All posts by Postępy Mikrobiologii

Skuteczność wykorzystania niskotemperaturowej plazmy w mikrobiologii i medycynie

Efficiency of using non-thermal plasma in microbiology and medicine
M. Laskowska, E. Bogusławska-Wąs, P. Kowal, M. Hołub, W. Dąbrowski

1. Wstęp. 2. Mechanizm działania zimnej plazmy na mikroorganizmy. 2.1. Efektywność działania sterylizującego. 3. Zastosowanie zimnej plazmy w medycynie. 4. Podsumowanie

Abstract: Plasma is a partially or totally ionized gas which occurs in nature (e.g. lightning discharge, outer space), but can be also created in the laboratory conditions. Non-thermal plasma generates free radicals of oxygen, nitrogen, high energy electrons and uncharged particles such as atoms and molecules, in aquatic and gas environment. Thus, plasma exerts its effect on both prokaryotic and eukaryotic cells. In many studies, non-thermal plasma was applied mainly to achieve the sterilization effects of e.g. surfaces and medical tools. The results obtained were largely dependent upon the applied parameters of plasma (e.g. frequency, voltage, type of gas). Non-thermal plasma can be applied in microbiology and also in medicine where it can be used to speed up wound healing process or as an effective tool in oncology.

1. Introduction. 2. Plasma action on microorganisms. 2.1. Sterilization efficiency. 3. Application of cold plasma in medicine. 4. Summary

Drobnoustroje radiotolerancyjne – charakterystyka wybranych gatunków oraz ich potencjalne zastosowanie

Radiotolerant microorganisms – characterization of selected species and their potential usage
D. M. Matusiak

1. Wprowadzenie. 1.1. Promieniowanie oraz jego wpływ na organizmy żywe. 1.2. Drobnoustroje radiotolerancyjne – definicja, teorie na temat pochodzenia, oporność na promieniowanie. 2. Charakterystyka wybranych organizmów radiotolerancyjnych. 2.1. Bakterie. 2.2. Archeony. 2.3. Grzyby mikroskopowe. 3. Podsumowanie

Abstract: Ionizing radiation damages DNA, proteins and lipids in cells in a direct (10–20% DNA damage) and indirect manner (80–90%) – causing water radiolysis and a redox potential increase (oxido-reductive stress). For instance, hydrogen peroxide and ozone are generated. Hydroxyl radical (OH.) is the most reactive and harmful reactive oxygen species (ROS). Radiotolerant microorganisms are extremophilic microbiota, sustaining high doses of radiation in a vegetative state. One of the most resistant and extensively studied species is Deinococcus radiodurans. This bacterium can reconstitute its genome shattered to dozens of fragments (double strand breaks) as a result of the exposure to radiation or dessication. Other examples include: bacteria: Acinetobacter radioresistens, Rubrobacter radiotolerans, Kineococcus radiotolerans, Ralstonia sp. and Burkholderia sp. (living in biofilm communities from spent fuel pools); archaea: Thermococcus gammatolerans; diverse microscopic, often melanized, presumably radiotropic fungi, e.g. Cladosporium spp., from the surrounding of the destroyed Chernobyl power plant. Many of such organisms can be found in desert areas as they are dehydratation-tolerant. Radioresistant species can be potentially utilized for bioremediation of radioactive environment contamination and for nuclear waste management (e.g. bioprecipitation, biosorption, bioaccumulation of uranium or other radioisotopes). For example, diverse molds isolated from the Chernobyl region can be used for mycoremediation due to their ability to decompose contaminated organic matter, adsorb, converse into a soluble form and accumulate radionuclides (e.g. caesium 137).

1. Introduction. 1.1. Radiation and its effect on organisms. 1.2. Radiotolerant microorganism – definition, theories about their origin, radioresistance. 2. Description of selected radiotolerant species 2.1. Bacteria. 2.2. Archaea. 2.3. Microfungi. 3. Summary

Wpływ stresu kwasowego i osmotycznego na wytwarzanie metabolitów przy użyciu mikroorganizmów

The efect of acid and osmotic stress onmetabolite production by microorganisms
J. Fiedurek, M. Trytek

1. Wstęp. 2. Stresy abiotyczne. 2.1. Stres kwasowy. 2.2. Stres osmotyczny. 3. Podsumowanie

Abstract: The efficiency of the overall biotechnological processes is strongly dependent on the interaction between the microbial biocatalyst and the stressful environment. Microorganisms have evolved to survive constant fluctuation in their external surroundings by special adaptation systems, including the reorganization of genomic expression by activation of transcriptional factors under stress conditions and the production of suitable metabolites. There is some evidence that more active microbial cells may be obtained by using abiotic stresses, such as osmotic and acidic stress, before or during the process. Also, changes in the conditions of stress application, for example its duration or simultaneous increase in temperature, may improve the yield, probably as a result of changes in the metabolic pathway of the microorganisms used. In this review, we have summarized the most important information from available literature on the effect
of acid and osmotic stress on the production of useful metabolites by microorganisms.

1. Introduction. 2. Abiotic stresses. 2.1. Acidic stress. 2.2. Osmotic stress. 3. Conclusions

Filowirusy – wirusy obecne od milionów lat – dlaczego teraz wybuchła tak wielka epidemia?

Filoviruses – viruses existing for millions of years – why do we have such a big outbreak now?
K. Pancer, W. Gut, B. Litwińska

1. Rys historyczny i charakterystyka. 2. Struktura i zmienność EBOV. 3. Rezerwuar zwierzęcy filowirusów. 4. Podstawowe etapy cyklu życiowego wirusa Ebola w komórce. 5. Wybrane mechanizmy patogenności wirusa Ebola. 6. Paleowirusologia. 7. Podsumowanie

Abstract: Ebola virus, discovered in 1976, caused the largest epidemic among humans in 2014. In this paper, we have discussed the systematic position of Ebolavirus, the ecology of these viruses, the essential elements of pathogenesis of infections as well as comparative characteristics of Filoviruses infectious biology. According to the paleovirological data, these features were developed during millions of years of the co-evolution process and co-existence of pathogens and hosts. It is likely that changes of Ebola virus biology are not the reason for such substantial changes in the epidemiology of Ebola virus infections. Analysis of factors associated with the characteristics of the present epidemic (size, region) indicate that the main reason for such big epidemic may be the changes related to both humans activity, mainly transformation of the environment, and the ability of bats (natural hosts of Filoviruses) to adapt to the new ecological conditions. These processes may cause more outbreaks in the future, also on a large scale, and require taking appropriate actions to reduce the risks.

1. History and characteristics of filoviruses. 2. The structure and variability of EBOV. 3. Animal reservoir of Filoviruses. 4. Basics of the Ebola virus life cycle in the cell. 5. Selected mechanisms of pathogenicity of Ebola virus. 6. Filovirus paleovirology. 7. Summary

Koncepcja chromidu i jej znaczenie dla klasyfikacji pozachromosomowych replikonów bakterii

The concept of chromid and its influence on the classification of bacterial extrachromosomal replicons
J. Czarnecki, D. Bartosik

1. Wprowadzenie. 2. Nazewnictwo replikonów niezbędnych. 3. Koncepcja chromidu. 4. Identyfikacja i klasyfikacja chromidów. 5. Chromidy w genomach bakterii. 6. Ewolucyjne korzyści wynikające z obecności chromidów. 7. Podsumowanie

Abstract: Extrachromosomal replicons are common components of bacterial genomes. While the genetic information essential for growth and division of bacterial cells is located within the chromosome, the extrachromosomal replicons, usually classified as plasmids, can provide functions which are critical for the survival of a bacterium in a specific environment; however, they are not indispensable for the viability of the host cells. Comparative genomic studies revealed that in many bacterial genomes some chromosomal genes had been transferred into the co-occurring plasmids. This phenomenon has led to the generation of essential extrachromosomal replicons, called chromids, sharing features of both chromosomes and plasmids. The prevalence of chromids in bacteria and their conserved character within certain taxonomic groups suggest an important role for these replicons in the evolution of bacteria.

1. Introduction. 2. Nomenclature of essential replicons. 3. The concept of chromid. 4. Identification and classification of chromids. 5. Chromids in bacterial genomes. 6. Evolutionary significance of chromids. 7. Summary

Najnowszy numer

Najnowszy numer

2019, 58, 2

O Towarzystwie


Celem Polskiego Towarzystwa
Mikrobiologów jest propagowanie rozwoju nauk mikrobiologicznych

i popularyzowanie osiągnięć
mikrobiologii wśród członków Towarzystwa oraz szerokich kręgów społeczeństwa. Formami działalności jest organizowanie zjazdów, posiedzeń naukowych, kursów, wykładów
i odczytów oraz konkursów prac naukowych; wydawanie i popieranie wydawania czasopism naukowych, książek
i innych publikacji
z dziedziny mikrobiologii; opiniowanie o stanie i potrzebach mikrobiologii polskiej

i występowanie w jej sprawach wobec
władz państwowych; współpraca
z pokrewnymi stowarzyszeniami
w kraju i za granicą.