In vitro propagation and chemical and biological studies of the essential oil of Salvia przewalskii Maxim

The procedure of Salvia przewalskii shoot multiplication and the ability of regenerated plants to produce essential oil is reported. The essential oil was obtained by hydrodistillation from leaves and flowering stems of field-grown plants, and their chemical composition was examined by GC, GC-MS and 1H NMR. The differences in yield as well as qualitative and quantitative composition between the oils isolated from in vitro and in vivo plants were observed. S. przewalskii essential oil was tested for its antimicrobial and cytotoxic properties. It was found that cytotoxicity against human leukemia HL-60 cells and antimicrobial activity (especially, against Staphylococcus aureus and S. epidermidis strains) of oils isolated from in vitro plants were higher than those for oils from in vivo S. przewalskii plants.     

Bacterial DNA repair genes and their eukaryotic homologues: 1. Mutations in genes involved in base excision repair (BER) and DNA-end processors and their implication in mutagenesis and human disease

Base excision repair (BER) pathway executed by a complex network of proteins is the major system responsible for the removal of damaged DNA bases and repair of DNA single strand breaks (SSBs) generated by environmental agents, such as certain cancer therapies, or arising spontaneously during cellular metabolism. Both modified DNA bases and SSBs with ends other than 3'-OH and 5'-P are repaired either by replacement of a single or of more nucleotides in the processes called short-patch BER (SP-BER) or long-patch BER (LP-BER), respectively. In contrast to Escherichia coli cells, in human ones, the two BER sub-pathways are operated by different sets of proteins. In this review the selection between SP- and LP-BER and mutations in BER and end-processors genes and their contribution to bacterial mutagenesis and human diseases are considered.     

The temperate Burkholderia phage AP3 of the Peduovirinae shows efficient antimicrobial activity against B. cenocepacia of the IIIA lineage

Burkholderia phage AP3 (vB_BceM_AP3) is a temperate virus of the Myoviridae and the Peduovirinae subfamily (P2likevirus genus). This phage specifically infects multidrug-resistant clinical Burkholderia cenocepacia lineage IIIA strains commonly isolated from cystic fibrosis patients. AP3 exhibits high pairwise nucleotide identity (61.7 %) to Burkholderia phage KS5, specific to the same B. cenocepacia host, and has 46.7–49.5 % identity to phages infecting other species of Burkholderia. The lysis cassette of these related phages has a similar organization (putative antiholin, putative holin, endolysin, and spanins) and shows 29–98 % homology between specific lysis genes, in contrast to Enterobacteria phage P2, the hallmark phage of this genus. The AP3 and KS5 lysis genes have conserved locations and high amino acid sequence similarity. The AP3 bacteriophage particles remain infective up to 5 h at pH 4–10 and are stable at 60 °C for 30 min, but are sensitive to chloroform, with no remaining infective particles after 24 h of treatment. AP3 lysogeny can occur by stable genomic integration and by pseudo-lysogeny. The lysogenic bacterial mutants did not exhibit any significant changes in virulence compared to wild-type host strain when tested in the Galleria mellonella moth wax model. Moreover, AP3 treatment of larvae infected with B. cenocepacia revealed a significant increase (P < 0.0001) in larvae survival in comparison to AP3-untreated infected larvae. AP3 showed robust lytic activity, as evidenced by its broad host range, the absence of increased virulence in lysogenic isolates, the lack of bacterial gene disruption conditioned by bacterial tRNA downstream integration site, and the absence of detected toxin sequences. These data suggest that the AP3 phage is a promising potent agent against bacteria belonging to the most common B. cenocepacia IIIA lineage strains.

     

Characterisation of biological properties of co‐composted Baltic seaweeds in germination tests

Large quantities of green seaweed, probably due to eutrophication, are found in the Baltic Sea, as well as on the beach. The tourist attractiveness of the seaside resorts is therefore reduced. The aim of this study was to find the method of the utilization of this algal biomass into fertilizers. Algae, collected from the Baltic Sea, were co‐composted with sawdust and quail manure in order to produce natural fertilizer. From the compost, algal extract was additionally produced that can act as a plant growth biostimulant. The compost and extract were biologically evaluated by the determination of the growth and multielemental composition of garden cress (Lepidium sativum) in germination tests. Additionally, the odour emissions during composting process were investigated. It was found that the dry biomass was comparable in all examined groups (compost, extract, distilled water). The average length of plants in the group with compost was 14.5% higher than in the group with the extract (difference not statistically significant). There has been observed a positive effect of the addition of compost on the content of micro‐ and macronutrients in the biomass of the cultivated plants, especially boron, calcium, iron and silicon. The averaged odour concentrations measured from the compost and extract samples were very low and reached the values of 8 and 24 ou_E/m³, respectively. According to the obtained results, by composting of seaweeds it is possible to produce a valuable organic fertilizer, which is the method of valorisation of this biomass.     

Electrofusion of protoplasts from Solanum tuberosum, S. nigrum and S. bulbocastanum

Leaf protoplasts of two wild species, Solanum nigrum var. gigantea (S. ngr gig) and S. bulbocastanum Dun. (S. blb), were electrofused with leaf protoplasts of two diploid potato clones, H-8105 and ZEL-1136, respectively, in order to confer the late blight-resistance from the wild species to the cultivated potato. The S. ngr gig mesophyll (+) H-8105 mesophyll combination resulted in regenerants of mostly normal ngr phenotype. Two regenerants from this combination were proved to be true hybrids by RAPD analysis but they rooted poorely in vitro and did not survive the transfer to soil. The S. ngr gig (+) H-8105 fusion combination was also performed with H-8105 cell suspension derived protoplasts enabling an easy identification of interspecific fusants on basis of their intermediate morphology. From the S. ngr gig mesophyll (+) H-8105 cultured cell combination, many abnormal shoots were regenerated. The two lines which survived had normal ngr phenotype but the presence of tuberosum (tbr) genome in those regenerants was not confirmed by RAPD analysis. No plants with tbr phenotype were obtained from both of S. ngr gig (+) H-8105 combinations. On the contrary, when S. blb mesophyll protoplasts were electrofused with ZEL-1136 mesophyll protoplasts, all regenerated plants had tbr phenotype, indicating much lower morphogenetic potential of S. bulbocastanum in comparison with that of S. nigrum var. gigantea. However, the hybridity of those regenerants has not been confirmed by RAPD analysis with two different primers. The efficiency of the applied fusion procedure and analysis of the regenerants is discussed.     

Nuclear DNA content of Solanum species grown in vitro, as determined by flow cytometry

The DNA relative content in nuclei from several Solanum species, which were used as partners for somatic hybridization, were determined using a flow cytometry method. The nuclei were isolated mechanically or via protoplasts from leaves of in vitro grown plants. In the case of S. nigrum as well as S. tuberosum cv. Bzura and dihaploid clone H8105, the nuclei were also obtained from suspension cultured cells by lysis of protoplasts. The source and the method of nuclei isolation affected the pattern of nuclear DNA in the genotypes studied. The mesophyll nuclei showed two distinct peaks on the DNA histograms, whereas the DNA peaks produced by cell suspension nuclei were broad and less distinct. The DNA content in the nuclei, calculated from the DNA histograms of the samples and a DNA standard historgam (Trout Red Blood Cells, having DNA content of 5.05 pg per nucleus), were much lower in mesophyll nuclei than in those obtained from the cell suspension for the same genotypes. The results are discussed in respect of the genetic instability of Solanum genotypes. The usefulness of a flow cytometry approach in somatic hybridization research is also discussed.     

Patients with Infections of The Central Nervous System Have Lowered Gut Microbiota Alpha Diversity

There are multiple lines of evidence for the existence of communication between the central nervous system (CNS), gut, and intestinal microbiome. Despite extensive analysis conducted on various neurological disorders, the gut microbiome was not yet analyzed in neuroinfections. In the current study, we analyzed the gut microbiome in 47 consecutive patients hospitalized with neuroinfection (26 patients had viral encephalitis/meningitis; 8 patients had bacterial meningitis) and in 20 matched for age and gender health controls. Using the QIIME pipeline, 16S rRNA sequencing and classification into operational taxonomic units (OTUs) were performed on the earliest stool sample available. Bacterial taxa such as Clostridium, Anaerostipes, Lachnobacterium, Lachnospira, and Roseburia were decreased in patients with neuroinfection when compared to controls. Alpha diversity metrics showed lower within-sample diversity in patients with neuroinfections, though there were no differences in beta diversity. Furthermore, there was no significant change by short-term (1–3 days) antibiotic treatment on the gut microbiota, although alpha diversity metrics, such as Chao1 and Shannon’s index, were close to being statistically significant. The cause of differences between patients with neuroinfections and controls is unclear and could be due to inflammation accompanying the disease; however, the effect of diet modification and/or hospitalization cannot be excluded.     

Enhanced biotransformation of mononitrophenols by Stenotrophomonas maltophilia KB2 in the presence of aromatic compounds of plant origin

Stenotrophomonas maltophilia KB2 used in this study is known to metabolise broad range of aromatic compounds including phenol, some chloro and methylphenols, benzoic acids, catochols and others. To study the applicability of the strain for degradation of mononitrophenols in monosubstrate as well as cometabolic systems its degradation potential in the presence of mononitrophenols or different aromatic compounds of plant origin was tested. Stenotrophomonas maltophilia KB2 strain was not able to degrade any of mononitrophenols used in the single substrate experiments. Effect of additional carbon source on nitrophenols degradation revealed that presence of benzoate, 4-hydroxybenzoate or 3,4-dixydroxybenzoate stimulate transformation of 2-nitrophenol, 3-nitrophenol as well as 4-nitrophenol. Depending on growth substrate and mononitrophenol used, decrease in cometabolite concentration was from 25 to 45%. Obtained results suggest that Stenotrophomonas maltophilia KB2 strain could be potentially used for cometabolic degradation of nitrophenols in the presence of aromatic acids, for the bioremediation of contaminated sites.     

NMR and DSC Water Study During Osmotic Dehydration of Actinidia deliciosa and Actinidia chinensis Kiwifruit

This study investigated mass transfer and water state changes promoted by osmotic dehydration on two kiwifruit species, Actinidia deliciosa and Actinidia chinensis. Osmotic treatment was performed in a 61.5% w/v sucrose solution at three different temperatures (25, 35 and 45 °C), with treatment time from 0 to 300 min. Treatment time positively influenced kiwifruit water loss and solid gain while temperature significantly affected only water loss. Peleg’s model highlighted that the main response differences between the two species occurred during the initial phase of the osmotic treatment. Thermal properties and relaxation time measurements offered a complementary view concerning the effects of osmotic dehydration on kiwifruit. DSC parameters appeared to be sensitive to water and solid exchange between fruit and osmotic solution. LF-NMR proton T₂ revealed the consequences of the water–solid exchange on the cell compartments, namely vacuole, cytoplasm plus extracellular space and cell wall. During the osmotic treatment, the initial freezing temperature and the freezable water content decrease was dependent on time and treatment temperature, showing a similar tendency for both the kiwifruit species. They evidenced the same treatment response also concerning the reduction of vacuole and the increase of cytoplasm plus extracellular space T₂ values.