Microbe-based decontamination of phenol-polluted environments has significant advantages over physical and chemical approaches by being relatively cheaper and ensuring complete phenol degradation. There is a need to search for commercially prospective bacterial strains that are resistant to phenol and other co-pollutants, e.g. oil hydrocarbons, in contaminated environments, and able to carry out efficient phenol biodegradation at a variable range of concentrations. This research characterizes the phenol-biodegrading ability of a new actinobacteria strain isolated from a lubricant-contaminated soil environment. Phenotypic and phylogenetic analyses showed that the novel strain UCM Ac-603 belonged to the speciesRhodococcus aetherivorans, and phenol degrading ability was quantitatively characterized for the first time.R.aetherivoransUCM Ac-603 tolerated and assimilated phenol (100% of supplied concentration) and various hydrocarbons (56.2–94.4%) as sole carbon sources. Additional nutrient supplementation was not required for degradation and this organism could grow at a phenol concentration of 500 mg L⁻¹without inhibition. Complete phenol assimilation occurred after 4 days at an initial concentration of 1750 mg L⁻¹for freely-suspended cells and at 2000 mg L⁻¹for vermiculite-immobilized cells: 99.9% assimilation of phenol was possible from a total concentration of 3000 mg L⁻¹supplied at daily fractional phenol additions of 750 mg L⁻¹over 4 days. In terms of phenol degradation rates,R.aetherivoransUCM Ac-602 showed efficient phenol degradation over a wide range of initial concentrations with the rates (e.g. 35.7 mg L⁻¹ h⁻¹at 500 mg L⁻¹phenol, and 18.2 mg L⁻¹ h⁻¹at 1750 mg L⁻¹phenol) significantly exceeding (1.2–5 times) reported data for almost all other phenol-assimilating bacteria. Such efficient phenol degradation ability compared to currently known strains and other beneficial characteristics ofR.aetherivoransUCM Ac-602 suggest it is a promising candidate for bioremediation of phenol-contaminated environments.

The published online version contains mistake in Table 3.

The second generation (2G) or cellulosic ethanol can help with diversification of the use of fossil energy sources. However, as bioconversion of plant waste into 2G bioethanol requires expensive additional steps of pre-treatment/hydrolysis of lignocellulosic materials, and this technology has not yet reached the technological readiness level which would allow it to be scaled-up, this process needs more interdisciplinary and comprehensive studies. This work was aimed at experimental study of a full cycle of successive processes of pre-treatment/saccharification using cellulolytic enzymes of filamentous fungi and fermentation of obtained syrups by xylose-fermenting yeast, using selected natural microorganisms for the fungal-based bioconversion of lignocellulosic agricultural waste to 2G ethanol. Using the Plackett-Burman and Box-Behnken methods of mathematical statistics, the optimal conditions for pre-treatment and enzymatic hydrolysis of wheat straw by a hemi- and cellulolytic multi-enzyme complex of the selected fungal strain Talaromyces funiculosus UCM F-16795 were established: microwave-assisted alkali pre-treatment with sodium hydroxide (NaOH) solutions (concentration range 4.6–4.8%), and saccharification conditions of medium pH 4, temperature 40 °С, hydrolysis duration 18 hours, and dilution of culture liquid with a buffer solution 1:1. The total energy of microwave irradiation 1.2 kJ and the ratio of substrate/enzyme solution 100 mg/1 mL were used. Under optimized conditions, wheat straw hydrolysates contained 5.0–7.5 g/L of reducing sugars, which, according to HPLC assessment, contained 0.7–1.0 g/L of glucose, 2.2–2.9 g/L of xylose and 0.7–0.8 g/L cellobiose. We used the selected strain of xylose-fermenting yeast in fermentation of mixtures of the most important monosaccharides in hydrolysates, xylose and glucose, in the concentration range relevant for syrups obtained by us during the optimized saccharification of lignocellulosic substrates with T. funiculosus enzymes. Based on sequencing and phylogenetic analysis, strain UCM Y-2810 was confirmed as Scheffersomyces stipitis; its nucleotide sequences of ITS region and 28S gene rDNA were deposited in GenBank under the accession numbers OP931914 and OP931915, respectively. The ethanologenic process for S. stipitis UCM Y-2810 was studied according to Box-Behnken design, assessing ethanol concentration by gas chromatography-mass spectrometry. Yeast fermentation under static microaerophilic conditions showed a 1.5 times higher rate of bioethanol production and 1.7 times greater efficiency of ethanologenesis per yeast biomass than for submerged cultivation. Optimization of the process of ethanologenesis resulted in the maximum rate of fermentation mixture of sugars, being 11.30 ± 0.36 g/L of ethanol, with optimal values of factors: 30 g/L of xylose, 5.5 g/L of glucose and cultivation for 5.5 days. It was revealed that the tested glucose concentrations did not significantly affect the process of xylose-fermentation by yeast, and non-competitive inhibition of xylose transport by glucose into yeast cells did not occur. This study demonstrated the potential of a full cycle bioconversion of lignocellulosic waste to 2G ethanol based on use of natural fungal strains and optimization of conditions for all steps.

Aim. The aim of this work is to determine the taxonomic position of the fungal strain MF18_10 isolated from the damaged wall with medieval painting of St. Sophia’s Cathedral (Kyiv, Ukraine). Methods. The fungus was isolated on selective medium for xerophilic fungi (70% sucrose Czapek agar). Мacro- and micro-morphological phenotypic characterization was carried out using light and scanning electron microscopy. Molecular-biological identification was performed using nucleotide sequences of the ITS-fragment. Results. On the basis of phenotypical characteristics of the fungal isolate MF18_10, it was established its affiliation to the genus Penicillium. ITS analysis revealed that the isolate belongs to the species P. chrysogenum demonstrating 100% identity with other 78 P. chrysogenum strains in GenBank database including the type strains NR_077145 and AY373902, also sharing several distinct differences in substitutions, deletions and insertions within this group. Conclusions. The isolated xerotolerant fungus was identified as P. chrysogenum, the typical representative of the indoor environments and dust, and also common for mycobiota of damaged historic-cultural artifacts. The differences in the analyzed P. chrysogenum ITS primary structures did not correlate with the source of isolation. Keywords: Penicillium chrysogenum, xero-tolerant fungi, ITS, scanning electron microscopy.

Біорізноманіття дріжджів з гуцульських молочних продуктів домашнього приготування, ідентифікованих за фенотиповими ознаками