Biodecolourization of azo and triphenylmethane dyes by <Emphasis Type="Italic">Dichomitus squalens</Emphasis> and <Emphasis Type="Italic">Phlebia</Emphasis> spp

Nine white-rot fungal strains were screened for biodecolourization of brilliant green, cresol red, crystal violet, congo red and orange II. Dichomitus squalens, Phlebia fascicularia and P. floridensis decolourized all of the dyes on solid agar medium and possessed better decolourization ability than Phanerochaete chrysosporium when tested in nitrogen-limited broth medium. Journal of Industrial Microbiology & Biotechnology (2002) 28, 201–203 DOI: 10.1038/sj/jim/7000222 Received 12 July 2001/ Accepted in revised form 22 October 2001     

SIRT3 deficiency decreases oxidative metabolism capacity but increases lifespan in male mice under caloric restriction

Mitochondrial NAD⁺‐dependent protein deacetylase Sirtuin3 (SIRT3) has been proposed to mediate calorie restriction (CR)‐dependent metabolic regulation and lifespan extension. Here, we investigated the role of SIRT3 in CR‐mediated longevity, mitochondrial function, and aerobic fitness. We report that SIRT3 is required for whole‐body aerobic capacity but is dispensable for CR‐dependent lifespan extension. Under CR, loss of SIRT3 (Sirt3 ^−/− ) yielded a longer overall and maximum lifespan as compared to Sirt3 ^+/+ mice. This unexpected lifespan extension was associated with altered mitochondrial protein acetylation in oxidative metabolic pathways, reduced mitochondrial respiration, and reduced aerobic exercise capacity. Also, Sirt3 ^−/− CR mice exhibit lower spontaneous activity and a trend favoring fatty acid oxidation during the postprandial period. This study shows the uncoupling of lifespan and healthspan parameters (aerobic fitness and spontaneous activity) and provides new insights into SIRT3 function in CR adaptation, fuel utilization, and aging.     

Enhanced photosynthetic output via dichroic beam-sharing

Microbial solar biofuels offer great promise for future sustainable food, fuels and chemicals but are limited by low productivities and a requirement for large land areas to harvest sunlight. A 71?% increase in combined photosynthetic activity was achieved by illuminating both Rhodobacter sphaeroides and Arthrospira (Spirulina) platensis from a single beam of simulated sunlight, divided using a dichroic mirror. Therefore, this technique is termed ‘dichroic beam-sharing’, in which the complementary action spectra of two different useful micro-organisms, belonging to green and purple groups, is exploited and allows a single beam of sunlight to be shared efficiently between separate photobioreactors. Because the action spectra of these two organisms are typical of large groups, this novel method could increase the productivity of photosynthetic micro-organisms in the production of diverse commodities.     

cAMP-dependent protein kinase and lipolysis in rat adipocytes. III. Multiple modes of insulin regulation of lipolysis and regulation of insulin responses by adenylate cyclase regulators

The relationship between cAMP-dependent protein kinase (A-kinase) activity ratios and lipolysis in the presence of insulin was compared to the standard relationship between these two parameters established with a variety of adenylate cyclase modulators (Honnor, R. C., Dhillon, G., and Londos, C. (1985) J. Biol. Chem. 260, 15130-15138). Three phases of insulin action were observed. First, when tested in control cells exhibiting A-kinase activity ratios up to approximately 0.25, insulin inhibition of lipolysis could be accounted for by the decrease in A-kinase activity. Second, in cells exhibiting A-kinase activity ratios greater than 0.3, the decrease in kinase activity by insulin did not account for the decrease in lipolysis. Finally, as the A-kinase activity ratio approached 0.6 the insulin effect on lipolysis was lost. The data suggest that protein phosphatase activation accounts for the cAMP-independent insulin action. Moreover, the insulin effect not accounted for by a decrease in A-kinase activity appears to be elicited only upon elevation of A-kinase activity. The method by which cells were stimulated determined the IC50 for insulin inhibition of: 1) A-kinase activity ratios, 2) lipolysis explained by the decrease in A-kinase activity ratios, and 3) lipolysis not explained by a decrease in A-kinase activity ratios. For all three parameters, cells stimulated by lipolytic hormones were approximately 5 times more sensitive to insulin than cells stimulated by incubation in a ligand-free environment achieved with adenosine deaminase; insulin IC50 values were approximately 120 and 600 pM, respectively. Such data establish a link between insulin actions in modifying cAMP concentrations and in modifying events apparently independent of changes in cAMP. It is proposed that the receptors and regulatory components associated with adipocyte adenylate cyclase are associated also with components of the insulin response system separate from cyclase.     

Properties of NADP-malic enzyme from glumes of developing wheat grains

Properties of partially purified NADP-malic enzyme (EC 1.1.1.40) from glumes of developing wheat grains were examined. The pH optimum for enzyme activity was influenced by malate and shifted from 7.3 to 7.6 when the concentration of malate was increased from 2 to 10 mM. The K_m values, at pH 7.3, for various substrates were: malate, 0.76 mM; NADP, 20 μM and Mn²⁺, 0.06 mM. The requirement of Mn²⁺ cation for enzyme activity could be partially replaced by Mg²⁺ or Co²⁺. Mn²⁺ dependent enzyme activity was inhibited by Pb²⁺, Ni²⁺, Hg²⁺, Zn²⁺, Cd²⁺, Al³⁺ and Fe³⁺. During the reaction, substrate molecules (malate and NADP) reacted with enzyme sequentially. Activity of malic enzyme was inhibited by products of the reaction viz pyruvate, HCO₃^? and NADPH₂. At a limiting fixed concentration of NADP, these products induced a positive cooperative response to increasing concentrations of malate.     

Molecular characterization of a gene from Saccharopolyspora erythraea (Streptomyces erythraeus) which is involved in erythromycin biosynthesis

A 7.3 kbp DNA fragment, encompassing the erythromycin (Em) resistance gene (ermE) and a portion of the gene cluster encoding the biosynthetic genes for erythromycin biosynthesis in Saccharopolyspora erythraea (formerly Streptomyces erythraeus) has been cloned in Streptomyces lividans using the plasmid vector pIJ702, and its nucleotide sequence has been determined using a modified dideoxy chain-termination procedure. In particular, we have examined the region immediately 5′ of the resistance determinant, where the tandem promoters for ermE overlap the promoters for a divergently transcribed coding sequence (ORF). Disruption of this ORF using an integrational pIJ702-based plasmid vector gave mutants which were specifically blocked in erythromycin biosynthesis, and which accumulated 3-O-α-L-mycarosylerythronolide B: this behaviour is identical to that of previously described eryC1 mutants. The eryC1-gene product, a protein of subunit M_r 39200, is therefore involved either as a structural or as a regulatory gene in the formation of the deoxyamino-sugar desosamine or in its attachment to the macro-lide ring.     

Mutants of phage HK239 defective in excluding phages lambda T4rII, P1, and P2

Summary Escherichia coli cells lysogenic for temperate phage HK239 exclude phages , HK022, P1 vir, P2, and rII mutants of phage T4. After mutagenic treatment, four isolates were obtained for their inability to exclude T4rII. It is shown that this mutation, designated exc, is located in the prophage HK239, and that, it also abolishes the exclusion of phages , HK022, P1 vir, and P2.     

GENETICS OF PHYTOPATHOGENIC FUNGI. V. HETEROCARYONS INVOLVING FORMAE OF FUSARIUM OXYSPORUM

Garber , E. D., Ellen G. Wyttenbach , and T. S. Dhillon . (U. Chicago, Chicago, Ill.) Genetics of phytopathogenic fungi. V. Heterocaryons involving formae of Fusarium oxysporum. Amer. Jour. Bot. 48(4): 325–329. 1961.—Heterocaryons involving mutant strains of 4 formae of Fusarium oxysporum were studied; the strains differed in nutritional requirements, resistance to acriflavine, and colonial morphology and color. Spores from the heterocaryons gave colonies on minimal medium which resembled one component strain in morphology and color; spores from heterocaryons involving f. pisi yielded colonies on complete medium containing a concentration of acriflavine inhibitory to the other component strain.     

Estimates of gene frequencies in two heterotic maize populations

Summary The present study was undertaken to obtain information on average gene frequency in two heterotic populations of maize (Zea mays L.), Mezcla Amarillo Selection (MAS) and J607. Sixty-four male plants were taken in each of the populations and each of these were crossed to a different set of eight plants, four of which belonged to the same population and four to the other population. This resulted in two groups of intra-population (within MAS and within J607) and two groups of inter-population (MAS X J607 and J607 X MAS) progenies. Each group consisted of 256 full-sib progenies on the pattern of the North Carolina Design I mating system. The male plants were selfed to produce 64 S₁ prgenies in each population. The materials were evaluated at two diverse locations, Ludhiana and Gurdaspur, for grain yield, ear length, ear girth, number of kernel rows, plant height, ear height and days to silk. An incomplete block design with two replications were used. The plot consisted of a 5 m long row. Ratios of estimated genetic components of variance and covariance were compared with corresponding theoretical ratios computed for a single locus for various gene frequencies and levels of dominance, and approximate ranges of the gene frequencies and their relative magnitude were worked out in the two populations. The average frequency of favourable genes for plant height was estimated as 0.6 in MAS and 0.8 in J607. For grain yield the average gene frequency was 0.8 to 0.9 in MAS and 0.7 to 0.8 in J607 whereas for ear height it was 0.5 to 0.7 in MAS and 0.4 to 0.6 in J607. The gene frequency in the two populations seemed to be similar for days to silk, ear length, ear girth and kernel rows.