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1.
The frequencies and spectra of surnames have been analyzed in groups of raions (districts) of the Belgorod oblast (region) with different degrees of population subdivision. The “family name portraits” of districts with low (0.00003 < < f*r < 0.00022, \(\overline {f_r^ * } \) = 0.00015) and moderate (0.00023 < f*r < 0.00042, \(\overline {f_r^ * } \) = 0.00029) inbreeding levels are similar both to each other and to the “family name portrait” of the Belgorod oblast as a whole. Districts with high subdivision levels (0.00043 < f*r < 0.00125, \(\overline {f_r^ * } \) = 0.00072) had very distinctive surname spectra and the highest surname frequencies. Intense immigration to the Belgorod oblast significantly affects its population genetic structure, decreasing the population subdivision.  相似文献   

2.
Summary The maltose utilization system of Candida utilis was affected by glucose through two different mechanisms: catabolite repression and inactivation. Maltose permease was under the control of both, whereas -glucosidase was only repressed.In glucose-maltose continuous culture, both sugars were consumed simultaneously at glucose steady-state concentrations in the fermentor below 100 mg/l, corresponding to dilution rates lower than 0.4 h-1. At higher dilution rates, and consequently higher glucose concentrations, repression increased steeply, being complete when glucose concentration reached 170 mg/l.Glucose induced inactivation of maltose permease, in maltose-growing and resting cells, by decreasing V max, without changing maltose affinity for its transport system. The inactivation process apparently required the entrance of the inactivator into the cell and its subsequent phosphorylation because: 1) The specific inactivation rate showed a dependence on glucose similar to that of glucose transport and 2) only rapidly phosphorylated glucose analogues could mimic the inactivation effect.  相似文献   

3.
The processes of photosynthesis, chemosynthesis and sulphate reduction were quantitatively studied in the brackish meromitic lake Faro (Sicily) with the aid of C14 and S35. The layer of “red water” was situated at the depht of the chemocline (13–14 m), where the average concentration of H2S was 10 mg/l. The total biomass of bacterioplankton consisted in this layer mostly of a brown Chlorobium which reached a wet weight of 30 g/m3. The production of photosynthesis in this layer was 30–60 µg C/l/day. The microbial population in the “red water” was found adapted to an extremely low light intensity and to show a light optimum at the depth µg 9m where only 2,5% of outside light penetrates. The photoautotrophic microflora is consumed by infusoria found in mass in the “red water” layer. An active H2S-production was found in the water column in the upper part of the H2S-zone and in the bottom sediments. The data are discussed from the view point of the trophology of meromitic basins.  相似文献   

4.
Summary Continuous fermentation fed by 150 kg/m3 of glucose with total cell recycling by tangential microfiltration enabled yeasts concentration of 300 kg/m3 (dry weight) to be reached with a dilution rate of 0,5h–1 and a cell viability greater than 75%. The stability of this system was tested for 50 residence times of the permeate. The method can be used both for the production of cell concentrates and for high rates of metabolite production.Nomenclature D. W. dry weight - XT (kg/m3) total cell concentration D.W. - XV (kg/m3) viable cell concentration D.W. - V viability of cell culture in per cent of total cell concentration - S (kg/m3) glucose concentration - P (kg/m3) ethanol concentration - D (h) dilution rate - R (kg/kg) fermentation yield - (h) specific growth rate - vp(kg/kg/h) specific alcohol production rate - (m) yeast size - (kg/kg) kg of intracellular water per kg of dry cells  相似文献   

5.
6.
The present study demonstrates that the mitochondrial respiratory chain includes not three but four energy coupling sites, the fourth site being localized at the NADPH→NAD+ step.
  1. The NADPH→NAD+-directed transhydrogenase reaction in sonicated beef heart submitochondrial particles energizes the particle membrane as judged by two membrane potential probes, i.e. uptake of a penetrating anion, phenyldicarbaundecaborane (PCB?), and enhancement of anilinonaphthalene sulfonate (ANS?) fluorescence.
  2. The reverse reaction (NADH→NADP+) is accompanied by the oppositely directed anion movement, i.e. PCB? efflux.
  3. Being insensitive to rotenone, antimycin, cyanide, and oligomycin, both the influx and efflux of PCB? coupled with transhydrogenase reaction can be prevented or reversed by uncouplers.
  4. Equalization of concentrations of the transhydrogenase substrates and products also prevents (or reverses) the PCB? influx coupled with oxidation of NADPH by NAD+, as well as the PCB? efflux coupled with reduction of NADP+ by NADH.
  5. The transhydrogenase-linked PCB? uptake depends linearly on the energy yield of the oxidation reaction calculated according to formula $$\Delta G = RTln\frac{{[NADPH] x [NAD^ + ]}}{{[NADP^ + ] x [NADH]^ \cdot }}$$ No threshold value of Δ was found. Measurable PCB? transport was still observed at Δ≤0.5 kcal/mole NADPH oxidized.
  6. Partial uncoupling of transhydrogenase reaction and PCB? transport, induced by low concentrations ofp-trifluoromethoxycarbonylcyanide phenylhydrazone (FCCP), dinitrophenol, or by removing coupling factor F1, results in the decrease of the slope of the straight line showing the PCB? uptake as a function of Δ. Oligomycin improves the coupling in F1-deprived particles, the slope being increased. Rutamycin, dicyclohexylcarbodiimide (DCCD) and reconstitution of particles with F1, also increase the coupling.
  7. In phosphorylating particles oxidizing succinate by O2, both the energy-dependent NADH→NADP+ hydrogen transfer and PCB? influx possess equal sensitivity to FCCP, which is lower than the sensitivity of oxidative phosphorylation. Similarly, the decrease in the succinate oxidation rate induced by malonate arrests first phosphorylation and then under higher malonate concentration, PCB? influx. The rate of NADPH→NAD+ transhydrogenase reaction was found to be lower than the threshold value of rate of succinate oxidation, still coupled with phosphorylation. Respectively, the values of PCB? uptake under transhydrogenase reaction are lower than those inherent in phosphorylating oxidation of succinate.
The conclusion is made that the NADPH→NAD+-directed transhydrogenase reaction generates the membrane potential of the same polarity as respiration and ATP hydrolysis but of a lower magnitude (“plus” inside particles; the forward hydrogen transfer). The NADH→NADP+-directed transhydrogenase reaction forms the membrane potential of the opposite polarity (“minus” inside particles; the reverse hydrogen transfer). Under conditions used, the transhydrogenase-produced membrane potential proves to be too low to support ATP synthesis (and, most probably, the synthesis of any other high-energy compound) maintaining, nevertheless, some electrophoretic ion fluxes. A conclusion is made that transhydrogenase forms a membrane potential with no high-energy intermediates involved.  相似文献   

7.
Long-term observations have shown that “totally” respiration-deficient (TRD) chromosomal mutants (p?+) isolated after nitrite treatment of haploidSaccharomyces cerevisiae strains very often give origin spontaneously to “partially” respiration-deficient (PRD) chromosomal mutants (p'?+). While cultures of vegetative (P??) and chromosomal (p?+) TRD-mutants cannot utilize non-fermentable carbon sources such as acetate, p'?+-strains can utilize acetate, although their consumption is slow and always less than that of P?+ (wild) strains with intact respiration.Qo2 andQco2 maesurements during the stationary phase on glucose substrate permit the calculation of the oxidative (OEP) and fermentative (FEP) and thus the total (GEP) energy production. From these values a strain-specific respiratory-activity-quotient (AQ) can be calculated. The group of the PRD strains shows a “continuous” transition from the TRD mutants to the “wild” P?+ strains. All RD mutants have a tendency to maintain their total energy production values by means of an intensified fermentation. The diminution of the OEP resulting from the RD mutation exeeds that of the GEP by approximately 60 to 70 %. The rate of oxygen uptake is increased by a raisedpo 2 in p'?+ mutants. This is not the case with TRD mutants. Whether or not the tendency to endogenous regeneration as shown by the frequent spontaneous occurence of the process p?+ → p'?+ can be regarded as a genetic “long-term regulation” is discussed.  相似文献   

8.
Results of the investigation of four isolates of the sour cherry necrotic ringspot virus are presented in this paper. The isolates used caused characteristic symptoms on woody indicators “Bing”, “Montmorency”, F 12/1, and on peach seedlings. The virus was transmitted mechanically to some herbaceous species:Antirrhinum majus, Cucumis sativus, Cucurbita maxima, Chenopodium quinoa Crotalaria juncea, Momordica balsamina, Petunia hybrida andLeonorus sibiricus. The attempts to transmit the virus mechanically to further 23 herbaceous species were unsuccessful. The thermal inactivation point of the virus lies between 46 and 58°C and the dilution end-point between 10?1 and 10?2. The virus is stable in vitro at room temperature for more than one day. Individual virus isolates gave a positive immunological reaction with the Fulton’s “G” antiserum.  相似文献   

9.
T. Kamaya 《Mycopathologia》1969,37(4):320-330
Young colonies of Sabouraud's glucose agar room temperature culture ofCandida species from human isolation were suspended in distilled water. The suspension was mixed with a solution of lysozyme and incubated in a 37° C water bath. Within 3–5 hours, various species ofCandida cells showed flocculation to varying degrees which occurred at varying periods of onset. Among sevenCandida species,Candida albicans andCandida stellatoidea showed the strongest flocculation, earliest onset and most solution clarity than did any other species.Candida stellatoidea was indistinguishable fromCandida albicans in its degree of flocculation, and in the clarity of solution.Candida species may be arranged in the following order according to their decreasing positivity in flocculation:
  1. Candida albicans
  2. Candida stellatoidea
  3. Candida tropicalis
  4. Candida krusei
  5. Candida pseudotropicalis
  6. Candida parapsilosis
  7. Candida guilliermondii
  8. Saccharomyces species may be placed afterCandida guilliermondii.
It seems possible to separate theCandida species into 3 groups by the rate of flocculation, and clarity of solution. Group I.Candida albicans andCandida stellatoidea. Group II.Candida tropicalis, C. krusei andCandida pseudotropicalis. Group III.Candida parapsilosis andCandida guilliermondii. Saccharomyces specimens (S. cerevisiae and others) were placed after group III.  相似文献   

10.
One of the kinteic equations derived previously from a series of sophisticated batch and continuous alcohol fermentations by using a respiration-deficient mutant of baker's yeast is as follows: where dp/dt = ethanol production rate, v0 = specific rate of ethanol production at p = 0, k2 = empirical constant, Ks = saturation constant, S = glucose concentration, and X = cell mass concentration. The above equation was confirmed in the previous paper to fit, the brewing of “sake.” The temperature of the specific brewing is not always constant (10 to 18°C). The effect of temperature on v0 was assessed from the Arrhenius plot, assuming that k2 was independent of temperature. Values of dp/dt taken from the “sake” brewing data were rearranged, taking the temperature change into account. These datu, corrected for the temperature, were found to follow quite favorably the kinetic equation mentioned above. So far, a prediction of the ethanol production rate in practice was rectified to the extent of p = 19%.  相似文献   

11.
  1. The respiratory chain energy conservation systems of Bacillus megaterium strains D440 and M have been investigated following growth in batch and continuous culture. Respiratory membranes from these strains contained cytochromes b, aa 3 , o and b, c, a, o, respectively; both readily oxidised NADH but neither showed any pyridine nucleotide transhydrogenase activity.
  2. Whole cells of both strains exhibited endogenous →H-/O ratios of approximately 4; when loaded with specific substrates the resultant →H+/O ratios indicated that proton translocating loops 1 and 2 were present in strain D440 and that loops 2 and 3 were present in strain M.
  3. In situ respiratory activities were measured as a function of dilution rate during growth in continuous culture. True molar growth yields with respect to oxygen (Y O 2) of approximately 50 g cells·mole oxygen-1 were obtained for most of the nutrient limitations employed. Average values for Y ATP of 12.7 and 10.8 g cells·mole ATP equivalents-1 were subsequently calculated for strains D440 and M respectively.
  4. Energy requirements for maintenance purposes were low in energy-limited cultures but were substantially increased when growth was limited by nitrogen source (NH 4 + ). Under the latter conditions there is probably a partial uncoupling of energy-conserving and energy-utilising processes leading to energy wastage.
  相似文献   

12.
High fermenter (volumetric) ethanol productivities (80 g/lh–1) were attained in a simple single-stage continuous-stirred-tank-reactor (CSTR) employing a flocculent mutant of Zymomonas mobilis with a feed containing 100g/l glucose. Under these conditions a final ethanol concentration of 47.6 g/l was obtained, representing a maximum conversion efficiency of 97% of theoretical.Nomenclature SR = Medium glucose concentration (g/l)X Biomass concentration (g/l) - P Ethanol concentration (g/l) - VP Volumetric productivity (g ethanol/l/h) - Yp/s Product yield coefficient (g ethanol/g glucose consumed) - Qp Specific rate of ethanol formation (g ethanol/g cells/h) - D Dilution rate (h–1) - Dmax Maximum dilution rate: ie., highest dilution rate at which the effluent glucose concentration 4g/l (h–1)  相似文献   

13.
The general morphology of cuticle-lined internal genitalia and oviduct is analyzed in intact females of the phytophagous mites, Loboquintus subsquamatus and Trisetacus cf bagdasariani (Acari: Eriophyoidea) using tetramethylrhodamine B isothiocyanate-phalloidin, three anaesthetics (magnesium sulphate, lidocaine and CO2-enriched water) and confocal laser scanning microscopy (CLSM). This is the first protocol adopted for CLSM studying musculature of mites. Revision of the previous terminology of eriophyoid internal genitalia from Nuzzaci and Alberti (Eriophyoid mites: their biology, natural enemies and control. World crop pests 6. Elsevier, Amsterdam, pp 101–150, 1996) resulted in the refinement of the terms “distal oviduct”, “genital chamber” and “spermatheca”. Relative position of the elements of cuticle-lined internal genitalia is discussed and a generalized 3D model and animation (available on-line as supplementary material) of eriophyoid genital apparatus are provided. The wall of eriophyoid oviduct contains strong longitudinal muscles attached to the cuticle genital chamber with folded walls. When the egg is being extruded by contraction of the oviduct muscles, it forms lobes corresponding to the internal topography of the oviduct and genital chamber; these lobes invaginate inward from the gonopore, resulting in the “flower-shaped” figures rarely observed in slide-mounted mites. Gnathosomal muscles (cheliceral muscles and extrinsic muscles of palps) and opisthosomal muscles D1 of Loboquintus mites are attached to the three posterior depressions near the rear prodorsal shield margin. Prospects of CLSM approach for studying different aspects of mite morphology are briefly discussed.  相似文献   

14.
15.
An enzyme catalyzing the transfer of the glucosyl moiety of UDP-glucose to the 3-hydroxyl group of cyanidin has been demonstrated in petal extracts of Silene dioica mutants with cyanidin-3-O-glucoside in the petals. This transferase activity was also present in young rosette leaves and calyces of these plants. The highest glucosyltransferase activity was found in petals of opening flowers of young plants. The enzyme was purified ninetyfold by PVP and Sephadex chromatography. The glucosyltransferase had a pH optimum of 7.5, had a “true Km value” of 4.1×10?4 m for UDP-glucose and 0.4×10?4 m for cyanidin chloride, and was not stimulated by divalent metal ions. Both p-chloromercuribenzoate and HgCl2 inhibited the enzyme activity. Pelargonidin chloride and delphinidin chloride at reduced rates also served as substrates. The enzyme did not catalyze the glucosylation of the 3-hydroxyl group of flavonols or the 5-hydroxyl group of anthocyanins. ADP-glucose could not serve as a glucosyl donor. The results of Sephadex G150 chromatography suggest that the glucosyltransferase can exist as dimer of about 125,000 daltons and as active monomers of 60,000 daltons. The genetic control of the glucosyltransferase activity is discussed.  相似文献   

16.
Glucose-limited chemostat cultures of Candida utilis were cultivated at various pH levels (3.0–7.5), temperatures (15–37.5°C), dilution rates (0.06–0.42 hr?1), and with different nitrogen sources (NH and NO). The ratio of total nucleic acid to protein increased with increase in dilution rate at constant temperature and decreased with increase in temperature at constant dilution rate. The pattern of these variations is consistent with the hypothesis that the nucleic acid to protein ratio is a function of the ratio of the actual dilution rate to the critical dilution rate corresponding to each one of the cultivation temperatures. This ratio is called “reduced dilution rate.” A basis is proposed on which various microorganisms may be compared with respect to the ratios of cell protein to nucleic acid, RNA, ribosomal RNA, and polysomes.  相似文献   

17.
Summary Deficiency of inorganic phosphate caused the hyper production of invertase and the derepression of acid phosphatase in a continuous culture ofSaccharomyces carlsbergensis. The specific invertase activity was 40,000 enzyme units per g dry cell weight at a dilution rate lower than 0.05 h–1 with a synthetic glucose medium of which the molecular ratio of KH2PO4 to glucose was less than 0.006. This activity is eight fold higher than in a batch growth and 1.5 fold as much as the highest enzyme activity observed so far in a glucose-limited continuous culture.For the hyper production of invertase, it is necessary to culture the yeast continuously by keeping the Nyholm's conservative inorganic phosphate concentration at less than 0.2 m mole per g dry weight cell. The derepression of acid phosphatase brought about by phosphate deficiency, was similar in both batch and continuous cultures.Nomenclature D dilution rate of continuous culture (h–1) - Ei invertase concentration in culture (enzyme unit l–1) - Ep acid phosphatase concentration in culture (enzyme unit l–1) - P inorganic phosphate concentration in culture (mM) - S glucose concentration in culture (mM) - X cell concentration in culture (g dry weight cell l–1) Greek Letter specific rate of growth (h–1) Suffix f feed - 0 initial value  相似文献   

18.
Summary The formation of acetic acid by the thermophilic nonsporeforming homoacetogenic bacterium Acetogenium kivui was studied under various conditions. In pH-controlled batch fermentation at pH 6.4 this bacterium was able to produce up to 625 mM of acetic acid from glucose within 50–60 h. The value of max obtained was about 0.17 h-1, the yield was about 2.55 mol of acetic acid per mol of glucose utilized. In continuous fermentation both substrate concentration and dilution rate (D) influenced the yield of acetate and the stationary concentration: a glucose concentration of 67 mM at D=0.09 h-1 resulted in 2.82 mol acetate/mol glucose and 190 mM acetate at a production rate of 17.1 mM/1 h. When the dilution rate was increased the production rate reached a maximal value of 43.2 mM/1 h at D=0.32 h-1. At a glucose concentration of 195 mM the dependence of yield upon dilution rate followed a similar pattern and an acetate concentration of 420 mM could be obtained. Enzymatic studies indicate that in A. kivui pyruvate ferredoxin-oxidoreductase and acetate kinase are inhibited at acetate concentrations higher than 800 mM. Based on these results a fed-batch fermentation was developed, which allowed to produce more than 700 mM acetic acid within 40–50 h.Dedicated to Prof. Dr. H. J. Rehm on the occasion of his 60th birthday  相似文献   

19.
An industrial scale reactor concept for continuous cultivation of immobilized animal cells (e.g. hybridoma cells) in a radial-flow fixed bed is presented, where low molecular weight metabolites are removed via dialysis membrane and high molecular products (e.g. monoclonal antibodies) are enriched. In a new nutrient-split feeding strategy concentrated medium is fed directly to the fixed bed unit, whereas a buffer solution is used as dialysis fluid. This feeding strategy was investigated in a laboratory scale reactor with hybridoma cells for production of monoclonal antibodies. A steady state monoclonal antibody concentration of 478 mg l-1 was reached, appr. 15 times more compared to the concentration reached in chemostat cultures with suspended cells. Glucose and glutamine were used up to 98%. The experiments were described successfully with a kinetic model for immobilized growing cells. Conclusions were drawn for scale-up and design of the large scale system.Abbreviations: cGlc – glucose concentration, mmol l-1; cGln – glutamine concentration, mmol l-1; cAmm – ammonia concentration, mmol l-1; cLac – lactate concentration, mmol l-1; cMAb – MAb concentration, mg l-1; D – dilution rate, d-1; Di – dilution rate in the inner chamber of the membrane dialysis reactor, d-1; D0 – dilution rate in the outer chamber of the membrane dialysis reactor, d-1; q*FB,Glc – volume specific glucose uptake rate related to the fixed bed volume, mmol lFB -1 h-1; q*FB,Gln – volume specific glutamine uptake rate related to the fixed bed volume, mmol lFB -1 h-1.  相似文献   

20.
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