Effects of the antinociceptive dipeptide L-tyrosine-L-arginine (kyotorphin) on the motivation, anxiety, and memory in rats

Introduction: The endogenous dipeptide L-tyrosine-L-arginine (kyotorphin, KTP) is found in brain structures related to the processing of information for nociception, the control of emotions, and memory formation. Besides the antinociceptive effect of KTP, it has a mild protective activity against the deleterious influence of the brain hypoperfusion and streptozotocin on the behavior and memory. Aim: We aimed to study the effects of the intracerebroventricular injection of effective antinociceptive doses of KTP on the motivational behavior, memory, and blood and hippocampal levels of the carbonylated proteins in healthy male adult Wistar rats.Materials and methods: We used a paw-pressure test for assessment of acute nociception, an open field test for assessment of exploration and habituation to a new environment, elevated plus maze test for the evaluation of anxiety-like behavior, and novel object recognition test for working memory. Carbonylated protein assay was used for the assessment of the oxidative impairment of the proteins. The results were analyzed by ANOVA.Results: The present data showed that all single doses of KTP exerted an antinociceptive effect, but this effect was not observed after chronic administration. Only the highest dose of 100 µg was able to induce anxiolytic and motor inhibiting effects. None of the doses used showed effects on the recognition memory or the level of the carbonylated protein. Conclusion: Our results showed that KTP exerted its antinociceptive effect without affecting negatively the blood and brain carbonylated protein or basic behavioral parameters related to the exploration, motivation, and memory formation in healthy rats

WOOD DECAY MACROFUNGI: STRAIN COLLECTION AND STUDIES ABOUT ANTIOXIDANT PROPERTIES

The study of wood decay macrofungi that naturally biodegrade lignocellulosic polymers has been steadily increasing due to their numerous and innovative applications. In the last decade, the researchers of Mycological Laboratory of Pavia University (Italy) isolated in pure culture wood decay macrofungi collected in their own country. A few species have been investigated as regards different aspects: the growth profile at different temperature and the capacity to secrete cell wall degrading enzymes growing on poplar wood chips and sawdust. The aim of the present study was to test four lignicolous species (Daedalea quercina, Fistulina hepatica, Lenzites warnieri, Schizophyllum commune) as regards their antioxidant activity. The two species poorly or not investigated till now for this activity, D. quercina and L. warnieri, revealed the most interesting results

Cell response of Antarctic strain <i>Penicillium griseofulvum</i> against low temperature stress

During the evolution organisms are subjected to the continuous impact of environmental factors. In recent years an increasing number of studies have focused on the physicochemical limits of life on Earth such as temperature, pressure, drought, salt content, pH, heavy metals, etc. Extreme environmental conditions disrupt the most important interactions that support the function and structure of biomolecules. For this reason, organisms inhabiting extreme habitats have recently become of particularly great interest. Although filamentous fungi are an important part of the polar ecosystem, information about their distribution and diversity, as well as their adaptation mechanisms, is insufficient. In the present study, the fungal strain Penicillium griseofulvum isolated from an Antarctic soil sample was used as a study model. The fungal cellular response against short term exposure to low temperature was observed. Our results clearly showed that short-term low temperature exposure caused oxidative stress in fungal cells and resulted in enhanced level of oxidative damaged proteins, accumulation of reserve carbohydrates and increased activity of the antioxidant enzyme defence. Ultrastructural changes in cell morphology were analysed. Different pattern of cell pathology provoked by the application of two stress temperatures was detected. Overall, this study aimed to observe the survival strategy of filamentous fungi in extremely cold habitats, and to acquire new knowledge about the relationship between low temperature and oxidative stress

Bacillus velezensis R22 inhibits the growth of multiple fungal phytopathogens by producing surfactin and four fengycin homologues

AbstractSignificant agricultural losses are caused by the phytopathogenic fungi Botrytis cinerea and Phytophthora infestans, as well as bacteria of the Ralstonia solanacearum species. The present work aimed to isolate rhizobacteria for simultaneous biocontrol of these three phytopathogenic species and to suggest the mechanisms of their antagonistic action. Among 120 Bacillus spp. isolated from soils, Bacillus velezensis and Bacillus licheniformis strains displayed the highest activity against all three phytopathogens. A rapid, polymerase chain reaction-based method for detecting nonribosomal peptide synthetase genes was developed to elucidate the genetic basis of these traits. The presence of fenA, srfAA, ppsA, and lchAA genes, encoding fengycin/surfactin/plipastatin synthetases and lichenysin synthase, was revealed in the strains’ genomes. The whole genome sequencing (WGS) of B. velezensis R22 showed that it contains 4,081,504 bp (with G + C content 46.35%), 4087 genes for 3935 proteins, 72 tRNAs, 14 rRNAs, and 5 ncRNAs. WGS allowed the prediction of 10 complete clusters for secondary metabolites with putative antimicrobial activity: difficidin, fengycin, bacillaene, butyrosin, bacillibactin, bacilysin, surfactin, macrolactin H, macrolactin R22, and velezensin. LC-MS and high-sensitivity UHPLC-Q-TOF LC-MS/MS analysis were used to search for the predicted metabolites in cell-free supernatants of B. velezensis R22. The compounds with the strongest antifungal activity are surfactin with a C15 β-OH fatty acid chain; two homologous forms of fengycin A; and two fengycin B homologues containing C16 and C17 β-hydroxy fatty acid chains. The broad antimicrobial spectrum of B. velezensis R22 and its molecular characterization provide a good basis for the future development of plant protection preparations

Temperature downshift induces antioxidantresponse in fungi isolated from Antarctica

Although investigators have been studying the cold-shock response in a variety of organisms for the last two decades or more, comparatively little is known about the difference between antioxidant cell response to cold stress in Antarctic and temperate microorganisms. The change of environmental temperature, which is one of the most common stresses, could be crucial for their use in the biotechnological industry and in ecological research. We compared the effect of short-term temperature downshift on antioxidant cell response in Antarctic and temperate fungi belonging to the genus Penicillium. Our study showed that downshift from an optimal temperature to 15° or 6°C led to a cell response typical of oxidative stress: significant reduction of biomass production; increase in the levels of oxidative damaged proteins and accumulation of storage carbohydrates (glycogen and trehalose) in comparison to growth at optimal temperature. Cell response against cold stress includes also increase in the activities of SOD and CAT, which are key enzymes for directly scavenging reactive oxygen species. This response is more species-dependent than dependent on the degree of cold-shock. Antarctic psychrotolerant strain Penicillium olsonii p14 that is adapted to life in extremely cold conditions demonstrated enhanced tolerance to temperature downshift in comparison with both mesophilic strains (Antarctic Penicillium waksmanii m12 and temperate Penicillium sp. t35)

Antimicrobial geopolymer paints based on modified natural zeolite

Many antimicrobial coatings deliver a peak release of antimicrobial agent at an early age, after which they lost antimicrobial activity over time. In the present study a novel geopolymer paints with long term antimicrobial activity were developed based on natural zeolite modified with silver and copper ions. The obtained geopolymer paints were applied by brushing on concrete, ceramic, gypsum paperboard and steel. The coating was characterized by excellent adhesive strength and hiding properties. The long-term antimicrobial effect was evaluated by accelerated aging in carbonation chamber. Microstructural changes were analyzed by powder X-ray diffraction and Fourier transformed infrared spectroscopy. Cytotoxicity, antibacterial, antifungal and virucidal properties were investigated on raw and carbonated geopolymer paints. Geopolymer paints based on modified natural zeolite seems promising antimicrobial coating material that can be implemented in the global fight against the spread of diseases and pathogens

<i>Bacillus velezensis</i> R22 inhibits the growth of multiple fungal phytopathogens by producing surfactin and four fengycin homologues

Significant agricultural losses are caused by the phytopathogenic fungi Botrytis cinerea and Phytophthora infestans, as well as bacteria of the Ralstonia solanacearum species. The present work aimed to isolate rhizobacteria for simultaneous biocontrol of these three phytopathogenic species and to suggest the mechanisms of their antagonistic action. Among 120 Bacillus spp. isolated from soils, Bacillus velezensis and Bacillus licheniformis strains displayed the highest activity against all three phytopathogens. A rapid, polymerase chain reaction-based method for detecting nonribosomal peptide synthetase genes was developed to elucidate the genetic basis of these traits. The presence of fenA, srfAA, ppsA, and lchAA genes, encoding fengycin/surfactin/plipastatin synthetases and lichenysin synthase, was revealed in the strains’ genomes. The whole genome sequencing (WGS) of B. velezensis R22 showed that it contains 4,081,504 bp (with G + C content 46.35%), 4087 genes for 3935 proteins, 72 tRNAs, 14 rRNAs, and 5 ncRNAs. WGS allowed the prediction of 10 complete clusters for secondary metabolites with putative antimicrobial activity: difficidin, fengycin, bacillaene, butyrosin, bacillibactin, bacilysin, surfactin, macrolactin H, macrolactin R22, and velezensin. LC-MS and high-sensitivity UHPLC-Q-TOF LC-MS/MS analysis were used to search for the predicted metabolites in cell-free supernatants of B. velezensis R22. The compounds with the strongest antifungal activity are surfactin with a C15 β-OH fatty acid chain; two homologous forms of fengycin A; and two fengycin B homologues containing C16 and C17 β-hydroxy fatty acid chains. The broad antimicrobial spectrum of B. velezensis R22 and its molecular characterization provide a good basis for the future development of plant protection preparations.</p

Structural and functional characterization of cold-active sialidase isolated from Antarctic fungus Penicillium griseofulvum P29

The fungal strain, Penicillium griseofulvum P29, isolated from a soil sample taken from Terra Nova Bay, Antarctica, was found to be a good producer of sialidase (P29). The present study was focused on the purification and structural characterization of the enzyme. P29 enzyme was purified using a Q-Sepharose column and fast performance liquid chromatography separation on a Mono Q column. The determined molecular mass of the purified enzyme of 40 kDa by SDS-PAGE and 39924.40 Da by matrix desorption/ionization mass spectrometry (MALDI-TOF/MS) analysis correlated well with the calculated mass (39903.75 kDa) from the amino acid sequence of the enzyme. P29 sialidase shows a temperature optimum of 37 °C and low-temperature stability, confirming its cold-active nature. The enzyme is more active towards α(2 → 3) sialyl linkages than those containing α(2 → 6) linkages.Based on the determined amino acid sequence and 3D structural modeling, a 3D model of P29 sialidase was presented, and the properties of the enzyme were explained. The conformational stability of the enzyme was followed by fluorescence spectroscopy, and the new enzyme was found to be conformationally stable in the neutral pH range of pH 6 to pH 9. In addition, the enzyme was more stable in an alkaline environment than in an acidic environment. The purified cold-active enzyme is the only sialidase produced and characterized from Antarctic fungi to date