Showing papers in "Brazilian Archives of Biology and Technology in 2006"

Enzymatic activity of endophytic bacterial isolates of Jacaranda decurrens Cham. (Carobinha-do-campo)

Abstract: The objectives of this work was to isolate endophytic bacteria from Jacaranda decurrens Cham. and screening of some enzymes of biotechnological interest. Ten (10) bacterial species were isolated and identified from the leaves and steams. All the isolates presented enzymatic activity, which was ranked as follows: proteolytic (60%) and amilolytic activity (60%), lipolytic (40%), esterasic (40%). However, cellulolytic and pectinolytic activities were not detected. This is the first report on the isolation and identification of endophytic bacteria from Jacaranda decurrens Cham.

Abiotic factors influencing tropical dry forests regeneration

Abstract: Tropical dry forests represent nearly half the trop ical forests in the world and are the ecosystems re gistering the greatest deterioration from the anthropogenic explo itation of the land. This paper presents a review o n the dynamics of tropical dry forests regeneration and t he main abiotic factors influencing this regenerati on, such as seasonal nature, soil fertility and humidity, and n atural and anthropic disturbances. The main purpose is to clearly understand an important part of TDF succession dyna mics.

Identification and colonization of endophytic fungi from soybean (Glycine max (L.) Merril) under different environmental conditions

Abstract: A total of 297 endophytic fungi were isolated from 1728 leaf and stem fragments collected about twenty and forty days after germination from soybean (Glycine max (L.) Merril) plants grown in the field and a greenhouse. The fungi belonged to eight groups, six dematiaceous genera (Alternaria, Cladosporium, Chaetomium, Curvularia, Drechslera and Scopulariopsis) and the non-dematiaceous genera Acremonium, Aspergillus, Colletotrichum, Fusarium, Paecilomyces and Penicillium along with some Mycelia sterilia.. There were qualitative and quantitative differences in the type and number of isolates obtained from greenhouse and field-grown plants, with more isolates being obtained from the latter. No difference was found in the number of fungi isolated from leaves and stems irrespective of where the plants was grown. For was field-grown plants, the number of isolates decreased as the plants aged and more fungi were found in tissues near the soil, while for greenhouse-grown plants the number of isolates increased as the plants aged but in this case no more fungi were isolated from those tissues nearer the soil. These results could have biotechnological relevance for the biological control of pests or plant growth promotion.

Antimicrobial action of the essential oil of Lippia gracilis Schauer

Abstract: Antimicrobial activity of the essential oil (EO) of Lippia gracilis Schauer over fungi and heliconia endophytic bacteria was evaluated. For the fungi Geotrichum candidum; Trichoderma viride; Torula herbarum; Paecillomyces sp.; Fusicoccum sp.; P. aeruginens; Curvularia lunata; Aspergillus nidulans; A. flavus; and A. niger mycelial discs were inoculated in PDA medium with oil (0; 420; 440; 460; 480 e 500 µL L-1). The inhibition percentage in 420 µL L-1 was 100% for all fungi, except for C. lunata and A. niger, which was 95.58% and 89.40% , respectively. In other experiment, a suspension of the Salmonella choleraceuis-diarizonae, Enterobacter asburiae, Bacillus thuringiensis, B. pumilus, B. cereus, Klebsiella pneumoniae, and E. hormaechei was individually added to the solid NYDA medium dishes. In each dish, wells were drilled in medium and filled with water or EO (420 µL L-1). The diameter of the inhibition halo was assessed. K. pneumoniae was the bacterial species less sensitive and E. hormaechei was the most sensitive.

Comparative leaf morphology and anatomy of three Asteraceae species

Abstract: The objective of this paper was to describe and compare the morphology and anatomy of mature leaves of Mikania glomerata Spreng., Porophyllum ruderale Cass. and Vernonia condensata Baker (Asteraceae) species that have different habits emphasizing their secretory structures. Longitudinal and transversal sections of mature leaf blades of the three species were analyzed at the apex, base, and medium third part of the midvein of the leaf blade and of the margin. M. glomerata had uniseriate glandular trichomes and secretory ducts; P. ruderale had hydathodes and secretory cavities; and V. condensata had idioblasts and uni- and biseriate glandular trichomes. Key words: Mikania glomerata, Porophyllum ruderale, Vernonia condensata, secretory structures, medicinal plants * Author for correspondence INTRODUCTION The Asteraceae family consists of approximately 25000 species (Barroso, 1986) included in over 1100 genera. These species frequently present herbaceous habits, although arboreous and voluble herbaceous habits also occur (Cronquist, 1981). Because of this variety of habits, the family presents various anatomical structures and in some cases ecological specialization may occur (Metcalfe and Chalk, 1950). Secretory structures are of great taxonomical interest and their restricted distribution has an important diagnosis value (Metcalfe and Chalk, 1950; Fahn, 1979). Frequently, in Asteraceae, they occupy distinct positions in different organs of the plant occurring in all, some or in only one organ (Solereder, 1908). Castro et al. (1997) reviewed the types of secretory structures in the leaves of seventy two representatives of the Asteraceae family from the cerrado vegetation in the Reserva Biologica de Mogi Guacu, Sao Paulo, Brazil. When analyzed together these secretory structures presented diagnosis value at genus level. Eight types of leaf secretory structures were mentioned: ducts, cavities, idioblasts, laticifers, hydathodes, extrafloral nectaries, trichomes and glandular appendixes. According to Metcalfe and Chalk (1950), anatomical diversity is commonly observed in the structure of leaves of species belonging to the Asteraceae. Among the features that vary are: (a) stomata distribution on leaf surfaces; (b) guard-cell positioning in relation to ordinary epidermal cells; (c) hypoderm development on the upper side of the leaf surface; (d) mesophyll and fibrovascular system differentiation; and (e) wax secretion on leaf surface (Solereder, 1908). The anatomical features that can be observed in Asteraceae are: (a) presence of various types of glandular or covering trichomes; (b) papillae on

Antifungal activity of essential oil isolated from Ocimum gratissimum L. (eugenol chemotype) against phytopathogenic fungi

Abstract: An investigation of antifungal activity of the essential oil obtained by steam-distillation (1.1% w/w) of the aerial parts of Ocimum gratissimum and of an ethanolic extract from the steam-distillation residue was carried out using the agar diffusion method. The results revealed that the essential oil inhibited the growth of all fungi tested, including the phytopathogens, Botryosphaeria rhodina, Rhizoctonia sp. and two strains of Alternaria sp., while the extract from the residue was inactive. The essential oil was subjected to TLC bioautography used to detect fungitoxic constituents. The compound that showed antifungal activity was isolated and identified as eugenol. GC/MS analysis showed that eugenol was the main constituent of the essential oil studied. The antifungal activity of eugenol was evaluated against a species of Alternaria isolated from tomato (A1) and Penicillium chrysogenum. The minimal inhibitory concentrations of eugenol were 0.16 and 0.31 mg/disc for Alternaria sp. (A1) and P. chrysogenum, respectively.

Production of alcohol by simultaneous saccharification and fermentation of low-grade wheat flour

Abstract: Two samples of low-grade wheat flour, namely low-grade 1 (LG1) and low-grade 2 (LG2), with different carbohydrate and fibrous content, were used as substrates. The samples were liquefied using various concentrations of a- or b-amylase, in order to optimize the production of fermentable sugars; the enzyme a-amylase revealed higher performance. After liquefaction, the simultaneous saccharification and fermentation was conducted in a jar fermentor. Amyloglucosidase was used for saccharification, and dry baker's yeast, S. cerevisiae, for fermentation simultaneously. Glucose was consumed promptly in both cases, LG1 and LG2; ethanol production was considerably higher in LG1 (38.6 g/L), compared to LG2 (24.9 g/L). The maximum ATP production was observed early in the SSF process. LG1 revealed higher potential as substrate for ethanol production.

Bioactive compounds content of chimarrão infusions related to the moisture of yerba maté (Ilex Paraguariensis) leaves

Abstract: The aim of this study was to evaluate the effects of the processing stages of yerba mate (Ilex paraguariensis) on the moisture content of the leaves and the efficiency of the aqueous extraction of some bioactive substances. Samples of yerba mate were analyzed for caffeine, phenolic acids (caffeic acid, 5-caffeoilquinic acid) and flavonoids (quercetin, kaempferol and myricetin) by HPLC equipped with a diode array detector. Processing widely influenced the caffeine and 5-caffeoilquinic acid content of the aqueous extract (p < 0.05), which was related to the moisture content of the leaves. Caffeic acid was present in 45% of the in infusions from dried mate leaves. Quercetin, myricetin and kaempferol were not detected.

Chemical composition of fruits of some important chestnut cultivars

Abstract: In this study, chemical compositions of the fruits of some important domestic chestnut types and cultivars were investigated. They contained (g/100g dry matter basis) total carbohydrates 75.32 - 86.31, total sugar 10.32 - 22.79, invert sugar 0.08 - 1.25, starch 54.45 - 69.70, sucrose 8.86 - 21.28, ash 1.02 - 3.22, crude cellulose 3.58 - 5.96, total fat 0.49 - 2.01, total protein 4.88 - 10.87. Ca, Mg, Fe, Mn, Cu, Zn, P, Na and K contents were (mg/100g) 43 - 230, 70 - 160, 0.4 - 5.7, 0.7 - 5.5, 0.6 - 3.8, 1.8 - 9.1, 107 - 191, 6 - 41, 761 - 1271, respectively.

Effect of plant growth regulators in the rooting of Pinus cuttings

Abstract: This work evaluated the rooting of Pinus caribaea var hondurensis Morelet cuttings under the action of different levels of plant growth regulators The cuttings consisted of 4-6 cm long shoots of P caribaea var hondurensis Morelet with their basal needles removed The basal part of the cuttings were treated for 2 seconds with the following treatments: 1- NAA 2000mg L -1 ; 2- NAA 4000mg L ; 3- NAA 6000mg L -1 ; 4- NAA 2000mg L + PBZ 100mg L -1 ; 5- NAA 4000mg L + PBZ; 6- NAA 6000mg L -1 + PBZ; 7- IBA 2000mg L ; 8- IBA 4000mg L ; 9- IBA 6000mg L -1 ; 10-IBA 2000mg L + PBZ; 11- IBA 4000mg L -1 + PBZ; 12- IBA 6000mg L -1 + PBZ; and a control After receiving the treatment, the cuttings were planted in tubes containing 50% carbonized rice hulls and 50% vermiculite The evaluations, performed 60 days after planting, showed that P caribaea var hondurensis cuttings treated with IBA produced a higher percentage of rooted cuttings than those treated with NAA; the most effective treatment was IBA 4000mg L

Rice bran as a substrate for proteolytic enzyme production

Abstract: Rice bran was used as the substrate for screening nine strains of Rhizopus sp. for neutral protease production by solid-state fermentation. The best producer, Rhizopus microsporus NRRL 3671, was used for optimizing the process parameters for enzyme production. Fermentation carried out with 44.44 % initial moisture content at a temperature of 30 C for 72 h was found to be the optimum for enzyme secretion by the fermenting organism. While most of the carbon supplements favored enzyme production, addition of casein resulted in a marginal increase in protease yield. Fermentation was then carried out under optimized conditions to obtain the crude extract of the enzyme, which was partially purified by precipitation and dialysis. A 3-fold increase in the enzyme purity was achieved in this manner. The enzyme was found to be a metalloprotease, being activated by Mn2+, with maximal activity at a temperature of 60 C and pH 7.0.

Dynamics of allochthonous organic matter in a tropical Brazilian headstream

Abstract: The species composition of the riparian vegetation and the seasonal contribution of input and storage of fine and coarse particulate organic matter were assessed in a 3rd order stretch. Fourteen tree species in the riparian zone were identified, with 3 species contributing with 68% of total litter input: Miconia chartacea Triana (43%), Miconia cyathanthera Triana (16%) and Erythroxylum pelletarianum St. Hil (9%). The allochthonous input of coarse particulate organic matter (CPOM) was composed mainly by leaves (over 50%). Species composition and the contribution of each plant species biomass for vertical, lateral and soil inputs and benthic stocks varied along the study period. The maximum values found in September, November and December coincided with the beginning of the rainy season. There were no differences between the allochthonous vertical and lateral inputs of CPOM to the stream. Differently to other studies, this result was probably due to the peculiar composition of stream’s riparian vegetation at Serra do Cipo.

Copper improves the production of laccase by the white-rot fungus Pleurotus pulmonarius in solid state fermentation

Abstract: Pleurotus pulmonarius (Fr) Quelet, produced laccase as the main ligninolytic enzyme when cultivated on solid-state cultures using corn cob as substrate. The addition of copper greatly increased the production of enzyme. The addition of 25.0 mM CuSO4 increased the level of laccase from 270 to 1,420 U.L-1 and the fungus showed high resistance to copper under the conditions used in this work.

Effects of simulated acid rain on leaf anatomy and micromorphology of Genipa americana L. (Rubiaceae)

Abstract: Experimentos foram conduzidos para avaliar o grau de susceptibilidade e determinar as injurias causadas pela chuva acida simulada na anatomia e micromorfologia foliar de Genipa americana. Plantas foram expostas a chuva com pH 3,0 durante 10 dias consecutivos. No tratamento controle utilizou-se apenas agua destilada (pH 6,0). Amostras foliares foram coletadas e fixadas para microscopia de luz e eletronica de varredura. Foram observados nas folhas expostas a chuva acida: necroses pontuais intervenais, colapso das celulas do mesofilo e da epiderme; hipertrofia do parenquima lacunoso e acumulo de compostos fenolicos e graos de amido. A analise micromorfologica evidenciou, nas areas necrosadas, plasmolise das celulas-guarda e ruptura da cuticula e da crista estomatica. Alteracoes anatomicas ocorreram antes que sintomas visuais fossem observados nas folhas. Estes resultados comprovam a importância de dados anatomicos na diagnose precoce da injuria e na determinacao da sensibilidade de G. americana a chuva acida.

Fisheries and conflicts in Guanabara Bay, Rio de Janeiro, Brazil

Abstract: Despite the magnitude of domestic and industrial pollution, fishery yield registered in several landing points at Guanabara Bay, between April 2001 and March 2002 was slightly over 19,000 tons, corresponding to a value of US$ 4.8 million. When considered only the fish directed to the food market, the total catch amounted to about 6,300 tons and a value of US$ 3.7 million. Only a few fish species reached expressive densities compatible with commercial fisheries. Among small pelagic fish, Atlantic anchoveta and Brazilian sardinella were the dominant species, while in terms of demersal fish, croakers, mullets and catfishes comprised the main part of the catch. The absence of landing data previous to the spilling of 1.3 million liters of oil in January 2000 led to claims by fishermen representative organizations of values corresponding to about 50 years of fish harvest in the bay. Possibly, a data collection network could be established in a participative way with the main fishermen local associations. The relatively stabilized fisheries in the bay suggested that reasonable inferences could be made, without, necessarily having a complete coverage of all landing points.

Behavioral and ecological interactions between reintroduced golden lion tamarins (Leontopithecus rosalia Linnaeus, 1766) and introduced marmosets (Callithrix spp, Linnaeus, 1758) in Brazil's Atlantic Coast forest fragments

Abstract: Marmosets (Callithrix spp.) have been introduced widely in areas within Rio de Janeiro state assigned for the reintroduction of the endangered golden lion tamarin (Leontopithecus rosalia). The objetives of this study were to estimate the marmoset (CM) population in two fragments with reintroduced golden lion tamarin to quantify the association and characterize the interactions between species. The CM population density (0,09 ind/ha) was higher than that of the golden lion tamarin (0,06 ind/ha). The mean association index between tamarins and marmosets varied among groups and seasons (winter=62% and summer=35%). During the winter, competition resulted in increases in territorial and foraging behavior when associated with marmosets. Evidence of benefits during the summer was reduced adult vigilance while associated to marmosets. Golden lion tamarins were also observed feeding on gums obtained from tree gouges made by the marmosets. Marmosets represented a threat for the conservation of golden lion tamarins.

Colonization of benthic organisms on different artificial substratum in Ilha Grande bay, Rio de Janeiro, Brazil

Abstract: The aim of this work was to evaluate the influence of three different types of artificial substrates - concrete, metal and rubber - on the colonization of benthic organisms, using a structure called Multiple Disc Sampling Apparatus or MDSA. The results confirmed the hypothesis that the communities of incrusting invertebrates have preferences in relation to the type and orientation of the substratum to be colonized. Concrete and rubber, rougher surfaces, were more attractive to the organisms than the metal used. The orientation also had big influence because of the sedimentation that probably acted on the superior face of the materials, hindered the colonization.

Relative growth of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) at Iguape, São Paulo, Brazil

Abstract: A total of 2,130 individuals of Ucides cordatus (1,255 males and 875 females) were captured in a m angrove forest at Iguape, Sao Paulo, Brazil. For each crab, the follo wing body structures were measured: carapace (width = CW; length = CL; depth = CD), 5 th abdominal somite (AW), major chelar propodus (leng th = PL; width = PW; depth = PD), and 1 st and 2 nd gonopod pairs (length = GL 1 and GL 2). The Student “t” and Snedecor “F” tests were used to verify any changes in growth allometric rates durin g ontogeny. The relationships CLxCW, PLxCW (for bot h sexes), GL 1xCW and GL 2xCW (males) and AWxCW (females), showed a better fi t by two equations for the juvenile and adult phases (p 59 mm). Females showed a si milar size interval: (juvenile CW ≤ 39 mm, pre-puberty 39 ≤ CW ≤ 53 mm, sub-adult 53 ≤ CW ≤ 58 mm, adult CW > 58 mm).

Effect of eugenol on growth and listeriolysin o production by Listeria monocytogenes

Abstract: The inhibitory effect of eugenol, a naturally occurring compound mainly present in the essential oil fraction of cloves, was studied on the growth and listeriolysin O (LLO) production by Listeria monocytogenes. Potassium efflux from cells promoted by eugenol was also determined after 24 h incubation in phosphate buffered saline. Eugenol promoted a delay on the growth of L. monocytogenes at concentrations of 100, 300 and 500 µg mL-1and above 800 µg mL-1 the effect was bactericidal. Production of LLO by L. monocytogenes in the presence of eugenol was reduced 80-100%. An accumulation of external K+ was observed above 300 µg mL-1 of eugenol which indicated that the cell membrane was affected. The results showed the effectiveness of eugenol in controlling growth and LLO production of L. monocytogenes cells.

Effect of proteins from the red seaweed Hypnea musciformis (Wulfen) Lamouroux on the growth of human pathogen yeasts

Abstract: A protein fraction, rich in lectin, obtained from the red seaweed Hypnea musciformis by precipitation with ammonium sulfate (F40/70) was screened for chitinase and b-1,3-glucanase activity and assessed for antifungal potential against the human pathogen yeasts Candida albicans and C. guilliermondii. The F40/70 fraction showed chitinase and b-1,3-glucanase enzymes, with specific activities of 276.43 and 1880.7 Units.mg -1 protein, respectively. It was capable of inhibiting the growth of C. guilliermondii at the concentrations of 45, 100 and 450 µg protein.ml -1 but it showed only a discrete inhibition against C. albicans irrespective of the tested concentrations. The inhibitory action was shown to be fungistatic and the presence of the glycoprotein fetuin, for which the lectin in the fraction had affinity, abolished the antifungal action. The complete growth recovery following fetuin treatment indicated that chitinase and b-1,3-glucanase were not involved in the growth inhibition of these yeasts.

Seminal analysis, cryogenic preservation, and fertility in matrinxã fish, Brycon cephalus (Günther, 1869)

Abstract: Aiming to improve fish reproduction techniques, the characterization and cryopreservation of semen of Brycon cephalus were performed. The seminal characteristics observed were: an almost transparent, milky semen with a mean volume of 4mL, and sperm concentration of 9.617 ±1.630 x 10 6 spermatozoa/mm 3 . Spermatozoa (length = 31.288 ±4.47 µm) were of the aquasperm type and displayed a small, round head (length = 1.727 ±0.18 µm; width = 1.752 ±0.17 µm) without acrosomal vesicle, nucleus with highly condensed chromatin forming coarse clots and centriolar complex located in the nuclear fossa; a midpiece (length = 2.561 ±0.44 µm), narrowed rearward, with a cytoplasmic canal; and a flagellum (length = 29.521 ±4.37 µm). Fertilization tests with thawed semen demonstrated a significant effect ( α= 0.05) on the increase of thawed semen fertility with diluent type B in both 0.5mL and 4.0 mL straws. No significant effect ( α= 0.05) on hatching rate was observed in both straw sizes used. Key words: Semen characteristics, Cryopreservation, Brycon cephalus, Ultrastructure, Fish

Sedative and anxiolytic effects of methanolic extract from the leaves of Passiflora actinia

Abstract: Folhas de diversas especies de Passiflora sao amplamente empregadas na medicina popular brasileira como ansiolitica e sedativa. Neste trabalho, as propriedades ansioliticas e sedativas e analise por cromatografia liquida dos extratos metanolicos de Passiflora actinia foram avaliados. O extrato metanolico e todas as suas fracoes apresentaram efeitos sedativos significativos nos testes de labirinto em cruz elevada e campo aberto. Somente a fracao aquosa do extrato metanolico mostrou seletiva atividade sedativa (30 mg/kg). Analise cromatografica das fracoes ativas mostraram a presenca de isovitexina e ausencia dos alcaloides b-carbolinicos classicos de Passiflora ou flavonoides como vitexina, rutina, swertisina, hesperidina e orientina. A tintura obtida de P. actinia (folhas) apresentou 0,27 mg/ml de isovitexina e ausencia de vitexina.

Testis and vas deferens morphology of the red-clawed mangrove tree crab (Goniopsis cruentata) (Latreille, 1803)

Abstract: The present study describes the structure of the testes and vas deferens of the red-clawed mangrove tree crab, Goniopsis cruentata. Testes and vas deferens were fixed with cold Bouin's solution and submitted to histological routine examinations. Light microscopy showed the testis to be divided into three regions: anterior, containing the germinal zone; intermediary, including the collecting duct; and posterior. The vas deferens, which was continuous with the testes, could be divided into two regions: one corresponding to the expansions and another lined by cubical epithelium, collagenous fibers and a circular layer of muscle cells and containing the androgenic gland. Spermatophores were observed in both vas deferens regions suggesting that they participated in the maturation of the spermatozoids preparing the male functionally for fertilization.

Effects of static magnetic field exposure on hematological and biochemical parameters in rats

Abstract: The present work was undertaken in order to investigate the effects of static magnetic field (SMF) on growth rates, hematopoiesis, plasmatic proteins levels, glucose concentration, lactate dehydrogenase (LDH) and transaminases activities in male rats. Sub-acute exposure of rats during 5 consecutive days to SMF (1h/day at 128mT) induced an increase of plasma LDH activity (+38%, p<0.05), and glucose concentration (+31%, p<0.05), whereas haematological parameters, protein levels, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities remained unchanged. SMF exposure of rats during 30 consecutive days (1hour/day at 128mT) decreased significantly growth rates by the second week and increased significantly the plasmatic total protein levels (+62%, p<0.05), hemoglobin (+10%, p<0.05), red blood cells (+7%, p<0.05), white blood cells (+17%, p<0.05), and platelet number (+10%, p<0.05). Sub-chronic exposure to SMF increased also LDH (+43%, p<0.05), AST (+ 41%, p<0.05) and ALT activities (+95%, p<0.05). In contrast, the glucose concentration was unaffected. These changes suggested that exposure to SMF had a possible effect on the proliferation of blood cells and enzymes release within blood indicating tissue alterations.

Comparison of chemical constituents of Chamomilla recutita (L.) rauschert essential oil and its anti-chemotactic activity

Abstract: Several essential oil samples from dried flower-heads of Chamomilla recutita (L.) Rauschert, grown and commercially available around Curitiba metropolitan area, South of Brazil, were analyzed by GC-MS and the chemical constituents were compared with an Egyptian sample obtained under similar conditions and used as a control. The local grown herbs showed levels of essential oil below the standards recommended by the Brazilian Pharmacopoeia. Also, differences in their composition as well as in the quantity of several components were found such as the unexpected inversion of the relative constitution of the A and B a-bisabolol oxides. Of particular interest was the striking effect of the chamomile extracts upon human leukocyte chemotaxis, a biological anti-inflammatory activity not reported before, in which cell migration was in vitro inhibited at the same level as showed by dexamethasone.

Effects of aerial exposure on antioxidant defenses in the brown mussel Perna perna

Abstract: Investigations were carried out to evaluate the antioxidant defenses in digestive gland of mussels Perna perna held in air for 4 hours, exposed to air for 4 hours followed by submersion in water for 30 minutes, and constantly submerged for 4.5 hours. No differences were observed in CAT and GPx activities and in the levels of total GSH. Mussels exposed to air had significantly higher SOD activity, possibly related to a preparative mechanism of defense against oxidative stress during reoxygenation . Key words: Antioxidant, hypoxia, mussel, Perna perna , aerial exposure ∗ Author for correspondence INTRODUCTION The intertidal zone is a rigorous environment for sessile animal life. To survive in this environment, animals must be able to endure periodic changes in oxygen and water availability, salinity, and temperature (Storey and Churchill, 1995). Oxygen limitation can arise in several ways including valve closure at low tide, burrowing into oxygen-depleted substrate or, especially for mussels, exposure to difficult environmental conditions that reduce seawater oxygen levels or stimulate prolonged periods of valve closure (e.g. high salt levels, toxin and pollutants, predator attack; Greenway and Storey, 1999). Under anoxic conditions, ATP is degraded to AMP and subsequently to hypoxanthine. Upon reoxygenation, hypoxanthine and xanthine are oxidized generating reactive oxygen species (ROS; Jones, 1986). Toxic effects caused by ROS are many and varied, including lipid peroxidation, nucleic acid damage, protein degradation and enzyme inactivation (Winston et al., 1990). The extent of biological damage caused by ROS is ameliorated by specific antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), which uses the tripeptide glutathione (GSH) as an electron donor to reduce peroxides (Hebbel, 1986; Sies, 1993). There is little information about the response of such antioxidant defense systems in the brown mussel Perna perna to air exposure. In this work, we analyzed the activity of the antioxidant enzymes SOD, CAT and GPx, as well as the levels of total GSH in digestive glands of mussels P. perna exposed to air during 4 hours, exposed to air for 4 hours then re-submersed for 30 min and in a control group, which was kept constantly immersed in seawater during whole experiment period.

Isolation and characterization of a newly isolated Pseudomonas mutant for protease production

Abstract: A potent bacterium for extracellular protease production was isolated from local soil and identified as Pseudomonas sp. RAJR 044. A mutant of this strain JNGR 242 with protease productivity 2.5 fold higher was obtained by ultraviolet irradiation under experimentally optimized conditions of pH 7.0, temperature of 34oC, inoculum volume of 1.0 mL and incubation time of 24 hours. Comparative analysis of the chemical characteristics i.e. assimilation of carbon and nitrogen sources were also carried out. Maximum growth of the mutant strain in 2% gelatin agar plate was obtained in presence of dextrose (2%), maltose (2%), ammonium sulfate (2%) and potassium nitrate (2%) whereas, that of the parent strain was found in sucrose (2%) and ammonium nitrate (2%). The purified proteases from both the strains (parent and mutant) appeared as single homogeneous bands corresponding to 14.4 kDa molecular weight on SDS-PAGE. On studying the kinetic properties of both strains it was observed that the rate of casein hydrolysis was maximum at pH 8.0 and 7.0 and temperatures 45o C and 60o C for the parent and mutant strains respectively. It was also observed that both the extracellular proteases were inhibited by a serine protease inhibitor i.e. PMSF at 2mM concentration.

Use of smoking to add value to the salmoned trout

Abstract: The objective of this study was to make a comparison between the characteristics of salmoned trout (Salmo truta) and salmon (Salmo salar) in terms of coloration (CIE L*a*b*), proximate composition, pH and sensory attributes of fresh and smoked fillets in order to obtain a possible alternative for the substitution of imported salmon for Brazilian salmoned trout as a commercial equivalent for retail sales. Results showed that no statistical difference was found for most of the sensory attributes analyzed and for pH. Although the coloration of the fillets presented a statistical difference, the trout presented a more intense coloration than the salmon, proving to be, therefore, convenient to agroindustry.

Extraction of amylase from fermentation broth in poly (Ethylene Glycol) salt aqueous two-phase system

Abstract: Studies were carried out on the partition of amylase from Bacillus subtilis in a minimal medium at 37 oC and 110 rpm. Enzyme recovery was carried out in aqueous two-phase system PEG-Phosphate salt were carried out. The best purification factor (5.4) was obtained in system PEG 1000 (16.7% w/w) with potassium phosphate (14.8% w/w), at pH 6.0, resulting in a recovery of 45.2% activity enzymatic in the salt-rich phase.

Investigation of the tolerability of oral stevioside in Brazilian hyperlipidemic patients

Abstract: The tolerability of stevioside (2.75 mg/kg/day) obtained from leaves of Stevia rebaudiana (Bert) Bertoni (Compositae) was investigated in hyperlipidemic patients. For this purpose a placebo controlled double blind study was performed. The patients were randomized in two groups: the first group received capsules containing placebo and the second group received capsules containing stevioside (50 mg) during 90 days. All capsules were ingested twice daily, i.e., 2 capsules before lunch and 2 capsules before dinner. After the selection of the patients and each 30 days body mass index and laboratory tests (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, total cholesterol, high density lipoprotein, low density lipoprotein, very low density lipoprotein, triglycerides and glucose) were performed. Stevioside did not show any clinical relevant modification in all parameters investigated. Moreover the patients did not report severe adverse effect. Thus, we can concluded that stevioside, at least in the doses employed in this study was safe.