All posts by Postępy Mikrobiologii

Kultury starterowe w piekarstwie – możliwość odzwierciedlenia tradycyjnego procesu fermentacji poprzez kształtowanie mikrobiota zakwasów piekarskich w przemysłowej produkcji pieczywa

Starter cultures for baked goods – the traditional fermentation process by formation of sourdough microbiota in the industrial bread production
K. Piasecka-Jóźwiak, B. Chabłowska, I. Stefańska
1 July 2017

1. Wstęp. 2. Bioróżnorodność mikrobiologiczna zakwasów. 3. Zdolność do rozwoju i adaptacji LAB w różnych typach zakwasów. Współzawodnictwo bakterii wprowadzonych z kulturą starterową z autochtoniczną mikrobiota zakwasów. 4. Niektóre właściwości LAB umożliwiające im konkurencyjną przewagę w ciastach zakwasowych. 5. Mikrobiota zakwasów ze zbóż niechlebowych i pseudozbóż. 6. Dobieranie składu kultur starterowych z autochtonicznych gatunków LAB czy unifikacja w oparciu o gatunki najbardziej rozpowszechnione. 7. Podsumowanie

Abstract: Application of sourdough, an old fermentation technology, in artisanal bakery allows us to obtain bread with specific flavor and texture. In recent years, this technology has been also reintroduced to the industrial practice, especially due to increased consumer demand for natural bread, without technological additives and preservatives, characterized by traditionally aroma and taste. In order to ensure reproducible and constant quality of bread, specific starter cultures containing lactic acid bacteria (LAB) or, optionally, LAB and yeast strains, are used. The paper discusses issues related to the biodiversity of LAB species representing biota of natural sourdoughs obtained from different cereals. It also presents the specific properties of the LAB strains which allow them to colonize and dominate in the souerdough environment. Moreover, is this review we focuse on the role of autochthonous bacterial strains in starter cultures. The use of such strains results in better quality of bread, its originalsensory properties and allows the industry to avoid the standardization of taste and smell of baked goods.

1. Introduction. 2. Microbial biodiversity of sourdough. 3. The ability of LAB to grow and adapt to different types of sourdough. Competition of bacteria introduced with the starter culture with the autochthonous microbiota of sourdough. 4. Selected properties of LAB giving them a competitive advantage in sourdough 5. Microbiota of sourdough non-bread cereals and pseudo-cereals. 6. Selection of LAB autochthonous species for the starter cultures (composition) versus the unification based on the most prevalent species. 7. Summary

Autor: Postępy Mikrobiologii
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Mikrobiom układu oddechowego w warunkach fizjologicznych i patologicznych

The respiratory tract microbiota in physiological and pathological conditions
M. Malinowska, B. Tokarz-Deptuła, W. Deptuła
1 July 2017

1. Wprowadzenie. 2. Charakterystyka mikrobiomu dróg oddechowych w warunkach fizjologicznych. 3. Mikrobiom dróg oddechowych w warunkach patologicznych. 4. Podsumowanie

Abstract: The human body is inhabited by millions of microorganisms, residing on and in the skin, in the gastrointestinal tract, on the mucous membranes of the upper respiratory tract and in the vagina. Lower respiratory tract has considered to be free of bacteria, but the current research on microorganisms, using 16S rRNA gene sequencing, led to the identification of the microbiome of this unique environment. It has been demonstrated that the bacterial flora of the lower respiratory tract is significantly different from that of the upper respiratory tract. Moreover, a difference in the microbiome of the lower respiratory tract of healthy individuals and patients suffering from chronic diseases such as asthma and chronic obstructive pulmonary disease (COPD), has been shown.

1. Introduction. 2. Characteristics of the respiratory tracts microbiota in physiological conditions. 3. Respiratory tract microbiota in pathological conditions. 4. Summary

Autor: Postępy Mikrobiologii
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Granule RNA – nowe elementy odporności regulujące homeostazę organizmu

Granule RNA – nowe elementy odporności regulujące homeostazę organizmu
P. Niedźwiedzka-Rystwej, B. Tokarz-Deptuła, W. Deptuła
1 July 2017

1. Wprowadzenie. 2. Granule stresu (SG – stress granules). 3. Ciałka degradujące (PB – processing bodies). 4. Granule egzosomalne (EG – exosome granules). 5. Granule powodowane promieniowaniem UV (UVG – UV granules). 6. Granule EGP (glucose depletion granules). 7. Podsumowanie

Abstract: One of the mechanisms of mRNA protection in dangerous conditions, such as stress or viral infections, is the formation of RNA granules. This mechanism depends on mRNA gathering within a granule, until the cell conditions are again stabile enoughto fulfill its functions. So far a number of RNA granule types have been described: stress granules (SG), processing bodies (PB), exosome granules, granules caused by UV, and glucose depletion P-bodies. Those elements are not only an extremely important factor influencing cell homeostasis, but also a new element of immunity.

1. Introduction. 2. Stress granules (SG). 3. Processing bodies (PB). 4. Exosome granules (EG). 5. UV granules (UVG). 6. Granule EGP (glucose depletion granules). 7. Summary

Autor: Postępy Mikrobiologii
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Symbioza rizobiów z roślinami bobowatymi (Fabaceae)

Symbiosis of rhizobia with legume plants (Fabaceae)
G. Stasiak, A. Mazur, P. Koper, K. Żebracki, A. Skorupska
1 July 2017

1. Znaczenie biologicznego wiązania azotu (BNF). 2. Partnerzy symbiozy. 3. Etapy symbiozy. 3.1. Inicjacja symbiozy. 3.2. Rozwój brodawki. 3.3. Typy brodawek korzeniowych. 4. Wiązanie azotu. 5. Genomy rizobiów. 6. Chromidy i megaplazmidy. 7. Plastyczność genomów rizobiów. 8. Podsumowanie

Abstract: Biological nitrogen fixation is one of the most important processes in which atmospheric nitrogen is reduced to ammonia by symbiotic bacteria called rhizobia, which belong to α- and β-proteobacteria. Legume plants (Fabaceae) have the capacity to enter into mutualistic symbiosis with nitrogen-fixing bacteria, enabling them to grow in nitrogen-limited agricultural soils. In these specific associations, new organs called root or shoot nodules are developed. Infection of plants by rhizobia is a series of sequential stages in which rhizobial lipochitooligosaccharide, called the Nod factor, activates plant transmission signaling and initiates nodule development. In the nodules the bacteria multiply and differentiate into nitrogen-fixing bacteroids. In return for reduced nitrogen compounds provided to the plants, rhizobia are supplied with plant carbon photosynthetic products and are protected from environmental stresses.
Genomes of rhizobia and other soil bacteria are large and multipartite, composed of the chromosome and plasmids (megaplasmids), which may comprise up to 50% of the genome. A common feature of the rhizobial genomes is that genes responsible for nodulation and nitrogen fixation are clustered on symbiotic plasmids (pSym) or incorporated into the chromosome as symbiotic islands. Plasmids are heterogeneous in size and gene content even in closely related rhizobia. Recently described extrachromosomal replicons, named “chromids”, have some chromosome and plasmid properties and are essential for bacterial growth under natural and laboratory conditions. The special architecture of rhizobial genomes may cause their dynamic state and plasticity, leading to significant diversity of rhizobia on the genetic and metabolic levels.

1. The importance of biological nitrogen fixation (BNF). 2. Symbiosis partners. 3. Symbiosis stages. 3.1. Initiation of symbiosis. 3.2. Nodule development. 3.3. Types of nodules. 4. Nitrogen fixation. 5. Rhizobial genomes. 6. Chromids and megaplasmids. 7. Plasticity of rhizobial genomes. 8. Summary

Autor: Postępy Mikrobiologii
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Związki interferujące z bakteryjnymi systemami wyczuwania liczebności i ich potencjalna funkcja terapeutyczna

Inhibitors of bacterial quorum sensing systems and their role as potential therapeutics
K. I. Wolska, A. M. Grudniak, K. Markowska
1 July 2017

1. Wprowadzenie. 2. Wyczuwanie liczebności jako sposób komunikowania się bakterii. 3. Organiczne inhibitory QS. 3.1. Inhibitory roślinne. 3.2. Inhibitory pochodzenia zwierzęcego. 3.3. Inhibitory produkowane przez bakterie. 4. Hamowanie QS przez nanocząstki. 5. Uwagi końcowe

Abstact: Quorum sensing (QS) is a commonly used way of cell-to-cell communication which plays a role in the regulation of gene expression and, therefore, controls bacterial social behavior and pathogenicity. The inhibition of QS, called quorum quenching (QQ), is considered as a promising strategy to combat bacterial infections without severe influence on bacterial survival. To date, several anti-QS approaches have been documented. In this article, two groups of potent QS inhibitors are described: 1) natural, organic compounds isolated from plants, animals and bacteria and 2) various types of nanoparticles. The ability of the sublethal concentration of these compounds to inhibit QS autoinducers synthesis as well as various steps of QS-regulated cellular response, and thus virulent traits of bacterial pathogens such as biofilm development, are discussed. QS inhibitors can constitute the promising future alternative to antibiotics, especially since until now, the development of bacterial resistance to neither group of these compounds has been reported.

1. Introduction. 2. Quorum sensing as a system of bacterial communication. 3. Organic inhibitors of QS. 3.1. Plant compounds. 3.2. Inhibitors of animal origin. 3.3. Inhibitors synthesized by bacteria. 4. QS inhibition by nanoparticles. 5. Concluding remarks

Autor: Postępy Mikrobiologii
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Advancements of Microbiology
Volume 63 (2024): Issue 1

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