In vivo hemolytic activity of group B streptococcus is dependent on erythrocyte-bacteria contact and independent of a carrier molecule

Experiments were performed to determine the interaction between the hemolysin of group B streptococcus (GBS) and sheep erythrocytes. Growing GBS were shown to possess a potent hemolysin at a very early stage of the growth cycle. After separation of the cells from the growth medium, all the hemolytic activity remained with the bacterial cells, and no activity could be detected in the growth medium. When fetal calf serum was added to the media, some soluble activity was detected. This activity, however was completely removed by ultracentrifugation, the hemolytic activity being found solely in the pellet. After the hemolysin had formed, no new protein synthesis was needed to cause hemolysis because the addition of chloramphenicol to cells caused no difference in their hemolytic potential. For proof that no short-lived, soluble factors are produced by the bacteria, bacteria and sheep erythrocytes were incubated in contiguous media, separated by a 0.22-m membrane. No hemolytic activity was detected on the erythrocyte side of the membrane, although high amounts of hemolysin could be extracted from the bacteria. Only when a detergent was added to the growth medium was hemolysis detected from the erythrocytes, showing that extracted hemolysin could indeed pass through the membrane. These results suggest that the hemolysin is attached to the surface of the cell and that contact is needed between the bacteria and erythrocyte to cause lysis. Where soluble activity was detected, it was connected to bacterial fragments.     

Peroxidase activities and contents of phenolic acids in embryogenic and nonembryogenic alfalfa cell suspension cultures

Contents of phenolic acids, peroxidase activities and growth curves showed significant differences in embryogenic (EC) and nonembryogenic (NEC) suspension cultures ofMedicago sativa L. NEC gave a typical growth curve while in EC the distinct phases were absent. The total content of phenolic acids was higher in NEC (related to EC), changed during the growth cycle and most of the acids occurred in ester-bound methanol soluble form. The level of phenolic acids in EC was significantly lower and did not change during 12-d cultivation. The major fraction was formed by phenolic acids ester-bound to the cell wall. The cytoplasmic peroxidase activity in NEC increased continuously during the growth and reached the maximum value at the end of exponential phase. In EC the extremely low cytoplasmic peroxidase activity did not change during cultivation. Ionically bound peroxidases in NEC represented 14 to 30% of the total extracted activity in dependence on the growth phase while in EC formed about 50% of the total activity and did not change during studied period. A possible participation of ionic peroxidase in the incorporation of phenolics into the cell wall is discussed.     

Kinetic aspects of inhibition of the phytopathogenic fungi growth by rhizosphere bacteria

Kinetics of growth inhibition of fungi Fusarium and Bipolaris caused by bacteria Pseudomonas sp. V-6798 and Azotobacter chroococum V-2272 D on dense nutrient media, both in single-crop system and by coinoculation, was demonstrated. The speed of fungal colonies growth as a function of bacteria concentration in inoculate was shown to be in accordance with the Ierysalimskii modified equation. The degree of antagonistic activity was suggested to be assessed by the constant of inhibition (K _i ) and residual rate of fungi growth. Constant of inhibition of fungal growth by bacteria varied within 10–100 cells/ml for observed species. More effective fungistatic influence of bacterial strains in combined culture was observed. Parameters reported in the present study allow comparing the degree of bacteria antifungal activity in vitro. Suggested screening method could be used for selection of bacteria as activity biofungicide and while selecting biomedication for defined plant pathogen disruption.     

Cooperative interaction of autocrine and paracrine mitogens for airway epithelial cells

Mitogens of the EGF family may play an important role in regulating the proliferation of airway epithelial cells (AEC). We examined the production of autocrine mitogenic activity by mouse AEC cultured from explants of tracheal tissue. DNA synthesis by growth-arrested AEC was stimulated by conditioned media from cells maintained in serum-free culture without exogenous growth factors. The mitogenic activity was blocked by a specific inhibitor of the EGF receptor tyrosine kinase. Furthermore, conditioned media from AEC contained molecular species that could compete with radiolabeled EGF in a receptor binding assay. However, mitogenic activity was not blocked by neutralizing antibodies to EGF or to transforming growth factor-, but was partly inhibited by co-incubation with heparin, suggesting that it might be due to a heparin-binding member of the EGF family. The activity was potentiated by co-incubation with IGF-1, analogous to the potentiation by IGF-1 of the mitogenic activity of EGF for AEC. Moreover, the autocrine mitogen produced by AEC exhibited cooperative interaction with the mitogenic activity in conditioned media from growth factor-deprived mouse lung fibroblasts, consistent with the hypothesis that interactions with mesenchymal cells could influence the proliferation of AEC in vivo.     

Effects of phosphorus supply on in vitro growth and phosphatase activity of Frankia isolates from Casuarina

An in vitro experiment was conducted to investigate the effects of different sources and levels of P supply on growth, viability and phosphatase activity of three tropical Frankia strains isolated from Casuarina. P concentration for optimum growth was between 0.1 and 10.0 M in the absence of external combined nitrogen. Specific viability was not influenced by P supply. Morphological features of Frankia, such as hyphal length and vesicle numbers, were found to largely mirror growth. Phosphatase activity was detected in all three Frankia strains and was highest when P was omitted from the culture solution. There were more than 10-fold differences between the Frankia strains in the level of phosphatase activities shown. This study suggested that soils low in P are unlikely to restrict micro-symbiont growth activity.     

Comparative study of effects of Escherichia coli M-17 exometabolites and fructooligosaccharides on the growth and antagonistic activity of Lactobacilli

Facts concerning the evaluation of the influence of E. coli M17 exometabolites and fructooligosaccharides (FOS) on the growth and antagonistic activity of lactobacilli are presented. As revealed by these facts, preparation "Aktoflor" accelerates the growth of lactobacillary cultures, increases the final yield of biomass and antagonistic activity. E. coli M17 exometabolites contained in "Aktoflor" have been shown to be more active in comparison with FOS. The character of their influence on lactobacilli is discussed and the conclusion is made that the restoration and maintenance of eubiosis is greatly determined by the pool of metabolites excreted by the bacteria.     

The decline in N2 fixation rate in common bean with the onset of pod-filling: Fact or artifact

It is not clear to what extent genetic, environmental and measurement factors are responsible for the commonly reported decline in nitrogenase activity with the onset of pod-filling in grain legumes. We address this question by observing nitrogenase activity and assimilate partitioning throughout the life span of an indeterminate variety of common bean (GN 1140) under controlled-environment and field conditions. Nitrogenase activity per plant was maintained well into pod-filling in GN 1140 under high-light conditions in growth cabinets. In contrast, plants exposed to a gradual reduction in light intensity during early reproductive growth had a decline in nitrogenase activity on a whole plant basis with the onset of pod-filling. However, the decline was due to an inability to maintain nodule growth, rather than a decrease in specific nitrogenase activity. Under field conditions, acetylene reduction assay of root crowns appeared to indicate a rapid decline in nitrogenase activity with the onset of pod-filling in GN 1140. This decline was not correlated with the water status of the soil or the plant. In contrast, acetylene reduction activity of root cores taken from outside the root crown region (non-crown) and N accumulation by above-ground biomass during pod-filling suggested that whole plant nitrogenase activity was maintained longer than that indicated by root crown assays. We conclude that although the occurrence of a decline in nitrogenase activity with the onset of pod-filling in grain legumes can be genetically determined, in many cases the decline can be the result of growing conditions and improper measurement techniques.     

Inhibition of the NADH oxidase activity of plasma membranes isolated from xenografts and cell lines by the antitumor sulfonylurea,N-(4-methylphenylsulfonyl)-N′-(4-chlorophenyl)urea (LY 181984) correlates with drug susceptibility of growth

Summary Inhibition of NADH oxidase activity of plasma membranes isolated from a series of human xenografts and cell lines by the antitumor sulfonylurea, N-(4-methylphenylsulfonyl)-N-(4-chlorophenyl) urea (LY 181984), correlated with the ability of the sulfonylurea to inhibit cell growth. Growth of rat kidney cells either untransformed or transformed with Kirsten-ras (K-ras) were unaffected by the sulfonylurea. Similarly, the NADH oxidase activity of isolated plasma membranes from K-ras transformed cells was unaffected by LY 181984. In contrast, when transformed with Harvey-ras (H-ras), both growth and NADH oxidase activity were inhibited. With the inactive but structurally related LY 181985 (N-4-methylphenyl-sulfonyl)-N-(phenyl)urea), neither growth nor plasma membrane NADH oxidase activity of either sulfonylurea-susceptible or -resistant tissues or cell lines was inhibited. Both sulfonylureas were inactive with rat liver plasma membranes but NADH oxidase activity of plasma membranes and growth with HeLa cells was inhibited by the active (LY 181984) but not by the inactive (LY 181985) sulfonylurea. The findings suggest a possible correlation between inhibition of plasma membrane NADH oxidase activity by the antitumor sulfonylureas and their oncolytic action.     

Effects of estrogen and growth hormone on steroid sulfatase activity and estrogen binding in rat liver

It is now well established that the activity of certain liver enzymes displays sex differences and that administration of human growth hormone to male rats alters the liver metabolism in a "female" direction. In this work we studied steroid sulfatase activity and binding of estradiol-17 beta in livers from intact rats and found a sex difference, with considerably higher enzyme activity in male as compared to female liver tissue. Continuous infusion of native and recombinant human growth hormone and estradiol-17 beta to male rats reduced sulfatase activity to "female" levels. A specific binding of estradiol-17 beta with receptor properties was found in the rat livers, but the concentration of binding sites did not change after administration of growth hormone or estradiol in this group of intact animals. Our data confirm previous reports that continuous administration of human growth hormone "feminize" liver metabolism, and since estradiol was found to have an identical effect on sulfatase activity it is suggested that the effect of estradiol-17 beta in this respect may be indirect, mediated via an altered secretory pattern of rat growth hormone.     

Growth of an interleukin 2/interleukin 4-dependent T cell line induced by granulocyte-macrophage colony-stimulating factor (GM-CSF)

Lymphokine activities in conditioned medium from activated helper T cell lines are most commonly defined by the proliferation of "specific" lymphokine-dependent cell lines. Various sublines of IL 2-dependent (and ostensibly specific) HT-2 and CTLL cells have now been shown to proliferate in response to BSF-1/IL 4 as well. After activation with antigen or mitogen, D10.G4.1, an antigen-specific cloned T helper cell that has recently been shown to produce IL 4 but not IL 2, secretes two distinct cytokines that induce the growth of HT-2 cells. These "T cell growth factors" (TCGF) can be separated by reversed phase high-performance liquid chromatography (RP-HPLC). The TCGF activity of one of these factors can be blocked by 11B11, an antibody specific for IL 4. The second TCGF activity is not affected by 11B11 or by antibodies specific for IL 2. This TCGF activity can be neutralized by a goat polyclonal antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF), and has a RP-HPLC elution profile identical to that of recombinant GM-CSF. Recombinant GM-CSF induces both proliferation and long-term growth of HT-2 but not CTLL cells, and this activity can be neutralized by the same antibody to GM-CSF. GM-CSF is best known as a factor that induces the maturation and growth of granulocytes and macrophages from bone marrow-derived hematopoietic precursor cells. The ability of GM-CSF to induce the growth of certain T cell lines indicates that this molecule may play a role in T cell-mediated immune responses, either as an autocrine growth factor or a paracrine stimulus from both lymphoid and nonlymphoid tissues that produce this cytokine.     

Fibrinolytic and collagenolytic activity of extracellular proteinases of the strains of micromycetes <Emphasis Type="Italic">Aspergillus ochraceus</Emphasis> L-1 and <Emphasis Type="Italic">Aspergillus ustus</Emphasis> 1

It was shown that extracellular proteinases produced by the strains of micromycetes A. ochraceus L-1 and A. ustus 1 differ by the activity at various pH as well as by the intensity of the effect on fibrillar proteins. It was revealed that the proteinases of A. ochraceus L-1 demonstrated maximum activity during the growth of the producer in the nitrate-free growth medium (the pH of enzyme reaction was 8.0), whereas those of A. ustus 1 showed maximal activity during the growth of the micromycete in the medium containing sodium nitrate (the pH of enzyme reaction was 6.0). Values of specific fibrinolytic and collagenolytic activities of A. ochraceus L-1 were 2.2 and 1.6 times higher than those of A. ustus 1. At the same time, A. ustus 1 showed very low values of total proteolytic (caseinolytic) activity and had a high ratio of fibrinolytic activity to total proteolytic (caseinolytic) activity (6.92). It makes the strain a promising producer of proteinases, which hydrolyze fibrin and collagen.     

Cellular location,activity states,and macromolecular organization of glucoamylase in Clostridium thermosaccharolyticum

By application of immunocytochemical techniques at the electron microscope level, glucoamylase was localized to the cell periphery in Clostridium thermosaccharolyticum during and following growth on starch, sucrose or glucose. Levels of immunolabelling were found to be relatively independent of growth substrate and of phase of growth, whereas previous studies had demonstrated strong dependence of glucoamylase activity on growth conditions; previously high levels of glucoamylase activity had been detected after growth on starch (i.e. during the stationary phase after growth) and only very low activities detected during exponential growth and following growth on glucose. The results presented demonstrate that levels of the glucoamylase protein are independent of measurable enzyme activity, and imply that the protein is constitutive. This indicates that the protein can exist in active and inactive states in the cell. By analogy with similar systems, we consider it likely that maturation or activation of newly synthesized glucoamylase occurs during (or following) transport through the cytoplasmic membrane. Electron microscopy of individual protein molecules which had been subjected to negative staining revealed that the enzyme consists of two domains of approximately equal size which are linked by a hinge region.     

Cultivation and antibiotic activity of mycorrhizal basidiomycetes

In 17 species (35 strains) of basidiomycetes which form mycorrhizas with Scotch pine (Pinus silvestris L.) the influence of media and method of cultivation on growth and manifestation of antibiotic activity were investigated under laboratory conditions. The antibiotic activity was influenced by the composition of the nutrient media as well as by mode of cultivation, while the ability and intensity of growth depended first of all on the composition of the media.Amanita citrina, Clitopilus prunulus, Lactarius helvus, Rhizopogon roseolus, Russula fragilis, Tricholoma albobrunneum, Tricholoma imbricatum, andTricholoma saponaceum exhibited antibiotic activity. The intracellular antibiotics ofTricholoma saponaceum andRhizopogon roseolus exerted the highest activity. It has been confirmed that the antibiotic activity of the cultures corresponds in most cases to the activity of the fruit-bodies grown in nature.     

Growth of a thermotolerant ethanol-producing strain of Kluyveromyces marxianus on cellobiose containing media

Summary The thermotolerant yeast strain, Kluyveromyces marxianus 1MB 3, was shown to be capable of limited growth on cellobiose containing media at 45°C. Growth, sugar utilization and ethanol production were shown to increase in the presence of exogenously added thermostable fungal -glucosidase. During active growth of the organism on cellobiose-containing media, -glucosidase activity was detected in cell lysate preparations with only minor amounts of activity present in the extracellular culture filtrate. The results suggest that limitations in ethanol production by this organism during growth on cellobiose containing media may be overcome by addition of exogenously added -glucosidase which results in increased substrate access to the biocatalytic unit.     

Toxicity of Mercaptoethanol to Mutant Strains of the Yeast Pichia methanolica Growing on Different Carbon Sources

Addition of -mercaptoethanol at a concentration of 2–3 mM to media containing methanol, glucose, or yeast extract caused a 50% inhibition of the growth of wild-type yeastPichia methanolica; mercaptoethanol at a concentration of 0.7 to 25 mM inhibited the growth of the mutant strain ecr1. The mutation mth1 of P. methanolica repressed its ability to consume methanol and was accompanied by the loss of alcohol oxidase (EC 1.1.3.13) activity. -Mercaptoethanol restored the ability of mth1 mutant cells to grow on methanol and stimulated their growth under derepression conditions. The growth effect of -mercaptoethanol during derepression was accompanied by partial restoration of alcohol oxidase activity.     

Effects of adenine and cytokinins on growth and protein kinase activity of Verticillium albo-atrum

Growth ofVerticillium albo-atrum in liquid Czapek-Dox broth was stimulated about four-fold by added 10 mM adenine, N⁶-benzyladenine, or kinetin. Less stimulation was evident at lower concentrations. With none of these included in the basal growth medium, detectable protein kinase activity in cell-free extracts was low and responded minimally to cAMP (adenosine 3, 5-cyclic monophosphate) in the reaction mixture. With each of these compounds as an additive to the growth medium, protein kinase activity was not only greater but also responded markedly (several fold) to cAMP. These results demonstrate a strong correlation between exogenously supplied adenine and related compunds, increased growth, increased protein kinase activity, and kinase response to cAMP in this organism.Journal Series No. 524, New Mexico State University Agricultural Experiment Station, Las Cruces.     

Effects of applied auxin,gibberellin and cytokinin on the activity of peroxidases in the peduncles of rose flowers

The activity of peroxidases in the proximal part of the flower peduncle of rose cv. Nubia was promoted by exogenous application of auxin but not by gibberellin or cytokinin. In cv. Mercedes the activity was promoted also by gibberellin and cytokinin. In the distal parts of the peduncles of both cultivars, peroxidase activity was not affected by any of the applied growth regulators. In young flowers of cv. Nubia the protein content of the penduncles was affected only by cytokinin, and in aged flowers only by auxin, while in Mercedes peduncles the content of protein was not affected by any of the applied growth regulators. The specific activity of peroxidases was promoted by auxin in peduncles of Nubia and by both auxin and cytokinin in peduncles of Mercedes flowers.     

Hemopoietic regulatory factors in human hemopoietic failures

There are two distinct hemopoietic activities in human serum that do not have the properties of the known hemopoietic lymphokines. These two activities appear not to be produced by immune competent cells. "Direct" stimulatory activity acts in primary target cultures of normal marrow. There does not appear to be a feedback mechanism between bone marrow failure and "direct" activity; it appears to reflect ongoing disease. Indirect "releaser" activity stimulates peripheral blood cells to produce hemopoietic growth factors. It is invariably elevated when release of hemopoietic growth factors is poor, indicating that a feedback mechanism exists. The peripheral blood cells of young patients, particularly young girls, respond poorly to autologous "releaser" stimulation. Results of treatment with ALG in this group are poor. However, all patients with aplastic anemia appear capable of producing adequate amounts "releaser" factor.     

Adaptation of blood sugar regulation during muscular activity. Effects of training]

Our aim was to study the adaptation of energetic metabolism to muscular activity and the effects of training upon these adaptations. So we realized swimming and running tests on young healthy adults, selected in "trained" and "untrained". The effects of muscular activity were reflected by a raise of serum F.F.A., clearly noted in "untrained" subjects ; the levels of glucose and growth hormone both raised, but especially in "trained" subjects. Cortisol level raised in varying degrees while insulinemia presented little changes.     

Phosphatase activity ofPenicillium citrinum submerged batch cultures and its relationship to fungal activity

Acid and alkaline phosphatase activities were evaluated using batch fermenter cultues ofPenicillium citrinum, an organism used in studies of fungal functioning in soil. Fungal activity was assessed by monitoring rates of O₂ utilization, glucose utilization, dry weight changes over time, and lengths of FDA-stained hyphae. At low growth rates (7 g dry wt increases·h^–1·ml^–1) and low culture activity, phosphatase activity at both pH 8.5 and 5.5 tended to decrease with culture age, with the exception that phosphatase activity at pH 8.5 peaked during early stationary phase. At higher growth rates (25 g dry wt increase·h^–1·ml^–1) and high culture activity, phosphatase activity tended to remain constant throughout the course of the experiment. The relationship between phosphatase activity and other measures of fungal activity was consistent only at low growth rates for acid phosphatase. These results suggest that phosphatase measurements will be of limited utility in assessing activity, except at low growth rates.