Scielo RSS <![CDATA[Brazilian Archives of Biology and Technology]]> vol. 55 num. 1 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<b>A rapid and reliable method for the clonal isolation of <i>Acanthamoeba </i>from environmental samples</b>]]> Acanthamoeba are abundant in a wide range of environments, and some species are responsible for cutaneous infections, keratitis, and granulomatous amoebic encephalitis (GAE). The conventional detection and isolation of amoeba from clinical and environmental samples involves sampling and culture on non-nutrient Ágar medium. Although efficient, this system requires several transfers in order to eliminate contaminants, and is not appropriate for the isolation of individual amoeba from samples with a biodiverse community. In this study we propose an alternative method for the isolation of monocystic clones of Acanthamoeba. The propose method involves sampling, enrichment, encystment induction, and direct cysts micromanipulation and culture on Ágar plates. <![CDATA[<b>Extraction of lipase from <i>Burkholderia cepacia </i>by PEG/Phosphate ATPS and its biochemical characterization</b>]]> This work aimed to study the partitioning of a lipase produced by Burkholderia cepacia in PEG/Phosphate aqueous two phase system (ATPS) and its characterization. Lipase was produced by B. cepacia strains in a fermenter. Enzyme partitioning occurred at pH 6.0 and 8.0, using PEG 1500 and 6000 on two tie lines. Metal ions, pH and temperature effects on enzyme activity were evaluated. Five milliliter of 7.5% olive oil emulsion with 2.5% gumarabic in 0.1M sodium phosphate buffer at pH 8.0 and 37ºC were used for the activity determinations. Results showed that crude stratum from B. cepacia was partitioned by PEG1500/phosphate ATPS at pH 6.0 or 8.0 for, which the partitioning coefficients were 108-and 209-folds. Lipase presented optimal activity conditions at 37ºC and pH 8.0; it showed pH-stability for 4 h of incubation at different pH values at 37ºC. Metal ions such as Mn2+ , Co2+, I-and Ca2+ sustained enzymatic activities; however, it was inhibited by the presence of Fe2+, Hg2+ and Al3+ . Km and Vmax values were 0.258 U/mg and 43.90 g/L, respectively. A molecular weight of 33 kDa and an isoelectric point at pH 5.0 were determined by SDS-PAGE and IFS electrophoresis, respectively. <![CDATA[<b>Induction of xylanase in thermophilic fungi <i>Scytalidium thermophilum </i>and <i>Sporotrichum thermophile</i></b>]]> Regulation of xylanase production in two thermophilic fungi Scytalidium thermophilum and Sporotrichum thermophile was investigated. The expression of xylanase was found to be inducible in both the cases. Various carbon sources were tested so as to identify the inducers. Soy flour and oat spelt xylan induced maximum level of xylanase in Scytalidium thermophilum and Sporotrichum thermophile respectively. Induction of xylanase in Scytalidium thermophilum led to simultaneous induction of cellulase. The zymography of enzyme preparations revealed that different carbon sources caused differential expression of multiple isoforms of xylanase in Scytalidium thermophilum, but same isoforms were expressed by Sporotrichum thermophile irrespective of the carbon source used. <![CDATA[<b>Recent developments in microbial oils production</b>: <b>a possible alternative to vegetable oils for biodiesel without competition with human food?</b>]]> Since centuries vegetable oils are consumed as human food but it also finds applications in biodiesel production which is attracting more attention. But due to being in competition with food it could not be sustainable and leads the need to search for alternative. Nowdays microbes-derived oils (single cell oils) seem to be alternatives for biodiesel production due to their similar composition to that of vegetable oils. However, the cold flow properties of the biodiesel produced from microbial oils are unacceptable and have to be modified by an efficient transesterification. Glycerol which is by product of transesterification can be valorised into some more useful products so that it can also be utilised along with biodiesel to simplify the downstream processing. The review paper discusses about various potent microorganisms for biodiesel production, enzymes involved in the lipid accumulation, lipid quantification methods, catalysts used in transesterification (including enzymatic catalyst) and valorisation of glycerol. <![CDATA[<b>Side-effects of pesticides used in the organic system of production on <i>Apis mellifera </i>Linnaeus, 1758</b>]]> This study aimed to evaluate the effects of pesticides, used in the organic system, on Apis mellifera under laboratory conditions. Four multiple (0.25x, 0.5x, 1x and 2x) concentrations as recommended by they manufacturers of the following products: Rotenat CE®, Pironat®, Biopirol 7M®, Organic neem®, Natuneem® and lime sulfur were tested by topical application and ingestion. Of all the products and concentrations tested, only the lime sulfur (5000 ml 100L-1 and 10000 mL 100L-1 of water) by ingestion, and Rotenat CE® (1200ml 100L-1 of water) on topical application were considered slightly harmful for A. mellifera, as the classification of IOBC/WPRS for the laboratory tests. <![CDATA[<b>Dental pulp vascular permeability changes induced by dental bleaching</b>]]> Aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. The bleaching agent (35 % hydrogen peroxide) was activated by halogen light; LED (Light Emitting Diode) or LED, followed by laser phototherapy (LPT) (λ = 780 nm; 3 J/cm²). After the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. The teeth were diaphanized and photographed. The amount of blue stain content of each dental pulp was quantified using a computer imaging program. The data was statistically compared (p < 0.05). The results showed a significant higher (p < 0.01) dye content in the groups bleached with halogen light, compared with the control, LED and LED plus LPT groups. Thus, tooth bleaching activated by LED or LED plus LPT induces lesser resulted in increased vascular permeability than halogen light. <![CDATA[<b>Fibromyalgia and the relevance of the whole-body vibration exercises in vibratory platforms</b>: <b>a short review</b>]]> Among nonpharmacological strategy to manage fibromyalgia, exercise (aerobic) has shown efficacy. Whole-body vibration (WBV) exercise has been proposed as a potential clinical intervention. WBV would induce increase in growth hormone (GH). An impairment of the hypothalamic-pituitary-GH-Insulin Growth Factor-1(IGF-1) axis has been implicated in the pathophysiology of fibromyalgia. This article aims to review the studies on exploring the relationship between WBV and fibromyalgia. Literature searches were performed in the PubMed database on 04/03/2010 using terms related to "pain", "whole body vibration" and "fibromyalgia". An important number of publications were identified with the term "pain" and in comparison, only a small number of articles were found related to "fibromyalgia". Three publications found with "whole body vibration" and fibromyalgia were analyzed.There are reports describing increase in serum IGF-1 following exposure to WBV in elderly patients. However, one randomized fibromyalgia trial revealed no changes in serum IGF-1 levels in women undergoing WBV. Due to the paucity of available, effective therapies for fibromyalgia, further studies that explore the relationship between the neuroendocrine system, fibromyalgia and WBV are merited. <![CDATA[<b>Production of rabbit antibodies against purified Glucose oxidase</b>]]> Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose) resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex G-200 column for gel filtration chromatography. It was observed that enzyme achieved 59.37 U mg-1of specific activity with 27.08 fold purity and 64.36% recovery. Purified glucose oxidase was injected into rabbits through intravenous route, to raise the glucose oxidase antibodies. After 30 days incubation period, the rabbits were slaughtered and serum was separated from blood. The antibodies were isolated by ammonium sulfate precipitation and confirmed by agar gel precipitation test. This could be a convenient and low cost alternate assay for the estimation of glucose oxidase in biological fluids. Moreover, such antibodies against the said enzyme could be used in various therapeutic and diagnostic applications. <![CDATA[<b>Control of papaya fruits anthracnose by essential oil of <i>Ricinus communis</i></b>]]> The aim of this work was to investigate the potential of castor oil for the control of papaya diseases caused by the fungus Colletotrichum gloeosporioides and the bacterium Pseudomonas caricapapayae. The treatment with 1% castor oil did not significantly affect the fungal growth. The effectiveness of castor oil for the control of anthracnose was shown when 5% and 10% (v/v) were used in the assays resulting in reduced mycelial growth. Fungal sporulation was strongly inhibited at 10% (v/v) concentration of essential oil. The studies with the fresh fruits treated with 5% (v/v) castor oil in aqueous emulsions resulted in effective reduction of pathogen spread in these fruits. No lesion was found in the fruits treated with oil, when compared to the control fruits. Castor oil showed no effect against the P. caricapapayae when tested in vitro. These results suggested the potential use of the castor bean essential oil and its fatty acids constituents for the control of anthracnose in papaya fruits. <![CDATA[<b>Effects of oral L-carnitine and DL-carnitine supplementation on alloxan-diabetic rats</b>]]> The effect of oral L-carnitine (LC) or DL-carnitine (DLC) supplementation during one or four weeks (200 or 400 in diabetic rats was investigated. After the supplementation period, the blood was collected for the evaluation of total (TC) and free L-carnitine (FC), glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triacylglycerol. Tissues were collected for the determination of TC and FC concentrations. The carnitine supplementation did not change levels of glucose, total cholesterol, HDL-C and LDL-C in the blood. Diabetic rats showed hypertriacylglycerolemia and decreased blood and tissue levels of FC and TC. Normalization of the blood triacylglycerol and increased blood and tissue levels of FC and TC were observed with the LC or DLC supplementation. However, the hyperglycemia remained unchanged. Thus, the reduction of blood triacylglycerol obtained with carnitine supplementation in the diabetic rats did not depend on an amelioration in the glycemia and was mediated partly at least by an increment of serum and tissue concentrations of FC and TC. <![CDATA[<b>Influence of light intensity on growth and physiological characteristics of common sage (<i>Salvia officinalis </i>L.)</b>]]> The aim of this work was to investigate the effects of four different light intensities on the growth characteristics, physiological parameters and leaf photosynthetic pigments of Salvia officinalis L. The plant's dry mass, number of the leaves and physiological parameters indicated a strong positive correlation with the light intensity. On the other hand, the plant's height and leaf photosynthetic pigments were increased at low light treated plants. These results suggest that the aromatic herb Salvia officinalis L. is adaptable to different light environments. <![CDATA[<b>Maize-Dwelling insects omnivory in <i>Spodoptera frugiperda </i>(J.E. Smith) (Lepidoptera: Noctuidae) egg masses</b>]]> This work reports the first record of omnivory behavior of Diabrotica speciosa (Coleoptera, Chrysomelidae), Leptoglossus zonatus (Hemiptera, Coreidae), Monocrepidius aff. posticus and Monocrepidius fuscofasciatus (Coleoptera, Elateridae) on fall armyworm Spodoptera frugiperda (Lepidoptera, Noctuidae) egg masses in maize fields. Macrophotography was used to record the activity of these insects on fall armyworm sentinel egg masses during 2009 and 2010 maize growing seasons. The presence of omnivorous insects changes the species population dynamics within the ecosystem. Therefore, the implications of these interactions should be understood and taken into consideration for integrated pest management enhancement. <![CDATA[<b>Testicular morphology of adult wistar rats treated with <i>Rudgea viburnoides </i>(Cham.) Benth. leaf infusion</b>]]> The present study was carried out to investigate the effects of Rudgea viburnoides infusion on the body biometry and testicular morphometry and stereology of adult Wistar rats. Two groups received the infusion daily at the concentration of 3 or 6 mg/mL for 40 days. The control group received only water. Neither the biometrical parameters nor the tubular diameter and the height of the seminiferous epithelium showed any significant alterations in the treated animals. Leydig cells stereology did not show any significant alterations in the treated animals. These results indicated that R. viburnoides did not cause alterations in body biometry and testicular morphometry. <![CDATA[<b>Effect of freezing and processing technologies on the antioxidant capacity of fruit pulp and jelly</b>]]> The effect of freezing and processing technology on the antioxidant capacity of grape (Vitis vinifera), apple (Malus domestica), strawberry (Fragaria x Anassa), pear (Pyrus communis L.), guava (Psidium guajava L.), and fig (Ficus carica L.) was evaluated for 90 days. Under a storage temperature of -15 º C, there was no significant difference in the antioxidant capacity of grape and fig pulp, and a higher antioxidant capacity was found for guava pulp (27 µmol/g). While the technological processing did not affect the antioxidant capacity of pear and apple jellies, all other jellies studied showed a reduced antioxidant capacity. The processing reduced the antioxidant capacity of grapes in 45%. Among the fruit products, the highest antioxidant activities were found for guava pulp and jelly (27 and 25 µmol/g, respectively), followed by grape pulp (22 µmol/g). <![CDATA[<b>Use of food wastes for the production of lactic silage</b>]]> The goal of the present work was to produce lactic silage from food wastes. A factorial 2³ experimental design was applied using the following factors and levels: yogurt inoculum concentration (1 and 15%), sucrose (2 and 15%) and temperature (22 and 35 ºC) and as response variable, the soluble nitrogen content (SNC) at the end of the fermentation was considered. The best SNC output was for the treatment with 1 % of inoculum, 2 % of sucrose and temperature of 22ºC. The increase of SNC with regards to its initial content, from 0.17 % to 1.67 % for protein contents (PC) < 5 % corresponded to 882 % and from 0.65 % to 2.36 % for PC &gt; 5 % represented 263 %. It was possible to produce a lactic silage and keep it stable for up to 30 days, which was enough storage time before being sent to a drying process for future use in animal feeding or compost. <![CDATA[<b>Yellow passion fruit seed oil (<i>Passiflora edulis </i>f. <i>flavicarpa</i>)</b>: <b>physical and chemical characteristics</b>]]> The aim of this study was to determine the chemical composition -physico-chemical properties, fatty acid and tocopherol compositions and total phenolic compounds -and evaluate the radical-scavenging activity of crude oil extracted from passion fruit (Passiflora edulis f. flavicarpa) seeds, aiming to use the agro-industrial by-products. The oil seed extraction was performed by Soxhlet method and the oil yield from the seeds was 30.39%. The oil showed high levels of unsaturated fatty acids (87.59%), including mainly linoleic (73.14%) and oleic (13.83%) acids, tocopherol (499.30 mg/kg) and phenolic compounds (1,314.13 mg GAE/kg). The physico-chemical characteristics were similar to those of other edible oils and the oil showed significant antioxidant activity. Therefore, the potential utilization of the passion fruit seed oil as a raw material for food, chemical and pharmaceutical industries could be favorable. <![CDATA[<b>Immobilization of <i>Bacillus megaterium </i>MTCC 2444 by Ca-alginate entrapment method for enhanced alkaline protease production</b>]]> Optimization of culture conditions and immobilization parameters for alkaline protease production was carried out by employing Bacillus megaterium MTCC2444. The partially purified enzyme was tested for its stability in the presence of oxidants, surfactants and commercial detergents. The optimum temperature, pH, incubation time and inoculum size were 55 ºC, 11, 48 h, 1 %, respectively. Calcium alginate was used as the immobilization matrix and the effects of gel concentration, bead size, age of immobilized cells, solidification period and initial biomass concentration on alkaline protease production and cell leakage were investigated. The results indicated that the immobilization was most effective with 4 % gel concentration, bead size of 3 mm, 24 h aged immobilized cells for a solidification period of 12 h at 1.5 % initial biomass concentration. The enzyme showed good stability in the presence of oxidants, surfactants and commercial detergents. <![CDATA[<b>Bioremediation of herbicide velpar K<sup>®</sup> in vitro in aqueous solution with application of EM-4 (effective microorganisms)</b>]]> This work assessed the bioremediation of herbicide Velpar K®, in vitro in aqueous solution, used against weeds in sugar cane in São Paulo state. The herbicide contained Hexazinone and Diuron. It was used the microbial inoculant denominated Effective Microorganisms (EM-4), pool of microorganisms from soil that contained lactic and photosynthetic bacteria, fungi, yeasts and actinomycetes for bioremediation. Results for the depth of cultivation on agar-agar inoculated with EM-4 showed the microorganisms growth in the concentrations between 0.2% and 1.0% of the Velpar K®in the gel. The analysis of high performance liquid chromatography (HPLC) showed that the EM-4 was effective for the bioremediation of the herbicide, which reached the values of 80% for diuron and 70% for hexazinone after 21 days in solution of 2:1 of Velpar K®/EM-4 ratio. These results could be useful for planning the bioremediation of contaminated areas with Velpar K®. <![CDATA[<b>Biomonitoring of microcystin and aflatoxin co-occurrence in aquaculture using immunohistochemistry and genotoxicity assays</b>]]> This work investigated the effects of co-occurring aflatoxin B1 (AFB1) and microcystin (MC) in aquaculture, using immunohistochemistry and genotoxicity methods. Tilapia (Oreochromis niloticus) were exposed to AFB1 by intraperitoneal and MC (cell extract of Microcystis aeruginosa) by intraperitoneal and immersion routes. The interaction of MC-AFB1 was evaluated co-exposing the intraperitoneal doses. Blood samples were collected after 8, 24, and 48h to analyze the micronucleus frequency and comet score. The interaction of MC-AFB1 showed a synergic mutagenic response by higher micronucleus frequency of co-exposed group. A slight genotoxic synergism was also observed in the comet score. Immunohistochemistry detected MC in al lthe fish liver tissues exposed to MC by intraperitoneal route, and only the immersed group with the highest dose of MC showed a positive response. Although MC was non-detectable in the edible muscle, the combination of immunohistochemistry with genotoxicity assay was an attractive biomonitoring tool in aquaculture, where the animals were frequently exposed to co-occurring synergic hazards. <![CDATA[<b>Cadmium and Chromium Toxicity to <i>Pseudokirchneriella subcapitata </i>and <i>Microcystis aeruginosa</i></b>]]> The toxicity of cadmium and chromium to Pseudokirchneriella subcapitata and Microcystis aeruginosa was evaluated through algal growth rate during 96h exposure bioassays. Free metal ion concentrations were obtained using MINEQL+ 4.61 and used for IC50 determination. Metal accumulations by the microorganisms were determined and they were found to be dependent on the concentration of Cd2+ and Cr6+. IC50 for P. subcapitata were 0.60 µmol L-1 free Cd2+ and 20 µmol L-1 free Cr6+, while the IC50 values for M. aeruginosa were 0.01 µmol L-1 Cd2+ and 11.07 µmol L-1 Cr6+ . P. subcapitata accumulated higher metal concentrations (0.001 -0.05 µmol Cd mg-1 dry wt. and 0.001 -0.04 µmol Cr mg-1 dry wt) than the cyanobacteria (0.001 -0.01 µmol Cd mg-1 dry wt and 0.001 -0.02 µmol Cr mg-1 dry wt). Cadmium was more toxic than chromium to both the microorganisms.