Scielo RSS <![CDATA[Brazilian Archives of Biology and Technology]]> vol. 57 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Azadirachtin biosynthesis induction in <i>Azadirachta indica</i> A</b><b>. </b><b>Juss cotyledonary calli with elicitor agents</b>]]> The use of cell and plant tissues culture techniques to produce economically important active metabolites has been growing. Among these substances, azadirachtin (AZA), produced by the neem tree (Azadirachta indica), has received considerable attention due to its bioinsecticide action. The main goal of this work was to analyze the AZA levels in neem cotyledonary calli. The calli were grown in agitated Woody Plant Medium (WPM) liquid medium, supplemented with glucose (Gl), hydrolyzed casein (HC) and methyl jasmonate (MeJ) as elicitor agent. An interaction was observed between these substances, depending on in vitro cultivation time with orbital agitation. The highest concentrations (average of 0.2470 µg g-1) of AZA were produced in the first and second weeks of culture when the cell mass was grown in a medium with 2% Gl v/v, 500 mg L-1 HC and 100 µM of MeJ. This corresponded to approximately 57% of the AZA content stored in the donor plants seeds, used as a source of explants to induce in vitro callus formation. It was concluded that the nutrition, as well as the concentration of MeJ as signal transduction of secondary metabolism in neem cells, might influence the AZA content produced in vitro. <![CDATA[<b>Bivalent RNA interference to increase isoflavone biosynthesis in soybean (<i>Glycine</i><i> max</i>)</b>]]> In this work, a bivalent RNA interference (RNAi) plant-transformation vector was constructed to silence both the flavanone 3-hydroxylase (F3H) gene and the flavone synthase II (GmFNSII) gene in soybean (Glycine max). Two further unit RNAi vectors were constructed for each of these two genes. RNAi-mediated suppression of these genes effectively regulated flavone and isoflavone production in hairy roots that arose from soybean cotyledons transformed with Agrobacterium rhizogenes ATCC15834. Notably, the bivalent RNAi vector had a significantly higher effect for increasing isoflavone production compared with the two unit RNAi vectors. The study highlighted molecular methods that could be used to enhance isoflavone production in soybean and demonstrated the challenges associated with such metabolic engineering for the production of plant natural products. <![CDATA[<b>Cultivation of <i>Nannochloropsis</i> sp<i>.</i> in brackish groundwater supplemented with municipal wastewater as a nutrient source</b>]]> The aim of this work was to study growth potential of the green microalgae Nannochloropsis sp. using brackish groundwater from a well in the semi-arid northeast region of Brazil as culture medium. The medium was supplemented with (%) 19.4, 22.0, 44.0 and 50.0% of municipal wastewater after UASB treatment as a low-cost nutrient source. The results showed that the culture tested was capable of growing in the brackish groundwater even at salinity levels as low as 2 ppt. Furthermore it was shown that municipal wastewater could be used as a sole nutrient source for Nannochloropsis sp. <![CDATA[<b>Diallel among soybean genotypes with high oil content and resistance to sudden death syndrome</b>]]> The objective of this work was to use a partial diallel to evaluate the combining ability of 14 soybean genotypes and recommend superior combinations. Seven of the genotypes had high oil yield; other seven exhibited tolerance to sudden death syndrome and they generated 49 hybrids in a diallel cross without reciprocals. F2plants of each cross and the parents were evaluated for the following traits: number of days to maturity (NDM), oil content in the seeds (OC), grain yield (GY) and oil yield (OY). The results indicated the existence of genetic variability in the parents and progeny for all the traits. The rank of the parents based on the means was similar to the rank based on general combining ability (GCA) for all the traits. The specific combining ability (SCA) and the GCA were significant for all the traits, with a predominance of additive effects. The parent with the highest GCA and mean for OC was the cultivar A 7002; on the other hand, the lowest values were found in PI 520733 and IAC 100. The crosses with the highest oil yields were those involving parent A 7002, except when it was crossed with IAC 100. <![CDATA[<b>Extracellular methionine amino peptidase (MAP) production by <i>Streptomyces gedanensis</i> in solid-state fermentation</b>]]> A bioprocess was developed for extracellular MAP production from Streptomyces gedanensis by solid-state fermentation. Response surface methodology of Box Behken Design was performed to evaluate the interaction effects of most significant variables {inoculum size, (NH4)2SO4 concentration, MgSO4.7H2O and tryptone) on MAP production after the single parameter optimization and it resulted a maximum MAP production of 55.26 IU/g PUF after 120 h of fermentation. The concentrated crude MAP displayed a pH and temperature optimum of 8.5 and 50°C. By analyzing the thermal stability, the MAP was found to be stable in a temperature range of 50 to 55°C but lost about 50% of its activity at 65°C after 30 min. This is a first report of this kind of study for MAP. <![CDATA[<b>Development of single tubing-type canister for cryo-storage of bull semen and their effect on sperm motility and viability</b>]]> The objective of this study was to evaluate the potential of using single tubing-type canister on sperm quality. Semen was collected from the Bali cattle bull by electroejaculation technique and was cryopreserved in liquid nitrogen using slow freezing cryopreservation method. Two type of canister volume was used in this study; commercial canister (342.25π x 278 mm²) and single tubing-type canister (4π x 90 mm²). Makler counting chamber and computer assisted sperm analyzer (CASA) were used to evaluate the sperm motility and viability of post-thaw sperm. Results showed that the bull sperm motility and viability at the bottom of tubing-type canister was statistically higher and significant as compared to the commercial canister (p<0.05). Significant changes were found in sperm kinetics (VCL, VAP, VSL) of tubing-type canister compared to commercial canister. No significant changes in the motility and viability of the bull sperm at the top of tubing-type canister and commercial canister. There were no significant changes in sperm progression (LIN, WOB, PROG) in both the canisters. Developed tubing-type canister in this study showed potential as an alternative to be used in bull sperm cryo-storage. <![CDATA[<b>Effects of GDF-9 and FSH on mRNA expression for FSH-R, GDF-9 and BMPs in <i>in vitro</i> cultured goat preantral follicles</b>]]> The aim of the present study was to determine the role of GDF-9 and/or FSH on the growth and mRNA expression for FSH-R, GDF-9, and BMPs in goat secondary follicles after culture in vitro. Goat secondary follicles (~200µm) were isolated and cultured for six days in minimum essential medium (MEM) supplemented with GDF-9 (200 ng/mL), FSH (50 ng/mL) or both. At the beginning and end of culture, the follicular diameter was evaluated and compared. The levels of mRNA for GDF-9, FSH-R and BMPs -2, -4, -6, -7 and -15 in cultured follicles were quantified by real time PCR. The results showed that a significant increase of follicle diameter after six days when compared to day 0, but the presence of GDF-9 and FSH did not influence the follicular growth in comparison with those cultured in MEM. Real time PCR showed that GDF-9 down-regulated the levels of mRNA for BMPs -2 and -15, while FSH either alone or in combination with GDF-9 did not affect the expression of GDF-9, FSH-R and BMPs. In conclusion, GDF-9 reduced the expression of BMP-2 and -15 in caprine preantral follicles after their culture, but FSH either alone or in association with GDF-9 did not control the expression of GDF-9, FSH-R and BMPs. <![CDATA[<b>Nanoparticle-based drug delivery systems</b>: <b>promising approaches against infections</b>]]> Despite the fact that many new drugs and technologies have been developed to combat the infectious diseases, these have continued to be global health challenges. The use of conventional antimicrobial agents against these infections is always associated with problems such as the development of multiple drug resistance and adverse side effects. In addition, the inefficient traditional drug delivery system results in inadequate therapeutic index, low bioavailability of drugs and many other limitations. In this regard, antimicrobial nanoparticles and nanosized drug delivery carriers have emerged as potent effective agents against the infections. Nanoparticles have unique properties owing to their ultra small and controllable size such as high surface area, enhanced reactivity, and functionalizable structure. This review focused on different classes of antimicrobial nanoparticles, including metal, metal oxide and others along with their mechanism of action and their potential use against the infections. The review also focused on the development of nanoparticle systems for antimicrobial drug delivery and use of these systems for delivery of various antimicrobial agents, giving an overview about modern nanoparticle based therapeutic strategies against the infections. <![CDATA[<b>Oxidative stress parameters as biomarkers of risk factor for diabetic foot among the patients with type 2 diabetes</b>]]> The aim of this study was to determine whether plasma levels of carbonylated proteins, total antioxidant capacity (TAC) and reduced protein thiols could be suitable biomarkers of risk factors for diabetic foot. Individuals with type 2 diabetes with normal protective sensation (normal foot group) vs. loss of protective sensation and/or signs of peripheral arterial disease and/or foot deformities and/or history of ulcers and/or neuropathic fractures and/or amputation (diabetic foot group) were compared. The diabetic foot group showed higher carbonylated protein levels (P = 0.0457) and lower levels of TAC (P = 0.0148) and reduced protein thiols (P = 0.0088), compared with the normal foot group. In general, several other parameters of risk of diabetes complication (blood levels of glycated hemoglobin, glucose and cholesterol, duration of diabetes, body mass index and waist circumference) showed a tendency of higher values in the diabetic foot group. The results suggest that the plasma levels of carbonylated proteins, TAC and reduced protein thiols could furnish information about the risk of diabetic foot, considering that the changes in these biomarkers were associated with the loss of sensitivity and foot ulcerations. <![CDATA[<b>TT virus in peripheral blood cells from patients with human papillomavirus (HPV)</b>: <b>investigating association with cervical carcinoma</b>]]> Torque Teno Virus (TTV) presence was investigated in peripheral blood of 117 brazilian women by nested polymerase chain reaction. TTV DNA was observed in 18.6% of healthy donors and in 24.32% Human Papillomavirus (HPV) patients. TTV presence was also investigated in the HPV positive group for comparison between the cervical cancer and noncancerous patients. TTV DNA prevalence was significantly higher among the HPV positive patients with cervical cancer (57.14%) than in HPV noncancerous patients (16.67%). Thus, the presence of TTV infection could be a risk factor for cancer development in the patients presenting HPV-TTV coinfection. Further studies are required to clarify the TTV influence in HPV pathogenesis. <![CDATA[<b>Antagonistic activity of antibiotic producing <i>Streptomyces</i> sp</b><b>.</b><b> against fish and human pathogenic bacteria</b>]]> In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100%) against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100%) but comparatively lower degree of antagonism against human pathogens (50-60%). Rest of the two isolates (N21 and N23) showed variability in their antagonism. Results showed that broad spectrum antibiotic(s) could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria. <![CDATA[<b><i>In vitro</i> sensitivity of antagonistic <i>Trichoderma atroviride</i> to herbicides</b>]]> Trichoderma atroviride was tested in vitro for its sensitivity to different herbicides. The dosages tested were recommended dosage (RD), half dosage (½RD), and double dosage (2RD). Germination, colony-forming units (CFU), radial growth, and spore production were evaluated. Carfentrazone-ethyl and sulfentrazone inhibited the germination at RD and 2RD. A reduction in the CFU was observed for glufosinate-ammonium, atrazine, carfentrazone-ethyl, diuron + paraquat dichloride, imazapyr, oxyfluorfen, and sulfentrazone at each of the tested dosages. Radial growth was influenced by ametryn, atrazine, carfentrazone-ethyl, oxyfluorfen, and sulfentrazone herbicides, with an 80% reduction of the colonial area. Spore production was affected by carfentrazone-ethyl, oxyfluorfen, and sulfentrazone with colonial area reductions of over 70%. It was concluded that 2,4 D, clomazone, and imazapyr herbicides showed the least toxicity to T. atroviride and should be used in the crops where the fungus has been applied for phytopathogen control. <![CDATA[<b><i>In silico</i> molecular modeling and docking studies on the leishmanial tryparedoxin peroxidase</b>]]> Leishmaniasis is one of the most common form of neglected parasitic disease that affects about 350 million people worldwide. Leishmanias have a trypanothione mediated hydroperoxide metabolism to eliminate endogenous or exogenous oxidative agents. Both of 2-Cys peroxiredoxin (Prx) and glutathione peroxidase type tryparedoxin peroxidase (Px) are the terminal enzymes in the trypanothione dependent detoxification system. Therefore absence of trypanothione redox system in mammals and the sensitivity of trypanosomatids against oxidative stress, enzymes of this pathway are drug targets candidates. In this study, 3D structure of tryparedoxin peroxidase (2-Cys peroxiredoxin type) from Leishmania donovani (LdTXNPx) was described by homology modeling method based on the template of tryparedoxin peroxidase from Crithidia fasciculata and selected compounds were docked to the active site pocket. The quality of the 3D structure of the model was confirmed by various web based validation programs. When compared secondary and tertiary structure of the model, it showed a typical thioredoxin fold containing a central beta-sheet and three alpha-helices. Docking study showed that the selected compound 2 (CID 16073813) interacted with the active site amino acids and binding energy was -118.675 kcal/mol. <![CDATA[<b>Pigment production and growth of <i>Alternanthera </i>plants cultured <i>in vitro </i>in the presence of tyrosine</b>]]> The aim of the present study was to investigate the influence of tyrosine on the in vitro growth and the production of the betacyanin pigment in Alternanthera philoxeroides and A. tenella. Nodal segments were inoculated in MS medium containing different concentrations of tyrosine (0, 25, 50 and 75 μM), and the number of sprouts and buds, height, root length, fresh matter of shoots and roots and betacyanin content were evaluated. In A. philoxeroides , the highest production of betacyanin (51.30 mg 100 g-1 FM) was in the stems with the addition of approximately 45 μM tyrosine, while the increase in the leaves was proportional to the tyrosine concentration, and the best average was obtained with a tyrosine concentration of 75 μM (15.32 mg 100 g-1 FM). Higher tyrosine concentrations were deleterious to the growth of A. tenella plants, and a concentration of 75 μM was considered toxic. However, a tyrosine concentration of 50 μM benefitted betacyanin production, which reached 36.5 mg 100 g-1 FM in the plant shoots. These results showed the positive effect of tyrosine on the production of betacyanin in both species; however, application at high concentrations hampered the growth of Alternanthera plants. <![CDATA[<b>Phytochemical and molluscicidal activity of <i>Mikania glomerata</i> Sprengel (Asteraceae) in different lifestages of <i>Subulina octona</i> (Mollusca, Subulinidade)</b>]]> The objective of this work was to study the molluscicidal activity of aqueous extract of Mikania glomerata on the land snail Subulina octona and to assess the changes caused on the snail's fecundity, growth, hatchability and the offspring produced after exposure. Eggs, newly hatched and 30 day old snails were exposed to the sublethal concentration of M. glomerata extract for 24 and 48 h and the observations were made for 120 days. The presence of tannins, flavonoids and saponins were shown by phytochemical tests. The extract reduced significantly the hatchability and the survival of the offspring hatched from the exposed eggs. The eggs exposed for 48 h presented lower hatchability rates. There was a reduction on survival and growth of newly hatched and 30-days old snails exposed to the extract. These results indicated that the aqueous extract of M. glomerata could be applied as an alternative molluscicide for the control of this snail species efficiently. <![CDATA[<b>Aflatoxin</b><b> M<sub>1</sub> contamination in grated parmesan cheese marketed in Rio de Janeiro - Brazil</b>]]> This study aimed to determine the occurrence of AFM1 contamination in the samples of grated parmesan cheese marketed in the Metropolitan Region of Rio de Janeiro -Brazil. Thirty samples representing 10 major brands marketed in the region were analyzed by High Performance Liquid Chromatography with fluorescence detection (HPLC-FLD) after purification with immunoaffinity column. The method showed recovery values within the range of 70-90%, with RSD lower than 15% and limits of detection and quantification below the maximum level allowed by the European Commission for the presence of AFM1 in cheeses. The mycotoxin was identified in 18 (60%) of the grated cheese samples tested. The highest value corresponded to 0.69 ± 0.02 µg/kg and the mean for all the analyzed samples was 0.16 µg/kg. All the samples were lower than the limit established by the Brazilian legislation (2.5 µg/kg) for AFM1 in cheeses in general. However, eight samples (26.7%) presented AFM1 levels above the tolerance limit of 0.25 µg/kg adopted by the European Commission. These results indicated that AFM1 levels in the grated cheese consumed in Rio de Janeiro -Brazil were relatively high and it could provide a potential hazard for the public health. <![CDATA[<b>Generation of intensity duration frequency curves and intensity temporal variability pattern of intense rainfall for Lages/SC</b>]]> The objective of this work was to analyze the frequency distribution and intensity temporal variability of intense rainfall for Lages/SC from diary pluviograph data. Data on annual series of maximum rainfalls from rain gauges of the CAV-UDESC Weather Station in Lages/SC were used from 2000 to 2009. Gumbel statistic distribution was applied in order to obtain the rainfall height and intensity in the following return periods: 2, 5, 10, 15 and 20 years. Results showed intensity-duration-frequency curves (I-D-F) for those return periods, as well as I-D-F equations: i=2050.Tr0,20.(t+30)-0,89, where i was the intensity, Tr was the rainfall return periods and t was the rainfall duration. For the intensity of temporal variability pattern along of the rainfall duration time, the convective, or advanced pattern was the predominant, with larger precipitate rainfalls in the first half of the duration. The same pattern presented larger occurrences in the spring and summer stations. <![CDATA[<b>Management of the environmental restoration of degraded areas</b>]]> The aim of this work was to study ecotechnology for the management of degraded areas originally covered by the Atlantic Rainforest and located at the coordinates 25º31'50''S, 9º09'30''W. The area included 12 islands, each consisting of six jute bags with 20 kg of substrate (cattle manure and soil transposed from forest fragments). In six of these bags, native plants and seeds were also included. Six additional islands were selected randomly in the vicinity as the control. The process of evaluation was monitored through the chemical and granulometric soil analysis and surveys of survival, biometrics, floristic and phytosociological vegetation. An improvement in soil properties was observed where the model was implemented, which could be attributed to the substrate and re-vegetation. In the floristic and phytosociological studies, out of the 118 identified species, 65 were observed in the first floristic inventory and 86 in the second floristic inventory with similarities between the subfields of 27.69% and 11.36%, respectively. The influence of the substrate seed bank in the implemented islands was also observed. Increased diversity was only significant in the subareas with the model. It was concluded that this technology was effective in accelerating the succession and promoting the beginning of the restoration. <![CDATA[<b>Crude glycerol from biodiesel industry as substrate for biosurfactant production by <i>Bacillus subtilis</i> ATCC 6633</b>]]> Glycerol, a co-product of the biodiesel industry, may be a suitable raw material for the production of high added-value compounds by the microorganisms. This study aimed to use the glycerol obtained from the biodiesel production process as the main carbon source for biosurfactant production by Bacillus subtilis ATCC 6633. Results indicated that the strain lowered the surface tension of the cell-free fermented broth to 31.5 ± 1.6 mN/m, indicating the production of biosurfactant. The critical micelle concentration (CMC = 33.6 mN/m) obtained was similar to the previously reported for biossurfactants isolated from other Bacillus. The produced biosurfactant was able to emulsify n-hexadecane and soybean oil. <![CDATA[<b>The 3D CFD study of gliding swimmer on passive hydrodynamics drag</b>]]> The aim of this study was to analyze the effect of depth on the hydrodynamic drag coefficient during the passive underwater gliding after the starts and turns. The swimmer hydrodynamics performance was studied by the application of computational fluid dynamics (CFD) method. The steady-state CFD simulations were performed by the application of k - omega turbulent model and volume of fluid method to obtain two-phase flow around a three-dimensional swimmer model when gliding near water surface and at different depths from the water surface. The simulations were conducted for four different swimming pool size, each with different depth, i.e., 1.0, 1.5, 2.0 and 3.0 m for three different velocities, i.e., 1.5, 2.0 and 2.5 m/s, with swimmer gliding at different depths with intervals of 0.25 m, each starting from the water surface, respectively. The numerical results of pressure drag and total coefficients at individual average race velocities were obtained. The results showed that the drag coefficient decreased as depth increased, with a trend toward reduced fluctuation after 0.5m depth from the water surface. The selection of the appropriate depth during the gliding phase should be a main concern of swimmers and coaches.