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The uptake of various 14C labelled compounds like (1-14C) glucose, (1-14C) acetate, (2-14C) uracil, (1-14C) leucine and (14C-CH3) methionine was studied in Aspergillus parasiticus. A comparative study of asparagine deficient, zinc deficient and SLS cultures revealed different growth patterns. High lipid levels under zinc and asparagine deficiency were observed. During the stationary phase the synthesis of proteins and DNA declined. The uptake of 14C labelled glucose, methionine and acetate was maximum in asparagine deficient cultures during the transitional and stationary phase of growth. Maximum uptake of labelled methionine and glucose occured during the exponential growth phase (45 h). The uptake of labelled leucine was highest under asparagine deficiency during the exponential and transitional phases but reached a minimum during stationary phase. The uptake of labelled uracil remained high throughout in the asparagine deficient cultures. The mechanism of inhibition of aflatoxin biosynthesis in the absence of zinc and asparagine seems to be different.

The effect of lithium on growth and aflatoxin production in chemically defined medium was studied on three aflatoxigenic strains of Asperigillus flavus group. The three strains used differed in their aflatoxin producing capacities. The possible mechanism of lithium induced stimulation of aflatoxin biosynthesis is discussed.

Zusammenfassung Zn++, Mg++ und Mn++-Ionen stimulieren bei gewissen Konzentrationen den Einbau von C14-acetat in Aflatoxinen durch ruhende Mycelien desAspergillus parasitic in tris-HCl-Puffer bei pH 7,2. Ba++ gaben Aktivierungen über einen weiten Konzentrationsbereich, während Äthanol den Einbau verhindert. Von den Intermedärprodukten des 3-Carbonsäure-Cyclus gab die Citronensäure ein Maximum an Aktivierung.

Zusammenfassung Der Einfluß einer einzigen Dose von Aflatoxin B1 auf die Aktivität der Kückenleber-Mitochondrien-Enzyme wie Succinat-Dehydrogenase, Malat-Dehydrogenase und Isocitrat-Dehydrogenase wurden 24 Std nach der Verabreichung des Toxins untersucht. Eine drastische Reduzierung der Aktivität der obengenannten Enzyme wurde beodachtet, was einen Mitochondrienschaden durch die Aflatoxin-Toxicitiit anzeigt. Eine signifikante Abnahme in der Aktivität der Transaminasen wurde festgestellt. Ein Anstieg in den Aktivitäten der alkalischen Serum-Phosphatase und der Serum-Aldolase der Kücken, zusammen mit einer Abnahme in den Aktivitäten der Leberenzyme, sind bezeichnend für geschädigte Leberfunktionen durch Aflatoxin B1.

Zusammenfassung Die Wirkung verschiedener Einflüsse wie pH-Wert, Puffer, Natriumchlorid und UV-Bestrahlung auf die Fluorescenz von Aflatoxin Bi und G1 wurde untersucht. Die Fluorescenzcharakteristik der Aflatoxine B1 und G1 unterliegt charakteristischen Veränderungen bei pH-Werten über 7,2. Verlängerte Bestrahlung mit UV führte zum Abbau der Aflatoxine, wobei die Intensität von der Natur des Lösungsmittels abhängig ist. Natriumchlorid schützte teilweise die Toxine vor dem Abbau durch UV oder in alkalischer Lösung.[/p]

The rates of breakdown and renewal of individual lipids in cultures of Mycobacterium smegmatis CDC 46 and Mycobacterium phlei ATCC 354 were investigated by means of a pulse labelling technique using palmitate-1-14C. The results indicated that in growing cultures of both strains phospholipids were broken down, and cardiolipin had a very rapid turnover. In chase experiments, almost 45% and 40% of the radioactivity of this component were lost respectively from M. smegmatis and M. phlei during one generation time of the cell. The other two major components, phosphatidyl ethanolamine and phosphatidylinositol mannosides showed relatively low turnover. The loss of radioactivity from phosphatidylinositol mannosides was greater in M. phlei than in M. smegmatis but the loss of radioactivity from phosphatidyl ethanolamine was higher in M. smegmatis. The pattern of loss of radioactivity from lipids was almost the same in both strains, the difference being only in the extent of loss. The differences in the cellular localization of the phospholipids indicate their different roles within the cell. Results obtained with the glyceride fraction indicated a very rapid turnover of triglycerides in both strains.

The metabolism of mycobacteria have been studied with reference to carbohydrate, lipids, nitrogen metabolism and oxidative phosphorylation. Some of the enzymes of glycolytic pathway, tricarboxylic acid cycle and lypogenic enzymes were purified, characterized and their kinetic properties investigated. The effect of age of the culture and environmental factors on different aspects of metabolism of mycobacteria were also studied. A comparison of lipid profile in various species of mycobacteria grown in different culture conditions were made. The metabolism of spheroplasts isolated from mycobacteria has been established with respect to their energy charge and to synthesize peptidoglycan using D-alanine as the precursor

Effect of excess feeding and depletion of vitamin A on the ability of adipose tissue to maintain plasma free fatty acid levels has been studied in rats. Both in hypervitaminosis A (fed 9 mg of retinol for 2 consecutive days) and in vitamin A deficiency (kept on a vitamin A-deficient diet for 6 weeks) the rats showed elevated levels of plasma free fatty acids. Hypervitaminosis A caused a decrease in the fatty acid release from adipose tissue on in vitroincubation, probably due to lowered levels of cyclic AMP. On the other hand, adipose tissue from vitamin A-deficient animals showed an increased lipolytic rate as compared to that of the controls. No change in the lipogenic ability was indicated in either of the conditions as indicated by the activities of enzymes involved in this process. We conclude that the fatty acid homeostasis can be greatly influenced by the vitamin A status of the animals.

Abstract: An aldolase was partially purified from fermenter grownMycobacterium tuberculosis H37Rv cells. The aldolase has a molecular weight of 150,000, possesses a tetrameric structure and cleaves both fructose diphosphate and fructose-1-phosphate, the former being cleaved 17 times faster. The enzyme was inactivated by treatment with NaBH4 in the presence of fructose diphosphate or dihydroxyacetone, phosphate suggesting Schiff base formation during its catalytic function. Thiol reagents, EDTA and metal ions had no apparent effect on the aldolase activity. These results show that aldolase is of Class I type. However, this enzyme, unlike the mammalian Class I aldolase, was unaffected by carboxypeptidase A. N-ethylmaleiniide and dithionitrobenzoic acid.

Wachsester vol nAspergillus flavus enthalten Palmitinsäure, Ölsäure und Oleylalkohole als Hauptkomponenten. Das Maximum der Aufnahme von markiertem (1—14C)-acetat in Wachsester wurde vom 2. Tage ab des Wachstums beobachtet (ungefähr 19%), während der Einbau in die Aflatoxine vom 10. Tage ab beobachtet wurde, wenn der Einbau in die Wachsester beträchtlich abnimmt. Die Wachsesterhydrolysate enthalten Vorstufen von Aflatoxin B1. Ein Neuntel der Radioaktivität des Aflatoxins ist auf die Ölsäure zurückzuführen. Es wird daher postuliert, daß der Pilz die Wachsester in die Aflatoxine metaboliert.

Summary The interaction of aflatoxin B1 with a number of biologically important substances has been investigated by spectrophotometric and fluorimetric techniques. The ultra-violet absorption of tryptophan, adenosine, RNA and DNA were altered by the addition of aflatoxin B1. Some amino-acids, purine and pyrimidine derivatives, bovine-serum albumin and DNA quenched the fluorescence of aflatoxin B1. Fluorescence polarization data suggested that the interaction of aflatoxin B1 with bovine-serum albumin was stronger than that with DNA.

The phospholipid-associated protein (55–67 kDa) fraction of Mycobacterium tuberculosis H37Rv was purified as the DE-V protein fraction. This DE-V fraction was used for diagnosis of tuberculosis by enzyme-linked immunosorbent assay (ELISA), detecting IgG antibody in sera collected from different categories of tuberculosis patients, i.e. with acid fast bacilli (AFB) culture-positive pulmonary tuberculosis, with AFB culture-negative, but radiologically suspected, pulmonary tuberculosis, extrapulmonary tuberculosis, and control groups of patients suffering from diseases other than tuberculosis (asthma and/or rhinitis, lepromatous leprosy) as well as from healthy volunteers. Encouraging operational ELISA validity could be achieved with 93% sensitivity, 100% specificity, 97% efficiency, 100% positive predictivity and 95% negative predictability even among the extrapulmonary and suspected pulmonary tuberculosis patients. The above assay was insensitive but with 100% specificity among control group of patients suffering from diseases other than tuberculosis. The DE-V protein fraction was associated with phosphatidyl inositol and phosphatidyl inositol mannosides. The dissociation of phospholipid-protein complex decreased ELISA specificity. ELISA reactivity of the DE-V fraction appeared to be thermostable; thus, it may have serodiagnostic utility in developing countries.

Uptake of radioactive tryptophan by Mycobacterium tuberculosisH37Rv grown in vitro and in vivo was investigated. Kmvalues indicated low affinity, and sodium azide inhibited uptake. Rifampin at the minimal inhibitory concentration had no effect, whereas ethambutol inhibited uptake only in the bacilli grown under in vitro conditions. The significance of these results is discussed.

1. Activation of glucose 6-phosphate is one of the unique properties of pyruvate kinase from Mycobacterium smegmatis. 2. Pyruvate kinase, partially purified from ultrasonic extracts of the mycobacteria by (NH4)2SO4 fractionation, exhibited sigmoidal kinetics at various concentrations of phosphoenolpyruvate, with a high degree of co-operativity (Hill coefficient, h = 3.7) and S0.5 value of 1.0 mM. 3. In the presence of glucose 6-phosphate, the degree of co-operativity shown by the phosphoenolpyruvate saturation curve was decreased to h = 2.33 and the S0.5 value was lowered to 0.47 mM. 4. The enzyme was activated by AMP and ribose 5-phosphate also, but the activation constant was lowest with glucose 6-phosphate (0.24 mM). 5. The enzyme was strongly inhibited by ATP at all phosphoenolpyruvate concentrations. The concentrations of ATP required to produce half-maximal inhibition of enzyme activity at non-saturating (0.2 mM) and saturating (2 mM) phosphoenolpyruvate concentrations were 1.1 mM and 3 mM respectively. 6. The inhibition of ATP was partially relieved by glucose 6-phosphate. 7. The enzyme exhibited Michaelis-Menten kinetics with ADP as the variable substrate, with an apparent Km of 0.66 mM. 8. The enzyme required Mg2+ or Mn2+ ions for activity. It was not activated by univalent cations. 9. The kinetic data indicate that under physiological conditions glucose 6-phosphate probably plays a significant role in the regulation of pyruvate kinase activity.

The interaction of aflatoxin B with a number of biologically important substances has been investigated by spectrophotometric and fluorimetric techniques. The ultra-violet absorption of tryptophan, adenosine, RNA and DNA were altered by the addition of aflatoxin B. Some amino-acids, purine and pyrimidine derivatives, bovine-serum albumin and DNA quenched the fluorescence of aflatoxin B. Fluorescence polarization data suggested that the interaction of aflatoxin B with bovine-serum albumin was stronger than that with DNA. [ABSTRACT FROM AUTHOR]

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Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Human adrenals have been reported to contain 40 to 50 mg total cholesterol and 20 mg phospholipids per g of tissue (Shohl, 1939). The adrenals of male Wistar rats have been found to contain 39·0 mg phospholipids, 3·0 mg free cholesterol, 50·4 mg cholesterol ester, 2·2 mg fatty acids and 18·0 mg triglycerides per g tissue (Angelico, Cavina, D'Antona & Giocoli, 1965). Observations on male guinea-pigs have revealed 230·3 mg total lipids, 30·0 mg phospholipids, 51·0 mg esterified cholesterol and 10·97 mg free cholesterol per g adrenal tissue (Misra, Misra & Venkitasubramanian, 1965).No information is available on the pattern of lipid changes in adrenals of guinea-pigs or other species during pregnancy. Details on phospholipid fractions and on incorporation studies of [1-14C]acetate are also lacking. The present investigation was undertaken to elicit the relevant information.Female

The incorporation of32P-orthophosphate into phospholipids by a toxigenic and a nontoxigenic strain ofAspergillus flavus was compared on a glucose-salts medium (AM medium) and a sucrose-yeast extract medium (YES medium). AM medium gave higher incorporation of32P than YES medium. In AM medium the highest specific activities were found in phosphatidyl choline and phosphatidyl ethanolamine but in YES medium phosphatidyl inositol and phosphatidyl serine also had specific activities of the same order as phosphatidyl choline and phosphatidyl ethanolamine. Mycelia of the toxigenic strain grown and resuspended in AM medium yielded 1.4 times specific activities given by nontoxigenic strain. The two strains did not differ very much in the incorporation obtained in the other media combination tried. These results are in contrast to the large differences obtained in the incorporation of14C-acetate in earlier studies. The significance of these findings are discussed.

Some biochemical properties ofTrigonella foenum-groecuminfected withPeronospora trifoliorumhave been investigated. Qualitative changes were observed in lipids, coumarins, amino acids and indole compounds only. A quantitative study of the phosphate content was also carried out. Neutral lipids did not show any significant changes. In addition to the fourteen phospholipid bands, the infected leaves contained a new band corresponding in Rfto phosphatidic acid or polyglycerophosphate. Seven coumarins were present in both the extracts. In addition 3-hydroxy coumarin, 5-hydroxy-4-methylcoumarin and 7-hydroxy-4-methyl-coumarin were detected in infected leaves. Higher levels of indole acetic acid and three of its derivatives were observed due to infection. Infection altered the free amino acid content. Tryptophan appeared and the total phosphate content increased. Increase in phenols and indoles suggest a higher respiratory rate whereas a higher content of inorganic phosphate suggests uncoupling of phosphorylation from respiration.

Aspergillus parasiticusATCC 15517 produced 28 to 30 mg of aflatoxin per 100 ml of a medium containing sucrose, asparagine, and salts in stationary and shaken cultures. In the absence of asparagine in the medium, the toxin yields fell drastically, and the thin-layer chromatograms of the chloroform extracts of the cultures indicated the total absence of aflatoxin G1and the presence of new intense blue and green fluorescent bands having RFvalues lower than aflatoxins. Initial pH was critical and had to be around 4.5 for good growth and high toxin production on this medium. Optimum concentrations of KH2PO4and MgSO4·7H2O in the medium were much lower than those normally used in fungal growth media.

The phospholipids and glycerides composition of spheroplasts of Mycobacterium smegmatis ATCC 14468 was examined. The percent total phospholipids in total lipids as well as cardio-lipin were found to be higher in spheroplasts as compared to their parent forms. Increase in cardiolipin and free fatty acids content and decrease in triglycerides levels were observed during spheroplasts formation. The results suggest that increase in cardiolipin content in sphero­ plasts is an adaptational change concomittant with the loss of cell walls.

Probable factors influencing resistance to aflatoxin synthesis in soybeans have been investigated by using cultures of Aspergillus parasiticusNRRL 3240. Soybeans contain a small amount of zinc (0.01 μg/g) bound to phytic acid. Autoclaving soybeans at 15 pounds (6803.88 g) for 15 min increases the aflatoxin production, probably by making zinc available. Addition of zinc to both autoclaved and nonautoclaved soybeans promotes aflatoxin production. However, addition of varying levels of phytic acid at a constant concentration of zinc depresses aflatoxin synthesis with an increase in the added phytic acid. In a synthetic medium known to give good yields of aflatoxin, the addition of phytic acid (10 mM) decreases aflatoxin synthesis.

An elevated level of phospholipids has been observed during the first half of pregnancy in sows (Bloor, Okey & Corner, 1930; Boyd & Eldon, 1935) and in rabbits (Morin, 1968), while guinea-pig ovaries were reported to contain 12·5 mg phospholipids per g of tissue, and this level was maintained constant throughout early, mid- and late pregnancy (Boyd, 1935). No other report on guinea-pigs, giving details of ovarian lipid composition, incorporation studies and changes involved in pregnancy, appears to be available. This investigation was accordingly undertaken to elicit such information.Female guinea-pigs of 5 to 6 months of age and in the 600- to 1000-g body wt range were selected at random. The experimental group was mated and maintained to mid-pregnancy while the control group was kept non-pregnant. Animals were injected intraperitoneally with [1-14C]acetate (sp.act. 3·2 mCi/

Zusammenfassung Die Aufnahme von Aflatoxin B1-C14 durch Leber- und Nierenschnitte verschiedener Spezies zeigt eindeutig, daß der Transport des Toxins zu den einzelnen Organen der betreffenden Spezies nicht die Hauptursache für die beobachtete Variation in der Speziesempfindlichkeit gegenüber Aflatoxin ist.

Aspergillus flavusNRRL 3251 grown on modified yeast extract-sucrose medium produced 1 mg of aflatoxin M1per 100 ml of medium.

Addition of Tween 80 to the growth medium brings about qualitative and quantitative changes in the lipids ofMycobacterium phleiATCC 354. The results suggest that Tween 80 itself may be a variant in the system.

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ANTIBIOTICS are known to have profound effects on nucleic acids and protein biosynthesis. Coniglio and Bell1reported that when antibiotics are administered orally to rats there is a significant increase in the incorporation of 14C-acetate into hepatic fatty acids. Chatterjee et al.2observed that dihydrostreptomycin significantly influences the lipid metabolism of intestine and whole body of rats. The neurotoxic effects of dihydrostreptomycin on prolonged use in tuberculosis treatment and other infections are well known3. The present work was undertaken to study the effects of DHS on lipid changes in various tissues of guinea-pigs.

Systemic action of nicotinamide significantly alters the activities of hepatic drug metabolizing enzymes. Male rats injected with nicotinamide have reduced levels of cytochrome P450, demethylases and aniline hydroxylase. The changes appear to be sex-dependent since in the case of female rats activities of p-nitroanisole-o-demethylase and aniline hydroxylase are enhanced whereas cytochrome P450 content remains unaltered.