Kinetic studies on clavulanic acid degradation

Clavulanic acid (CA), a potent beta-lactamase inhibitor, is very sensitive to pH and temperature. It is produced by Streptomyces clavuligerus and to optimize both the fermentation step and the downstream process, the expression of the hydrolysis kinetics has to be determined. In the present work the CA degradation rate from various sources was investigated at temperatures of 10, 20, 25, 30 and 40degreesC and PH values of 6.2 and 7.0. The results showed that first-order kinetics explained very well the hydrolysis kinetics and the Arrhenius equation could be applied to establish a relationship between the degradation rate constant and temperature, at both pHs. It has been observed that CA from fermentation medium was much more unstable than that from standard solution and from a commercially available medicine. Also, it was observed that CA was more stable at PH 6.2 than at pH 7.0, irrespective of the CA source. (C) 2004 Elsevier B.V. All rights reserved.

The influence of sardine consumption on the omega-3 fatty acid content of mature human milk

Objectives: The purpose of this study was to investigate what effect the ingestion of sardines, rich in omega-3 series polyunsaturated fatty acids, has on the composition of breastmilk. Methods: This was a prospective study of 31 nursing mothers under observation at the Hospital Guilherme Álvaro. Each was given 2 kg of fresh sardines twice with a 15-day interval. Milk was sampled and a 24-hour dietary recall questionnaire was applied on days 0, 15 and 30. Milk was assayed for fatty acid content by gas chromatography. Statistical analysis of the results was performed using nonparametric tests with significance set at p < 0.05. Results: The results demonstrate that the nutritional intake of the nursing mothers was adequate at all three sample points. With regard to the omega-3 series fatty acid content of the breastmilk, it was observed that regular consumption and shorter intervals between ingestion and milk collection resulted in higher concentrations of docosapentaenoic acid and docosahexaenoic acid at 15 and 30 days into the study. Fatty acids from the omega-3 and omega-6 series exhibited a significant correlation, r 2 was 0.58 and 0.59 at 15 and 30 days, respectively. Conclusion: These results suggest that incorporating fish into the diets of nursing mother during lactation, in the form of 100 g of sardines two or three times a week, contributes to an increase in omega-3 series fatty acids. Copyright © 2006 by Sociedade Brasileira de Pediatria.

ZmPUMP encodes a fully functional monocot plant uncoupling mitochondrial protein whose affinity to fatty acid is increased with the introduction of a His pair at the second matrix loop

Uncoupling proteins (UCPs) are specialized mitochondrial transporter proteins that uncouple respiration from ATP synthesis. In this study, cDNA encoding maize uncoupling protein (ZmPUMP) was expressed in Escherichia coli and recombinant ZmPUMP reconstituted in liposomes. ZmPUMP activity was associated with a linoleic acid (LA)-mediated H+ efflux with Km of 56.36 ± 0.27 μM and Vmax of 66.9 μmol H+ min-1 (mg prot)-1. LA-mediated H+ fluxes were sensitive to ATP inhibition with Ki of 2.61 ± 0.36 mM (at pH 7.2), a value similar to those for dicot UCPs. ZmPUMP was also used to investigate the importance of a histidine pair present in the second matrix loop of mammalian UCP1 and absent in plant UCPs. ZmPUMP with introduced His pair (Lys155His and Ala157His) displayed a 1.55-fold increase in LA-affinity while its activity remained unchanged. Our data indicate conserved properties of plant UCPs and suggest an enhancing but not essential role of the histidine pair in proton transport mechanism. © 2006 Elsevier Inc. All rights reserved.

Fatty acid production by four strains of Mucor hiemalis grown in plant oil and soluble carbohydrates

Four Mucor hiemalis strains (M1, M2, M3 and M4), isolated from soil at a depth of 0 - 15 cm in the Juréia-Itatins Ecology Station (JIES), in the state of São Paulo, Brazil and were evaluated for the production of γ-linolenic (GLA) and other unsaturated fatty acids. Five growth variables (temperature, pH, carbon source, nitrogen source, and vegetable oils) were studied. Liquid media containing 2% vegetable oil (palm oil, canola oil, soybean oil, sesame oil, or sunflower oil) or 2% carbohydrate (fructose, galactose, glycerol, glucose, lactose, maltose, sucrose, sorbitol or xylose) and 1% yeast extract as a nitrogen source were used. The greatest biomass production was observed with M3 and M4 strains in palm oil (91.5 g l -1) and sunflower oil (68.3 g l -1) media, respectively. Strain M4 produced greater quantities of polyunsaturated acids in medium containing glucose. The GLA production in the M4 biomass was 1,132.2 mg l -1 in glucose medium. Plant oils were inhibitors of fatty acid production by these strains. © 2007 Academic Journals.

Spatio-temporal distribution of fatty acid-binding protein 6 (fabp6) gene transcripts in the developing and adult zebrafish (Danio rerio)

We have determined the structure of the fatty acid-binding protein 6 (fabp6) gene and the tissue-specific distribution of its transcripts in embryos, larvae and adult zebrafish (Danio rerio). Like most members of the vertebrate FABP multigene family, the zebrafish fabp6 gene contains four exons separated by three introns. The coding region of the gene and expressed sequence tags code for a polypeptide of 131 amino acids (14 kDa, pI 6.59). The putative zebrafish Fabp6 protein shared greatest sequence identity with human FABP6 (55.3%) compared to other orthologous mammalian FABPs and paralogous zebrafish Fabps. Phylogenetic analysis showed that the zebrafish Fabp6 formed a distinct clade with the mammalian FABP6s. The zebrafish fabp6 gene was assigned to linkage group (chromosome) 21 by radiation hybrid mapping. Conserved gene synteny was evident between the zebrafish fabp6 gene on chromosome 21 and the FABP6/Fabp6 genes on human chromosome 5, rat chromosome 10 and mouse chromosome 11. Zebrafish fabp6 transcripts were first detected in the distal region of the intestine of embryos at 72 h postfertilization. This spatial distribution remained constant to 7-day-old larvae, the last stage assayed during larval development. In adult zebrafish, fabp6 transcripts were detected by RT-PCR in RNA extracted from liver, heart, intestine, ovary and kidney (most likely adrenal tissue), but not in RNA from skin, brain, gill, eye or muscle. In situ hybridization of a fabp6 riboprobe to adult zebrafish sections revealed intense hybridization signals in the adrenal homolog of the kidney and the distal region of the intestine, and to a lesser extent in ovary and liver, a transcript distribution that is similar, but not identical, to that seen for the mammalian FABP6/Fabp6 gene. © 2008 The Authors.

Tocopherol content and fatty acid profile in soybean oil supplemented with salvia extract (Salvia officinalis L.) during heating

This paper aimed to assess the tocopherol content and evaluate the fatty acid profile in soybean oil supplemented with salvia extract during heating, so as to verify the isolated and synergistic effect of natural and synthetic antioxidants. In order to obtain the extract, the lyophilized and crushed salvia was subjected to extraction by ethyl alcohol for 30 min, with a 1:20 salvia:ethyl alcohol ratio, under continuous agitation. Afterwards, the mixture was filtered and the supernatant was subjected to the rotary evaporator at 40 °C. Later the control treatments, ES (3000 mg kg-1 salvia extract), TBHQ (50 mg kg-1), and mixture (ES+50 mg kg-1 TBHQ) were prepared and subjected to 180 °C for 20 h. Samples were taken in time intervals 0, 10, and 20 h and analysed in terms of tocopherol content and fatty acid profile. Regarding the tocopherol and fatty acid profile analysis, it was found that the extract proved efficient in oil protection, when added isolated to soybean oil subjected to thermo oxidation. According to the results, salvia extract is a viable alternative that might be applied in industrialized processing of oils as natural antioxidant.

Lipid and selenium sources on fatty acid composition of intramuscular fat and muscle selenium concentration of Nellore steers

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

Nutrients balances and milk fatty acid profile of mid lactation dairy cows supplemented with unsaturated fatty acid

The objective was to evaluate the effect of unsaturated fatty acid sources supplementation on nutrients balances and milk fatty acid profile of mid lactation dairy cows. Twelve Brazilian Holstein cows in the mid lactation (mean of 128 days) and (580 ± 20kg of weight; mean ± SD) with milk yield of 25kg/d were assigned randomly into three 4 × 4 Latin square, fed the following diets: control (C); refined soybean oil; (SO); whole soybean raw (WS) and; calcium salts of unsaturated fatty acids (CSFA). Milk yield was 26.6; 26.4; 24.1 and 25.7 to the diets CO, SO, WS and CSFA respectively. Cows fed the WS treatment produced less milk (1.95kg/d of milk), fat and lactose than did cows fed the SO and CSFA. Cows fed the CSFA treatment showed less blood, urine (g/d) concentrations of N more energetic efficiency and intake of energy than did cows fed the SO treatment. Cows fed the unsaturated fatty acids sources showed more C18:2 cis-9, trans-11 CLA and trans-C18:1 FA concentration in milk than did cows fed the CO treatment. Diets with whole soybeans and soybeans oil provide more efficient digestive processes, and increase milk composition of unsaturated fatty acids.

Chemical composition and fatty acid contents in farmed freshwater prawns

The objective of this work was to evaluate the chemical composition and fatty acid contents of Amazonian and giant river prawns. After four-month farming, with the same diet for both species, palmitic and stearic acids were the main saturated fatty acids. Oleic acid was the main monounsatured fatty acid, and the eicosapentaenoic and docosahexaenoic acids were the most abundant polyunsaturated acids. Amazonian prawn has higher levels of protein and polyunsaturated fatty acids than those of the giant river prawn, which shows its potential for aquaculture.

Intramuscular fat and fatty acid profile of muscle of lambs finished in irrigated pasture

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of lipid sources with different fatty acid profiles on the intake, performance, and methane emissions of feedlot Nellore steers

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

Fatty acid profile, carcass and meat quality traits of young Nellore bulls fed crude glycerin replacing energy sources in the concentrate

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

Chemical and Fatty acid composition of different cuts cooked or uncooked from yearling bulls fed oil sources

This study evaluated the chemical and lipid composition of uncooked or cooked loin (Longissimus thoracis) and rump (Biceps femoris) in samples of 2.54 cm thick from 35 carcasses of Nellore young bulls finished in feedlot for 96 days and slaughtered at an average weight of 532.17 ± 30.25 kg and 24 months of age. The rump had the lowest level of protein and ash (18.57 and 0.90%, respectively) and the highest level of ether extract compared to loin (3.37 and 1.90%, respectively). Higher levels of cholesterol were found in rump compared to loin (40.91 e 30.93 mg 100 g-1, respectively). The uncooked loin showed lower content of saturated fatty acids and higher content of polyunsaturated fatty acids. The best values for the omega-6: omega-3 ratio was observed in the uncooked beef. In the present study, the loin was healthier due to the higher amount of polyunsaturated fatty acids compared to rump. Cooking the meat decreases the levels of polyunsaturated fatty acids, omega-3, omega-6 and the omega-6: omega-3 ratio.