In recent years, infections are more often caused by pathogens with high multi-drug resistance, classified as the “ESKAPE” microorganisms. Therefore, investigation of these pathogens, e.g., Klebsiella pneumoniae, often requires biomass production for treatment testing such as antibiotics or bacteriophages. Moreover, K. pneumoniae can be successfully applied as a biocatalyst for other industrial applications, increasing the need for this bacteria biomass. In the current study, we proposed a novel magnetically assisted bioreactor for the cultivation of K. pneumoniae cells in the presence of an external alternating magnetic field (AMF). High efficiency of the production requires optimal bacteria growth conditions, e.g., temperature and field frequency. Therefore, we performed an optimization procedure using a central composite design for these two parameters in a wide range. As an objective function, we utilized a novel, previously described growth factor that considers both biomass and bacteria growth kinetics. Thus, based on the response surface, we could specify the optimal growth conditions. Moreover, we analysed the impact of the AMF on bacteria proliferation, which indicated positive field frequency windows, where the highest stimulatory effect of AMF on bacteria proliferation occurred. Obtained results proved that the magnetically assisted bioreactor could be successfully employed for K. pneumoniae cultivation.

The paper presents an analysis of a 100-meter wind measurement guyed mast located in the north-western part of the United States, in the state of Oregon. Using the RFEM software [1], the influence of the wind on the mast was analyzed according to the guidelines of two standards: American TIA-222-H [2] and European EN 1993-3-1 [3]. The purpose of this work is to show the differences between the results of static computations of the mast in terms of the considered standards. Due to the limited content of the work, the icing load on the structure was ignored in the analysis and the focus was on determining the response of the mast only in terms of wind action. The author tried to describe the differences in this respect between the standard guidelines [2] and [3]. The comments and conclusions regarding the analysis of guyed masts presented in the article have some practical aspects and can be used in design practice.

This paper presents distribution and properties of soils within the Fuglebekken catchment in neighbourhood of the Polish Polar Station in Hornsund, SW Spitsbergen (Svalbard Archipelago). The present study describes 8 representative soil profiles out of 34 profiles studied for the whole catchment. Soils of the Fuglebekken catchment show initial stage of their formation because of very slow rate of chemical and biological weathering in Arctic climate conditions . Uplifted marine terraces of the Fuglebekken catchment are characterized by domination of Haplic Cryosols which ar e related to stony and gravelly parent material (reworked marine sediments). Such soils constitute of 17% of the studied area. Turbic Cryosols forming characteristic micro−relief occur on flat surfaces and gentle slopes. Such soils (covering 7% of the catchment) are formed from loamy parent material. Along streams Hyperskeletic Cryosols (Reduc taquic) and Turbic Histic Cryosols occur. The last two soil units (constituting 11% of the catchment) are mantled by continuous and dense vegetation cover (especially mosses) due to high content of water rich in nutrients flowing from colonies of sea birds located on slopes of Ariekammen and Fugleberget. The studied soils are generally characterized by shallow occurrence of permafrost ( i.e. at 30–50 cm), high content of pebbles, sandy or sandy loam texture, and neutral or s lightly alkaline reaction. Soils occurring along streams and near colonies of sea birds show higher content of nutrients (N and P) in comparison with other soils and are covered by more dense vegetation. This indicates important impact of bird guano on chemical composition of soil solution and fertility of such soils.