 104 isolates showed significant antagonism against Xanthomonas oryzae pv. oryzae, and only one of these (VPS50.2) synthesizes bacteriocin. An additional screening tested whether 51 isolates contained genes involved in the biosynthesis of lipopeptides of the iturin and surfactin classes. Results show that 33 isolates harbour the operon for iturin biosynthesis, and six of them carry the sfp gene, responsible for the biosynthesis of surfactin. Lipopeptide purification from the supernatant of isolate SS12.9 (identified as B subtilis or B amyloliquefaciens) was performed using ethyl acetate extraction, ultrafiltration and reversed phase HPLC. Mass spectrometry analysis confirmed that isolate SS12.9 produces a substance of the iturin class with potential for biocontrol of X oryzae pv. oryzae. Key words: Bacillus sp., Xanthomonas oryzae pv. oryzae, lipopeptides, iturin, bacteriocin
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