Draft genome sequences of two Xanthomonas vesicatoria strains from the Balkan peninsula

Xanthomonas vesicatoria causes bacterial spot disease of pepper and tomato plants. We report here the first genome sequences of X. vesicatoria strains that have been isolated from pepper plants. These data will be used for comparative genomics and will allow the development of new detection and typing tools for epidemiological surveillance

Representations of Three Balkan Cities in the Context of Dark Tourism

Stone (2006) argues that dark tourism involves visits to sites, attractions and exhibitions, which main or dominant themes have real or animated scenes of death, suffering, massacres. The paper focuses on the representations of the cities in the context of dark tourism on The Balkans, often imagined as “a shadow-land of mystery” (Todorova 2009: 29). The aim of the paper is to explore the concept of dark tourism, its implementation and the communication of collective/national memory and (political) ideology through dark sites. From Stone’s typological perspective, dark attractions themselves are classified into a number of different types

Antimicrobial activity of extracts from in vivo and in vitro propagated Lamium album l. plants

The antimicrobial activity of 18 different extracts from in vivo and in vitro grown L. album L. plants was evaluated against clinical bacteria and yeasts using the well diffusion method. All the used extracts demonstrated  antibacterial activity, whereas only the water extracts from leaves (in vivo) possessed antifungal activity against Candida albicans NBIMCC 72 and Candida glabrata NBIMCC 8673 (14 and 20 mm diameter of inhibition zones and MIC 10 mg/ml, respectively). The methanol and ethanol extracts obtained from the in vitro propagated plants had a broader  spectrum of antibacterial activity than those from in vivo plants, while the opposite tendency was observed for the chloroform extracts. All tested flower extracts possessed antimicrobial activity. The chloroform extract from in vivo flowers demonstrated the highest activity against E. faecalis NBIMCC 3915, S. aureus NBIMCC 3703, P. hauseri NBIMCC 1339 and P. aeruginosa NBIMCC 3700 (22 mm, 13 mm, 11 mm, 23 mm zone diameter of inhibition and MIC 0.313 mg/ml, respectively). The water extracts from leaves (both in vivo and in vitro) possessed higher antibacterial activity than extract from flowers. The obtained results showed that both in vivo and in vitro propagated L. album L. could be used as a source of antibacterial substances.Keywords: Lamium album, in vitro propagation, plant extracts,  antimicrobial activit

Differentiation of Xanthomonas

During the last 20 years, the causative agents of bacterial spot of tomato and pepper have been subjected to many studies and reclassifications. According to the current data, the species are four (X. euvesicatoria, X. vesicatoria, X. gardneri, and X. perforans) and cause similar symptoms in plants but possess different phenotypic properties. This work provides the full metabolic characteristics obtained by Biolog system of bacterial spot’s xanthomonads based on a large selection of strains from different vegetable-producing regions of Bulgaria with accent on their major differentiating properties which could be used for species differentiation by metabolic profiles. The results are compared to the data available in the literature in order to clarify the strong features of each species and distinguish the variable ones. Simple characteristics like amylase activity and utilization of cis-aconitate cannot serve alone for differentiation

New Knowledge on Distribution and Abundance of Toxic Microalgal Species and Related Toxins in the Northwestern Black Sea

Numerous potentially toxic plankton species commonly occur in the Black Sea, and phycotoxins have been reported. However, the taxonomy, phycotoxin profiles, and distribution of harmful microalgae in the basin are still understudied. An integrated microscopic (light microscopy) and molecular (18S rRNA gene metabarcoding and qPCR) approach complemented with toxin analysis was applied at 41 stations in the northwestern part of the Black Sea for better taxonomic coverage and toxin profiling in natural populations. The combined dataset included 20 potentially toxic species, some of which (Dinophysis acuminata, Dinophysis acuta, Gonyaulax spinifera, and Karlodinium veneficum) were detected in over 95% of the stations. In parallel, pectenotoxins (PTX-2 as a major toxin) were registered in all samples, and yessotoxins were present at most of the sampling points. PTX-1 and PTX-13, as well as some YTX variants, were recorded for the first time in the basin. A positive correlation was found between the cell abundance of Dinophysis acuta and pectenotoxins, and between Lingulodinium polyedra and Protoceratium reticulatum and yessotoxins. Toxic microalgae and toxin variant abundance and spatial distribution was associated with environmental parameters. Despite the low levels of the identified phycotoxins and their low oral toxicity, chronic toxic exposure could represent an ecosystem and human health hazard

Lukanka, a Semi-Dried Fermented Traditional Bulgarian Sausage: Role of the Bacterial Cultures in its Technological, Safety and Beneficial Characteristics

Background: Production of different fermented meat products is a well-known practice done in different European countries since ancient times. Fermentation of primary materials and/or smoking and salting processes are part of the preservation processes and is important for the formation of final products which is inherent in South European countries. Originally, fermentation of meat products is intended for preservation and safe storage for long periods of time. However, nowadays, gastronomical properties of fermented meat products are essential in obtaining specific flavor, odor, color and structure of the sausages which consumers highly prefer. Emphasis is given on gastronomic characteristics, which results from the various combination of raw meat, specific spices and the natural microbiota or conducted fermentation processes by application of specific starter cultures. Seven bacterial genera (Lactobacillus, Leuconostoc, Staphylococcus, Enterococcus, Lactococcus, Micrococcus and Streptococcus) are commonly used as meat starter cultures. Complex fermentation processes that occur during the ripening of the fermented meat products are the results of the interaction between bacterial starter cultures, remaining enzymes in the muscle and fat tissue and available bacterial enzymes. Objective: The present overview aims to provide information related to the characterization of the specific microbiota associated with lukanka, a naturally-fermented semi-dried Bulgarian sausage. What is the specificity of its fermentation processes; how do different starter and indigenous meat microbiota interfere to form specific final products; what is the role of starter and adjunct cultures in the safety of the products; how is the Bulgarian lukanka classified in the perspective of other Mediterranean dry fermented sausages? These are some of the questions that this review will discuss

Conversion of electrospun chitosan into chitin: a robust strategy to tune the properties of 2D biomimetic nanofiber scaffolds

New biomimetic micro- and nano-CsU-based fibrous scaffolds electrospun from solution containing high purity-medical grade chitosan (CsU) of fungus origin (CsU1, Mv ~174,000 and CsU2, 205,000, degree of deacetylation (DDA) ~65%) and polyethylene oxide (PEO, Mv ~ 900,000), in the presence of given amounts of Triton X-100 (from 0.01 to 0.5 wt%) as surfactant were fabricated. We demonstrate that by carefully selecting compositions and surfactant levels, porous mats with CsU content up to 90% (at this molecular weight and DDA) were achieved. Remarkable long-term stability in water or phosphate buffer solution storage were obtained by developing post-electrospinning treatment allowing the complete elimination of the PEO from the CsU-fibers as demonstrated by TGA, DSC and ESEM analysis. Subsequent reacetylation procedure was applied to convert 2D biomimetic chitosan mats to chitin (CsE)-based ones while preserving the nanofiber structure. This innovative procedure allows tuning and modifying the thermal, mechanical properties and more importantly the biodegradation abilities (fast enzymatic biodegradation in some cases and slower on the others) of the prepared nanofibrous mats. The established reproducible method offers the unique advantage to modulate the membrane properties leading to stable 2D biomimetic CsU and/or chitin (CsE) scaffolds tailor-made for specific purposes in the field of tissue engineering.Peer reviewe

Phytoplankton light absorption in the deep chlorophyll maximum layer of the Black Sea

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Churilova, T., Suslin, V., Sosik, H. M., Efimova, T., Moiseeva, N., Moncheva, S., Mukhanov, V., Rylkova, O., & Krivenko, O. Phytoplankton light absorption in the deep chlorophyll maximum layer of the Black Sea. European Journal of Remote Sensing, 52, (2019): 123-136, doi: 10.1080/22797254.2018.1533389.Bio-optical data, obtained during six cruises in the Black Sea carried out during periods of seasonal stratification in years between 1996 and 2016, have been used to parametrize phytoplankton light absorption (aph(λ)) in the deep chlorophyll maximum (DCM) layer located near the bottom of euphotic zone. Relationships between aph(λ) and the sum of chlorophyll-a and phaeopigment concentrations (Chl-a) differed from those for the summertime upper mixed layer (UML). Notably, chlorophyll a specific absorption coefficients (a∗ph(λ)) were lower in the DCM and more comparable with a∗ph(λ) values typical for winter phytoplankton in the Black Sea. The aph(λ) spectral shapes in the DCM differed markedly from those in winter and in the summer UML, due to a shoulder at ~490 nm and a local maximum at ~550 nm corresponding to the absorption bands of phycourobilin and phycoerythrobilin. Light absorbing properties of phytoplankton in the DCM (amplitude and spectral shape of a∗ph(λ)) reflected physiological acclimation to local conditions on the cellular level and population shifts leading to changes in the biomass-dominant species, with Synechococcus spp. domination in the DCM. The parameterization of phytoplankton absorption in the DCM will enable refined spectral models of the downwelling radiance and primary production in the Black Sea.RAS funded this research [grant numbers АААА-А18-118020890112-1, АААА-А18-118020790229-7 and АААА-18-118012690119-7]. This work was partly supported by the Russian Foundation for Basic Research, projects [numbers 17-05-00113 and 18-45-920070]

Marine biodiversity and ecosystem function relationships: The potential for practical monitoring applications

Abstract There is an increasing demand for environmental assessments of the marine environment to include ecosystem function. However, existing schemes are predominantly based on taxonomic (i.e. structural) measures of biodiversity. Biodiversity and Ecosystem Function (BEF) relationships are suggested to provide a mechanism for converting taxonomic information into surrogates of ecosystem function. This review assesses the evidence for marine BEF relationships and their potential to be used in practical monitoring applications (i.e. operationalized). Five key requirements were identified for the practical application of BEF relationships: 1) a complete understanding of strength, direction and prevalence of marine BEF relationships, 2) an understanding of which biological components are influential within specific BEF relationships, 3) the biodiversity of the selected biological components can be measured easily, 4) the ecological mechanisms that are the most important for generating marine BEF relationships, i.e. identity effects or complementarity, are known and 5) the proportion of the overall functional variance is explained by biodiversity, and hence BEF relationships, has been established. Numerous positive and some negative BEF relationships were found within the literature, although many reproduced poorly the natural species richness, trophic structures or multiple functions of real ecosystems (requirement 1). Null relationships were also reported. The consistency of the positive and negative relationships was often low that compromised the ability to generalize BEF relationships and confident application of BEF within marine monitoring. Equally, some biological components and functions have received little or no investigation. Expert judgement was used to attribute biological components using spatial extent, presence and functional rate criteria (requirement 2). This approach highlighted the main biological components contributing the most to specific ecosystem functions, and that many of the particularly influential components were found to have received the least amount of research attention. The need for biodiversity to be measureable (requirement 3) is possible for most biological components although difficult within the functionally important microbes. Identity effects underpinned most marine BEF relationships (requirement 4). As such, processes that translated structural biodiversity measures into functional diversity were found to generate better BEF relationships. The analysis of the contribution made by biodiversity, over abiotic influences, to the total expression of a particular ecosystem function was rarely measured or considered (requirement 5). Hence it is not possible to determine the overall importance of BEF relationships within the total ecosystem functioning observed. In the few studies where abiotic factors had been considered, it was clear that these modified BEF relationships and have their own direct influence on functional rate. Based on the five requirements, the information required for immediate ‘operationalization’ of BEF relationships within marine functional monitoring is lacking. However, the concept of BEF inclusion within practical monitoring applications, supported by ecological modelling, shows promise for providing surrogate indicators of functioning

Ecosystem processes: litter breakdown patterns in Mediterranean and Black Sea transitional waters

1 - Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. 2 - Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. 3 - Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. 4 - Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. 5 - It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. 6 - The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors