Volumen 56 (2017): Heft 4 (January 2017)

The growing demand for natural gas is primarily due to an increase in the share of gas in electricity production. Replacing coal with natural gas results in a significant decrease in emissions of greenhouse gases and dusts. The presence of microorganisms may be the cause of underground gas storage (UGS) facilities and pipelines deterioration. Microorganisms and their metabolic products contribute to the formation of sudden and unexpected failure causing loss of energy security by: decline in the quality of stored gas or disruption of its transmission. The paper presents a variety of microbiomes of the underground storage facilities and pipelines, showing that not only the sulfate-reducing bacteria are able to grow and develop in these extreme environments. Microorganisms producing CH₄ may change the composition of the gas, and the produced H₂S and CO₂ are not only gas pollutants, but also generate corrosion of transmission networks. At the same time, the presence of bacteria and archaea in pipelines hinders the correct operation of the network, through the accumulation of biofilm and reduction in the pipe diameter.

1. Introduction. 2. Microorganisms in underground gas storage facilities. 3. Microorganisms in natural gas pipelines. 4. Summary

Bovine viral diarrhea virus (BVDV) is classified as a member of the Pestivirus genus of the Flaviviridae family. BVDV is one of the most important viral pathogens of ruminants worldwide, causing severe economic losses. Infection results in a wide range of clinical manifestations, ranging from mild respiratory disease to fetal death and mucosal disease. The virus particles are small and contain a singlestranded, positive-sense RNA molecule of approximately 12.3 kb with one large open reading frame flanked by two untranslated regions (5’UTR and 3’UTR). The polyprotein is proteolytically cleaved by viral and host proteases resulting in the formation of mature viral proteins. It is well established that BVDV strains show considerable genetic diversity. BVD viruses are classified as two species: BVDV-1 and BVDV-2. Quite recently, a new putative species, BVDV-3, was detected. The viruses exist as one of two biotypes: cytopathic or non- cytopathic, based on their activity in cell cultures. The phylogenetic analysis of the 5’UTR and N^pro region has revealed at least 21 distinct subtypes of BVDV-1 and 4 subtypes of BVDV-2. Genetic diversity of BVD viruses has serious clinical implications such as immune evasion, increase of virulence, host range alteration and also affects the efficacy of vaccination programmes and diagnostic methods.

1. Introduction. 2. Characteristics of BVD virus. 3. Genetic diversity. 4. The importance of genetic variation. 5. Conclusion

Due to the development of civilization, people’s needs and expectations increase. The global development of civilization, the desire of some countries to expand their borders and achieve a higher political, social and military influence, cause insecurity among the people. Security is one of the main factors for the proper functioning of individuals and whole societies. Currently, a major threat to people is terrorism. Especially dangerous is the use of biological weapons for this purpose, which significantly interferes with a sense of security and restricts the freedom of human activities. Currently, biological terrorism is a global threat associated with the use of weapons for political or religious reasons. The threat from radical religious fundamentalists is particularly dangerous.

The most common biological threat agents are microorganisms causing zoonoses, i.e. diseases which can be transmitted from animals to humans. The most dangerous are Bacillus anthracis, Yersinia pestis and Francisella tularensis. They are characterized by high virulence, ease of spread and the possibility to obtain and use them at low cost.

The aim of this paper is to characterize, based on the available literature, the most dangerous microorganisms which pose a potential threat to humans as biological warfare. The article also provides basic information on the diagnosis and treatment of diseases caused by pathogens which can be used in a bioterrorist attack.

1. Introduction. 2. Anthrax (Bacillus anthracis). 2.1. Pathogenicity of anthrax. 2.2. Diagnosis and treatment of anthrax. 3. Plague (Yersinia pestis). 3.1. Pathogenicity of Yersinia pestis. 3.2. Diagnosis and treatment of plague. 4. Tularemia (Francisella tularensis). 4.1. Pathogenicity of Francisella tularensis. 4.2. Diagnosis and treatment of Francisella tularensis. 5. Ebola virus. 5.1. Pathogenicity of Ebola virus.5.2. Diagnosis and treatment of Ebola Virus Disease (EVD). 6. Summary

Metschnikowia spp. are extensively studied “non-conventional” yeasts. Strains belonging to these genera are considered as non-pathogenic and safe. The unique properties of Metschnikowia spp. allow us to look at these microorganisms as a promising subject for evolutionary genetics, taxonomy, ecology, as well as a natural biocontrol agent in biotechnology. This article provides a synthesis of the systematics, morphology, ecology and physiology of Metschnikowia spp., with special attention to M. pulcherrima. These yeasts are able to produce a number of important metabolites, including organic acids, aroma compounds, oil or pulcherrimic acid. In addition, this review discusses possible applications of these non-conventional yeasts in biotechnology.

1. Introduction. 2. Taxonomy. 3. Ecology. 4. Morphology and physiology. 5. Parasexual cycle. 6. Metschnikowia pulcherrima– biochemical activity and application potential. 7. Summary

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

In this article, the secondary metabolism as a basis for antibiotics production by industrial strains of Streptomyces, Penicillium chrysogenum and Acremonium chrysogenum is discussed. Images from transmission electron microscopy reveal some important features of the mycelial cells which are related to antibiotics biosynthesis. This discovery is important for further industrial strain improvement and has economic significance. Possibilities of new strategies for antimicrobial treatment are discussed.

1. Introduction. 2. Industrial strain improvements. 3. The pathways of antibiotic biosynthesis by Streptomyces spp. 4. Compartmentalization in antibiotic biosynthesis by Streptomyces spp. 5. The pathway of penicillin G biosynthesis by Penicillium chrysogenum. 6. Compartmentalization in penicillin G biosynthesis by Penicillium chrysogenum. 7. The pathway of cephalosporin C biosynthesis by Acremonium chrysogenum.8. Compartmentalization in cephalosporin biosynthesis by Acremonium chrysogenum. 9. The future of antibiotic therapy. 10. Conclusions

Free living, cosmopolitan amoebae of the genus Acanthamoeba present a serious risk to human health. As facultative human parasites, these amoebae may cause health and life-threatening diseases, such as Acanthamoeba keratitis (AK), granulomatous amoebic encephalitis (GAE) and cutaneous acanthamebiasis. AK is a severe, vision-threatening cornea infection with non-specific symptoms and course. GAE is a unique central nervous system disease, almost always leading to death. Cutaneous acanthamebiasis is most common in patients with AIDS. The pathogenesis and pathophysiology of the diseases is still incompletely understood, therefore no definitive effective therapy is currently available. Prevention is very difficult due toAcanthamoeba ubiquity and resistance. Further studies on effective solutions for the prevention and treatment of Acanthamoeba infections are needed.

1. Introduction. 2. Genus Acanthamoeba. 2.1. Occurrence. 2.2. Pathogenicity. 3. Acanthamoeba keratitis – AK. 3.1. Risk factors. 3.2. Course of the disease. 3.3. Diagnostics. 3.4. Treatment and prevention. 4. Granulomatous amebic encephalitis – GAE. 4.1. Course of disease. 4.2. Diagnostics and treatment. 5.Cutaneousacanthamebiasis. 5.1. Course of disease. 5.2. Diagnostics and treatment. 6. Summary

Bacillus cereus sensu lato is a group of several species of Gram-positive sporeformers ubiquitous in nature and showing huge impact on human activities. They are often found in soil, air, plant material, animal tissues and digestive tracts as well as in food products. Their genetic similarities and frequent horizontal gene transfer causes doubts regarding their taxonomy. In addition, their toxicity and psychrotolerance constitute serious problems in the dairy industry, being responsible for food-poisonings and spoilage of cold-stored products. Finally, recent finding indicate that B. cereus sensu lato toxicity plays an important role not only in their virulence, but also in social interactions with other bacteria.

1. Introduction. 2. The most important aspects of B. cereus sensu lato biology. 2.1. First challenge – coherent taxonomy. 2.2. Second challenge – life cycles and interactions with the environment. 2.3. Third challenge – adaptation to low temperatures. 2.4. Fourth challenge – toxins of B. cereus sensu lato. 3. Summary

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

Prokaryotic diversity increases every year with each new described species. Since the first discoveries of microorganisms, researchers’endeavours are dedicated to the systematisation of all known living organisms in a consistent taxonomy. Originally based on morphology, in recent years modern taxonomy develops thanks to the implemenation of new discoveries in the fields of biochemistry and genetics. In the last thirty years, ribotyping was the leading technique used to classify microorganisms. Due to problems with the comparison of certain species, novel methods based on the analysis of proteins have been applied. In-depth analysis of Enterobac teriaceae family showed that its members are more dissimilar than previously thought, which eventually led to dividing this family into seven families and resulted in a change to the name of the order: from Enterobacteriales to Enterobacterales. These changes were applied in some biggest accessible databases. However, there are still many other which have not modified their taxonomy records to date. Such situation may lead to unnecessary confusion, which strengthens the necessity to create one, unified taxonomy which is approved by the whole scientific community.

1. Introduction. 2. Principles regarding the introduction of taxonomical changes. 3. Justification of taxonomical changes. 4. Modifications in the order Enterobacterales ord. nov. 5. Databases and changes in the taxonomy of the order Enterobacterales ord. nov. 6. Summary