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Alphaea stanislava, a new species from Vietnam and Laos (Lepidoptera: erebidae: Arctiinae: arctiini) /
No full textA new species of the genus Alphaea, Alphaea stanislava sp. n. is described from central Vietnam and north-eastern Laos. The new species belongs to the subgenus Nayaca Moore, 1879 and is similar to A. chiyo Dubatolov & Kishida, 2005 and A. imbuta (Walker, 1855). The female genitalia of A. chiyo and A. imbuta are illustrated for the first time
Vaisių mikobiotos struktūra ir jos komponentų – Saccharomyces genties mielių biocidinių sistemų funkcionavimo mechanizmai.
No full textYeasts are widespread unicellular eukaryotic fungal microorganisms, abundant in the air, water, soil and on various parts of plants, especially on fruits and berries. Certain yeasts possess killer trait and produce toxins that are killing sensitive yeasts and in this manner, killer yeasts can regulate the structure of microbiota. This work has extended the knowledge about mycobiota of widely consumed fruits and berries: composition of fungal microorganisms‘ communities of white, black, and red currants, chokeberries, sea buckthorn berries, and apples, depending on the plant, fruit ripening stage, and external environment as well as prevalence of yeast viral killer systems. The aim of this thesis is to evaluate the structure of mycobiota present on fruits and berries and to perform the screening for killer systems of Saccharomyces spp. yeasts and investigate their mechanisms of functioning. Investigation of the abundance of yeasts on the surface of fruits and berries led to the identification of S. paradoxus AML-15-66 strain, producing double stranded RNA-encoded K66 toxin. A novel viral dsRNA killer system was described, genetic factors involved in the resistance to K66 toxin were identified. S. paradoxus K66 and S. cerevisiae K2 killer systems were compared based on the action and cellular response mechanisms
Seven new species of Rhynchobombyx Aurivillius, 1909 from Congolian lowland forests (Lepidoptera: Lasiocampidae) /
No full textSeven new species of the Afrotropic Lasiocampidae genus Rhynchobombyx are described and illustrated: Rh. gavinfilippone Prozorov, Saldaitis & Müller sp. n., Rh. avadomenicarocchio Prozorov, Saldaitis & Müller sp. n., Rh. julianjameseaton Prozorov, Saldaitis & Müller sp. n., Rh. anthonychristophereaton Prozorov, Saldaitis & Müller sp. n., Rh. nicolasroberteaton Prozorov, Saldaitis & Müller sp. n., Rh. arijakefriend Prozorov, Saldaitis & Müller sp. n., Rh. madisonellafriend Prozorov, Saldaitis & Müller sp. n. All species originate from the poorly studied Congolian lowland forests ecoregion of Congo and Democratic Republic of the Congo. Lectotype and paralectotype of Rh. nasuta Aurivillius, 1909 are designated here, the species type locality is specified
Nisin-loaded ulvan particles: Preparation and characterization /
No full textNisin is an attractive alternative to chemical preservatives in the food industry. It is a cationic peptide of 34 amino acid residues that exhibits antimicrobial activity against Gram-positive bacteria. To ensure nisin stability in food matrices, new nisin-loaded ulvan particles were developed by the complexation method. The interaction of nisin with ulvan was demonstrated by FT-IR spectroscopy and differential scanning calorimetry. The encapsulation efficiency was calculated at different pH values within the range of 4.0–7.0 and was found to have the highest value at pH 7.0. The size and surface charge of particles fabricated at different concentrations of nisin and pH values were determined. Nisin-loaded ulvan particles exhibited antimicrobial activity against Gram-positive bacteria comparable to that of free nisin. Therefore, the developed complexes have the potential for application as biopreservatives in the food industry. For the first time, the potential of ulvan as a carrier of antimicrobial agent nisin was demonstrated
The Complete Genome Sequence of Xanthomonas theicola, the Causal Agent of Canker on Tea Plants, Reveals Novel Secretion Systems in Clade-1 Xanthomonads /
No full textXanthomonas theicola is the causal agent of bacterial canker on tea plants. There is no complete genome sequence available for X. theicola, a close relative of the species X. translucens and X. hyacinthi, thus limiting basic research for this group of pathogens. Here, we release a high-quality complete genome sequence for the X. theicola type strain, CFBP 4691T. Single-molecule real-time sequencing with a mean coverage of 264x revealed two contigs of 4,744,641 bp (chromosome) and 40,955 bp (plasmid) in size. Genome mining revealed the presence of nonribosomal peptide synthases, two CRISPR systems, the Xps type 2 secretion system, and the Hrp type 3 secretion system. Surprisingly, this strain encodes an additional type 2 secretion system and a novel type 3 secretion system with enigmatic function, hitherto undescribed for xanthomonads. Four type 3 effector genes were found on complete or partial transposons, suggesting a role of transposons in effector gene evolution and spread. This genome sequence fills an important gap to better understand the biology and evolution of the early-branching xanthomonads, also known as clade-1 xanthomonads
Shifts in gene expression variability in the blood-stage of Plasmodium relictum /
No full textAvian malaria is a common and widespread disease of birds caused by a diverse group of pathogens of the genera Plasmodium. We investigated the transcriptomal profiles of one of the most common species, Plasmodium relictum, lineage SGS1, at multiple timepoints during the blood stages of the infection under experimental settings. The parasite showed well separated overall transcriptome profiles between day 8 and 20 after the infection, shown by well separated PCA profiles. Moreover, gene expression becomes more heterogenous within the experimental group late in the infection, either due to adaptations to individual differences between the experimental hosts, or due to desynchronisation of the life-cycle of the parasite. Overall, this study shows how the avian malaria system can be used to study gene expression of the avian Plasmodium parasite under controlled experimental settings, thus allowing for future comparative analysis of gene responses of parasite with different life-history traits and host effects
Stable isotopes reveal the dominant species to have the widest trophic niche of three syntopic Microtus voles /
No full textDiets and the trophic positions of animals are fundamental issues in their ecology. We analysed the isotopic niches (as a proxy for trophic niches) of common (Microtus arvalis), field (M. agrestis), and root (M. oeconomus) voles co-occurring in orchards, berry plantations, and nearby meadows using isotopic (δ15N and δ13C) compositions from hair samples. We tested if the niche of the dominant common vole was widest, whether its width was related to the presence of other Microtus species, and whether there were intraspecific differences in average δ13C and δ15N stable isotope values. The obtained results showed relative stability in the trophic niche across the vegetative period. The isotopic niche of the common vole was the widest, exceeding the other two Microtus species by 1.6–3 times. Co-occurring vole species were separated according to δ13C (i.e., used different plants as main food), but they maintained similarity according to δ15N distribution. The effect of animal age and gender on the width of the trophic niche was strongest in root vole, which is a species that has spread across the country in the last 70 years. These results give new insights into the trophic ecology small herbivores, showing the impact of species co-occurrence
Response of ectomycorrhizal and other Pinus sylvestris root-associated fungi to the load of allochthonous material from a great cormorant colony /
No full textColonies of piscivorous birds nesting in forests bring in loads of allochthonous material in amounts significantly exceeding atmospheric depositions, eventually causing major ecosystem changes. We studied the effect of increasing ornithogenic impact on ectomycorrhizal (EMF) and other root-associated fungi in a Scots pine forest affected by a colony of great cormorants. We evaluated quantitative data of ectomycorrhiza (numbers of root tips and morphotypes) and identified fungal species from pine root tips and from sporocarps collected in three designated study zones: D (zone of active nesting), E (colony margin), and G (pristine forest). Species-bearing sporocarps were absent in zone D, and their number steadily decreased in zone E and was significantly lower than in zone G. Species communities and occurrence frequencies of individual species differed significantly between the zones. Environmental factors, both directly (nutrient addition) and indirectly (changes in vegetation cover), associated with bird activity have significantly influenced fungal communities. We hypothesize that the first signs of increased avian impact on root-associated fungi are the reduced diversity of sporocarps and the low presence and diversity of boletoid fungi in root tips
Exploring viral diversity in a gypsum karst lake ecosystem using targeted single-cell genomics /
No full textLittle is known about the diversity and distribution of viruses infecting green sulfur bacteria (GSB) thriving in euxinic (sulfuric and anoxic) habitats, including gypsum karst lake ecosystems. In this study, we used targeted cell sorting combined with single-cell sequencing to gain insights into the gene content and genomic potential of viruses infecting sulfur-oxidizing bacteria Chlorobium clathratiforme, obtained from water samples collected during summer stratification in gypsum karst Lake Kirkilai (Lithuania). In total, 82 viral contigs were bioinformatically identified in 62 single amplified genomes (SAGs) of C. clathratiforme. The majority of viral gene and protein sequences showed little to no similarity with phage sequences in public databases, uncovering the vast diversity of previously undescribed GSB viruses. We observed a high level of lysogenization in the C. clathratiforme population, as 87% SAGs contained intact prophages. Among the thirty identified auxiliary metabolic genes (AMGs), two, thiosulfate sulfurtransferase (TST) and thioredoxin-dependent phosphoadenosine phosphosulfate (PAPS) reductase (cysH), were found to be involved in the oxidation of inorganic sulfur compounds, suggesting that viruses can influence the metabolism and cycling of this essential element. Finally, the analysis of CRISPR spacers retrieved from the consensus C. clathratiforme genome imply persistent and active virus–host interactions for several putative phages prevalent among C. clathratiforme SAGs. Overall, this study provides a glimpse into the diversity of phages associated with naturally occurring and highly abundant sulfur-oxidizing bacteria
Prevalence and genetic diversity of avian Haemosporidian parasites in Southern Iran /
No full textAvian haemosporidians are widespread and diverse and are classified in the genera Plasmodium, Haemoproteus, Leucocytozoon, and Fallisia. These species are known to cause haemosporidiosis and decreased fitness of their hosts. Despite the high diversity of habitats and animal species in Iran, only few studies have addressed avian haemosporidians in this geographic area. This study was performed in the south and southeast of Iran during the bird breeding seasons in 2017 and 2018, with the aim to partly fill in this gap. Blood samples of 237 passerine birds belonging to 41 species and 20 families were collected. Parasite infections were identified using a nested PCR protocol targeting a 479-base-pair fragment of the mitochondrial cytochrome b (cytb) gene of Haemoproteus, Plasmodium and Leucocytozoon species. The overall prevalence of haemosporidian parasites was 51.1%, and 55 different lineages were identified, of which 15 cytb lineages were new globally. The lineages of Haemoproteus predominated (63.6% of all detected lineages), followed by Leucocytozoon and Plasmodium. Nineteen new host records of haemosporidian cytb lineages were identified, and the majority of them were found in resident bird species, indicating local transmission. Thirteen co-infections (9.8% of infected individuals) of Haemoproteus and Leucocytozoon parasites in seven host species were observed. This study shows the presence of active local transmission of parasites to resident bird species in the southeast of Iran and contributes to the knowledge on haemosporidian parasite biodiversity in this poorly studied region of the world