Wyniki wyszukiwania - Biblioteka Nauki

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Health-promoting properties exhibited by Lactobacillus helveticus strains

100%

Skrzypczak K. , Gustaw W. , Waśko A.

Acta Biochimica Polonica

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2015

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tom 62

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nr 4

713-720

EN

Many strains belonging to lactobacilli exert a variety of beneficial health effects in humans and some of the bacteria are regarded as probiotic microorganisms. Adherence and capabilities of colonization by Lactobacillus strains of the intestinal tract is a prerequisite for probiotic strains to exhibit desired functional properties. The analysis conducted here aimed at screening strains of Lactobacillus helveticus possessing a health-promoting potential. The molecular analysis performed, revealed the presence of a slpA gene encoding the surface S-layer protein SlpA (contributing to the immunostimulatory activity of L. helveticus M 92 probiotic strain) in all B734, DSM, T80, and T105 strains. The product of gene amplification was also identified in a Bifidobacterium animalis ssp. lactis BB12 probiotic strain. SDS-PAGE of a surface protein extract demonstrated the presence of a protein with a mass of about 50 kDa in all strains, which refers to the mass of the S-layer proteins. These results are confirmed by observations carried with transmission electron microscopy, where a clearly visible S-layer was registered in all the strains analyzed. The in vitro study results obtained indicate that the strongest adhesion capacity to epithelial cells (HT-29) was demonstrated by L. helveticus B734, while coaggregation with pathogens was highly diverse among the tested strains. The percentage degree of coaggregation was increasing with the incubation time. After 5 h of incubation, the strongest ability to coaggregate with Escherichia coli was expressed by T104. The T80 strain demonstrated a significant ability to co-aggregate with Staphylococcus aureus, while DSM with Bacillus subtilis. For B734, the highest values of co-aggregation coefficient was noted in samples with Salmonella. The capability of autoaggregation, antibiotic susceptibility, resistance to increasing salt concentrations, and strain survival in simulated small intestinal juice were also analyzed.

2

Wybrane właściwości technologiczne i probiotyczne szczepów z gatunku Lactobacillus helveticus

86%

Skrzypczak K. , Gustaw W. , Wasko A.

Żywność Nauka Technologia Jakość

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2015

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tom 22

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nr 5

PL

Wciąż poszukiwane są szczepy bakterii, które wykazują pożądane cechy technologiczne i mogą wpływać na poprawę właściwości fizykochemicznych i reologicznych produktów spożywczych, a równocześnie wykazywać działanie prozdrowotne. Celem pracy było scharakteryzowanie skrzepów kwasowych uzyskanych w wyniku procesu fermentacji mleka, który prowadzono przy udziale szczepów Lactobacillus helveticus, porównanie wrażliwości analizowanych bakterii na obecność soli żółci w podłożu oraz określenie wpływu procesu fermentacji, prowadzonego przy udziale badanych drobnoustrojów, na właściwości przeciwrodnikowe wyselekcjonowanego preparatu białka serwatkowego. W badaniach wykazano, że analizowane szczepy bakterii były zróżnicowane pod względem wrażliwości na obecność soli żółci w podłożu hodowlanym. Udział tego składnika w pożywce, w ilości 0,25 %, spowodował zahamowanie dynamiki wzrostu wszystkich badanych drobnoustrojów. Najwrażliwszymi na ten czynnik były szczepy Lb. helveticus T80 oraz T15, natomiast największą odporność wykazywał szczep T105. Aktywność przeciwrodnikowa α-laktoalbuminy, kształtująca się na poziomie 15,4 %, znacząco wzrosła po procesie fermentacji. W zależności od użytego szczepu bakterii wartość ta zawierała się w zakresie 45,1 ÷ 75,3 %. W próbkach fermentowanych bakteriami z polskiej kolekcji najwyższą aktywność przeciwrodnikową wykazywał Lb. helvetius 80 (63,4%). Pod względem zdolności do tworzenia najtwardszych, jednorodnych skrzepów kwasowych największą przydatność technologiczną wykazały szczepy T104 oraz T105. Twardość skrzepów uzyskanych przy udziale tych szczepów wynosiła odpowiednio: 0,275 N i 0,316 N.

EN

There are continually sought strains of bacteria that exhibit desirable technological features and are able to help improve physical-chemical and rheological characteristics of food products, and which, at the same time, can have health-promoting effects. The objectives of the research study were: to characterize acid curds produced as a result of the milk fermentation process conducted with the participation of Lactobacillus helveticus, to compare the sensitivity of the bacteria analyzed to bile salts present in the growth medium, and to determine the effect of fermentation process run with the participation of the microbes studied on the antiradical properties of the selected milk protein preparation. Based on the analyses performed, it was shown that the bacterial strains analyzed differed in terms of their sensitivity to bile salts present in the growth medium. That component added to the culture medium in an amount of 0.25% caused the growth dynamics of all the tested microorganisms to be inhibited. The Lb. helveticus T80 and T15 strains were the most sensitive to this component; the T105 strain showed the highest resistance. The antiradical activity of α-lactalbumin at a level of 15.4% increased significantly after the fermentation process. Depending on the bacterial strain used, that level ranged between 45.1 and 75.3%. In the samples fermented with the use of bacteria from the Polish collection, the Lb. helveticus 80 strain showed the highest antiradical activity (63.4%).The T104 and T105 strains exhibited the highest technological suitability in terms of the ability to produce the hardest homogeneous acid curds. The hardness of the gels produced with the participation of those strains was 0.275 N and 0.316 N, respectively.

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Rola i znaczenie proteinaz związanych z powierzchnią komórek bakterii Lactobacillus helveticus

72%

Skrzypczak K. , Gustaw W. , Wasko A.

Postępy Mikrobiologii

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2014

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tom 53

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nr 1

4

Investigation into the susceptibility of Lactobacillus helveticus and Lactobacillus casei dairy cultures to heavy metals

72%

Kottferova J. , Korenekova B.

Bulletin of the Veterinary Institute in Puławy

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1998

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tom 42

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nr 2

EN

Standard Pb, Cd, Zn and Cu additives were investigated for their effects on the fermenting activity of Lactobacillus helveticus and Lactobacillus casei. In milk enriched with a Lb. helveticus dairy culture and containing the standard Cu additive, activation of dairy bacteria could be observed. Standard amounts of Pb and Zn did not cause changes in titration acidity when compared to the control sample. On the other hand, increased growth inhibition was observed in these bacteria after adding 0.01 and 0.05 mg.kg⁻¹ Cd. Susceptibility of bacteria to increased Cd levels became evident in inhibition of the former. Pb-induced inhibition was obvious only after the addition of the 500% of the !egal level. Moderate activation was observed in samples containing Cu. The remaining elements did not cause changes in titration acidity.

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Antagonistic effect of chosen lactic acid bacteria strains on Yersinia enterocolitica species in model set-ups, meat and fermented sausages

58%

Gomolka-Pawlicka M. , Uradzinski J.

Polish Journal of Veterinary Sciences

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2003

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tom 06

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nr 2

6

Tolerance of Lactobacillus and Bifidobacterium strains to low pH, bile salts and digestive enzymes

58%

Olejnik A. , Lewandowska M. , Obarska M. , Grajek W.

Electronic Journal of Polish Agricultural Universities. Series Food Science and Technology

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2005

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tom 08

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nr 1

EN

Probiotic strains of L. casei, L. acidophilus, L. helveticus, B. animalis, B. lactis and two strains of B. bifidum were examined for their survival at pH 3.0 and 3% bile salts. Additionally, the viability of L. casei cells was tested in presence of pepsin, trypsin, chymotrypsin, alpha-amylase and lipase, and after heating at 90ºC for 30 min. It was found that all pre-treatments caused significant decrease in bacteria survival. The most sensitive strain for stress factors was B. bifidum 1. Using Caco-2 monolayer culture as the in vitro adhesion model, the significant reduction of adherence after thermal treatment, digestion with pepsin, trypsin and chymotrypsin, and bile salts were observed. The inhibition of bacteria adhesion after thermal denaturation and proteolysis proved an hypothesis that adhesion factors are of proteinaceous origin.