Functional characteristics of yeast cells in nutrient aqueous solution enriched with ortho-H2O isomers

It has been experimentally established that cultivation of yeast cells in depleted, dietary or normal nutrient aqueous solutions enriched with ortho-H₂O spin isomers is accompanied by an increase in the amount of carbon dioxide produced by the cells and an increase in their biomass. It has been revealed that the rate of metabolic processes and biological activity depends on the quality of nutrition and enhances in time in both nutrient solutions. In contrast, the reproductive function and the rate of cell division are insusceptible to the components of nutrition, but intensified in a solution enriched with ortho-H₂O similar to retardation of aging. The observed effects are discussed in assumption that an increase of a portion of ortho-H₂O molecules occurs in the neighborhood of water channels in the cell membrane that let through only monomers of H₂O and determine the rate vicinity of metabolic processes.     

Cytogenetic study of the effect of gossypol on mouse germ cells

The clastogenic and mutagenic activities of a new antifertility and antitumor agent gossypol were studied in the mouse male germ cells. Results of the present work indicate that at the doses 125 and 250 mg/kg the drug does not significantly increase frequencies of the micronuclei in the early spermatids and sperm head abnormalities. Hence, genotoxic influence can not be proposed as responsible for the antifertility effect of gossypol.     

Chitinolytic Enterobacter agglomerans Antagonistic to Fungal Plant Pathogens

Three Enterobacter agglomerans strains which produce and excrete proteins with chitinolytic activity were found while screening soil-borne bacteria antagonistic to fungal plant pathogens. The chitinolytic activity was induced when the strains were grown in the presence of colloidal chitin as the sole carbon source. It was quantitated by using assays with chromogenic p-nitrophenyl analogs of disaccharide, trisaccharide, and tetrasaccharide derivatives of N-acetylglucosamine. A set of three fluorescent substrates with a 4-methylumbelliferyl group linked by (beta)-1,4 linkage to N-acetylglucosamine mono- or oligosaccharides were used to identify the chitinolytic activities of proteins which had been renatured following their separation by electrophoresis. This study provides the most complete evidence for the presence of a complex of chitinolytic enzymes in Enterobacter strains. Four enzymes were detected: two N-acetyl-(beta)-d-glucosaminidases of 89 and 67 kDa, an endochitinase with an apparent molecular mass of 59 kDa, and a chitobiosidase of 50 kDa. The biocontrol ability of the chitinolytic strains was demonstrated under greenhouse conditions. The bacteria decreased the incidence of disease caused by Rhizoctonia solani in cotton by 64 to 86%. Two Tn5 mutants of one of the isolates, which were deficient in chitinolytic activity, were unable to protect plants against the disease.     

The effect of camphor on bacterial bioluminescence

Summary The inhibitory effect of camphor on bioluminescence of both bacteria and bacterial luciferase has been examined. The camphor has been shown to be a substrate of cytochrome P-450 of the luminous bacteria Photobacterium fischeri. The inhibition of the luminescence reaction provided evidence for the competitive nature of the interaction of camphor and aliphatic aldehyde at the binding site for luciferase. Camphor is also supposed to interact with P-450. The findings indicate that the hydroxylation process of camphor affects the kinetics of the luminescence.     

Bioluminescent Toxicity Assay of Polyethylenimine-Based Sorbents

Applied Biochemistry and Microbiology - The toxicity of polyethylenimine-based sorbents and their extracts was evaluated, and their effect on the bioluminescence of Photobacterium phosphoreum...     

Variation in eggshell traits between geographically distant populations of pied flycatchers Ficedula hypoleuca

The expression and impact of maternal effects may vary greatly between populations and environments. However, little is known about large‐scale geographical patterns of variation in maternal deposition to eggs. In birds, as in other oviparous animals, the outermost maternal component of an egg is the shell, which protects the embryo, provides essential mineral resources and allows its interaction with the environment in the form of gas exchange. In this study, we explored variation of eggshell traits (mass, thickness, pore density and pigmentation) across 15 pied flycatcher populations at a large geographic scale. We found significant between‐population variation in all eggshell traits, except in pore density, suggesting spatial variation in their adaptive benefits or in the females’ physiological limitations during egg laying. Between‐ population variation in shell structure was not due to geographic location (latitude and longitude) or habitat type. However, eggshells were thicker in populations that experienced higher ambient temperature during egg laying. This could be a result of maternal resource allocation to the shell being constrained under low temperatures or of an adaptation to reduce egg water loss under high temperatures. We also found that eggshell colour intensity was positively associated with biliverdin pigment concentration, shell thickness and pore density. To conclude, our findings reveal large‐ scale between‐population variation of eggshell traits, although we found little environmental dependency in their expression. Our findings call for further studies that explore other environmental factors (e.g. calcium availability and pollution levels) and social factors like sexual selection intensity that may account for differences in shell structure between populations.     

Biosensitive element in the form of immobilized luminescent photobacteria for detecting ecotoxicants in aqueous flow‐through systems

We demonstrated the possibility of long‐term and efficient application of a biosensitive element (BE) in the form of Photobacterium phosphoreum photobacteria immobilized in poly(vinyl alcohol) (PVA) cryogel for detecting various ecotoxicants ( Zn ^{2 +} , Cu ^{2 +} , Hg ^{2 +} , Pb ^{2 +} , 2,4‐dichlorophenoxyacetic acid, 2,6‐dimethylphenol, pentachlorophenol, coumaphos, malathion, chlorpyrifos and methyl parathion) in flow‐through media. The range of detectable concentrations of ecotoxicants was determined at 1 × 10 ^?8 to 1 × 10 ^?4 M for heavy metal ions and at 1 × 10 ^?8 to 1 × 10 ^?5 M for phenol derivatives and organophosphorus pesticides. Immobilized cells of photobacteria quantitatively reacted with these ecotoxicants; cell sensitivity exhibited no flow rate dependence in the range from 45 to 180 mL/h. At a constant concentration of ecotoxicant in the flow, the bioluminescence quenching profile of immobilized cells demonstrated an integral response. The BE could remain in a flow‐through medium for at least 10 days while retaining 95% of luminescent activity in the absence of ecotoxicants. The BE tested in this work was demonstrated to have a long shelf life (> 60 weeks) at ?80°C without changes in the baseline level of bioluminescence. Copyright © 2016 John Wiley & Sons, Ltd.     

Generalized and species-specific prediction models for aboveground biomass in semi-steppe rangelands

Aims The accurate estimation of aboveground biomass in vegetation is critical for global carbon accounting. Regression models provide an easy estimation of aboveground biomass at large spatial and temporal scales. Yet, only few prediction models are available for aboveground biomass in rangelands, as compared with forests. In addition to the development of prediction models, we tested whether such prediction models vary with plant growth forms and life spans, and with the inclusion of site and/or quadrat-specific factors.