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141.
The ultrastructural changes in the populations of the pertussis causative agent maintained for a prolonged period of time on nutrient media containing antibiotics were studied with the method of electron microscopy. Significant changes in the ultrastructure of the cells and the population composition due to the effect of tetracycline, levomycetin or erythromycin were observed. The ultrastructure of the populations affected by penicillin or streptomycin and their biological properties were most similar to those of the initial strains. The electronogrammes revealed morphological heterogeneity of the initial and experimental cultures and changes in the subpopulation composition induced by the antibiotics. 相似文献
142.
M. V. Efimova L. V. Kolomeichuk E. V. Boyko M. K. Malofii A. N. Vidershpan I. N. Plyusnin I. F. Golovatskaya O. K. Murgan Vl. V. Kuznetsov 《Russian Journal of Plant Physiology》2018,65(3):394-403
The mechanisms of potato (Solanum tuberosum L.) plants’ tolerance to chloride salinity were investigated in cv. Lugovskoi regionalized in Russia. Regenerated plants were produced in vitro from apical meristem and grown on half-strength Murashige and Skoog medium (0.5 MS) using a hydroponic unit in controlled-climate conditions. At the age of six weeks, the plants were exposed to salt stress (50–150 mM NaCl, 7 days). Plant response to salt stress was estimated by growth parameters (fresh and dry biomass of the aboveground and underground parts of plants, linear dimensions of shoot and root, area of leaf surface, and number of stolons) and physiological characteristics (level of photosynthetic pigments, accumulation of sodium, potassium, and calcium ions in the aboveground and underground parts of plants, content of proline, activity of antioxidant enzymes, plant tissue hydration, osmotic potential, and POL). It was found that, in response to salinity, the plants of potato, cv. Lugovskoi, showed a considerable inhibition of growth processes, reduction in chlorophyll a content, and suppression of stolon formation, which points to a rather low salinity tolerance of the cultivar. At the same time, under weak or moderate salt stress, the plants preserved water homeostasis owing to effective osmoregulation, actively accumulated proline that acted as a stress protector, and showed hardly any signs of oxidative stress. It was assumed that low salt tolerance of this cultivar depends on the inability of its root system to retain sodium ions and ensure selective ion transport to the aboveground part of the plant and on inefficiency of the system of sodium ions’ removal from the cytoplasm of leaf cells and their compartmentalization in the central vacuole with the purpose of reducing their toxic effect. The obtained results may be useful for working out a technique of improving salt tolerance of this cultivar by the methods of molecular genetics. 相似文献
143.
Milla Salmela Tapio Lehtinen Elena Efimova Suvi Santala Ville Santala 《Biotechnology and bioengineering》2019,116(8):1934-1945
Lignin has potential as a sustainable feedstock for microbial production of industrially relevant molecules. However, the required lignin depolymerization yields a heterogenic mixture of aromatic monomers that are challenging substrates for the microorganisms commonly used in the industry. Here, we investigated the properties of lignin-related aromatic compounds (LRAs), namely coumarate, ferulate, and caffeate, in the synthesis of biomass and products in an LRA-utilizing bacterial host Acinetobacter baylyi ADP1. The biosynthesis products, wax esters, and alkanes are relevant compounds for the chemical and fuel industries. Here, wax esters were produced by a native pathway of ADP1, whereas alkanes were produced by a synthetic pathway introduced to the host. Using individual LRAs as substrates, the growth and product formation were monitored with internal biosensors and off-line analytics. Of the tested LRAs, coumarate was the most propitious in terms of product synthesis. Wax esters were produced from coumarate with yield and titer of 37 mg/gcoumarate and 202 mg/L, whereas alkanes were produced with a yield of 62.3 µg /gcoumarate and titer of 152 µg/L. This study demonstrates the microbial preference for certain LRAs and highlights the potential of A. baylyi ADP1 as a host for LRA upgrading to value-added products. 相似文献
144.
Kolomeichuk L. V. Khripach V. A. Kuznetsov V. V. Efimova M. V. 《Doklady. Biochemistry and biophysics》2022,502(1):25-29
Doklady Biochemistry and Biophysics - We compared the defensive response of rape plants to treatment with 24-epibrassinoldide (10 nM, EBL) before the onset of salt stress (preadaptation stage) and... 相似文献
145.
Smoke inhalation can produce acute pulmonary edema. Previous studies have shown that the bronchial arteries are important in acute pulmonary edema occurring after inhalation of a synthetic smoke containing acrolein, a common smoke toxin. We hypothesized that inhalation of smoke from burning cotton, known to contain acrolein, would produce in sheep acute pulmonary edema that was mediated by the bronchial circulation. We reasoned that occluding the bronchial arteries would eliminate smoke-induced pulmonary edema, whereas occlusion of the pulmonary artery would not. Smoke inhalation increased lung lymph flow from baseline from 2.4 +/- 0.7 to 5.6 +/- 1.2 ml/0.5 h at 30 min (P < 0.05) to 9.1 +/- 1 ml/0.5 h at 4 h (P < 0.05). Bronchial artery ligation diminished and delayed the rise in lymph flow with baseline at 2.8 +/- 0.7 ml/0.5 h rising to 3.1 +/- 0. 8 ml/0.5 h at 30 min to 6.5 +/- 1.5 ml/0.5 h at 240 min (P < 0.05). Wet-to-dry ratio was 4.1 +/- 0.2 in control, 5.1 +/- 0.3 in smoke inhalation (P < 0.05), and 4.4 +/- 0.4 in bronchial artery ligation plus smoke-inhalation group. Smoke inhalation after occlusion of the right pulmonary artery resulted in a wet-to-dry ratio after 4 h in the right lung of 5.5 +/- 0.8 (P < 0.05 vs. control) and in the left nonoccluded lung of 5.01 +/- 0.7 (P < 0.05). Thus the bronchial arteries may be major contributors to acute pulmonary and airway edema following smoke inhalation because the edema occurs in the lung with the pulmonary artery occluded but not in the lungs with bronchial arteries ligated. 相似文献
146.
The distribution of students of Moscow State University with respect to the types of profile of lateral organization of motor and sensory functions was studied. The results were compared to previous data (1980–1995) obtained for an identical sample of subjects by the same methods. A considerable decrease in the proportion of “pure” right-handers and increases in the percentages of ambidextrous subjects and left-handers, as well as right-handed subjects with different variants of ear and eye domination, were detected. 相似文献
147.
148.
A possibility was shown of purification of the concentrated toxoids of the Cl. perfringens and Cl. oedematiens species in examination of KSK-2, KSK-2,5; MCA-2 silicagels. The specific activity of the preparations obtained and the yield approached the analogous indices obtained in stratification of Sephadex G-75. The effect of preliminary silicagel treatment and also of the nature of buffer solutions on the efficacy of the process of purification of the gangrenous toxoids was established. 相似文献
149.
M G Efimova V A Blagoveshchenski? B V Khatuntseva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1982,(12):87-92
The data on the study of the protective activity of theta hemolysin and Cl. perfringens lecithinase preparations and the corresponding antitoxic sera obtained by indirect immune affinity chromatography are presented. Experiments in mice and guinea pigs indicate that the injection of antihemolytic serum and immunization with anatheta hemolysin ensures the protection of the animals from theta toxin. The enrichment of analecithinase preparation with anatheta hemolysin has been found to increase its protective properties against Cl. perfringens culture and toxin. 相似文献
150.
The combined action of polyene macrolid antibiotic amphotericin B and styryl dye RH 421 in model lipid membranes and in yeast Saccharomyces cerevisiae is studied. Addition of RH 421 to ergosterol-containing lipid bilayers leads to an increase by 8.5 ±3.2 times of the equilibrium number of open amphotericin channels. The agar-diffusion method shows that RH 421 enhances the antimicrobial effect of amphotericin B, leading to an increase by 1.5 times of the zone of growth inhibition of S. cerevisiae strain. Our data suggest that RH 421 is a potential synergist of amphotericin B and can be used in novel drugs with improved pharmacological properties. 相似文献