Altered patterns of maltose and glucose fermentation by brewing and wine yeasts influenced by the complexity of nitrogen source

Maltose and glucose fermentations by industrial brewing and wine yeasts strains were strongly affected by the structural complexity of the nitrogen source. In this study, four Saccharomyces cerevisiae strains, two brewing and two wine yeasts, were grown in a medium containing maltose or glucose supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Diauxie was observed at low sugar concentration for brewing and wine strains, independent of nitrogen supplementation, and the type of sugar. At high sugar concentrations altered patterns of sugar fermentation were observed, and biomass accumulation and ethanol production depended on the nature of the nitrogen source and were different for brewing and wine strains. In maltose, high biomass production was observed under peptone and casamino acids for the brewing and wine strains, however efficient maltose utilization and high ethanol production was only observed in the presence of casamino acids for one brewing and one wine strain studied. Conversely, peptone and casamino acids induced higher biomass and ethanol production for the two other brewing and wine strains studied. With glucose, in general, peptone induced higher fermentation performance for all strains, and one brewing and wine strain produced the same amount of ethanol with peptone and casamino acids supplementation. Ammonium salts always induced poor yeast performance. The results described in this paper suggest that the complex nitrogen composition of the cultivation medium may create conditions resembling those responsible for inducing sluggish/stuck fermentation, and indicate that the kind and concentration of sugar, the complexity of nitrogen source and the yeast genetic background influence optimal industrial yeast fermentation performance.

Peanut seed tegument is affected by liming and drying method

Calcium plays a fundamental role in cell division and growth, and is an important constituent of the cell wall. An increase in Ca concentration in the tegument of peanut (Arachis hypogea L.) seeds in response to lime application can affect its structure. The tegument structure can also be affected by the drying method of the seeds. The effects of lime application and drying methods as affecting the peanut seed tegument structure were studied in seeds from a field experiment conducted in Sao Manuel, São Paulo, Brazil. Peanut (cv. Botutatu, Valencia Type) was grown in presence or absence of 2.1 Mg ha(-1) of lime and dried in an oven, in shade and in the field. The tegument anatomical features were described and its structure was analysed. Pectic substances, lipidic reserves and starch accumulation were studied. The peanut tegument exhibited well differentiated exotesta, mesotesta and endotesta rich in pectates and covered by a cuticle. Tannin was not observed but there was lipid accumulation in mature teguments. Lignin was observed in the vascular bundles. Lime increased the tegument thickness and decreased the central cavity mainly in the exotesta cells when the period of seed drying was shortened. The effect of drying method upon the tegument was more noticeable in seeds grown without lime. It can be inferred that liming increased the resistance of the tegument.

Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones. as a function of A, exhibits a change in its slope at similar to20 ppm-a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data. thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose. even for the lowest uranium dosage.

Biomass production and secretion of hydrolytic enzymes are influenced by the structural complexity of the nitrogen source in Fusarium oxysporum and Aspergillus nidulans

The structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. Fusarium oxysporum and Aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids), peptides (peptone) and protein (gelatin). In glucose, when the initial pH was adjusted to 5.0, for both microorganisms, higher biomass production occurred upon supplementation with a nitrogen source in the peptide form (peptone and gelatin). With a close to neutrality pH, biomass accumulation was lower only in the presence of the ammonium salt. When grown in starch, biomass accumulation and secretion of hydrolytic enzymes (amylolytic and proteolytic) by Fusarium also depended on the nature of the nitrogen supplement and the pH. When the initial pH was adjusted to 5.0, higher growth and higher amylolytic activities were detected in the media supplemented with peptone, gelatin and casamino acids. However, at pH 7.0, higher biomass accumulation and higher amylolytic activities were observed upon supplementation with peptone or gelatin. Ammonium sulfate and casamino acids induced a lower production of biomass, and a different level of amylolytic enzyme secretion: high in ammonium sulfate and low in casamino acids. Secretion of proteolytic activity was always higher in the media supplemented with peptone and gelatin. Aspergillus, when grown in starch, was not as dependent as Fusarium on the nature of nitrogen source or the pH. The results described in this work indicate that the metabolism of fungi is regulated not only by pH, but also by the level of structural complexity of the nitrogen source in correlation to the carbon source.

Regeneration of poly-L-lysine modified carbon electrodes in the accumulation and cathodic stripping voltammetric determination of the cromoglycate anion

Cromoglycate is accumulated on a poly-L-lysine (PLL) modified carbon electrode best from pH 4 solution, where it is anionic and the PLL is cationic, and at which pH the cromoglycate gives a good reduction peak at -0.82 V. The PLL film can be regenerated readily by washing the electrode with 3 M sodium hydroxide solution, in which the PLL is deprotonated. Regeneration of the film is not required as frequently when larger amounts of PLL are incorporated into it. This allows standard addition procedures to be carried out without regenerating the electrode. Linear calibration graphs have been obtained typically in the range 0.1 - 1.5 mug ml(-1). Detection limits have been calculated to be 10 ng ml(-1). The standard addition method has been applied satisfactorily to diluted urine solutions. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Macrophages and mast cells control the neutrophil migration induced by dentin proteins

Dentin sialoprotein (DSP) and dentin phosphoprotein (DPP), the major dentin proteins, have been shown to induce neutrophil migration through release of IL-1beta, TNF-alpha, MIP-2, and KC. However, the sources of these mediators were not determined. Here, the roles of macrophages and mast cells (MC) in dentin-induced neutrophil accumulation were investigated. Peritoneal MC depletion or the enhancement of macrophage population increased DSP- and DPP-induced neutrophil extravasation. Moreover, supernatants from DSP- and DPP-stimulated macrophages caused neutrophil migration. The release of neutrophil chemotactic factor by macrophages was inhibited by dexamethasone or the supernatant of DSP- treated MC. Consistently, dexamethasone and the MC supernatant inhibited the production of IL-1beta, TNF-alpha, and MIP-2 by macrophages. This inhibitory activity of the DSP- stimulated MC was neutralized by anti-IL-4 and anti-IL-10 antibodies. These results indicate that dentin induces the release of the neutrophil chemotactic substance(s) by macrophages, which are down-modulated by MC-derived IL-4 and IL-10.

Determination of the vinylsulphone azo dye, remazol brilliant orange 3R, by cathodic stripping voltammetry

Remazol brilliant orange 3R shows only a voltammetric peak for the reduction of the azo group. No peak was observed for the reduction of the sulfatoethylsulfone or vinylsulfone reactive groups. The reduction of a pre-protonated ate group involving a two-electron process, gives a hydrate derivative in acidic solution. In alkaline solution the reduction process occurs at more negative potential with the formation of an unstable hydrate compound which decomposes via HN-NH bond cleavage and loss of a sulfate group. Optimum conditions are given for the cathodic stripping voltammetric determination of dir: dye in aqueous solution. The optimum accumulation potential and time were 0 V and up to 60 s, respectively. Linear calibration graphs were obtained from 30 to 300 ng ml(-1) in pH 4 and 6.2 to 62 ng ml(-1) in pH 10. The limit of determination obtained was 1.5 ng ml(-1) (pH 10). The coefficient of variation was 2.6% (n = 7) at 62 ng ml(-1) of the reactive dye. (C) 1999 Elsevier B.V. B.V. All rights reserved.

The use of silica-immobilized brown alga (Pilayella littoralis) for metal preconcentration and determination by inductively coupled plasma optical emission spectrometry

The brown alga Pilayella littoralis was used as a new biosorbent in an on-line metal preconcentration procedure in a flow-injection system. Al, Co, Cu and Fe were determined in lake water samples by inductively coupled plasma optical emission spectrometry (ICP-OES) after preconcentration in a silica-immobilized alga column. Like other algae, P. littoralis exhibited strong affinity for these metals proving to be an effective accumulation medium. Metals were bound at pH 5.5 and were displaced at pH < 2 with diluted HCl. The enrichment factors for Cu-II, Fe-III, Al-III and Co-II were 13, 7, 16 and 11, respectively. Metal sorption efficiency ranged from 86 to 90%. The method accuracy was assessed by using drinking water certified reference material and graphite furnace atomic absorption spectrometry (GFAAS) as a comparison technique. The column procedure allowed a less time consuming, easy regeneration of the biomaterial and rigidity of the alga provided by its immobilization on silica gel. (C) 2003 Elsevier B.V. All rights reserved.

REGULATION OF BOVINE ENDOMETRIAL SECRETION OF PROSTAGLANDINS AND SYNTHESIS OF 2',5'-OLIGOADENYLATE SYNTHETASE BY INTERFERON-ALPHA MOLECULES

Experiments were performed to (1) verify the inhibitory effect of bovine trophoblast protein-1 (bTP-1) on uterine prostaglandin synthesis, (2) evaluate whether other interferon-alpha (IFN-alpha) molecules also inhibit prostaglandin secretion, and (3) test whether the enzyme 2',5'-oligoadenylate synthetase (2-5A synthetase) can be induced in endometrium by interferon-alpha. In experiment 1, all interferon molecules (bTP-1, oTP-1, bIFN-alpha and hIFN-alpha) equally inhibited secretion of PGF and PGE2 from endometrial explant cultures obtained at day 17 of the estrous cycle. In experiment 2, endometrial explants obtained from day 17 of the cycle were cultured with and without bovine serum albumin (BSA; 50-mu-g/ml) and bIFN-alpha (0, 0.84, 4.2, and 42 nM). Addition of BSA to the culture medium greatly enhanced the accumulation of PGF into the medium. The bIFN-alpha inhibited accumulation of PGF and PGE2 in both the presence or absence of BSA by 12 h. All three concentrations of bIFN-alpha were equally effective in inhibiting prostaglandin accumulation. Additionally, all concentrations of bIFN-alpha increased the amounts of 2-5A synthetase in endometrium. In conclusion, these results confirm the inhibitory effect of bTP-1 on PGF release from endometrium and demonstrate that bTP-1 can also inhibit PGE2 secretion. Furthermore, other interferon-alpha molecules, including bIFN-alpha, hIFN-alpha, and oTP-1, also reduced PGF and PGE2 secretion in culture. It is likely, therefore, that conceptus and other interferon-alpha molecules exert similar effects on endometrium in vitro and that the antiluteolytic effects of bIFN-alpha in vivo are mediated in part by changes in endometrial prostaglandin synthesis.

Mast cells in the eyes of Calomys callosus (Rodentia : Cricetidae) infected by Toxoplasma gondii

The mast cell is a powerful effector cell for the innate immune system, acting through the secretion of several distinct mediators. Few studies have demonstrated the relationship between mast cells and toxoplasmosis. In this study, mast cells were investigated in two experimental Toxoplasma infections using Calomys callosus (Rodentia: Cricetidae) as the host. Animals were inoculated either intraperitoneally or via the conjunctiva with tachyzoites of Toxoplasma gondii (RH strain) and sacrificed after 5 days or 24 h, respectively. Enucleated eyes were processed for histological and ultrastructural analysis. Neither experimental infection altered the localization of mast cells compared to control eyes, but they did lead to an accumulation in some tissues as well as to their activation. There was a significant increase in the number of mast cells within 5 days and 24 h after infection. The ocular lesions were characterized by the presence of tachyzoites, inflammatory cells and vasodilatation in the iris and retina. In conclusion, mast cells were mobilized in these experimental infections, suggesting that they play an important role in the host inflammatory response after infection with T. gondii.

Effect of different tannery sludge compost amendment rates on growth, biomass accumulation and yield responses of Capsicum plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Paracoccidioides brasiliensis gp70 antigen is encoded by a putative member of the flavoproteins monooxygenase family

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Downregulation of nuclear factor-kappa B (NF-kappa B) pathway by silibinin in human monocytes challenged with Paracoccidioides brasiliensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fluorapatite solubilization by Aspergillus niger in vinasse medium

Fluorapatite solubilization by Aspergillus niger using diluted vinasse at a relative density of 45° Brix may be an alternative to the usual processes for obtaining soluble phosphate. After 13 days of culture, a production of 1.2g l-1 soluble phosphate was obtained for 5g l-1 fluorapatite added to the vinasse, as well as production of 11 gl-1 dry mycelial mass and a substantial reduction of the polluting components of the medium, i.e. a 78 and 94% reduction of total and reducing sugars, respectively, and a 48 and 80% reduction of total and soluble solids, respectively. In less diluted medium, increased sugar content led to a greater production of dry mass but also to a reduction of soluble phosphate content. When fluorapatite concentration in vinasse was increased from 5.0 to 7.5 or 10.0 g l-1, soluble phosphate accumulation increased by 0.28 and 0.15 g l-1, respectively. Addition of ammonium nitrate or rotary shaking of the culture mixture did not lead to the production of larger amounts of soluble phosphate than obtained in the absence of these factors. © 1990.

Nickel chloride: potential accumulation from the airway. Toxicokinetics in rats.

The rate removal of nickel from the airway was measured in vivo. Removal in vivo was studied by intratracheal injection of nickel chloride solutions. Regardless of time after injection, the lungs and heart retained the greatest concentration of nickel and 40 days after 1.68 mumol administration they were the organs where nickel was still significantly measurable. The slow removal of nickel may indicate the presence of high affinity binding sites in the lung. Nickel can interact with others metals, such as copper and zinc, so that nickel exposure may have public health implications.