Adaptative Potential of the Lactococcus Lactis IL594 Strain Encoded in Its 7 Plasmids

The extrachromosomal gene pool plays a significant role both in evolution and in the environmental adaptation of bacteria. The L. lactis subsp. lactis IL594 strain contains seven plasmids, named pIL1 to pIL7, and is the parental strain of the plasmid-free L. lactis IL1403, which is one of the best characterized lactococcal strains of LAB. Complete nucleotide sequences of pIL1 (6,382 bp), pIL2 (8,277 bp), pIL3 (19,244 bp), pIL4 (48,979), pIL5 (23,395), pIL6 (28,435 bp) and pIL7 (28,546) were established and deposited in the generally accessible database (GeneBank). Nine highly homologous repB-containing replicons, belonging to the lactococcal theta-type replicons, have been identified on the seven plasmids. Moreover, a putative region involved in conjugative plasmid mobilization was found on four plasmids, through identification of the presence of mob genes and/or oriT sequences. Detailed bioinformatic analysis of the plasmid nucleotide sequences provided new insight into the repertoire of plasmid-encoded functions in L. lactis, and indicated that plasmid genes from IL594 strain can be important for L. lactis adaptation to specific environmental conditions (e.g. genes coding for proteins involved in DNA repair or cold shock response) as well as for technological processes (e.g. genes encoding citrate and lactose utilization, oligopeptide transport, restriction-modification system). Moreover, global gene analysis indicated cooperation between plasmid- and chromosome-encoded metabolic pathways

Immune-enhancing activity of potential probiotic strains of Lactobacillus plantarum in the common carp (Cyprinus carpio) fingerling

Introduction: Immune-potentiating functions of Lactobacillus plantarum strains in the common carp were evaluated

Wpływ zwiększania suchej masy w surowcu na teksturę i mikrostrukturę twarogu kwasowego

Celem badań była ocena wpływu zwiększenia zawartości suchej masy w surowcu na teksturę i mikrostrukturę twarogu kwasowego. Surowcem do produkcji twarogu było mleko pasteryzowane o zawartości 2% tłuszczu, zagęszczane metodą wyparną lub ultrafiltracji (UF) do ok. 25% suchej masy. Twaróg kontrolny produkowano z mleka niezagęszczonego. Produkcję twarogu realizowano, stosując kulturę doświadczalną IBBB3. W twarogach oznaczono zawartość suchej masy, białka ogółem, laktozy, tłuszczu oraz popiołu. W badaniach tekstury dokonano pomiarów twardości i adhezyjności twarogów. Mikrostrukturę odwodnionych liofilizacyjnie twarogów badano przy użyciu mikroskopu elektronowego skaningowego. Między twarogami z mleka niezagęszczonego, zagęszczonego wyparnie oraz koncentratu UF występowały istotne różnice w podstawowym składzie chemicznym. Twarogi z mleka niezagęszczonego oraz koncentratu UF charakteryzowały się porównywalnym udziałem białka, tłuszczu oraz laktozy w składzie suchej masy, natomiast twaróg z mleka zagęszczonego wyparnie wykazywał znacznie mniejszy udział białka i tłuszczu oraz ponad 3-krotnie większy laktozy w suchej masie w porównaniu do twarogu z mleka niezagęszczonego i koncentratu UF. Twarogi uzyskane z surowca o zwiększonej zawartości suchej masy zawierały ok. 1,7-2,0- krotnie więcej popiołu w porównaniu do produktu z mleka niezagęszczonego. Twarogi z mleka zagęszczonego wyparnie i koncentratu UF wykazywały istotnie mniejszą twardość i adhezyjność w porównaniu do twarogów z mleka niezagęszczonego. Twardość i adhezyjność twarogów zwiększała się ze wzrostem zawartości białka w ich składzie. Twarogi z mleka niezagęszczonego wykazywały porowatą mikrostrukturę o stosunkowo dużych porach, natomiast mikrostruktura twarogów uzyskanych z mleka zagęszczonego wyparnie oraz koncentratu UF była bardziej zwarta. Słowa kluczowe : mikrostruktura, tekstura, twaróg kwasowy, ultrafiltracja (UF), zagęszczanie wyparn

Kultury starterowe do produkcji twarogów kwasowych – rola i oczekiwania.

Lactic acid bacteria are industrially important microbes used all over the world in a large variety of industrial food fermentations. Cheese, cottage cheese, especially acid curd cheese, are characteristic dairy products for some Central and Eastern European countries. For production of acid curd cheese, only two components are needed: milk and lactic acid bacteria starter cultures. Starter cultures determine in large extent the technological process, the quality of the resulting quark and its shelf life. The composition of quark acid bacteria cultures is constituted in majority by Lactococcus and Leuconostoc bacteria. Selection of strains and construction of cultures with balanced species and stable composition for acid curd production is still very complex and presents a difficult challenge for producers of dairy cultures

In vitro study of Lactobacillus plantarum properties as a potential probiotic strain and an alternative method to antibiotic treatment of fish

The presence of lactic acid bacteria (LAB) favors the stabilization of intestinal flora, facilitates digestion, improves the assimilability of fodder, and has an immunomodulatory effect on the immune system. According to current research, the application of LAB following antibiotic treatment prevents the development of opportunistic bacteria inhabiting the digestive tract. In the study the potential probiotic properties of Lactobacillus plantarum strains, which can be administered as an alternative to antibiotic treatment in aquaculture, were investigated under in vitro conditions. The strains of L. plantarum were characterized for important properties such as the ability to grow in the presence of 10% fish bile, a tolerance of low pH, and antagonism to pathogens dangerous for fish such as Aeromonas salmonicida and Pseudomonas fluorescens; therefore, they meeting the criteria for strains with probiotic properties. In view of currently increasing resistance to antibiotics and a decrease of their efficiency, probiotic bacteria can serve to support immunity to infections in the future

Lactic acid bacteria as a surface display platform for Campylobacter jejuni antigens.

BACKGROUND Food poisoning and diarrheal diseases continue to pose serious health care and socioeconomic problems worldwide. Campylobacter spp. is a very widespread cause of gastroenteritis. Over the past decade there has been increasing interest in the use of lactic acid bacteria (LAB) as mucosal delivery vehicles. They represent an attractive opportunity for vaccination in addition to vaccination with attenuated bacterial pathogens. METHODS We examined the binding ability of hybrid proteins to nontreated or trichloroacetic acid (TCA)-pretreated LAB cells by immunofluorescence and Western blot analysis. RESULTS In this study we evaluated the possibility of using GEM (Gram-positive enhancer matrix) particles of Lactobacillus salivarius as a binding platform for 2 conserved, immunodominant, extracytoplasmic Campylobacter jejuni proteins: CjaA and CjaD. We analyzed the binding ability of recombinant proteins that contain C. jejuni antigens (CjaA or CjaD) fused with the protein anchor (PA) of the L. lactis peptidoglycan hydrolase AcmA, which comprises 3 LysM motifs and determines noncovalent binding to the cell wall peptidoglycan. Both fused proteins, i.e. 6HisxCjaAx3LysM and 6HisxCjaDx3LysM, were able to bind to nontreated or TCA-pretreated L. salivarius cells. CONCLUSION Our results documented that the LysM-mediated binding system allows us to construct GEM particles that present 2 C. jejuni antigens

The influence of autologous and heterologous extract of antimicrobial peptides on leukocytes isolated during titanium implant insertion in rabbit and ovine model

This study evaluated the in vitro leukocyte response to titanium implants in the presence of autologous or heterologous antimicrobial peptides extracts. Antimicrobial peptides (AMPs) appeared to be a new approach both against microorganisms and for regulation of inflammatory and repair processes. To evaluate their potential usefulness in regenerative medicine, we prepared different extracts of neutrophil-derived AMPs from rabbit, ovine or porcine blood which contained AMPs of different compositions, mainly defensins, cathelicidins and fragments thereof. Then, we assessed in vitro the influence of different AMPs extracts on the neutrophils and monocyte-derived macrophages (MDM) activity. For this purpose, these cells were obtained from experimental animals, rabbits, or sheep submitted to insertion of a titanium implant into the tibial defect. The cultured cells stimulation was autologous or heterologous, dependently on the AMPs extract origin and the experimental animal species. The neutrophil activity was assessed on the basis of the enzymes release from azurophilic and secondary granules and the free radicals generation. The MDM functional assessment was based on the NO and superoxide generation and arginase activity. Additionally, morphological changes were evaluated in the cell cultures. Our results indicated that the origin of AMPs extract is crucial for its activity. The autologous extracts stimulated anti-inflammatory responses, whereas the heterologous extracts displayed pro-inflammatory effect on neutrophils and macrophages. These results might be considered during the introduction of new preparations in regenerative medicine

Influence of synbiotics delivered in ovo on immune organs development and structure.

Prebiotics and probiotics applied alone or together (synbiotics) can influence the intestinal microbiota and modulate the immune response. We analyzed the impact of in ovo administration of synbiotics on immune system development in Ross (broiler) and Green-legged Partridgelike (GP, dual-purpose fowl) chickens. For in ovo delivery on the 12th day of the eggs incubation, two strains of lactic acid bacteria (LAB) were used, i.e. Lactococcus lactis subsp. lactis IBB SL1 (S1) and Lactococcus lactis subsp. cremoris IBB SC1 (S2), combined with raffinose family oligosaccharides (RFO) prebiotic. Other treatments included in ovo delivery of commercial synbiotic (S3), RFO prebiotics alone (P) and physiological saline (C). Immune system development was analyzed by relative weight (indices) and histology of the lymphatic organs (bursa of Fabricius, thymus and spleen) at two time points (3rd and 6th week of life). The results indicate that the development of the lymphatic organs was significantly affected by in ovo treatment. The bursa and bursa to spleen index was higher in P and S2 groups of broilers (P < 0.05) when compared to S3. In GP at the 3rd week of age, the spleen index was significantly higher in S2 (P < 0.05). The histological image of the thymus displayed an increase of thymocytes in the cortex in all synbiotic-treated groups (S1, S2, S3). In ovo delivery of synbiotics is an efficient mode of immune system stimulation in chickens but its efficiency depends on chicken genotype

Potential of Lactobacillus plantarum IBB3036 and Lactobacillus salivarius IBB3154 to persistence in chicken after in ovo delivery

The aim of this study was to characterize and compare selected Lactobacillus strains originating from different environments (cow milk and hen feces) with respect to their applicative potential to colonize gastrointestinal track of chickens before hatching from an egg. In vitro phenotypic characterization of lactobacilli strains included the investigation of the important prerequisites for persistence in gastrointestinal tract, such as a capability to survive in the presence of bile salts and at low pH, enzymatic and sugar metabolic profiles, adhesion abilities, and resistance to osmolytes, temperature, and antibiotics. Regarding the resistance of lactobacilli to most of the various stress factors tested, the milk isolate Lactobacillus plantarum IBB3036 showed better abilities than the chicken feces isolate Lactobacillus salivarius IBB3154. However, regarding the acidification tolerance and adherence ability, L. salivarius IBB3154 revealed better characteristics. Use of these two selected lactobacilli isolates together with proper prebiotics resulted in the preparation of two S1 and S2 bioformulations, which were injected in ovo into hen Cobb500 FF fertilized eggs. Furthermore, in vivo tests assessing the persistence of L. plantarum IBB3036 and L. salivarius IBB3154 in the chicken gastrointestinal tract was monitored by PCR‐based classical and quantitative techniques and revealed the presence of both strains in fecal samples collected 3 days after hatching. Subsequently, the number of L. salivarius IBB3154 increased significantly in the chicken intestine, whereas the presence of L. plantarum IBB3036 was gradually decreased