The aim of this paper was to investigate the effect of heating rate on char, bio-oil and gas yield obtained via slow pyrolysis of energy crops. Experiments were performed in thermobalance coupled with mass spectrometer. The initial temperature was 303 K and it was gradually increased at heating rate 5, 10 and 20 K×min^-1 to 873 K. Dried and grounded energy crops – Miscanthus giganteus, Sida hermaphrodita and Sorghum Moench – were used as the substrate. The greatest degree of thermal decomposition under the condition of 873 K and 5 K×min^-1 was obtained for Sida hermaphrodita (76.6 wt.%) and the smallest degree for Sorghum Moench (70.5 wt.%). With the increase in heating rate, the yield of char decreased, the yield of bio-oil increased and the yield of gas was almost on the same level.

The physicochemical parameters of the liquid phase have influence significantly on the rate of oxygen absorption in liquid. Feasibility of wave-type agitated single-use bioreactors for bioprocesses involving in vitro cultures makes the study of the influence of liquid properties on values of the volumetric mass transfer coefficient (k a) interesting and actual research issue. ReadyToProcess WAVE^TM25 single-use bioreactor system (WAVE 25; GE Healthcare Bio-Sciences AB, Sweden), equipped with 2 dm³ polymer-based culture bag, has been used for studying the oxygen absorption rate in the wave-induced agitation system. The influence of viscosity of liquid on the rate of oxygen absorption under wave-type agitation has been discussed. The increase of liquid phase viscosity negatively influenced on the rate of oxygen absorption, and lead to decreasing in values of the k_La coefficient in studied system. Fetal bovine serum strongly limited significantly the rate of oxygen absorption into the liquid phase, what resulted in a significant decrease in the k_La coefficient.

Erythritol is a zero caloric polyol applied in food industry as a replacement of sucrose. The biosynthesis of erythritol is possible with the use of Yarrowia lipolytica yeast, glycerol and high osmotic pressure. The aim of this study was to design the erythritol separation process from the yeast culture broth and develop the method of utilization of the liquid waste derived from purification process. As a result of two-stage crystallization process the crystals of erythritol with 90.6% of purity were obtained. The liquid waste from crystallization was recycled to biosynthesis process, in which yeast produced 170 g dm^-3 of erythritol, with productivity and yield of 0.9 g dm^-3 h^-1 and 0.57 g g^-1, respectively. Proposed solutions allowed to design the waste free and fully integrated process of erythritol crystals production.

The paper deals with selection of mixing equipment for sludge suspensions. The concentrated sludge suspensions exhibit significant non-Newtonian flow behaviour and tend to create well mixed cavern around rotating impeller and stagnant unmixed liquid in the rest of vessel. The aim of the paper was to determine agitator speed at which all vessel content is well mixed (no stagnant zones exist) and to compare power consumption needed by different agitators to reach this state. The scale-up rule of mixing equipment was also proposed in the work.

The aerobic, batch biodegradation of corn stillage was conducted in STR bioreactor. The aim of the study was to determine the influence of selected parameters of the process on the efficiency and the specific rate of the COD removal. Increase of the stirrer speed did not affect the efficiency of stillage pollution load removal. However the stirrer speed influenced over the specific COD removal rate. The higher was the initial pH of the stillage the higher was the specific COD removal rate. The COD reduction rate of the stillage amounted to 73,8%.

Key words: Yarrowia lipolytica, α-ketoglutaric acid, pyruvic acid, rapeseed oil, glycerol, fed-batch culture

Nanobubbles are defined as spherical gaseous objects in bulk liquid of diameter not exceeding 1000 nm. They display numerous interesting properties, including antibacterial and antimycotic effect. This promising characteristic can be utilised in disinfection. However, up to this point, the effect of nanodispersions on animal cell lines was not investigated. In this paper, nanodispersions of oxygen bubbles were generated using porous silicon carbide modules. Bubbles were characterised by Sauter diameter of 180 nm. Cytotoxicity of nanodispersions for mice cells from L929 line were investigated using MTT tests. Various medium concentrations diluted by either nanodispersion or distilled water were used. Results of tests showed the increase of metabolic activity of cells in samples diluted by nanodispersions compared to samples without nanodispersion addition.

Single-use (i.e. disposable) bioreactors are commonly applied in biotechnology, as well as in biopharmaceutical industry, to efficient scaling-up of cultures of animal cells. Wave-type agitated systems provide sufficient mass transfer conditions in single-use culture bags. Spherical microcarriers made with biocompatible polymers are applying to obtain higher levels of biomass yield in various types of in vitro systems for culture of anchorage-dependent (i.e. adherent) cells. The aim of the study was to determine the applicability of three spherical microcarriers, i.e. Cytodex 1, Cytodex 3 and Cytopore, which differ in surface properties of granules, for submerged batch culture of mice anchorage-dependent L929 fibroblasts under conditions of wave-type agitation. Based on the results of cultures performed in small-scale wave-agitated system (5 cm³, laboratory cradle), the Cytodex 3 microcarrier has been identified as the spherical granules promoting proliferation of L929 cells. Cytodex 3 has been also successfully applied in the ReadyToProcess WAVETM25 bioreactor system (WAVE 25, GE Healthcare Bio-Sciences AB, Sweden) equipped with polymer-based culture bag in volume of 300 cm³, what resulted in enhanced growth of L929 cells characterized by Y*X/S equaled to 1.48∙109 cells∙gglucose^-1.