Browsing tag: bakterie kwasu mlekowego


Metabolites of lactic acid bacteria – overview and industrial applications
Katarzyna Ratajczak, Agnieszka Piotrowska-Cyplik

1. Wstęp. 2. Bakterie kwasu mlekowego. 2.1. Homofermentacja. 2.2. Heterofermentacja. 3. Metabolity bakterii kwasu mlekowego. 3.1. Kwasy organiczne. 3.2. Diacetyl. 3.3. Nadtlenek wodoru. 3.4. Dwutlenek węgla. 3.5. Bakteriocyny. 3.5.1. Charakterystyka bakteriocyn. 3.5.2. Klasyfikacja bakteriocyn. 3.5.3. Problemy w zastosowaniu bakteriocyn w przemyśle spożywczym. 4. Podsumowanie

Abstract: Lactic acid bacteria are one of the most commonly found microorganisms in food. One of the reasons behind their popularity are their probiotic properties. Lactic acid bacteria produce a wide range of metabolites which often find use as antimicrobial agents or preservatives. The efficacy and efficiency of these compounds are vastly different. The most promising group of lactic acid bacteria metabolites are bacteriocins. However, there are crucial issues with the application of bacteriocins in the food industry. The goal of this study was to provide an overview of the lactic acid bacteria metabolites most commonly used in industry.

1. Introduction. 2. Lactic acid bacteria. 2.1. Homofermentation. 2.2. Heterofermentation. 3. Metabolites of lactic acid bacteria. 3.1. Organic acids. 3.2. Diacetyl. 3.3. Hydrogen peroxide. 3.4. Carbon dioxide. 3.5. Bacteriocins. 3.5.1. Characteristics of bacteriocins. 3.5.2. Classification of bacteriocins. 3.5.3. Issues with the application of bacteriocins in the food industry. 4. Conclusion


Characteristics and potential applications of circular bacteriocins
Urszula Błaszczyk, Kamila Dąbrowska

1. Charakterystyka i klasyfikacja bakteriocyn cyklicznych. 2. Genetyka bakteriocyn cyklicznych. 3. Biosynteza bakteriocyn cyklicznych. 4. Struktura bakteriocyn cyklicznych. 5. Mechanizmy działania bakteriocyn cyklicznych. 6. Enterocyna AS-48. 7. Potencjalne zastosowanie bakteriocyn cyklicznych. 8. Podsumowanie

Abstract: Bacteriocins are ribosomally synthesized peptides or proteins exerting anatagonistic activity toward organisms which are closely related to the producer strain. Circular bacteriocins are produced by Gram-positive bacteria, mainly lactic acid bacteria, and to a lesser extent by Bacillus, Clostridium and Staphylococcus genera. These bacteriocins are characterized by the head-to-tail cyclization of their backbone. The circular nature of these peptides makes them resistant to many proteolytic enzymes and provides great thermal and pH stability. Circular bacteriocins are divided into 2 subgroups based on their physicochemical properties and sequence identity. These bacteriocins are synthesized as linear precursors with a leader sequence which is cleaved off during maturation. The mature circular peptides are composed of 58–70 amino acid residues. Biosynthesis of circular bacteriocins requires three stages: cleavage of the leader sequence, circularization and export out of the cell. Circular bacteriocins have broad antimicrobial activity spectrum, including many food spoilage bacteria and pathogens, such as Listeria, Staphylococcus and Clostridum spp. Circular bacteriocins permeabilize the membrane of sensitive bacteria, causing loss of ions and dissipation of the membrane potential, and finally cell death. Enterocin AS-48 was the first identified circular bacteriocin and is best characterized so far. Circular bacteriocins or bacteriocin-producing lactic acid bacteria have great potential in food preservation, and possibly in pharmaceutical and cosmetic industries. Thanks to their properties, circular bacteriocins could be an alternative not only to preservatives and methods used to provide microbial food safety presently, but also to less stable, linear bacteriocins.

1. Characteristics and classification of circular bacteriocins. 2. Genetics of circular bacteriocins. 3. Biosynthesis of circular bacteriocins. 4. Structure of circular bacteriocins. 5. Modes of action of circular bacteriocins. 6. Enterocin AS-48. 7. Potential applications of circular bacteriocins. 8. Summary

Bakterie kwasu mlekowego (LAB) jako wektory do konstrukcji szczepionek

LAB (lactic acid bacteria) as live vectors for the development of safe mucosal vaccines
A. Wyszyńska, P. Kobierecka, E. K. Jagusztyn-Krynicka

1. Charakterystyka bakterii kwasu mlekowego o potencjalnym zastosowaniu w immunoprofilaktyce. 2. LAB jako nośniki heterologicznych antygenów bakteryjnych, pasożytniczych i wirusowych. 2.1. Porównanie drogi podania. 2.2. Rola lokalizacji i ilości antygenu. 2.3. Porównanie skuteczności działania żywych szczepów LAB i cząstek GEM (Gram-positive Enhancer Matrix). 3. LAB jako szczepionki DNA. 4. Modulacja działania układu odpornościowego. 5. LAB w immunoterapiach chorób nowotworowych. 6. Podsumowanie

Abstract: Lactic acid bacteria are a group of Gram-positive bacteria that include many species, such as Lactococcus, Lactobacillus, Leuconostoc and others. They have health benefits such as immunomodulation and production of antimicrobial substances active against gastric and intestinal pathogens and other microbes. Over the past decade, there has been increasing interest in the use of LAB as mucosal delivery vectors. They represent an attractive alternative for vaccinations employing attenuated bacterial pathogens. In this review, we focused on recent results on the use of lactic acid bacteria as delivery vehicles for heterologous antigens, cytokines, and DNA vaccines. To date, many bacterial, parasitic and viral antigens have been successfully expressed in LAB strains, mainly in L. lactis and Lb. plantarum, and their positive immunological outcomes were documented using mainly mouse model and oral, intragastric or intranasal route of immunization.

1. Characterization of lactic acid bacteria with immunoprophylactic effects. 2. LAB as delivery vehicles for bacterial, parasitic and viral antigens. 2.1. Comparison of administration routes. 2.2. Amount and localization of antigens. 2.3. Comparison of live and killed LAB vaccines – GEM (Gram-positive Enhancer Matrix) particles, 3. LAB as a DNA vaccine. 4. Modulation of immune system. 5. LAB in cancer therapy. 6. Conclusions