Bio-treatment of soil from international airport in Ostrava

The paper deals with an examination of possible application of biodegradation in the decontamination of soil samples from international airport in Ostrava. The laboratory biodegradation tests were carried out with a pure bacterial culture of Pseudomonas putida, a pure laboratory culture of Rhodococcus sp, their mixture and a mixture prepared combining their media free of bacteria. The results of the paper imply that for biodegradation of airport pollutants is most suitable to apply a mixed bacterial culture of Pseudomonas putida and Rhodococcus sp. The results show that the biodegradation method is applicable for the pollution.

DIAZOTROPH ACTIVITY REGULATING STRATEGY UNDER THEIR INTRODUCTION IN AGROCENOSES

Objective. Investigate approaches to managing the activity of soil diazotrophs and propose a strategy for its regulation. Methods. Theoretical, vegetation and field experiments, microbiological, gas chromatographic, mathematical and statistical. Results. The activity of beneficial soil microorganisms can change under the action of temperature, humidity, chemical compounds of various origin, and other microorganisms. It was established that, taking into account a significant variety of factors, it is necessary to develop a set of specific ways to increase the growth and functional activity of nitrogen-fixing bacteria, as well as their viability. It has been proved that the combination of diazotrophs forms an effective symbiotic leguminous-rhizobial system, which provides additional biological nitrogen in agrocenoses. At the same time, there was an increase in plant mass, chlorophyll content in the leaves, protein and oil content in the products. The combined use of diazotrophs increases the yield, in particular, soybeans by 9–16 % compared with inoculation by pure bacterial culture. Conclusion. Based on the analysis and generalization of the obtained research results, a strategy for regulating the activity of diazotrophs for their effective introduction into agrocenoses is proposed, which consists in combining bacteria of different species, selecting conditions for their co-cultivation and application upon stabilisation of the number of viable bacterial cells. The proposed strategy involves solving the problem by obtaining an inoculant, which is characterized by a high titre and a stable number of viable cells, which allows to obtain an effective nitrogen-fixing system. The strategy is tried-and-tested on the example of regulating the growth and functional activity of soybean nodule bacteria by combining diazotrophs of different species, substantiating the conditions of their co-cultivation and application to ensure positive interaction in the form of commensalism, as well as by regulating viability of diazotrophs by adding stabilisers to the medium.

Clostridium difficile infection in pediatric patients of oncological hospital: cultivation of anaerobic intestinal flora and treatment

In recent years, the number of infectious diseases caused by Clostridium difficile in the world has grown with a significant increase in relapses and mortality in patients, particularly among the cancer patients in hospitals. There is also observed an increase in the resistance of Clostridium difficile to the first-line drugs, namely metronidazole and vancomycin, which makes the search for new methods of treatment and prevention of this infection even more urgent. In this review, we analyze the recent data on the methods of cultivation and isolation of the pure bacterial culture of Clostridium difficile and other anaerobic enteropathogens over the course of enterocolitis treatment with antimicrobial drugs in pediatric patients with oncopathology. Novel approaches to the therapy of this infection are discussed.

Biodegradation of Sleeper Subsoil

The paper deals with laboratory testing of PAHs biodegradation in samples of sleeper subsoil via two chosen microorganisms, bacteria Pseudomonas monteilii and Rhodococcus degradans. The obtained results show that the pure bacterial culture R. degradans removed 46 % PAHs in 28 days. Bacterium P. monteilii was far more successful in degrading PAHs, it managed to remove 74 % PAHs. The worst result was from the mixture of both bacteria which degraded only 34 % PAHs.

Co-encapsulation of slow release compounds and Rhodococcus rhodochrous ATCC 21198 in gellan gum beads to promote the long-term aerobic cometabolic transformation of 1,1,1-trichloroethane, cis-1,2-dichloroethene and 1,4-dioxane

Presented here is a novel approach where passive long-term cometabolic treatment can be achieved by co-encapsulating in a gellan gum hydrogel a pure bacterial culture and a slow release compound that hydrolyses to produce a growth-supporting substrate.

A high-throughput method to characterize the gut bacteria growth upon engineered nanomaterial treatment

We developed a DNA-based quantification (DBQ) method in a 96-well plate format. The applicability of this method for several types of ENMs was proved in both pure bacterial culture and in vitro human gut microbiome community.

Removal of emerging pathogenic bacteria using metal-exchanged natural zeolite bead filter

Hospital wastewaters can become a route for dissemination of antibiotic-resistant bacteria to the environment if not properly treated. Some of these bacteria are able to survive conventional disinfection treatments (e.g. chlorination, UV irradiation), which evokes the need for novel disinfection methods. The metal-exchanged zeolites were tested as novel antibacterial agents for wastewater treatment. The natural zeolite clinoptilolite enriched with silver (AgNZ) showed far better antibacterial activity towards hospital pathogenic bacterium Acinetobacter baumannii when compared with copper-exchanged zeolite (CuNZ), with minimal bactericidal concentration of 0.25–2 (AgNZ) compared with 32–64 mg L−1 (CuNZ) in a batch system and respective log 5.6 reduction compared with log 0.5 reduction in a flow system with pure bacterial culture. In the flow system with real effluent wastewater from the treatment plant, the removal of carbapenem-resistant bacteria using AgNZ was 90–100% during the 4 days of the experimental run. These results indicate that the AgNZ efficiently removes pathogenic bacteria from the wastewater, including A. baumannii, and is promising as a disinfectant material in a bead filter system.

Site-directed mutagenesis to deactivate two nitrogenase isozymes of Kosakonia radicincitans DSM16656T

Biological nitrogen fixation (BNF) is considered one of the key plant-growth-promoting (PGP) factors for diazotrophic organisms. Whether the iron and iron–molybdenum nitrogenases of Kosakonia radicincitans contribute to its PGP effect is yet to be proven. Hence, for the first time, we conducted site-directed mutagenesis in K. radicincitans to knock out anfH and (or) nifH as a mean to deactivate BNF in this strain. We used 15N2-labeled air to trace BNF activities in ΔanfH, ΔnifH, and ΔanfHΔnifH mutants. Assessing bacterial growth, nitrogen content, and 15N incorporation revealed that BNF is impaired in K. radicincitans DSM16656T ΔnifH and ΔanfHΔnifH. However, we detected no significant contribution of the Fe nitrogenase to biological dinitrogen assimilation under our pure bacterial culture experimental conditions. Such nondiazotrophic K. radicincitans DSM16656T mutants represent excellent tools for investigating nitrogen nutrition in K. radicincitans-inoculated plants.

Inflammation, suppuration, putrefaction, fermentation: Joseph Lister's microbiology

This paper focuses on Lister's inaugural lecture at King's College, London, in October 1877. As the new Professor of Clinical Surgery, Lister had much to report, including impressively high survival rates from complex operations previously regarded as foolhardy. Instead, he chose to address the processes of fermentation in wine, blood and milk. His reasons are not obvious to a modern audience, just as they probably were not to those who heard him in the Great Hall at King's. Having brought microbiological apparatus from his laboratory to the lecture theatre and presented proof of bacterial variety and specificity, Lister publicly demonstrated the creation of the first pure bacterial culture in the history of microbiology. It was an ingenious and well-thought-out strategy designed to generate a frame of mind among his new colleagues and future students, receptive to the causative role of bacteria in septic diseases. His timing was impeccable.