Global effects of ade8 deletion on budding yeast metabolism
AbstractPurine auxotrophy is a typical marker for many laboratory yeast strains. Supplementation of additional purine source (like adenine) is necessary to cultivate these strains. If not supplied in adequate amounts, purine starvation sets in. We tested purine starvation effects in budding yeast Saccharomyces cerevisiae ade8 knockout. We explored effects brought by purine starvation in cellular, central carbon metabolism and in the global transcriptome level.We observed that cells cultivated in purine depleted media became significantly more tolerant to severe thermal, oxidative and desiccation stresses when compared to the cells cultivated in media with all necessary supplements. When sta…
Effect of hydrogen peroxide on the dehydrogenase and quinone-reductase activity of irradiated Lactobacillus plantarum cells
Abstract The resistance of lactobacilli to oxidative stress is of great importance for their applicability as probiotics. This study aimed to evaluate the response of Lactobacillus plantarum strain ATCC® 14917™, grown in either de Man, Rogosa, and Sharpe agar (MRS medium) or tryptic soy broth (TSB medium), to 1–2 mM H2O2 after the exposure to different doses of ionising radiation. Two bacterial extracellular enzyme groups, dehydrogenases (DHAs) and quinone reductases (QRs), served as the criteria of viability and antioxidant activity, respectively. The irradiated L. plantarum culture grown in TSB showed increased QR activity at irradiation doses of 2–50 Gy, with the maximum activity at 10 G…
Drying enhances immunoactivity of spent brewer's yeast cell wall β-D-glucans.
Due to immunological activity, microbial cell wall polysaccharides are defined as 'biological response modifiers' (BRM). Cell walls of spent brewer's yeast also have some BRM activity. However, up to date there is no consensus on the use of spent brewer's yeast D-glucan as specific BRM in humans or animals. The aim of this paper is to demonstrate the potential of spent brewer's yeast β-D-glucans as BRM, and drying as an efficient pretreatment to increase β-D-glucan's immunogenic activity. Our results revealed that drying does not change spent brewer's yeast biomass carbohydrate content as well as the chemical structure of purified β-D-glucan. However, drying increased purified β-D-glucan TN…
Spectroscopic and electrochemical study of interactions between DNA and different salts of 1,4-dihydropyridine AV-153
1,4-dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antimutagenic and DNA-binding activity. The latter activity was first described for water-soluble 1,4-DHP with carboxylic group in position 4, the sodium salt of the 1,4-DHP derivative AV-153 among others. Some data show the modification of physicochemical properties and biological activities of organic compounds by metal ions that form the salts. We demonstrated the different affinity to DNA and DNA-protecting capacity of AV-153 salts, depending on the salt-forming ion (Na, K, Li, Rb, Ca, Mg). This study aimed to use different approaches to collate data on the DNA-binding mode of AV-153-N…
Spectrophotometric study of DNA interactions with ftorafur and its elementoorganic derivatives
ABSTRACTFtorafur is an antimetabolite antitumour drug successfully used for treatment of various tumours. It is generally accepted that ftorafur is converted to 5-fluoruracil. However, some data indicate direct interactions of the compound with DNA. To test this hypothesis we have performed spectrophotometric study of DNA interactions of ftorafur and some of its elementoorganic derivatives with DNA. UV-VIS spectra of the tested compounds were recorded in absence and presence of increasing amounts of DNA. DNA caused a hypochromic effect in spectra of ftorafur, similar, but weaker effect was observed in 5-fluoruracil spectra. Trimethylgermyl derivative of ftorafur manifested a higher DNA-bind…
Modeling the mobility of glyphosate from two contrasting agricultural soils in laboratory column experiments
Glyphosate (GLP) currently is one of the most widely used herbicides worldwide. The persistence of GLP and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment has been described by other authors. This study was aimed at comparing the GLP and AMPA behavior in sandy and loamy sand soils after spiking with enhanced (445 µg g−1) concentrations of GLP in herbicide KLINIK® (Nufarm, Austria) and bioaugmentation followed by 40 days weathering and a consistent three-stage leaching in a laboratory column experiment. Soil samples were obtained from mineral topsoil (0–10 cm) within former agricultural lands where soil parent material was formed by glacigenic deposits. The total a…
Optimization of Nitrification Process by a Bacterial Consortium in the Submerged Biofiltration System with Ceramic Bead Carrier
Laboratory-scale solid phase submerged system was developed to study the process of ammonium biodegradation. Ceramic beads were found to be an appropriate carrier material for the attachment of thePNN bacterial consortium (Pseudomonas sp., Nitrosomonas sp., Nitrobacter sp.) exhibiting nitrification/denitrification activity. This consortium was previously isolated from a biological activated sludge process at a fish factory wastewater treatment plant. Three organic amendments - molasses, humic acid extract, and malt extract - were used for the ceramic bead pretreatment. Molasses significantly enhanced (p<0.05) the process of bacteria attachment onto the ceramic carrier and further ammonium r…