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In this study, 24 Antarctic bacteria, isolated from sediment and soil samples from Deception and Galindez Islands, were characterized for their antimicrobial activity and response to 13 antibiotics and seven heavy metals. Multiple antibiotic resistance was observed for 67% of sediment isolates and 92% of soil isolates, suggesting medium anthropogenic impact in these Antarctic regions. The results revealed a varying response of the Antarctic bacteria to the tested heavy metals. All isolates showed multiple metal resistance towards two to six heavy metals, with minimum inhibitory concentrations ranging from 1.0 mM to 23.2 mM. The majority of the strains in both groups were resistant to lead, nickel, copper and zinc. Plasmids were detected in 21% of isolates. A consortium of highly metal-resistant bacteria could be developed with potential application for biological treatment of wastewaters. Strains that are highly sensitive to cadmium would be promising for developing biosensors to detect this highly toxic heavy metal in environmental samples. All Antarctic bacteria were found to inhibit the growth of one to all eight of the tested indicator bacteria, and 87% inhibited the growth of one to all four of the yeast indicator cultures. Promising psychrotolerant strains were detected as a valuable source of new antimicrobial compounds.

A novel psychrotolerant, strictly aerobic, non-motile, rod-shaped bacterial strain, designated IM13 T , was isolated from a sample taken from prehistoric guano paintings in Magura Cave, northwest Bulgaria and subjected to a polyphasic taxonomic study. Strain IM13 T formed yellow colonies on LB agar plates and was Gram-staining-negative, heterotrophic and alkalitolerant. It grew optimally at pH 7.5 and 30 6C in the absence of NaCl. Phylogenetic analysis of the whole 16S rRNA gene revealed that strain IM13 T branched with representatives of the genus Myroides with sequence similarity of 93-94 % with other species of the genus. The novel isolate contained iso-C 15 : 0 (49.1 %), iso-C 17 : 1 v9c (18.2 %) and iso-C 17 : 0 3-OH (14.0 %) as dominant fatty acids. The DNA G+C content of strain IM13 T was 33.5 mol%. Based on phylogenetic inference and phenotypic characteristics, it was concluded that strain IM13 T represents a novel species of the genus Myroides, for which the name Myroides guanonis sp. nov. is proposed. The type strain is IM13 T (5DSM 26542 T 5NBIMCC 8736 T ).

We report three newly registered localities of the javelin sand boa - Eryx jaculus along the Black Sea Coast. The nearest known localities (outside of the study area) of the species are situated at a considerable distance (100-230 km) from the recently discovered ones. The data presented here confirm the presence of E. jaculus along the Bulgarian Black Sea Coast and expand the knowledge on its distribution both in the country and in the Balkans.

Sialidase preparations are applied in structural and functional studies on sialoglycans, in the production of sialylated therapeutic proteins and synthetic substrates for use in biochemical research, etc. They are obtained mainly from pathogenic microorganisms; therefore, the demand for apathogenic producers of sialidase is of exceptional importance for the safe production of this enzyme. Here, we report for the first time the presence of a sialidase gene and enzyme in the saprophytic actinomycete Oerskovia paurometabola strain O129. An electrophoretically pure, glycosylated enzyme with a molecular weight of 70 kDa was obtained after a two-step chromatographic procedure using DEAE cellulose and Q-sepharose. The biochemical characterization showed that the enzyme is extracellular, inductive, and able to cleave α(2→3,6,8) linked sialic acids with preference for α(2→3) bonds. The enzyme production was strongly induced by glycomacropeptide (GMP) from milk whey, as well as by sialic acid. Investigation of the deduced amino acid sequence revealed that the protein molecule has the typical six-bladed β-propeller structure and contains all features of bacterial sialidases, i.e., an YRIP motif, five Asp-boxes, and the conserved amino acids in the active site. The presence of an unusual signal peptide of 40 amino acids was predicted. The sialidase-producing O. paurometabola O129 showed high and constant enzyme production. Together with its saprophytic nature, this makes it a reliable producer with high potential for industrial application.