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Bacillus velezensis R22 was isolated from a rice rhizosphere in Bulgaria. Its genome (assembled into 14 scaffolds) has a size of 4.08 Mbp and a G + C content of 46.35%. Nine full biosynthetic clusters for antimicrobials were predicted, among them two new gene clusters probably encoding polyketides named macrolactin R22 and velezensin., Competing Interests: The authors declare no conflict of interest.

The properties of Bacillus thuringiensis strains as a biopesticide with potent action against moths, beetles, and mosquitoes have been known for decades, with individual subspecies showing specific activity against a particular pest. The aim of the present work is to characterize strains that can be used for broad-spectrum pest control in agriculture. Twenty strains of B. thuringiensis were isolated from Bulgarian soil habitats. The strains were screened for genes encoding 12 different crystal (Cry) endotoxins by PCR with specific primer pairs. Seven of the isolates contained cry genes in their genomes. B. thuringiensis strains PL1, PL3, and PL20 contained at least three different cry genes, while B. thuringiensis serovar galleriae BTG contained at least four. Moreover, scanning electron microscopy (SEM) investigation revealed the production of bipyramidal (PL1, PL3, PL20), polygonal (PL1), cubic (BTG), and spherical crystals (BTG and PL20). Potentially containing the most cry genes, the BTG genome was sequenced and annotated. It comprises 6,275,416 base pairs, does not contain plasmids, has a GC content of 35.05%, and contained 7 genes encoding crystal toxins: cry1Ab35 , cry1Db , cry1Fb , cry1Ib , cry2Ab , cry8Ea1 , and cry9Ba . This unique combination would possibly enable the simultaneous pesticidal action against pest species from orders Lepidoptera, Coleoptera, Diptera, and Hemiptera, as well as class Gastropoda. Whole-genome sequencing provided accurate information about the presence, localization, and classification of Cry toxins in B. thuringiensis BTG, revealing the great potential of the strain for the development of new broad-spectrum bio-insecticides.

The Antarctic fungal strain Aspergillus glaucus 363 produces cold-active (CA) Cu/Zn-superoxide dismutase (SOD). The strain contains at least one gene encoding Cu/Zn-SOD that exhibited high homology with the corresponding gene of other Aspergillus species. To our knowledge, this is the first nucleotide sequence of a CA Cu/Zn-SOD gene in fungi. An effective laboratory technology for A. glaucus SOD production in 3 L bioreactors was developed on the basis of transient cold-shock treatment. The temperature downshift to 10 °C caused 1.4-fold increase of specific SOD activity compared to unstressed culture. Maximum enzyme productivity was 64 × 10(3) U kg(-1) h(-1). Two SOD isoenzymes (Cu/Zn-SODI and Cu/Zn-SODII) were purified to electrophoretic homogeneity. The specific activity of the major isoenzyme, Cu/Zn-SODII, after Q-Sepharose chromatography was 4000 U mg(-1). The molecular mass of SODI (38 159 Da) and of SODII (15 835 Da) was determined by electrospray quadropole time-of-flight (ESI-Q-TOF) mass spectrometry and dynamic light scattering (DLS). The presence of Cu and Zn were confirmed by inductively coupled plasma mass spectrometry (ICP-MS). The N-terminal amino acid sequence of Cu/Zn-SODII revealed a high degree of structural homology with Cu/Zn-SOD from other fungi, including Aspergillus species., (Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

The degradation kinetics of different phenolic substrates utilised by Trichosporon cutaneum R57 was studied. The following compounds were used as substrates: phenol , resorcinol, hydroquinone, 3-nitrophenol, 2,6-dinitrophenol, 3-chloro phenol and p -cresol. The specific degradation rates ( Q s ) were described by a Haldane kinetic model. The unknown model parameters were estimated using the mathematical optimisation procedure for direct search. The results obtained demonstrated that Q s varied greatly in the experiments carried out. The level of biodegradability depended on the different structure and toxicity of compounds used as carbon substrates. The highest Q s values were observed for less toxic hydroxylated phenols (0.77-0.85 h -1 ), while the most toxic chlorinated phenols were characterised with the lowest Q s values (0.224 h -1 ). The results obtained with different concentrations of resorcinol (from 0.2 to 0.8 g L -1 ) and 2,6-dinitrophenol (from 0.2 to 0.7 g L -1 ) demonstrated a growing inhibitory effect directly correlating with the extended time necessary for complete degradation of both compounds.

Taxonomic identification of three newly isolated Antarctic fungal strains by their 18S rDNA sequences revealed their affiliation with Aspergillus fumigatus. Phenol (0.5 g/l) as the sole carbon source was completely degraded by all strains within less than two weeks. Intracellular activities of three key enzymes involved in the phenol catabolism were determined. Activities of phenol hydroxylase (EC 1.14.13.7), hydroquinone hydroxylase (EC 1.14.13.x), and catechol 1,2-dioxygenase (EC 1.13.11.1) varied significantly between strains. The rates of phenol degradation in the three strains correlated best with the activity of catechol 1,2-dioxygenase. Six pairs of oligonucleotide primers were designed on the basis of the Aspergillus fumigatus Af293 genome sequence (NCBI Acc. No. XM_743491.1) and used to amplify phenol hydroxylase-related gene sequences. DNA sequences of about 1200 bp were amplified from all three strains and found to have a high degree of sequence identity with the corresponding gene of Aspergillus fumigatus Af293.

In an attempt to estimate the occurrence of phenol hydroxylase-related gene sequences we performed a dot blot hybridization assay with DNA from phenol utilizing Trichosporon cutaneum R57 strain NBIMCC 2414 and microbial isolates from different wastewaters. The used oligonucletides were homologous to the 5'-end of TORPHD locus (NCBI)-coding phenol hydroxylase in Trichosporon cutaneum ATCC 46490 and to the 5'-end of TORCCMLE locus (NCBI)-coding cis,cis-muconate-lactonizing enzyme in Trichosporon cutaneum ATCC 58094. Two microbial strains, Escherichia coli JM 109 and Lactobacillus acidophilus ATCC 4356, incapable to degrade phenol were used as negative controls. We established the presence of hybridization with both used oligonucleotide probes in T. cutaneum R57 and T. cutaneum ATCC 46490 yeast strains. The experiments implemented with microbial isolates obtained from three industrialized areas in Bulgaria showed that 7 of them may carry sequences hybridizing with a phenol hydroxylase oligonucleotide probe. A subsequent hybridization test for the cis,cis-muconate-lactonizing enzyme showed that only 3 of them displayed a positive signal. Lactobacillus acidophilus ATCC 4356 and Escherichia coli JM 109 strains' DNA used as negative controls in the experiments did not reveal any sequence similarity to the both applied oligonucleotides. The partial nucleotide sequences of 16S rDNAs of the isolated strains C1 and K1 obtained as PCR products were determined and sequenced. A comparison of these nucleotide sequences with similar sequences in NCBI Data Bank indicated that both C1 and K1 strains are closely related to the genera Acinetobacter and Burkholderia.

The phenol-degrading strain Trichosporon cutaneum R57 utilizes various aromatic and aliphatic compounds as a sole carbon and energy source. The intracellular activities of phenol hydroxylase [EC 1.14.13.7] of a Trichosporon cutaneum R57 strain grown on phenol (0.5 g/l) were measured. Different toxic phenol derivatives (cresols, nitrophenols and hydroxyphenols) were used as substrates in the reaction mixture for determination of the enzyme activity. The data obtained showed that the investigated enzyme was capable to hydroxylate all applied aromatic substrates. The measured activities of phenol hydroxylase varied significantly depending on the aromatic compounds used as substrates. The rate of phenol hydroxylase activity with phenol as a substrate (1.0 U/mg total cell protein) was accepted as 100%.

The lung functions of 285 workers were investigated. It was found that the ventilatory functions of 20.5% of the female and 23.5% of the male testes were impaired. Prevalence of mild obstructions was established which can be attributed to both cigarette smoking and the length of service. Maximal expiratory flows are worth a special attention in mild airflow obstructions as they could be decreased when forced expiratory volume in the first second (FEV1) remains unchanged.