351 resultados para Sardine Lipases


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Strain improvement is one of the major objectives for maximizing the microbial production of industrially significant primary and secondary metabolites. This goal can be achieved by judicious tuning of the organisms by monitoring its growth parameters and optimizing adequate supply of micro and macro nutrients, inducers, pH, temperature and other factors which control fermentation. Though C. rugosa has been under extensive studies for lipases, maximum world production is only 36 units. In fact, in India, enhanced production conditions for lipases have not yet been initiated. C. rugosa has been cultivated in diverse environments like liquid, semi-solid, solid—state and immobilized conditions, though major emphasis is on SmF or suspension culture. Hence the present investigations mainly focused on increasing the yield by adjusting the physico-chemical growth parameters and to characterize the lipase isoforms secreted by C. rugosa in the culture medium. Maximum possible improved methods were investigated to achieve these objectives. Within this under-optimised background, enhancement of lipase production and its characterization were investigated, employing modified liquid, semi-solid, solid—state and immobilized fermentation strategies

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Fish, a natural resource, has received great attention from all over the world. since it provides a cheap protein, employment and income to the millions of people for centuries. So fishermen, industrialist and multinationals are trying to exploit the marine resources to their maximum benefit by using modern craft, advance fishing equipments and efficient gear. Fishery resources in the open system particularly in oceans, were considered to be unlimited. However, recent developments in the innovation of efficient craft and gear using well tested material fitted with modern equipments that have greatly enhanced the mobility of craft, agility of gear and the ability of equipments to locate fishery resources have proved otherwise. Hence as the exploitation increases with more effort entering the fishery, the catch per unit of fishing effort starts to decline due to the limitness of the resources. The heavy fishing pressure in the recent past led to commercial extinction of a number of stocks such as. the North Sea herring, California sardine, Japanese Sardine and Peruvian anchovy (FAO. 1968: Gulland, 1974). In India, seer fish from Palk-Bay declined due to uncontrolled fishing (Devaraj 1983).

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Considering the potential of marine environment present study was designed for the screening and isolation of a potential salt tolerant. alkaline and thennotolerant lipase producing bacteria from the costal belts of South India and consequent development of ideal bioprocess for industrial production, purification characterisation and evaluation of the potential of the lipase enzyme for various industrial applications 1. Screening and isolation of a potential lipase producing bacteria. 2. Optimization of various physicochemical factors in Submerged fennentation for the production of alkaline lipase 3. Purification ofthe lipase enzyme 4. Characterisation of the enzyme 5. Evaluation of the enzyme for various industrial applications

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Cochin University of Science And Technology

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Enzymes are powerful tools in organic synthesis that are able to catalyse a wide variety of selective chemical transformations under mild and environmentally friendly conditions. Enzymes such as the lipases have also found applications in the synthesis and degradation of polymeric materials. However, the use of these natural catalysts in the synthesis and the post-synthetic modification of dendrimers and hyperbranched molecules is an application of chemistry yet to be explored extensively. In this study the use of two hydrolytic enzymes, a lipase from Candida cylindracea and a cutinase from Fusarium solani pisii, were investigated in the selective cleavage of ester groups situated on the peripheral layer of two families of branched polyamides. These branched polyamides were conjugated to simple fragrances citronellol and L-menthol via ester linkages. Hydrolysis of the ester linkage between the fragrances and the branched polyamide support was carried out in aqueous buffered systems at slightly basic pH values under the optimum operative conditions for the enzymes used. These preliminary qualitative investigations revealed that partial cleavage of the ester functionalities from the branched polyamide support had occurred. However, the ability of the enzymes to interact with the substrates decreased considerably as the branching density, the rigidity of the structure and the bulkiness of the polyamide-fragrance conjugates increased.

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An exaggerated postprandial lipaemic response is thought to play a central role in the development of an atherogenic lipoprotein phenotype, a recognized lipid risk factor for coronary heart disease. A small number of limited studies have compared postprandial lipaemia in subjects of varying age, but have not investigated mechanisms underlying age-associated changes in postprandial lipaemia. In order to test the hypothesis that impaired lipaemia in older subjects is associated with loss of insulin sensitivity, the present study compared the postprandial lipaemic and hormone responses for 9 h following a standard mixed meal in normolipidaemic healthy young and middle-aged men. Lipoprotein lipase (LPL) and hepatic lipase (HL) activities were determined in post-heparin plasma 9 h postprandially and on another occasion under fasting conditions. Postprandial plasma glucose (P < 0.02), retinyl ester (indirect marker for chylomicron particles; P < 0.005) and triacylglycerol (TAG)-rich lipoprotein (density < 1.006 g/ml fraction of plasma) TAG (P < 0.05) and retinyl ester (P < 0.005) responses were higher in middle-aged men, whereas plasma insulin responses were lower in this group (P < 0.001). Fasting and 9 h postprandial LPL and HL activities were also significantly lower in the middle-aged men compared with the young men (P < 0.006). In conclusion, the higher incremental postprandial TAG response in middle-aged men than young men was attributed to the accumulation of dietary-derived TAG-rich lipoproteins (density < 1.006 g/ml fraction of plasma) and occurred in the absence of marked differences in fasting TAG levels between the two groups. Fasting and postprandial LPL and HL activities were markedly lower in middle-aged men, but lack of statistical associations between measures of insulin response and post-heparin lipase activities, as well as between insulin and measures of postprandial lipaemia, suggest that this lower activity cannot be attributed to lack of sensitivity of lipases to activation by insulin. Alternatively, post-heparin lipase activities may not be good markers for the insulin-sensitive component of lipase that is activated postprandially.

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The aim was to determine in 32 healthy young men from northern and southern Europe whether differences in the secretion of insulin and glucose-dependent insulinotropic polypeptide (GIP) might explain these findings through the actions of these hormones on lipoprotein lipase. In a randomized, single-blind, crossover study the effects of 2 test meals of identical macronutrient composition but different saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) contents were investigated on postprandial GIP, insulin, the ratio of incremental triacylglycerol to apolipoprotein B-48 (a marker of chylomicron size), and the activity of postheparin lipases. Fasting and postprandial GIP concentrations and postheparin hepatic lipase (HL) activities were higher in the southern Europeans (P<0.001 and P<0.02, respectively). Lipoprotein lipase activity after the SFA-rich meal was higher in the northern Europeans (P<0.01). HL activity 9 h after the SFA-rich meal and the area under the curve (AUC) for the postprandial insulin response correlated with the AUC for the postprandial GIP response (r=0.44 (P<0.04) and r=0.46 (P<0.05), respectively). There were no significant differences in chylomicron size between the 2 groups for either meal, but when the groups were combined there was a difference in chylomicron size between the SFA- and MUFA-rich meals (P<0.05), which could be due to the formation of larger chylomicrons after the MUFA-rich meal. The significantly higher GIP and insulin responses and HL activities in southern Europeans may provide an explanation for a previous report of attenuated postprandial triacylglycerol and apolipoprotein B-48 responses in them.

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Background: The relationship between CETP and postprandial hyperlipemia is still unclear. We verified the effects of varying activities of plasma CETP on postprandial lipemia and precocious atherosclerosis in asymptomatic adult women. Methods: Twenty-eight women, selected from a healthy population sample (n = 148) were classified according to three CETP levels, all statistically different: CETP deficiency (CETPd <= 4.5%, n = 8), high activity (CETPi >= 23.8, n = 6) and controls (CTL, CETP >= 4.6% and <= 23.7%, n = 14). After a 12 h fast they underwent an oral fat tolerance test (40 g of fat/m(2) of body surface area) for 8 hours. TG, TG-rich-lipoproteins (TRL), cholesterol and TRL-TG measurements (AUC, AUIC, AR, RR and late peaks) and comparisons were performed on all time points. Lipases and phospholipids transfer protein (PLTP) were determined. Correlation between carotid atherosclerosis (c-IMT) and postprandial parameters was determined. CETP TaqIB and I405V and ApoE-epsilon 3/epsilon 2/epsilon 4 polymorphisms were examined. To elucidate the regulation of increased lipemia in CETPd a multiple linear regression analysis was performed. Results: In the CETPi and CTL groups, CETP activity was respectively 9 and 5.3 higher compared to the CETPd group. Concentrations of all HDL fractions and ApoA-I were higher in the CETPd group and clearance was delayed, as demonstrated by modified lipemia parameters (AUC, AUIC, RR, AR and late peaks and meal response patterns). LPL or HL deficiencies were not observed. No genetic determinants of CETP deficiency or of postprandial lipemia were found. Correlations with c-IMT in the CETPd group indicated postprandial pro-atherogenic associations. In CETPd the regression multivariate analysis (model A) showed that CETP was largely and negatively predicted by VLDL-C lipemia (R(2) = 92%) and much less by TG, LDL-C, ApoAI, phospholipids and non-HDL-C. CETP (model B) influenced mainly the increment in ApoB-100 containing lipoproteins (R(2) = 85% negatively) and phospholipids (R(2) = 13%), at the 6(th)h point. Conclusion: The moderate CETP deficiency phenotype included a paradoxically high HDL-C and its sub fractions (as earlier described), positive associations with c-IMT, a postprandial VLDL-C increment predicting negatively CETP activity and CETP activity regulating inversely the increment in ApoB100-containing lipoproteins. We hypothesize that the enrichment of TG content in triglyceride-rich ApoB-containing lipoproteins and in TG rich remnants increases lipoproteins` competition to active lipolysis sites, reducing their catabolism and resulting on postprandial lipemia with atherogenic consequences.

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The first application of lipases as catalysts to obtain optically active boron-containing amines and amides is described. We studied several reaction conditions to achieve the kinetic resolution of boron-containing amines via enantioselective acylation mediated by Candida antarctica lipase B (CAL-B). Excellent enantioselectivity (E>200) and high enantiomeric excess (up to >99%) of both the remaining amines and amides were obtained. (C) 2010 Elsevier Ltd. All rights reserved.

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The first application of enzymes as catalysts to obtain optically pure boron compounds is described. The kinetic resolution of boron-containing chiral alcohols via enantioselective transesterification catalyzed by lipases was studied. Aromatic, allylic, and aliphatic secondary alcohols containing a boronate ester or boronic acid group were resolved by lipase from Candida antartica (CALB), and excellent E values (E > 200) and high enantiomeric excesses (up to >99%) of both remaining substrates and acetylated product were obtained.

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Uma série de derivados quirais (e.e. > 99%) foram sintetizados a partir do meso- exo-(3R,5S)-3,5-dihidróximetilenotriciclo[5,2.1.02,6]decano com altos rendimentos, usando catálise enzimática (lipases) em reações de transesterificação. A resolução do respectivo diéster racêmico através da hidrólise catalisada com esterase (PLE) não forneceu o monoéster opticamente enriquecido; enquanto que a dessimetrização do anidrido usando indutores quirais (quinina e quinidina) resultou no monoéster opticamente enriquecido (e.e.≅ 60%). O respectivo amino-álcool protegido foi preparado. Alguns análogos inéditos de peptídeos restritos incorporados do triciclodecano foram sintetizados.

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O fungo entomopatogênico e acaricida Metarhizium anisopliae é patógeno de uma vasta gama de insetos, sendo extensivamente utilizado em experimentos, bem como, no controle efetivo de alguns insetos-praga. Seu potencial uso para o controle de carrapatos como Boophilus microplus é também considerável. O processo de infecção de M. anisopliae é o melhor caracterizado entre os fungos entomopatogênicos, e combina pressão mecânica, por diferenciação do apressório, síntese e secreção de enzimas hidrolíticas altamente reguladas como proteases e, provavelmente, quitinases e lipases. As quitinases em fungos também são importantes em processos que requerem digestão celular, como germinação, crescimento e ramificação das hifas e autólise, visto que a quitina é o maior constituinte da parede celular desses organismos, sendo um sistema altamente regulado. Objetivamos neste trabalho, obter mais informações sobre o sistema quitinolitico do fungo M. anisopliae var. anisopliae linhagem E6 durante o processo de infecção do hospedeiro ou na morfogênese e crescimento. Com o objetivo de analisarmos o gene chi2 de M. anisopliae E6, clonamos e caracterizamos sua seqüência genômica, incluindo a região flanqueadora 5’. O gene chi2 é interrompido por dois pequenos íntrons típicos, de 210 pb e 75 pb, respectivamente. A ORF do gene chi2 apresenta 1.545 pb e codifica uma proteína predita de 419 aminoácidos (denominada CHI2), com massa molecular estimada de 44 kDa. Um peptídeo sinal característico com sítio de clivagem no aminoácido V19 está presente. A forma madura dessa proteína tem uma massa molecular estimada de 42 kDa e um pI teórico de 4,8. Análise por Southern de DNA genômico indica cópia única de chi2 no genoma de M. anisopliae. A seqüência de consenso SXGG, correspondendo ao sítio de ligação à quitina, foi identificada e a seqüência NGFDFDIE, que compõem o domínio catalítico de quitinases, está presente em CHI2. A construção de uma árvore filogenética determinou que a quitinase CHI2 pertence a um grupo diferente daquele da CHIT42 a qual provavelmente não está envolvida na patogenicidade. Uma análise in sílico da seqüência 5’ franqueadora do gene chi2 para determinação de possíveis elementos regulatórios foi efetuada. A regulação da transcrição dos genes chit1 e chi2 em M. ansisoplaie frente a diferentes fontes de carbono e em diferentes tempos de cultivo foi analisada. Os genes chit1 e chi2 apresentaram uma expressão tardia no fungo, a partir de 30 horas. O gene chi2 foi expresso majoritariamente em cultivos com quitina e sua expressão foi reprimida por glicose. O gene chit1 foi induzido em presença de fontes de carbono facilmente assimiláveis, como glicose e NAcGlc. Ambos os genes, chit1 e chi2, apresentaram alta expressão quando a fonte de carbono já estava exaurida e o fungo estava em autólise, sugerindo o requerimento dessas enzimas nessa fase. O cDNA do chit1 foi inserido em um vetor de expressão, em ambas orientações senso e antisenso, sob regulação do promotor do gene tef1α de M. anisopliae e o terminador do gene trpC de A. nidulans. Os transformantes com o gene chit1 na orientação senso mostraram superexpressão de atividade de quitinase e o transformante com o gene na orientação antisenso apresentou uma redução na atividade de quitinase. Também construímos quatro deleções na região flanqueadora 5’ do gene chit1 fusionadas com a proteína repórter SGFP, para localizar seqüências reguladoras no promotor e, destas construções, três foram transformadas em M. anisopliae.

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Metarhizium anisopliae é um fungo cosmopolita com capacidade de infectar uma grande variedade de hospedeiros, estando entre eles o carrapato Boophilus microplus. A penetração de M. anisopliae em seus hospedeiros ocorre de forma ativa onde a cutícula constitui a principal barreira. A penetração é um processo multifatorial, porém, o emprego de pressão mecânica e a secreção de enzimas hidrolíticas parecem ser fundamentais para o seu sucesso. M. anisopliae, quando cultivado em meios com fontes de carbono que mimetizam a cutícula de seus hospedeiros, secreta enzimas como proteases, quitinases e lipases. Atualmente, o emprego de técnicas que identificam genes diferencialmente expressos (RDA) mostrou o possível envolvimento de outras enzimas, como as β-glicanases, durante o processo de penetração. A descoberta da ocorrência de modificações morfológicas como espessamento e perda da definição da parede celular nas extremidades das hifas que penetram na cutícula do carrapato sustentam ainda mais o possível envolvimento de enzimas que degradam as β-glicanas nas etapas iniciais da infecção. Neste trabalho, foi investigada a produção de β-1,3- glicanases pela linhagem E6 de M. anisopliae como também, buscou-se purificar as enzimas produzidas. A síntese e secreção de β-1,3-glicanases foram verificadas em meio contendo diferentes fontes de carbono sendo a secreção diferenciada dependendo da condição testada. A utilização de glicose em determinadas concentrações pareceu inibir a secreção enzimática. Duas das condições testadas, N-acetilglicosamina (NAG) 0,5% e parede celular de Rizoctonia solani 0,5%, foram utilizadas para a produção enzimática em larga escala. O sobrenadante dos cultivos em fermentador foi submetido ao processo de purificação que constou de três etapas: concentração por ultrafiltração com membrana de celulose regenerada, aplicação em coluna de troca iônica QSepharose Fast Flow e aplicação em coluna de filtração em gel Superdex 75. O emprego deste protocolo permitiu a purificação parcial de uma β-1,3-glicanase com aproximadamente 95kDa, secretada durante a fermentação em presença de parede celular de Rizoctonia solani, e de outra, com aparentemente a mesma massa molecular secretada em fermentação utilizando NAG 0,5% como fonte de carbono. Durante este trabalho, também foi confirmada a presença de pelo menos um gene que codifica uma exo-β-1,3-glicanase no genoma da linhagem E6 de M. anisopliae. Por fim, o estudo das β-1,3 glicanases em M. anisopliae é justificado pela importância destas enzimas em variados aspectos do desenvolvimento do fungo bem como, pelo seu possível envolvimento na infecção de hospedeiros.

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Estudou-se experimentalmente a escama de sardinha (Sardinella brasiliensis) como substituto de córneas no reparo de ceratectomias superficiais em cães. Utilizaram-se 14 animais, machos e fêmeas, sem raça definida, com peso médio de 10 kg, considerados sadios. Analisaram-se, macro e microscopicamente, as córneas receptoras bem como o material implantado aos 1, 3, 7, 14, 30 e 60 dias de pós-operatório. As evidências clínicas para a enxertia lamelar mostraram fotofobia e blefarospasmo mais incidentes nos períodos iniciais e intermediários, com tendência à regressão nos tardios. Revelaram edema discreto e igualmente regressivo; neoformação vascular mais incidente nas fases intermediárias e pouco nas tardias. O estudo microscópico evidenciou quadro reacional compatível com padrão benigno a exemplo do que fora visto macroscopicamente. Ambos retrataram boa adesividade da prótese, epitélio e estroma neoformados, sob e sobrepostos a ela. A transparência das córneas receptoras, junto às zonas de enxertia, manteve-se por 14 dias. Para a enxertia interlamelar, observou-se quadro reacional pouco significativo. Para ambas as enxertias, não foram observados sinais de extrusão do material implantado. A escama de sardinha pode ser empregada para fins tectônicos, com bons resultados em ceratoplastias lamelares em cães.

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This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acauã a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acauã of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil.