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1.
Chinese Journal of Biotechnology ; (12): 1946-1952, 2022.
Article in Chinese | WPRIM | ID: wpr-927829

ABSTRACT

In order to improve the salt tolerance of banana NHX genes, we cloned a MaNHX5 gene from Musa acuminata L. AAA group and predicted the key salt-tolerant amino acid sites and mutant protein structure changes of MaNHX5 by using bioinformatics tools. The 276-position serine (S) of MaNHX5 protein was successfully mutated to aspartic acid (D) by site-directed mutagenesis, and the AXT3 salt-sensitive mutant yeast was used for a functional complementation test. The results showed that after the mutated MaNHX5 gene was transferred to AXT3 salt-sensitive mutant yeast, the salt tolerance of the mutant yeast was significantly improved under 200 mmol/L NaCl treatment. It is hypothesized that Ser276 of MaNHX5 protein plays an important role in the transport of Na+ across the tonoplast.


Subject(s)
Amino Acids/metabolism , Gene Expression Regulation, Plant , Musa/metabolism , Plant Proteins/metabolism , Plants, Genetically Modified , Saccharomyces cerevisiae/metabolism
2.
Chinese Journal of Biotechnology ; (12): 831-845, 2021.
Article in Chinese | WPRIM | ID: wpr-878599

ABSTRACT

As a model industrial host and microorganism with the generally regarded as safe (GRAS) status, Corynebacterium glutamicum not only produces amino acids on a large scale in the fermentation industry, but also has the potential to produce various new products. C. glutamicum usually encounters various stresses in the process of producing compounds, which severely affect cell viability and production performance. The development of synthetic biology provides new technical means for improving the robustness of C. glutamicum. In this review, we discuss the tolerance mechanisms of C. glutamicum to various stresses in the fermentation process. At the same time, we highlight new synthetic biology strategies for boosting C. glutamicum robustness, including discovering new stress-resistant elements, modifying transcription factors, and using adaptive evolution strategies to mine stress-resistant functional modules. Finally, prospects of improving the robustness of engineered C. glutamicum strains ware provided, with an emphasis on biosensor, screening and design of transcription factors, and utilizing the multiple regulatory elements.


Subject(s)
Amino Acids/metabolism , Corynebacterium glutamicum/metabolism , Fermentation , Metabolic Engineering , Synthetic Biology
3.
Rev. argent. microbiol ; 51(3): 201-207, set. 2019. graf
Article in English | LILACS | ID: biblio-1041825

ABSTRACT

The consumption of soybean isoflavones (IS) is associated with several beneficial properties on human health. Some lactic acid bacteria possess ß-glucosidase enzyme, that allows to obtain the active form of IS (aglycone). The solid state fermentation (SSF) has received great attention in the last years in order to obtain several valuable compounds. SSF, using soybean as substrate and Lactobacillus rhamnosus CRL 981 as starter, was studied in the present work. Sucrose was added into soybean paste to study the effect on the behavior of the selected strain. The development of L. rhamnosus CRL 981 through pH and recount measures, sugar intake, organic acid production, ß-glucosidase activity and IS conversion were analyzed. No significant differences in growth and acidity were observed between soybean pastes with and without sucrose added, but the production of lactic acid was higher in the latter paste. The ß-glucosidase activity was detected in both pastes and the complete hydrolysis of IS at 12 h of fermentation was observed. Also, this strain was able to increase the free amino acids in soybean paste. SSF, using soybean as substrate and L. rhamnosus CRL 981 as starter culture, is an alternative process to obtain a soybean product bio-enriched in active IS with attractive nutritional characteristics.


El consumo de isoflavonas de soja (IS) está asociado a diversos beneficios para la salud humana. Ciertas bacterias lácticas poseen la enzima ß-glucosidasa, que permite obtener la forma bioactiva (agliconas) de las IS. La fermentación en sustrato sólido (FSS) ha recibido gran atención en los últimos anos debido a sus numerosas ventajas, y permite la obtención de productos con valor agregado. En el presente trabajo se estudió la FSS utilizando soja como sustrato y Lactobacillus rhamnosus CRL981 como cultivo iniciador. Con el fin de estudiar el efecto de una fuente de carbono externa sobre el comportamiento de la cepa seleccionada, se adicionó sacarosa a la pasta de soja. Se evaluó el crecimiento de L. rhamnosus CRL 981 a través de medidas de pH y recuento en placa. Además, se analizó el consumo de azúcares, producción de ácidos orgánicos, actividad ß-glucosidasa y conversión de IS. No se observaron diferencias significativas en el crecimiento y acidez entre las pastas de soja sin adición de sacarosa y con ella, sin embargo, la producción de ácido láctico fue mayor en esta última. La actividad de ß-glucosidasa se detectó en ambas pastas y se observó la hidrólisis completa de IS a las 12 h de fermentación. Además, esta cepa fue capaz de aumentar los aminoácidos libres en la pasta de soja. La FSS, utilizando soja como sustrato y L. rhamnosus CRL 981 como cultivo iniciador, es un proceso alternativo para obtener un producto de soja bioenriquecido en IS bioactivas con características nutricionales atractivas.


Subject(s)
Soybeans/metabolism , Lactobacillus rhamnosus/metabolism , Fermentation , Vegetable Products/analysis , Isoflavones/biosynthesis , Sucrose/pharmacology , Bacterial Proteins/metabolism , beta-Glucosidase/metabolism , Lactic Acid/biosynthesis , Food Microbiology , Amino Acids/metabolism , Hydrolysis
4.
Braz. j. microbiol ; 49(4): 685-694, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974282

ABSTRACT

ABSTRACT To mitigate the deleterious effects of abiotic stress, the use of plant growth-promoting bacteria along with diazotrophic bacteria has been increasing. The objectives of this study were to investigate the key enzymes related to nitrogen and carbon metabolism in the biological nitrogen fixation process and to elucidate the activities of these enzymes by the synergistic interaction between Bradyrhizobium and plant growth-promoting bacteria in the absence and presence of salt stress. Cowpea plants were cultivated under axenic conditions, inoculated with Bradyrhizobium and co-inoculated with Bradyrhizobium sp. and Actinomadura sp., Bradyrhizobium sp. and Bacillus sp., Bradyrhizobium sp. and Paenibacillus graminis, and Bradyrhizobium sp. and Streptomycessp.; the plants were also maintained in the absence (control) and presence of salt stress (50 mmolL-1 NaCl). Salinity reduced the amino acids, free ammonia, ureides, proteins and total nitrogen content in nodules and increased the levels of sucrose and soluble sugars. The co-inoculations responded differently to the activity of glutamine synthetase enzymes under salt stress, as well as glutamate synthase, glutamate dehydrogenase aminating, and acid invertase in the control and salt stress. Considering the development conditions of this experiment, co-inoculation with Bradyrhizobium sp. and Bacillus sp. in cowpea provided better symbiotic performance, mitigating the deleterious effects of salt stress.


Subject(s)
Carbon/metabolism , Sodium Chloride/metabolism , Vigna/metabolism , Nitrogen/metabolism , Soil Microbiology , Sodium Chloride/analysis , Actinobacteria/physiology , Plant Roots/growth & development , Plant Roots/metabolism , Plant Roots/microbiology , Bradyrhizobium/physiology , Agricultural Inoculants/physiology , Vigna/growth & development , Vigna/microbiology , Amino Acids/metabolism , Nitrogen Fixation
5.
Electron. j. biotechnol ; 33: 46-51, May. 2018. ilus, graf
Article in English | LILACS | ID: biblio-1022928

ABSTRACT

Background: During L-tryptophan production by Escherichia coli, the by-products, acetic acid and NH4 +, accumulate in the fermentation broth, resulting in inhibited cell growth and activity and decreased L-tryptophan production. To improve the L-tryptophan yield and glucose conversion rate, acetic acid and NH4 + were removed under low-temperature vacuum conditions by vacuum scraper concentrator evaporation; the fermentation broth after evaporation was pressed into another fermenter to continue fermentation. To increase the volatilisation rate of acetic acid and NH4 + and reduce damage to bacteria during evaporation, different vacuum evaporation conditions were studied. Results: The optimum operating conditions were as follows: vacuum degree, 720 mm Hg; concentration ratio, 10%; temperature, 60°C; and feeding rate, 300 mL/min. The biomass yield of the control fermentation (CF) and fermentation by vacuum evaporation (VEF) broths was 55.1 g/L and 58.3 g/L at 38 h, respectively, (an increase of 5.8%); the living biomass yield increased from 8.9 (CF) to 10.2 pF (VEF; an increase of 14.6%). L-tryptophan production increased from 50.2 g/L (CF) to 60.2 g/L (VEF) (an increase of 19.9%), and glucose conversion increased from 18.2% (CF) to 19.5% (VEF; an increase of 7.1%). The acetic acid concentrations were 2.74 g/L and 6.70 g/L, and the NH4 + concentrations were 85.3 mmol/L and 130.9 mmol/L in VEF and CF broths, respectively. Conclusions: The acetic acid and NH4 + in the fermentation broth were quickly removed using the vacuum scraper concentrator, which reduced bacterial inhibition, enhanced bacterial activity, and improved the production of L-tryptophan and glucose conversion rate.


Subject(s)
Tryptophan/biosynthesis , Acetic Acid/metabolism , Amino Acids/metabolism , Vacuum , Waste Products , Evaporation , Escherichia coli , Fermentation
6.
Electron. j. biotechnol ; 28: 95-100, July. 2017. tab
Article in English | LILACS | ID: biblio-1016080

ABSTRACT

Mannheimia haemolytica leukotoxin (LKT) is a known cause of bovine respiratory disease (BRD) which results in severe economic losses in the cattle industry (up to USD 1 billion per year in the USA). Vaccines based on LKT offer the most promising measure to contain BRD outbreaks and are already commercially available. However, insufficient LKT yields, predominantly reflecting a lack of knowledge about the LKT expression process, remain a significant engineering problem and further bioprocess optimization is required to increase process efficiency. Most previous investigations have focused on LKT activity and cell growth, but neither of these parameters defines reliable criteria for the improvement of LKT yields. In this article, we review the most important process conditions and operational parameters (temperature, pH, substrate concentration, dissolved oxygen level, medium composition and the presence of metabolites) from a bioprocess engineering perspective, in order to maximize LKT yields.


Subject(s)
Animals , Cattle , Bacterial Toxins/biosynthesis , Mannheimia haemolytica/metabolism , Bovine Respiratory Disease Complex/microbiology , Exotoxins/biosynthesis , Temperature , Trace Elements , Carbon/metabolism , Mannheimia haemolytica/pathogenicity , Amino Acids/metabolism , Hydrogen-Ion Concentration , Kinetin
7.
Braz. j. microbiol ; 48(3): 544-550, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889154

ABSTRACT

Abstract Presence of the relatively new sulfonylurea herbicide monosulfuron-ester at 0.03-300 nmol/L affected the growth of two non-target nitrogen-fixing cyanobacteria (Anabaena flos-aquae and Anabaena azotica) and substantially inhibited in vitro Acetolactate synthase activity, with IC50 of 3.3 and 101.3 nmol/L for A. flos-aquae and A. azotica, respectively. Presenting in 30-300 nmol/L, it inhibited protein synthesis of the cyanobacteria with less amino acids produced as its concentration increased. Our findings support the view that monosulfuron-ester toxicity in both nitrogen-fixing cyanobacteria is due to its interference with protein metabolism via inhibition of branch-chain amino acid biosynthesis, and particularly Acetolactate synthase activity.


Subject(s)
Pyrimidines/toxicity , Sulfonylurea Compounds/toxicity , Anabaena/drug effects , Anabaena/metabolism , Dolichospermum flos-aquae/drug effects , Dolichospermum flos-aquae/metabolism , Esters/toxicity , Herbicides/toxicity , Nitrogen Fixation/drug effects , Anabaena/genetics , Dolichospermum flos-aquae/genetics , Amino Acids/metabolism , Nitrogen/metabolism
8.
Acta cir. bras ; 32(6): 459-466, June 2017. tab, graf
Article in English | LILACS | ID: biblio-886207

ABSTRACT

Abstract Purpose: To investigate the effects of dexmedetomidine (DEX) on amino acid contents and the cerebral ultrastructure of rats with cerebral ischemia-reperfusion injury (I/R). Methods: Thirty-six, male, Wistar rats were randomly divided into three groups: the sham operation group (group C), the ischemia-reperfusion group (group I/R), and the DEX group (group D). The middle cerebral artery occlusion model was prepared by the modified Longa method. The time of ischemia was 180 min, and 120 min after reperfusion, the amount of glutamate (Glu), and γ-aminobutyric acid (GABA) in the brain were measured, and the ultrastructure-level changes in the cerebral cortex were examined using electron microscopy. Results: Compared to group C, Glu contents in group D, and I/R significantly increased. Compared to group I/R, Glu contents in group D significantly decreased. Compared to group C, GABA contents in group D, and I/R significantly increased, and those in group D significantly increased, as compared to group I/R. The cerebral ultrastructure was normal in group C. Vacuolar degeneration in the plastiosome and nervous processes, was more critical than in group D. Vascular endothelial cells (VEC) were damaged. On the contrary, these changes in group D significantly improved. Conclusion: Dexmedetomidine is capable of decreasing glutamergic content, and increasing GABAergic content, in order to decrease the injury of the cerebral ultrastructure, following cerebral ischemia-reperfusion injury.


Subject(s)
Animals , Male , Rats , Reperfusion Injury/metabolism , Cerebral Cortex/chemistry , Brain Ischemia/drug therapy , Neuroprotective Agents/pharmacology , Dexmedetomidine/pharmacology , Glutamine/metabolism , Cerebral Cortex/ultrastructure , Brain Ischemia/metabolism , Rats, Wistar , gamma-Aminobutyric Acid/drug effects , gamma-Aminobutyric Acid/metabolism , Amino Acids/drug effects , Amino Acids/metabolism
9.
Nutrire Rev. Soc. Bras. Aliment. Nutr ; 41: 1-17, Dec. 2016. tab, ilus
Article in English | LILACS | ID: biblio-880303

ABSTRACT

Muscle mass is the major deposit of protein molecules with dynamic turnover between net protein synthesis and degradation. In human subjects, invasive and non-invasive techniques have been applied to determine their skeletal muscle catabolism of amino acids at rest, during and after different forms of physical exercise and training. The aim of this review is to analyse the turnover flux and the relative oxidation rate of different types of muscle proteins after one bout of exercise as well as after resistance and endurance condition of training. Protein feeding in athletes appears to be a crucial nutrition necessity to promote the maintenance of muscle mass and its adaptation to the need imposed by the imposed technical requirements. In resting human individuals, there commended protein daily allowance is about 0.8 g (dry weight) kg−body weight per 24 h knowing that humans are unable to accumulate protein stores in muscle tissues. Nevertheless, practical feeding recommendations related to regular exercise practice are proposed to athletes by different bodies in order to foster their skills and performance. This review will examine the results obtained under endurance and resistance type of exercise while consuming single or repeated doses of various ingestions of protein products (full meat, essential amino acids, specific amino acids and derivatives, vegetarian food). From the scientific literature, it appears that healthy athletes(and heavy workers) should have a common diet of 1.25 g kg−24 h to compensate the exercise training muscle protein degradation and their resyn thesis within the following hours. A nitrogen-balance assay would berecommended to avoid any excessive intake of protein. Eventually, a daily equilibrated food intake would beof primer importance versus inadequate absorption of some specific by-products.


Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Amino Acids/biosynthesis , Amino Acids/metabolism , Exercise , Muscle Proteins
10.
Indian J Exp Biol ; 2014 Jul; 52(7): 728-738
Article in English | IMSEAR | ID: sea-153753

ABSTRACT

Effect of environmental hypertonicity, due to exposure to 300 mM mannitol solution for 7 days, on the induction of ureogenesis and also on amino acid metabolism was studied in the air-breathing walking catfish, C. batrachus, which is already known to have the capacity to face the problem of osmolarity stress in addition to other environmental stresses in its natural habitats. Exposure to hypertonic mannitol solution led to reduction of ammonia excretion rate by about 2-fold with a concomitant increase of urea-N excretion rate by about 2-fold. This was accompanied by significant increase in the levels of both ammonia and urea in different tissues and also in plasma. Further, the environmental hypertonicity also led to significant accumulation of different non-essential free amino acids (FAAs) and to some extent the essential FAAs, thereby causing a total increase of non-essential FAA pool by 2-3-fold and essential FAA pool by 1.5-2.0-fold in most of the tissues studied including the plasma. The activities of three ornithine-urea cycle (OUC) enzymes such as carbamoyl phosphate synthetase, argininosuccinate synthetase and argininosuccinate lyase in liver and kidney tissues, and four key amino acid metabolism-related enzymes such as glutamine synthetase, glutamate dehydrogenase (reductive amination), alanine aminotransaminase and aspartate aminotransaminase were also significantly up-regulated in different tissues of the fish while exposing to hypertonic environment. Thus, more accumulation and excretion of urea-N observed during hypertonic exposure were probably associated with the induction of ureogenesis through the induced OUC, and the increase of amino acid pool was probably mainly associated with the up-regulation of amino acid synthesizing machineries in this catfish in hypertonic environment. These might have helped the walking catfish in defending the osmotic stress and to acclimatize better under hypertonic environment, which is very much uncommon among freshwater teleosts.


Subject(s)
Air , Amino Acids/metabolism , Ammonia/analysis , Animals , Catfishes/growth & development , Catfishes/metabolism , Diuretics, Osmotic/pharmacology , Environment , Hypertonic Solutions/pharmacology , Mannitol/pharmacology , Ornithine/metabolism , Osmosis/drug effects , Respiration , Urea/analysis , Urea/metabolism , Walking
11.
Electron. j. biotechnol ; 16(3): 17-17, May 2013. ilus, tab
Article in English | LILACS | ID: lil-684015

ABSTRACT

Metabolic engineering was formally defined more than two decades ago (Bailey, 1991) and it is now an established discipline. Metabolic engineering is generally defined as the directed improvement of product formation or cellular properties through the modification of specific biochemical reactions or the introduction of new ones with the use of recombinant DNA technology (Bailey, 1991; Stephanopoulos et al. 1998). Therefore, the analysis and engineering/synthesis of metabolic pathways is of central importance to metabolic engineering. The analytical part uses a number of experimental and modeling techniques for the systematic study of cellular responses (in terms of RNA, protein and metabolite levels, metabolic fluxes, etc.) to genetic and environmental perturbations. This facilitates a rational design of metabolic modifications, which are implemented using recombinant DNA technology. Both, the analysis and the synthesis of metabolic pathways will be covered in this review. Recent efforts on the engineering of fermentative and biosynthetic pathways for biofuel production in Escherichia coli, as well as those enabling the utilization of novel feedstocks, will be highlighted.


Subject(s)
Escherichia coli/metabolism , Biofuels , Metabolic Engineering , Oxidation-Reduction , Terpenes/metabolism , Fatty Acids/metabolism , Fermentation , Amino Acids/metabolism
12.
Indian J Exp Biol ; 2013 Mar; 51(3): 241-248
Article in English | IMSEAR | ID: sea-147588

ABSTRACT

With a view to investigate the ameliorative effects of sitosterol esters against degenerative effects of hypercholesterolemia brain antioxidant enzyme assays, brain lipid profile, brain phospholipid compositional change and brain neurotransmitter concentrates (glutamic acid, asparctic acid, glycine) were measured in hypercholesterolemic rats. The results indicated that phytosterol esters have a role in countering hypercholesterolemia-related changes in the brain by decreasing the cholesterol levels, increasing the phospholipid levels and increasing the level of antioxidant enzymes. The results suggest that phytosterol esters may be of therapeutic significance and may offer new and effective options for the treatment of hypercholesterolemia-induced changes in the brain.


Subject(s)
Amino Acids/metabolism , Animals , Antioxidants/metabolism , Brain/drug effects , Brain/metabolism , Chromatography , Docosahexaenoic Acids/metabolism , Eicosapentaenoic Acid/metabolism , Esters/pharmacology , Fish Oils/metabolism , Glutathione/metabolism , Hypercholesterolemia/metabolism , Male , Neurotransmitter Agents/metabolism , Phytosterols/pharmacology , Rats , Rats, Wistar , Sitosterols/pharmacology , alpha-Linolenic Acid/metabolism
13.
Article in English | WPRIM | ID: wpr-135452

ABSTRACT

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.


Subject(s)
African Americans/genetics , Alleles , Amino Acids/metabolism , Asians/genetics , Dihydrouracil Dehydrogenase (NADP)/genetics , Ethnicity/genetics , Whites/genetics , Fluorouracil/metabolism , Gene Frequency , Genotype , Humans , Polymorphism, Single Nucleotide , Sequence Analysis, DNA
14.
Article in English | WPRIM | ID: wpr-135449

ABSTRACT

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.


Subject(s)
African Americans/genetics , Alleles , Amino Acids/metabolism , Asians/genetics , Dihydrouracil Dehydrogenase (NADP)/genetics , Ethnicity/genetics , Whites/genetics , Fluorouracil/metabolism , Gene Frequency , Genotype , Humans , Polymorphism, Single Nucleotide , Sequence Analysis, DNA
15.
Article in English | WPRIM | ID: wpr-45626

ABSTRACT

Clonorchis sinensis is a biological carcinogen inducing human cholangiocarcinoma, and clonorchiasis is one of the important endemic infectious diseases in East Asia. The present study investigated survival longevity of C. sinensis adult worms in various in vitro conditions to find the best way of keeping the worms longer. The worms were maintained in 0.85% NaCl, 1xPBS, 1xLocke's solution, RPMI-1640, DMEM, and IMDM media, and in 1xLocke's solution with different supplements. All of the worms died within 3 and 7 days in 0.85% NaCl and 1xPBS, respectively, but survived up to 57 days in 1xLocke's solution. The worms lived for 106 days in DMEM, and 114 days in both RPMI-1640 and IMDM media. The survival rate in RPMI-1640 medium was the highest (50%) compared to that in DMEM (20+/-10%) and in IMDM (33.3+/-25.2%) after 3 months. The 1xLocke's solution with 0.005% bovine bile supplement showed increased duration of maximum survival from 42 days to 70 days. Higher concentration of bile supplements than 0.005% or addition of glucose were disadvantageous for the worm survival. The worms died rapidly in solutions containing L-aspartic acid, L-glutamic acid, and adenine compared to L-arginine, L-serine, and L-tryptophan. In conclusion, the 1xLocke's solution best supports the worms alive among inorganic solutions for 57 days, and the RPMI-1640 medium maintains living C. sinensis adults better and longer up to 114 days in vitro than other media.


Subject(s)
Adenine/metabolism , Amino Acids/metabolism , Animals , Bile/parasitology , Bile Acids and Salts/metabolism , Cattle , Cell Survival , Clonorchiasis/parasitology , Clonorchis sinensis/growth & development , Culture Media , Cyprinidae , Fish Diseases/parasitology , Humans , Rabbits , Rats , Time Factors
16.
Braz. j. med. biol. res ; 43(8): 698-704, Aug. 2010. ilus
Article in English | LILACS | ID: lil-554963

ABSTRACT

The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv tomato (Pst) DC3000 use the virulence factor coronatine to suppress stomate-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases.


Subject(s)
Amino Acids/metabolism , Indenes/metabolism , Lycopersicon esculentum/physiology , Plant Leaves/physiology , Plant Stomata/physiology , Pseudomonas syringae/pathogenicity , Virulence Factors/physiology , Amino Acids/genetics , Lycopersicon esculentum/genetics , Lycopersicon esculentum/microbiology , Plant Leaves/microbiology , Plant Stomata/microbiology , Pseudomonas syringae/genetics , Virulence Factors/genetics
17.
São Paulo; s.n; 2010. 116,X p. ilus, tab, graf.
Thesis in Portuguese | LILACS | ID: lil-594523

ABSTRACT

A restrição calórica (RC) é uma intervenção dietética capaz de estender a longevidade de vários organismos. O modelo para RC em Saccharomyces cerevisiae consiste da diminuição da concentração de glicose no meio de cultura e mostra um aumentado tanto do tempo de vida cronológico quanto replicativo. Nosso objetivo foi investigar experimentalmente a ação da RC, focando principalmente nas causas e consequências das modificações de geração de EROs mitocondriais e como estas estão associadas ao processo de envelhecimento. Em um primeiro período de estudos, verificamos quais as fontes mitocondriais de EROs, e comprovamos que uma quantidade significativa se origina de proteínas da matriz mitocondrial, e não da cadeia de transporte de elétrons. Nós estudamos a participação de glicose e de outras fontes de carbono sobre o tempo de vida cronológico em leveduras e mostramos que o aumento da longevidade promovida pela RC está associado à uma mudança de metabolismo fermentativo para respiratório, com participação da via de sinalização de glicose. No estágio realizado no laboratório do Professor Francis Sluse na Université de Liegè, Bélgica, estudamos a ação da RC em leveduras focando nas consequências das modificações no proteoma mitocondrial. Em nosso estudo proteômico, encontramos grandes modificações em proteínas envolvidas com o metabolismo de aminoácidos. Monitoramos a atividade de enzimas relacionadas ao metabolismo de aminoácidos e o tempo de vida cronológico de S. cerevisiae e as mutantes nulas bat2Δ, gdh1Δ, gdh2Δ e gdh3Δ, que codificam a aminotransferase de aminoácidos de cadeia ramificada citosólica, NADP glutamato desidrogenase citosólica, a NAD glutamato desidrogenase mitocondrial, e a NADP glutamato desidrogenase mitocondrial, respectivamente. A atividade da NAD glutamato desidrogenase é aumentada em RC, mas a de NADP glutamato desidrogenase decresce em células controle. Aumentos do tempo de vida cronológico foram observados nas mutantes...


Calorie restriction (CR) is a dietary intervention capable of extending lifespans in a wide range of organisms. A yeast model of CR has been developed in which limiting the concentration of glucose in growth media of Saccharomyces cerevisiae leads to enhanced chronological and replicative life spans. Our aim was to experimentally investigate the effects of CR, focusing mainly on the causes and consequences of changes in mitochondrial reactive oxygen species (ROS) generation and how these are associated with the aging process. Initially, we looked for sources of mitochondrial ROS, and found that a significant amount of ROS comes from mitochondrial matrix enzymes and not from the electron transport chain. We studied the participation of glucose and other carbon sources in chronological lifespan and show that increased longevity promoted by CR is associated with a metabolism change from fermentation to respiration, with participation of glucose repression pathway. During studies performed in the laboratory of Professor Francis Sluse at the Université de Liège, Belgium, we studied the effect of CR in yeast with focus on the consequences of changes in the mitochondrial proteome. We found large proteomic changes in proteins involved in amino acid metabolism. We monitored the activity of enzymes related to amino acid metabolism and chronological life span of S. cerevisiae null mutants bat2Δ, gdh1Δ, gdh2Δ, and gdh3Δ, which encode for the cytosolic branched-chain amino acid aminotransferase, cytosolic NADP glutamate dehydrogenase, mitochondrial NAD glutamate dehydrogenase and mitochondrial NADP glutamate dehydrogenase, respectively. The activity of NAD glutamate dehydrogenase is increased in CR, but NADP glutamate dehydrogenase decreases in control cells. Increases in chronological life span due to RC were observed in bat2Δ and gdh1Δ mutants, but no significant difference was found in Gdh2p and Gdh3p null mutants in the stationary phase…


La restriction calorique (RC) est une intervention diététique capable de prolonger la durée de vie dans divers organismes. Un modèle de RC pour la levure a été developpé dans lequel limiter la concentration de glucose dans le milieu de culture de Saccharomyces cerevisiae a montré une augmentation de vieillessement chronologique et réplicative. Notre objectif était d’étudierexpérimentalement l’effet de la RC, en se concentrant principalement sur les causes et les conséquences des changements dans la production des espèces d’oxygène réactive (ROS) mitochondriales et de la façon dont elles sont associée au processus de vieillessement. Dans une première période d’études, qui a trouvé la source de ROS mitochondriale, nous montrons qu’une quantité importante vient d’enzyme de la matrice et pas de la chaîne de transport d’électrons. Nous avons étudié la participation de glucose et d’autres sources de carbone sur le vieillissement chronologique dans la levure et nous avons montré que l’augmentation de la longévité promure par RC est associée à un changement du métabolisme fermentaire à respiratoire, avec la participation de la voie de signalisation du glucose. Dans le laboratoire du professeur Francis Sluse à l’Université de Liège, en Belgique, nous avons étudié l’effet du RC dans la levure en se concentrant sur les conséquences des changements du protéome mitochondrial. Dans notre étude, nous avons constaté de grands changements des protéines impliquées dans le métabolisme des acides amines. Nous avons surveillé l’activité des enzymes liées au métabolisme des acides aminés et le vieillissement chronologique de S. cerevisiae et des mutants nul bat2Δ, gdh1Δ, gdh2Δ et gdh3Δ, qui codent aminotransférase pour les acides aminés à chaîne ramifiée cytosolique, NADP glutamate déshydrogénase cytologique, NAD glutamate déshydrogénase mitochondriale et NADP glutamate déshydrogénase mitochondriale, respectivement. L’activité de la NAD glutamate...


Subject(s)
Caloric Restriction , Mitochondria/chemistry , Saccharomyces cerevisiae/genetics , Time Factors , Amino Acids/metabolism , Dihydrouracil Dehydrogenase (NADP) , Reactive Oxygen Species , Proteome/analysis
18.
Acta bioquím. clín. latinoam ; 43(4): 647-661, oct.-dic. 2009. graf, tab
Article in Spanish | LILACS | ID: lil-633097

ABSTRACT

Las aminoacidopatías son errores innatos del metabolismo intermediario de los aminoácidos. Su confirmación diagnóstica y seguimiento se realiza con la cuantificación de aminoácidos libres en fluidos biológicos por técnicas como la cromatografía líquida de alta eficiencia (HPLC), para lo que es necesario comparar con valores de referencia normales. La población colombiana no cuenta con estos valores disponibles y el diagnóstico es realizado por comparación con los de otras poblaciones. En el presente trabajo se obtuvieron valores de referencia de aminoácidos en plasma en una población de niños (n=36) y adultos no afectados (n=17), mediante HPLC por derivatización postcolumna con ninhidrina. Los valores de referencia obtenidos fueron ligeramente más elevados que los informados para otras poblaciones y permitieron la identificación de doce casos de aminoacidopatías, incluyendo fenilcetonuria clásica, hiperfenilalaninemia, hiperglicinemia no cetósica, desórdenes del ciclo de la urea, tirosinemia. La implementación de la cuantificación de aminoácidos por HPLC y la obtención de los valores de referencia de aminoácidos en plasma permitirán aumentar el conocimiento sobre la incidencia de las aminoacidopatías en el país para garantizar, junto con otros factores, su diagnóstico preciso y oportuno y la implementación de un adecuado seguimiento nutricional.


Aminoacidopathies are inborn errors of the amino acid intermediary metabolism. The benchmark method used for their diagnosis and monitoring is the quanti!cation of free amino acids in biological fluids using High Performance Liquid Chromatography (HPLC), which needs to be compared against normal reference values. However, those amino acid reference values are not available for the Colombian population and the diagnosis is usually made using values from American or European populations. In this work, plasma amino acid reference values in non-affected children (n=36) and adults (n=17) were established, using an HPLC method with a postcolumn derivatization with ninhidrine. Plasma amino acid reference values in a Colombian population were slightly higher compared with those reported for other populations, and enabled the identification of twelve aminoacidopathies including urea cycle disorders, phenylketonuria, hyperphenylalaninemia, nonketotichyperglycinemia, hepatorrenaltyrosinemia and maple syrup urine disease. The implementation of amino acid cuantification by HPLC and the construction of plasma amino acid reference values is very useful for a suitable and precise diagnosis of amino acid disorders, the implementation of proper nutritional treatments, and an increased knowledge of aminoacidopathy incidence in Colombia.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Adult , Middle Aged , Amino Acid Metabolism, Inborn Errors/diagnosis , Amino Acid Metabolism, Inborn Errors/blood , Amino Acids/metabolism , Reference Values , Chromatography, Liquid , Amino Acids/blood
19.
J Environ Biol ; 2008 Nov; 29(6): 893-6
Article in English | IMSEAR | ID: sea-113515

ABSTRACT

The tasar silkworm, Antheraea mylitta Drury, Andhra local ecorace is an exclusive race of Andhra Pradesh. It is on the verge of extinction due to difficulty of acclimatisation at breeding and rearing stages. As an attempt to protect this race, a method of total indoor rearing has been done. In this context, the estimation of free amino acids, excretory products- urea and uric acid were compared during the fourth and fifth instars of tasar silkworm, reared under outdoor and indoor conditions. The study has revealed that amino acids decreased in the fat body in outdoor and indoor reared larvae in contrast to that in the haemolymph where it has gradually increased from first to third crops. This is an important finding as it reveals that indoor worms seem to adopt proteolytic activity in the haemolymph. Secondly, in the fifth instar the excretory products are more compared to fourth instar in the indoor reared worms. During fifth instar, formation of nitrogenous products lessens as silk synthesis enhances. The present study reveals that decrease in uric acid in fifth instar implies increase in growth rate and silk synthesis in both outdoor and indoor worms. The findings of the present investigation is helpful in the conservation and protection of the A. mylitta, Andhra local ecorace.


Subject(s)
Amino Acids/metabolism , Animals , Bombyx/growth & development , Conservation of Natural Resources , Fat Body/metabolism , Hemolymph/metabolism , Larva/growth & development , Urea/metabolism , Uric Acid/metabolism
20.
Medicina (B.Aires) ; 68(5): 398-404, sep.-oct. 2008. ilus
Article in Spanish | LILACS | ID: lil-633577

ABSTRACT

El Trypanosoma cruzi es el agente causal de la enfermedad de Chagas, endémica en Argentina y en toda América Latina. Presenta numerosas características metabólicas diferenciales respecto a sus hospedadores insectos y mamíferos. Algunas de estas diferencias fueron consecuencia de millones de años de adaptación al parasitismo en los cuales estos organismos protozoarios reemplazaron, a lo largo de su evolución, muchas rutas metabólicas de biosíntesis por sistemas de transporte de metabolitos desde el hospedador. En esta revisión se describen los avances en el conocimiento de los sistemas de transporte tanto bioquímicos como también de las moléculas involucradas en dichos procesos. Se aborda con especial énfasis los transportadores de aminoácidos y poliaminas de T. cruzi de la familia AAAP (Amino Acid/Auxin Permeases) ya que parece ser exclusiva de los tripanosomátidos. Teniendo en cuenta que estas moléculas se encuentran completamente ausentes en mamíferos podrían ser consideradas como potenciales blancos contra el Trypanosoma cruzi.


Trypanosoma cruzi is the etiological agent of Chagas disease, a disease endemic not only in Argentina but also in all of Latinamerica. T. cruzi presents several metabolic characteristics which are completely absent in its insect vectors and in mammalian hosts. Some of these differences were acquired after millions of years of adaptation to parasitism, during which this protozoan replaced many biosynthetic routes for transport systems. In the present review, we describe the advances in the knowledge of T. cruzi transport processes and the molecules involved. In particular, we focus on aminoacid and polyamine transporters from the AAAP family (Amino Acid/Auxin Permeases), because they seem to be exclusive transporters from trypanosomatids. Taking into account that these permeases are completely absent in mammals, they could be considered as a potential target against Trypanosoma cruzi.


Subject(s)
Animals , Humans , Amino Acids/metabolism , Chagas Disease/metabolism , Polyamines/metabolism , Trypanosoma cruzi/metabolism , Argentina , Amino Acids/chemistry , Biological Transport , Chagas Disease/therapy , Host-Parasite Interactions , Polyamines/chemistry , Protozoan Proteins/biosynthesis
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