Interference effects of Cassia uniflora Mill on Parthenium hysterophorus L.

In some parts of Karnataka and Maharashtra states (India), a leguminous undershrub, Cassia uniflora has effectively replaced the problematic weed Parthenium hysterophorus (parthenium). The studies revealed that the phenolic leachates from different parts of C. uniflora, specially from germinating seeds significantly inhibited the germination of parthenium seeds and retarded the growth of seedlings from the successfully germinated parthenium seeds. At field level, seedlings of C. uniflora outcompeted the seedlings of summer generation of parthenium causing reduction in height, dry weight and number of inflorescences of the latter which ultimately resulted in reduction of their seed output. Because of its longer life span, C. uniflora effectively prevented the establishment of parthenium plants of the winter generation in its area of growth. Results indicate that C. uniflora replaces parthenium through interference.     

Production of ethanol from sugars in wood hydrolysate byFusarium oxysporum

Wood hydrolysate used for ethanol production by two strains ofFusarium oxysporum contained 2.3% (w/v) reducing sugars (xylose and glucose). Ethanol production at the optimum reducing sugar concentration of 54.8 g/l medium, at pH 5.5, and 30°C was 12.3 g/l and 11.7 g/l byF. oxysporum D-140 and NCIM-1072, respectively in shake flasks during 96 h fermentation. The maximum production of ethanol under optimum cultural conditions, and in the presence of yeast extract plus minerals, was 13.2 g/l medium byF. oxysporum D-140 over 108 h fermentation.

---

Résumé L'hydrolysat de bois utilisé pour la production d'éthanol par deux souches deFusarium oxysporum contenait 2.3% (poids/vol.) de sucres réducteurs (xylose et glucose). La production d'éthanol, à la concentration optimum en sucres réducleurs de 54.8 g par litre de milieu à pH 5.5 et à 30°C était de 12.3 g/l et 11.7 g/l respectivement chezF. oxysporum D-140 et NCIM-1072, en flacons agités pendant 96 h de fermentation. La production maximum d'éthanol, dans les conditions optimum de culture, et en prosence d'extrait de levure et de minéraux a mit de 13.2 g par litre de milieu chezF. oxysporum D-140 en 108 h de lermentation.

     

Inactivation of G1ucose-6-Phosphate Dehydrogenase Isozymes from Human and Pig Brain by Aluminum

Prolonged intake of low levels of aluminum from the drinking water has been found to increase the aluminum content in rat brain homogenates and to reduce the activity of hexokinase and glucose-6-phosphate dehydrogenase (G6PD). To determine the interaction of G6PD with aluminum in the brain, we have recently purified two isozymes of G6PD (isozymes I and II) from human and pig brain. Unlike isozyme I, isozyme II also had 6-phosphogluconate dehydrogenase (6-PGD) activity. We report here that G6PD isozymes I and II from human and pig brain purified to apparent homogeneity are inactivated by aluminum. Aluminum did not affect the 6-PGD activity of isozyme II. The aluminum-inactivated enzyme contained 1 mol of aluminum/mol of enzyme subunit. The protein-bound metal ion was not dissociated by exhaustive dialysis at 4 degrees C against 10 mM Tris-HCl (pH 7.0) containing 0.2 mM EDTA. Preincubation of aluminum with citrate, NADP+, EDTA, NaF, ATP, and apotransferrin protected the G6PD isozymes against aluminum inactivation. However, when the G6PD isozymes were completely inactivated by aluminum, only citrate, NaF, and apotransferrin restored the enzyme activity. The dissociation constants for the enzyme-aluminum complex of the isozymes varied from 2 to 4 microM, as measured by using NaF, a known chelator for aluminum. Inhibition of G6PD by low levels of aluminum further strengthens the suggested role of aluminum toxicity in the energy metabolism of the brain.     

Differential utilization of beta-tubulin isotypes in differentiating neurites

beta-Tubulin is encoded in vertebrate genomes by a family of six to seven functional genes that produce six different polypeptide isotypes. We now document that although rat PC-12 cells express five of these isotypes, only two (classes II and III) accumulate significantly as a consequence of nerve growth factor-stimulated neurite outgrowth. In contrast to previous efforts that have failed to detect in vivo distinctions among different beta-tubulin isotypes, we demonstrate using immunoblotting with isotype-specific antibodies that three beta-tubulin polypeptides (classes I, II, and IV) are used preferentially for assembly of neurite microtubules (with approximately 70% of types I and II assembled but only approximately 50% of type III in polymer). Immunofluorescence localization shows that an additional isotype (V) is partially excluded from neurites. Distinctions in in vivo localization of the neuron-specific, class III isotype have also been directly observed using immunofluorescence and immunogold electron microscopy. The sum of these efforts documents that some in vivo functional differences between tubulin isotypes do exist.     

Ferritin—A general metal detoxicant

Binding of nonferrous metal ions to ferritin was compared to that of the phosphate-free or phosphate containing synthetic iron cores. The Scatchard plots for the synthetic cores reveal a high affinity site for Cd, Zn, Be, and Al, with K_D in the range 10^?5–10^?7 M. Preloading the cores with phosphate increased the number of metal ions bound without altering the K_D. The metal ions with smaller ionic radii (Be, Al) were bound in larger numbers than those with larger ionic radii (Cd, Zn). Ferritin isolated from soybean (Glycina max), horse spleen, and rat liver bound the metal ions in amounts larger than predicted from their iron core. Whereas the iron cores and their nonferrous metal ion complexes were insoluble, those in the protein shell remained in solution. Thus apoferritin precipitated with lower concentrations of aluminum than did holoferritin. Also, Al bound to apoferritin reduced the rate of iron loading into the protein.     

Field observations on impact of egg parasiteTelenomus remus [Hym.: Scelionidae] on tobacco caterpillar,Spodoptera litura [Lep.: Noctuidae] in tobacco nurseries in Andhra Pradesh,India

The tobacco caterpillar,Spodoptera litura F. is a major pest in the tobacco nurseries causing damage by defoliation. Inundative releases were carried out with 650,000 parasites from 1st July, 1974 to 30th November, 1976. This paper reports the effectiveness from 1976 to 1979 of the parasite in reducing the population of tobacco caterpillar.Telenomus remus Nixon was found significantly effective in reducing the pest population at the peak of infestation in the site of release as compared to control nurseries where no parasites were released. However, the difference inSpodoptera population between the site of release and control was minimal during the last 1979 nursery season which suggests the necessity of inundative releases ofT. remus after every 2 years for effectively checking the population ofS. litura in tobacco nurseries.

---

Résumé La noctuelle du tabac,Spodoptera litura F. est un ravageur très important des pépinières de tabac du fait de ses défoliations. On a procédé à des lachers inondatifs de 650.000 parasites du 1^er juillet 1874 au 30 novembre 1976. Cette note indique l'action du parasite entre 1976 et 1979 dans la réduction des populations de chenilles du tabac. On a constaté queTelenomus remus Nixon a une activité significative dans la réduction des populations du ravageur au moment du maximum d'infestation dans le lieu de lacher par rapport aux pépinières témoins sans introduction de parasites. Cependant la différence des niveaux de population entre le lieu de lacher et le terrain a été minimum lors de la dernière période de plantation en pépinière en 1979, ce qui suggère la nécessité d'effectuer tous les 2 ans des lachers inondatifs deT. remus pour lutter efficacement contreSpodoptera dans les pépinières de tabac.

---

---

Paper presented at the 4th Tobacco Symposium held at Rajahmundry-533 105, India, 19–22 Jan. 1981.     

Xanthanolides from Xanthium indicum

From the aerial parts of Xanthium indicum, in addition to known compounds, two new xanthanolides were isolated and the stereochemistry of xanthumin     

Reactivity of fluorodinitrobenzene with intact human leucocytes: Examination of sites of action and the molecular entities involved in interaction

The epsilon amino groups of lysine and to a lesser extent amino groups on phosphotidyl ethanolamine and phosphotidyl serine situated on cell membranes of normal human leucocytes have been identified as the sites of dinitrophenylation.In situ conversion of 10,000 hydrophylic amino sites into hydrophobic sites on cell surfaces causes conformational changes in cell membranes with exposures of leukaemic cell-specific neo-antigens on tagged cell surfaces.     

MB78, a virulent bacteriophage of Salmonella typhimurium

The isolation and some properties of a virulent bacteriophage of Salmonella typhimurium, MB78, which is morphologically, serologically, and physiologically unrelated to P22, are reported. The phage has a noncontractile long tail with partite ends. It cannot multiply in minimal medium in the presence of citrate. MB78-infected cells are, however, killed in such medium. This phage cannot grow in rifampin-resistant mutants of the host. The latent period of growth of this phage is much shorter than that of P22. Both sieA and sieB genes of the resident P22 prophage are required to exclude the superinfecting MB78 phage, whereas all temperate phages related to P22 are excluded by either one or both of the genes individually. Restriction endonuclease cleavage patterns of P22 and MB78 are distinctly different. The absence of homology between the two phages P22 and MB78 suggests that MB78 is not related to phage P22.