Current status of whitening agents and enzymes in Dentistry

Abstract This study reviews the knowledge on the use of conventional dental whitening and the use of enzymes as a new approach in bleaching. A review of the literature was based on academic articles and on patents related to the use of enzymes in dental bleaching. Tooth whitening techniques used nowadays are well reported in the literature, and its mechanism of action consists of an oxidoreduction reaction with the release of free radicals. The great instability of radicals, when in contact with the tissues, promotes oxidation and reduction in the size of the pigment chains incorporated into them. These pigments are eventually broken down into smaller and smaller molecular chains and end up being diffused from the dental structure. In turn, the use of enzymes aimed at tooth whitening can be a less harmful alternative to the tooth because their specificity regarding the substrate makes them of great interest to perform specific reactions, reducing collateral effects. The use of proteolytic enzymes and oxidoreductases paired with the application of peroxides, can be a promising alternative for obtaining even better results in the dental bleaching process.

Caracterización, clasificación y usos de las enzimas lipasas en la producción industrial / Characterization, classification and uses of lipase enzymes in industrial production

Introducción: La bioquímica, como ciencia particular dentro de las ciencias médicas, ha tenido un gran desarrollo. Las enzimas lipasas se obtienen de organismos vivos que abundan en la naturaleza y han sido utilizadas en la producción de alimentos, jabones, detergentes, aceites y otros productos industriales. Actualmente se han logrado nuevas clasificaciones de estas, subdivididas en grupos y subgrupos. Se aprecia además interés de utilizarlas en la producción de biodiesel y en la biotecnología y genética médica. Objetivo: Recopilar las principales consideraciones teóricas actualizadas acerca la caracterización, clasificación y usos de las enzimas lipasas. Método: La búsqueda y análisis de la información se realizó desde el primero de septiembre al 23 de diciembre de 2019, con un total de 50 artículos publicados en las bases de datos PubMed, Hinari, SciELO y Medline, mediante el gestor de búsqueda y administrador de referencias EndNote. se utilizaron 42 citas seleccionadas para realizar la revisión, de ellas 38 de los últimos cinco años. Conclusiones: Las enzimas lipasas son proteínas que catalizan procesos biológicos. son activas en un amplio rango de sustrato, realizan reacciones de síntesis, hidrólisis o de intercambio de grupos. Poseen diversas actividades catalíticas, son menos costosas y menos contaminantes, se obtienen en gran cantidad, se producen de forma regular. Son estables y su proceso de producción es más factible y seguro. Se caracterizan por su capacidad de catalizar reacciones de acidólisis, alcohólisis, aminólisis, esterificación, interesterificación y transesterificación, entre otras características(AU)

Introduction: Biochemistry has experienced great development as a particular medical science. Lipase enzymes are obtained from living organisms which are abundant in nature, and have been used in the manufacture of foods, soap, detergents, oils and other industrial products. New classifications are now available of lipase enzymes, and they have been subdivided into groups and subgroups. An interest is also noticed in using them for biodiesel production and in biotechnology and medical genetics. Objective: Collect the main updated theoretical considerations about the characterization, classification and uses of lipase enzymes. Method: The search for and analysis of the information extended from 1 September to 23 December 2019, for a total 50 papers published in the databases PubMed, Hinari, SciELO and Medline, using the search engine and reference manager EndNote. Forty-two citations were selected for the review, 38 of which were from the last five years. Conclusions: Lipase enzymes are proteins that catalyze biological processes. They are active in a wide range of substrates, performing synthesis reactions, hydrolysis or group exchanges. They display a variety of catalytic activities, are less costly and less contaminating, are obtained in large quantities and are produced in a regular manner. They are stable and their production process is more feasible and safer. They are characterized by their ability to catalyze reactions of acidolysis, alcoholysis, aminolysis, esterification, interesterification and transesterification, among other characteristics(AU)

Enzymes modulation by dried grape pomace from the manufacture of wines and juices

The processing of grapes for the manufacture of juices and wines, generates large quantities of by-products rich in metabolites with antioxidant, antimicrobial, anti-inflammatory and cicatrizing activities. The high homology between human enzymes and snake venoms makes the latter valuable laboratory tools for the study of pathophysiological processes. Proteases and phospholipases A2 act in processes related to hemostasis and inflammatory response. Thus, in this work, dried pomace obtained from grape (Isabel, Niagara, Bordô, BRS Violeta and Blend cultivars) processing were evaluated on phospholipase, proteolytic, hemolytic and thrombolytic activities induced by snakes venoms and the content of phenolic compounds and minerals was evaluated. The dried pomace exerted inhibitory and potentiating actions in all analyzed activities. The enzymatic modulators present in the evaluated dried pomace have potential for therapeutic use, although their broad characterization is still necessary, in order to define adequate amounts and formulations to obtain efficacy and safety in their use.

N-Myristoyltransferases as antileishmanial targets: a piggyback approach with benzoheterocyclic analogues

Leishmaniasis is one of the neglected diseases that remain in need for pharmacological alternatives. In this context, N-Myristoyltransferases (NMT) arise as interesting targets to explore since they are involved in the co/post-translational processing of peptides which are responsible for host cell invasion. Studies that consider these enzymes as targets point out the potential of benzoheterocyclic compounds as inhibitors of Candida albicans's N-myristoyltransferase. Here we applied a combination of comparative binding site analysis and molecular docking studies based on a Piggyback approach in the search for new Leishmania major NMT ligands. Our results revealed that NMT enzymes from both pathogens present enough structural similarity to allow extrapolation of the knowledge available from C. albicans studies to develop new L. major NMT inhibitors. Molecular docking studies with benzoheterocyclic analogues indicate the potential of benzothiazole derivatives as L. major NMT ligands, giving rise to a completely new class of chemical compounds to be explored in the development of antileishmanial drugs.

Effect of the addition of papain enzyme on digestive parameters and palatability of extruded diets for dogs / Efeito da adição da enzima papaína em rações extrusadas para cães sobre parâmetros digestivos e palatabilidade

Common protein sources used in the manufacturing of diets for dogs are derived from by-products, which may have reduced digestibility depending on the source. This study evaluated the effect of the addition of a protease, the papain enzyme, as a supplement to extruded diets on palatability, nutrient digestibility, and fecal production and quality of dogs. A diet was formulated with poultry by-product meal, meat and bone meal, and feather meal as protein sources. This formula was divided into three isonutrient diets: one negative control (NC), without enzymes; treatment one (EZ1) with addition of 855.000UI of papain per kilogram of diet, and treatment two (EZ2) with addition of 2.280.000UI of papain per kilogram of diet, both added before extrusion. The experiment followed a randomized block design, with two blocks of nine animals (three animals per treatment in each block), 18 dogs in total, and six replicates per treatment. Data were submitted to analysis of variance and the means of three treatments were compared by polynomial contrasts (P <0.05). No differences in the coefficients of total tract apparent digestibility of nutrients nor changes in palatability, pH, and fecal production among treatments were found with the addition of different doses of enzyme to the diets (P > 0.05). The fecal score was reduced with increased addition of enzyme (P < 0.05).(AU)

As fontes comuns de proteína utilizadas na fabricação de rações para cães são oriundas de coprodutos, os quais podem apresentar digestibilidade reduzida de acordo com a fonte. Este estudo avaliou os efeitos da adição da enzima papaína em dietas secas e extrusadas na palatabilidade, digestibilidade dos nutrientes, qualidade e produção fecal de cães adultos. Uma dieta foi formulada contendo farinha de vísceras de frango, farinha de carne e ossos e farinha de penas hidrolisadas como fontes proteicas. Esta foi posteriormente dividida em três dietas isonutrientes: controle negativo (CN) sem adição da enzima; adição de 855.000 UI de papaína por quilograma de ração (EZ1); e adição de 2.280.000 UI de papaína por quiilograma de ração (EZ2), ambas adições feitas antes da extrusão. O experimento seguiu delineamento em blocos casualizados, com dois blocos de nove animais (três animais por tratamento em cada bloco), totalizando 18 cães, e seis repetições por tratamento. Os dados obtidos foram submetidos a análise de variância, com as médias dos três tratamentos comparadas por contrastes polinomiais (P < 0,05). Não foram verificadas diferenças nos coeficientes de digestibilidade aparente dos nutrientes ou mesmo alterações na palatabilidade, pH e produção de fezes entre os tratamentos com diferentes inclusões de enzima (P > 0,05). Apenas o escore fecal reduziu com o aumento da adição da enzima (P < 0,05).(AU)

Arginine enzymatic deprivation and diet restriction for cancer treatment

ABSTRACT Recent findings in amino acid metabolism and the differences between normal, healthy cells and neoplastic cells have revealed that targeting single amino acid metabolic enzymes in cancer therapy is a promising strategy for the development of novel therapeutic agents. Arginine is derived from dietary protein intake, body protein breakdown, or endogenous de novo arginine production and several studies have revealed disturbances in its synthesis and metabolism which could enhance or inhibit tumor cell growth. Consequently, there has been an increased interest in the arginine-depleting enzymes and dietary deprivation of arginine and its precursors as a potential antineoplastic therapy. This review outlines the most recent advances in targeting arginine metabolic pathways in cancer therapy and the different chemo- and radio-therapeutic approaches to be co-applied.

Glycolysis and gluconeogenesis in the liver of catfish fed with different concentrations of proteins, lipids and carbohydrates / Glicólise e gliconeogênese no fígado de jundiá alimentado com diferentes concentrações de proteínas, lipídeos e carboidratos

The activities of enzymes from a number of metabolic pathways have been used as a tool to evaluate the best use of nutrients on fish performance. In the present study the catfish Rhamdia quelen was fed with diets containing crude protein-lipid-carbohydrate (%) as follows: treatment (T) T1: 19-19-44; T2: 26-15-39; T3: 33-12-33; and T4: 40-10-24. The fish were held in tanks of re-circulated, filtered water with controlled temperature and aeration in 2000L experimental units. The feeding experiment lasted 30 days. The following enzymes of the carbohydrate metabolism were determined: Glucokinase (GK), Phosphofructokinase 1 (PFK-1), Pyruvate kinase (PK), Fructose-1,6-biphosphatase 1 (FBP-1). The activities of 6 phosphogluconate dehydrogenase (6PGDH) and glucose 6 phosphate dehydrogenase (G6PDH) were also assayed. The influence of nutrient levels on the enzyme activities is reported. The increase of dietary protein plus reduction of carbohydrates and lipids attenuates the glycolytic activity and induces hepatic gluconeogenesis as a strategy to provide metabolic energy from amino acids. The fish performance was affected by the concentrations of protein, lipid and carbohydrates in the diet. The greatest weight gain was obtained in fish fed diet T4 containing 40.14% of crude protein, 9.70% of lipids, and 24.37% of carbohydrate, respectively.(AU)

As atividades de enzimas das vias metabólicas têm sido utilizadas como uma ferramenta para avaliar a melhor utilização dos nutrientes e o desempenho dos peixes. No presente estudo, o jundiá foi alimentado com rações contendo diferentes concentrações de proteína bruta, lipídeos e carboidratos (%), da seguinte forma: tratamento (T) T1: 19-19-44; T2: 26-15-39; T3: 33-12-33; e T4: 40-10-24. Os peixes foram mantidos em tanques de recirculação, com água filtrada, temperatura controlada e aeração em unidades experimentais de 2.000L. O período experimental foi de 30 dias. Foram aferidas as atividades das enzimas glicoquinase (GK), fosfofrutoquinase 1 (PFK-1), piruvato quinase (PK) e frutose-1,6-difosfatase (FBP-1). Também foram aferidas as atividades da 6-fosfogluconato desidrogenase (6PGDH) e glicose-6-fosfato desidrogenase (G6PDH) da via das pentoses. É relatado que níveis de nutrientes influenciam as atividades enzimáticas das vias metabólicas. No presente estudo, o aumento da proteína da dieta e a redução de hidratos de carbono e lipídeos reduziram a atividade glicolítica e induziram a gliconeogênese hepática como uma estratégia para fornecer energia pelos aminoácidos. O desempenho dos peixes foi afetado pelas concentrações de proteínas, lipídeos e carboidratos na dieta. O maior ganho de peso foi obtido em peixes alimentados com dieta T4 contendo 40,14% de proteína bruta, 9,70% de lipídeos, e 24,37% de carboidratos, respectivamente.(AU)

Actividad de las enzimas hidrolíticas en cepas del hongo shiitake (Lentinula edodes) cultivadas en pulpa de café / Hydrolytic enzyme activities in shiitake mushroom (Lentinula edodes) strains cultivated on coffee pulp

Se estudió la producción de enzimas hidrolíticas (celulasas, laminarinasas y xilanasas) en cultivos de Lentinula edodes en pulpa de café estéril. Se tomaron muestras de sustrato colonizado por el micelio después de 7, 14, 21, 28 y 35 días de incubación a 25°C (W1 a W5) y durante el período de fructificación en diferentes etapas: formación de primordios (PF), primera cosecha (H) y una semana después de la primera cosecha (PH). La actividad enzimática fue menor al inicio del crecimiento micelial y mostró mayores niveles en la formación y el desarrollo de basidiomas. Durante la etapa reproductiva del hongo, las muestras se sometieron a un tratamiento de remojo. Sin embargo, no fue posible relacionar este tratamiento con el aumento de la producción de enzimas. Los niveles de actividad enzimática sugieren que la secreción de las enzimas estudiadas no influye en la capacidad de adaptación de las cepas al sustrato

Hydrolytic enzyme production (cellulases, laminarinases and xylanases) was studied in cultures of Lentinula edodes on sterilized coffee pulp. Samples of substrate colonized by mycelia were taken after 7, 14, 21, 28 and 35 days of incubation at 25°C (W1 to W5) and during the fruiting period at different stages: formation of primordia (PF), first harvest (H) and one week after the first harvest (PH). The enzymatic activity was lower during the early mycelial growth and showed higher levels during the formation and development of fruiting bodies. During the reproductive stage of the fungus, the samples were subjected to a soaking treatment; however, it was not possible to relate this soaking treatment to the increase in enzyme production. The levels of enzymatic activity suggest that secretion of the studied enzymes does not influence the adaptability of the strains to the substrate

Purification, characterization and synthetic application of a thermally stable laccase from Hexagonia tenuis MTCC-1119.

A thermally stable laccase was purified from the culture filtrate of Hexagonia tenuis MTCC-1119. The method involved concentration of the culture filtrate by ammonium sulphate precipitation and an anion-exchange chromatography on diethylaminoethyl (DEAE) cellulose. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis (native-PAGE) both gave single protein bands, indicating that the enzyme preparation was pure. The molecular mass of the enzyme determined from SDS-PAGE analysis was 100 kDa. The purification fold and percentage recovery of the enzyme activity were 12.75 and 30.12%, respectively. The pH and the temperature optima were 3.5 and 45○C, respectively. The enzyme was most stable at pH 4.0 when exposed for 1 h. Using 2,6-dimethoxyphenol (DMP), 2,2’ [azino-bis-(3-ethylbonzthiazoline-6-sulphonic acid) diammonium salt] (ABTS) and 3,5-dimethoxy-4-hydroxybenzaldehyde azine (syringaldazine) as the substrates, the Km, kcat and kcat/Km values of the laccase were 80 μM, 2.54 s-1, 3.17 × 104 M-1s-1, 36 μM, 2.54 s-1, 7.05 × 104 M-1s-1 and 87 μM, 2.54 s-1, 2.92 × 104 M-1s-1, respectively. The purified laccase was finally used for the selective biotransformation of aromatic methyl group to aldehyde group in presence of diammonium salt of ABTS as the mediator and products were characterized by HPLC, IR and 1H NMR. The percentage yields of these transformed products were >91%.

Influence of parity on concentrations of enzymes, proteins, and minerals in the milk of cows / Influência do número de parições nas concentrações de enzimas, proteínas e minerais no leite de vacas

Avaliou-se a influência do número de parições nos valores de alguns parâmetros bioquímicos e do perfil eletroforético do soro lácteo de vacas de corte. Trinta e cinco vacas da raça Canchim foram alocadas em cinco grupos: vacas de primeira lactação, segunda lactação, terceira e quarta lactações, quinta lactação e sexta lactação. As amostras de secreção láctea foram coletadas imediatamente após (dia 0) e 1, 2, 7, 15 e 30 dias após o parto. As concentrações de gamaglutamiltranferase (GGT), proteína total, cálcio, fósforo, magnésio e cálcio ionizado foram avaliadas. A separação eletroforética das proteínas foi realizada em matriz de gel de poliacrilamida (SDS-PAGE). A atividade de GGT e as concentrações de imunoglobulina G, cálcio e fósforo não foram influenciadas pelo número de parições. As concentrações de proteína total, cálcio ionizado, magnésio imunoglobulina A, lactoferrina, β - lactoglobulina e α - lactoalbumina, foram influenciadas pelo número de partos das vacas. À exceção dos teores de fósforo e α - lactoalbumina em poucos grupos, a concentração d a s demais características decresceu no decorrer do período de lactação.

Sunflower meal and supplementation of an enzyme complex in diets for growing and finishing pigs / Farelo de girassol e suplementação de complexo enzimático em dietas para suínos em crescimento e terminação

This study aimed to evaluate the inclusion of sunflower meal and an enzyme complex supplement on the performance and carcass parameters in swine from 30 to 100 kg live weight. A total of 96 pigs with average live weight of 32.19 ± 3.27 kg were distributed in a randomized blocks design with a 4 × 2 factorial arrangement of treatments (four levels of sunflower meal-SM: 0, 8, 16 and 24%, with or without inclusion of an enzyme complex-EC), factorial arrangement with six replicates and two animals per experimental unit. The analyzed variables were feed intake (kg), weight gain (kg), feed conversion (kg/kg), backfat thickness (mm), carcass muscularity (kg), hot carcass weight (%), lean meat carcass percentage (%), and lean meat carcass weight (kg). There was no interaction between factors for any of the studied variables. Feed conversion of animals from 30 to 70 kg live weight was improved by the inclusion of EC. This enzyme complex inclusion did not affect carcass characteristics. Increasing levels of SM in the test subject feed diet rations presented a quadratic effect on weight gain and on backfat thickness that reached maximum values in parameters of 7.26% and 8.16%, respectively.

Este estudo teve como objetivo avaliar a inclusão de farelo de girassol e a suplementação de complexo enzimático sobre os parâmetros de desempenho e características de carcaça de suínos, dos 30 aos 100 kg de peso vivo. Foram utilizados 96 suínos com peso vivo médio de 32,19 ± 3,27 kg distribuídos em um delineamento experimental de blocos casualiza- dos, em esquema fatorial 4 x 2 (quatro níveis de farelo de girassol-FG: 0, 8, 16 e 24% com ou sem inclusão do complexo enzimático-CE), com seis repetições e dois animais por unidade experimental. As variáveis analisadas foram: o consumo de ração (kg), o gancho de peso (kg), a conversão alimentar (kg/kg), a espessura de toucinhos (mm), a musculosidade (kg), o peso da carcaça quente (%), a porcentagem de carne magra na carcaça (%), a quantidade de carne magra na carcaça (kg). Na houve interação entre os fatores para nenhuma de variáveis estudadas. A conversão alimentar dos animais dos 30 aos 70 kg de peso foi diminuida pela inclusão do CE, porém não afetou os parâmetros de carcaça. Níveis crescentes de FG na ração apresentaram efeito quadrático sobre o ganho de peso dos animais e sobre a espessura de toucinho, com valores máximos destas variáveis em 7,26% e 8,16% de inclusão do FG, respectivamente

Molecular characterization of lactobacilli isolated from fermented idli batter

Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis.

Enzymes in clinical medicine: An overview.

Enzymes are biocatalysts and because of their remarkable properties, they are extensively used in medical diagnosis. Researches in the last two decades have concentrated more on enzymes such as creatine kinase–MB, alanine transaminase, aspartate transaminase, acid phosphatase, alkaline phosphatase etc. for clinical applications. Enzymes are the preferred markers in various disease states such as myocardial infarction, jaundice, pancreatitis, cancer, neurodegenerative disorders, etc. They provide insight into the disease process by diagnosis, prognosis and assessment of response therapy. Even though the literature on the use of enzymes in various disease conditions has accumulated, a comprehensive analysis is lacking and hence this review.

Typing of Streptococcus mutans strains isolated from caries free and susceptible subjects by multilocus enzyme electrophoresis

This study was evaluated the clonal diversity of Streptococcus mutans in caries-free and caries-active subjects using MLEE. Strains from caries-free subjects were grouped in a single taxon. Unrooted dendrogram showed that different strains clustered in four different clades, also showed that more than one clonal type can be found in a same individual.

Properties of catechol 1, 2 dioxygenase in the cell free extract and immobilized extract of Mycobacterium fortuitum

Polycyclic aromatic hydrocarbons (PAH) are carcinogenic compounds which contaminate water and soil, and the enzymes can be used for bioremediation of these environments. This study aimed to evaluate some environmental conditions that affect the production and activity of the catechol 1,2-dioxygenase (C12O) by Mycobacterium fortuitum in the cell free and immobilized extract in sodium alginate. The bacterium was grown in mineral medium and LB broth containing 250 mg L-1 of anthracene (PAH). The optimum conditions of pH (4.0-9.0), temperature (5-70 ºC), reaction time (10-90 min) and the effect of ions in the enzyme activity were determined. The Mycobacterium cultivated in LB shown higher growth and the C12O activity was two-fold higher to that in the mineral medium. To both extracts the highest enzyme activity was at pH 8.0, however, the immobilized extract promoted the increase in the C12O activity in a pH range between 4.0 and 8.5. The immobilized extract increased the enzymatic activity time and showed the highest C12O activity at 45 ºC, 20 ºC higher than the greatest temperature in the cell free extract. The enzyme activity in both extracts was stimulated by Fe3+, Hg2+ and Mn2+ and inhibited by NH4+ and Cu2+, but the immobilization protected the enzyme against the deleterious effects of K+ and Mg2+ in tested concentrations. The catechol 1,2-dioxygenase of Mycobacterium fortuitum in the immobilized extract has greater stability to the variations of pH, temperature and reaction time, and show higher activity in presence of ions, comparing to the cell free extract

Aspergellus niger como produtor de enzimas celuloliticas a partir farelo de cacau (theobroma cacao) / Aspergellus niger as a producer of cellulolytic enzymes from cocoa (Theobroma cacao) meal

O objetivo deste trabalho foi estudar a aplicação do fungo Aspergillus niger como produtor das enzimas celulolíticas CMCase, FPase e Xilanase, através da fermentação em estado sólido de cacau (Theobroma cacao). Avaliaram-se o efeito do tempo de fermentação (24, 72, e 120 horas) e da atividade de água (0,963; 0,976 e 0,983) sobre a produção das enzimas. As fermentações foram realizadas a 30º C em estufa bacteriológica. A otimização das condições ideais para produção de enzimas foi realizada a partir da Metodologia de Superfície de Resposta (MSR). Estatisticamente, as melhores atividades para a CMCase obtidas foram 14,18 U/mL em 0,972 aw e 70,07 horas de fermentação, para a FPase 7,51 U/mL 0,974 aw 80,56 horas e para a Xilanase foi 11,86 U/mL 0,971 aw e 64,24 horas.

Aspergellus niger as a producer of cellulolytic enzymes from cocoa (Theobroma cacao) meal. The aim of this work was to study the application of the fungus Aspergillus niger as a producer of the cellulolytic enzymes CMCase, FPase and Xylanase by solid-state fermentation of cocoa (Theobroma cacao). We evaluated the effect of fermentation time (24, 72, and 120 hours) and water activity (0.963, 0.976 and 0.983) on the production of enzymes. Fermentations were performed at 30º C in a bacteriological incubator. The optimization of ideal conditions for enzyme production was carried out using the response surface methodology (RSM). Statistically, the best activity obtained for CMCase was 14.18 U/mL at aw 0.972 and 70.07 hours fermentation, for FPase it was 7.51 U/mL at 0.974 aw and 80.56 hours, while for Xylanase was 11.86 U/mL at aw 0.971 and 64.24 hours.

Biochemical and genetic alterations in the freshwater neotropical fish Prochilodus lineatus after acute exposure to Microcystis aeruginosa

Microcystins are secondary metabolites produced by different species of cyanobacteria, such as Microcystis aeruginosa (MA). In this study, the biochemical and genetic effects of lyophilized MA were evaluated in the neotropical fish Prochilodus lineatus exposed to 1 or 2 mg L-1 lyophilized MA (treated group) or only water (control group) in static toxicity tests for 24 and 96 h. The gills and liver were used in the analysis of biotransformation enzymes and antioxidant defenses, blood and gill cells in genetic analysis and in brain and muscle it was determined the activity of acetylcholinesterase (AChE). The results showed the biotransformation pathway activation due to the increase in hepatic CYP1A and in branchial and hepatic glutathione S-transferase (GST). The antioxidant defense proved to be greatly affected by MA exposure leading to changes, both in gills and liver, in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and in the content of tripeptide glutathione (GSH). Lipid peroxidation was not detected, but damage to DNA molecule was observed in blood cells. In conclusion, it can be state the lyophilized MA is able to promote changes in the biochemical and genetic parameters of P. lineatus.

As microcistinas são metabólitos secundários produzidos por diferentes espécies de cianobactérias, como a Microcystis aeruginosa (MA). Neste estudo, os efeitos bioquímicos e genéticos de liofilizado de MA foram avaliados para juvenis da espécie de peixe Neotropical Prochilodus lineatus expostos a 1 ou 2 mg L-1 de liofilizado de MA (grupo tratado) ou apenas à água (grupo controle), em testes de toxicidade estáticos, durante 24 e 96 h. As brânquias e o fígado foram usados para as análises das enzimas de biotransformação e defesas antioxidantes, células do sangue e das brânquias para análises genéticas e no cérebro e músculo foi determinada a atividade da acetilcolinesterase (AChE). Os resultados mostraram ativação da via de biotransformação devido ao aumento da atividade da CYP1A hepática e da atividade da glutationa S-transferase (GST) hepática e branquial. As defesas antioxidantes foram muito afetadas pela exposição a MA levando a alterações, tanto no fígado como nas brânquias, na atividade da superóxido dismutase (SOD), da catalase (CAT), da glutationa peroxidase (GPx), glutationa redutase (GR) e no conteúdo do tripeptídeo glutationa (GSH). Apesar dessas alterações a peroxidação lipídica não foi detectada em nenhum dos tecidos, mas danos na molécula de DNA foram observados nas células do sangue. Em conclusão, pode-se afirmar que o liofilizado de MA é capaz de promover alterações em parâmetros bioquímicos e genéticos de P. lineatus.

Bioprospecting thermophiles for cellulase production: a review

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production.

Alkali pretreated of wheat straw and its enzymatic hydrolysis

The efficiency of enzymatic hydrolysis of cellulose can be improved by various pretreatments of the substrate. In order to increase the efficiency of enzymatic saccharification of the wheat straw, we determined the effect of different pretreatments on the physical structure, chemical components and enzymatic saccharification of wheat straw. Our results showed that combination of grinding and sodium hydroxide (NaOH) treatment had high effect on the enzymatic hydrolysis of wheat straws. The optimal pretreatment condition was to grind the wheat straws into the sizes of 120 meshes followed by treatment with 1.0% NaOH for 1.5 h (121°C/15psi). Under this condition, the cellulose content of wheat straw was increased by 44.52%, while the content of hemicellulose and lignin was decreased by 44.15% and 42.52%, respectively. Scanning Electronic Microscopy and infrared spectrum analyses showed that significant changes occurred in the structure of wheat straws after pretreatment, which is favorable for the hydrolysis and saccharification. Cellulase produced by Penicillium waksmanii F10-2 was used to hydrolyze the pretreated wheat straw and the optimal condition was determined to be 30 h of enzymatic reaction under the temperature of 55°C, pH 5.5 and substrate concentration of 3%.

Screening of actinomycetes from earthworm castings for their antimicrobial activity and industrial enzymes

Actinomycetes from earthworm castings were isolated and screened for their antimicrobial activity and industrial enzymes. A total of 48 isolates were obtained from 12 samples of earthworm castings. Highest numbers of isolates were recovered from forest site (58.33 %) as compared to grassland (25%) and agricultural land (16.66%). The growth patterns, mycelial coloration of abundance actinomycetes were documented. The dominant genera Identified by cultural, morphological and physiological characteristics were Streptomyces (60.41%) followed by Streptosporangium (10.41%), Saccharopolyspora (6.25%) and Nocardia (6.25%). Besides these, other genera like Micromonospora, Actinomadura, Microbispora, Planobispora and Nocardiopsis were also recovered but in low frequency. Among the 48 isolates, 52.08% were found active against one or more test organisms. Out of 25 active isolates 16% showed activity against bacterial, human fungal as well as phytopathogens. Among 48 isolates 38, 32, 21, 20, 16 and 14 produced enzyme amylase, caseinase, cellulase, gelatinase, xylanase and lipase respectively while 10 isolates produced all the enzymes. More interestingly 2, 3, and 1 isolates produced amylase, xylanase and lipase at 45°C respectively. In the view of its antimicrobial activity as well as enzyme production capability the genus Streptomyces was dominant. The isolate EWC 7(2) was most promising on the basis of its interesting antimicrobial activity and was identified as Streptomyces rochei. The results of these findings have increased the scope of finding industrially important actinomycetes from earthworm castings and these organisms could be promising sources for industrially important molecules or enzymes.