RESUMO O espaçamento de plantio determina a forma e produtividade das árvores em plantações florestais. Entretanto, seus efeitos sobre a produtividade de plantações de espécies arbóreas da Amazônia ainda são pouco compreendidos. Objetivou-se examinar os efeitos de seis regimes de espaçamento (3 x 4, 4 x 4, 4 x 5, 5 x 5, 5 x 6, e 6 x 6 m) sobre o crescimento e morfometria de plantações de Bertholletia excelsa aos 20 anos de idade. Observamos alta sobrevivência independentemente do espaçamento (> 70%). Para fins de produção de madeira, os regimes de espaçamento intermediário e dois maiores apresentaram valores mais altos de características de produção, principalmente diâmetro, biomassa e volume, embora alguns não diferiram significativamente do menor espaçamento. Um dos espaçamentos intermediários (5 x 5 m) tendeu a maior altura comercial. As copas das árvores tenderam a ser mais largas e longas nos espaçamentos maiores, indicando potencial desses regimes para a produção de frutos. As copas das árvores excederam o espaço vital de crescimento em todos os espaçamentos, sugerindo a necessidade de desbaste antes dos 20 anos em todos os espaçamentos, para reduzir a competição intraespecífica e aumentar a produtividade. Estimamos que uma densidade de 84 árvores remanescentes por hectare seria necessária para atingir um diâmetro médio de 40 cm aos 20 anos. Portanto, B. excelsa apresentou alta sobrevivência em todos os regimes de espaçamento testados, enquanto os regimes de espaçamento intermediário e maiores proporcionaram melhor crescimento e morfometria das árvores.

ABSTRACT Plant spacing is a potential driver of tree form and yield in forest plantations. However, its effects on the productivity of tree plantations in the Amazon are still little known. This study examined the effects of six spacing regimes (3 x 4, 4 x 4, 4 x 5, 5 x 5, 5 x 6, and 6 x 6 m) on the growth and morphometry of a 20-year-old plantation of Bertholletia excelsa. We observed high, spacing-independent survival (> 70%). For timber production purposes, intermediate and two large spacing regimes tended to higher values of yield components, mainly diameter, biomass, and volume, although some did not differ significantly from the smallest spacing. One of the intermediate spacings (5 x 5 m) tended to higher commercial height. Tree crowns tended to be wider and longer in the larger spacings, which indicates the potential of these regimes for fruit production. Tree crowns exceeded the vital growth space in all spacing regimes, which suggests the need for thinning before the age of 20 years in all spacings to reduce intraspecific competition and increase yield. We estimated that a density of 84 remaining trees per hectare would be necessary to reach an average diameter of 40 cm at the age of 20 years. Thus, B. excelsa had high survival in the tested range of spacing regimes, while the intermediate and the largest spacing regimes led to better tree growth and morphometry.

RESUMEN Bixa orellana L. es una planta nativa de Brasil, pero también está presente en otros países tropicales como Perú, Colombia, Ecuador, México, Indonesia, India y África Oriental. Es conocida popularmente como Urucum en Brasil. Esta revisión expone el potencial de los compuestos bioactivos derivados de B. orellana para tratar enfermedades debido a sus propiedades antimicrobianas y antioxidantes. Esta planta también está relacionada como un agente antiinflamatorio para el tratamiento de enfermedades pulmonares e incluso como gotas para los ojos para el enrojecimiento. Sus hojas se utilizan para el tratamiento de la mordedura de serpiente, diarrea, gonorrea, hepatitis, gastritis, diuréticos, antipiréticos y para enfermedades de la piel. Ese conocimiento popular ha fomentado la identificación de compuestos bioactivos en esa planta. Los compuestos β-criptoxantina, geranilgeraniol, luteína, procianidina B2, procianidina B3, isómero elagitanino y ácido elágico desoxihexosa inhibieron microorganismos patógenos como bacterias, hongos, protozoos y virus. En ese sentido, B. orellana es una fuente prometedora de compuestos que podrían aplicarse en la terapia antimicrobiana. Este trabajo de revisión puede ayudar a comprender e incentivar nuevas investigaciones para los descubrimientos de antimicrobianos que utilizan diferentes compuestos de B. orellana.

SUMMARY Bixa orellana L. is a native plant from Brazil, but it is also present in other tropical countries such as Peru, Colombia, Ecuador, Mexico, Indonesia, India and East Africa. It is popularly known as Urucum in Brazil. This review shows the potential of bioactive compounds derived from B. orellana to treat infectious diseases due their antimicrobial and antioxidant properties. This plant is also related as an antiinflammatory agent for treatment of pulmonary diseases, or even as eye drops for redness. Its leaves are used for treatment of snakebite, diarrhea, gonorrhea, hepatitis, gastritis, diuretic, antipyretic, and for skin disease. This popular knowledge has encouraged the identification of bioactive compounds in this plant. Compounds as β-cryptoxanthin, geranylgeraniol, lutein, procyanidin B2, procyanidin B3, ellagi tannin isomer and ellagic acid deoxyhexose have been described. These compounds inhibited pathogenic microorganisms such as bacteria, fungi, protozoan and viruses. In addition, some compounds with anti-inflammatory and antioxidant activities were also described. In this sense, B. orellana is a promising source of compounds that could be applied in antimicrobial therapy. This review work may help in the understanding and incentive of new research for antimicrobial discoveries using different B. orellana compounds.

Initially, all major factors that affect the rate of the AldH-catalyzed reaction (enzyme concentration, substrate concentration, temperature and pH) were investigated. Optimal activity was observed between pH values of 7.5 and 9.5 in the temperature range of 25 to 50 ºC. Kinetic parameters, such as Km (2.92 µmol L-1) and Vmax (1.33 10-2 µmol min-1) demonstrate a strong enzyme-substrate affinity. The sensors were based on screen-printed electrodes modified with the Meldola Blue-Reinecke salt (MBRS) combination. Operational conditions (NAD+ and substrate contents, enzyme loading and response time) were optimized. Also, two enzyme immobilization procedures were tested: entrapment in poly(vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) and crosslinking with glutaraldehyde. Chronoamperometry was employed to observe the biosensor responses during enzymatic hydrolysis of propionaldehyde and also to construct inhibition curves with maneb and zineb fungicides. Best results were found with the following conditions: [NAD+] = 0.25 mmol L-1; [propionaldehyde] = 80 µmol L-1; enzyme loading = 0.8 U per electrode; response time = 10 min, and inhibition time = 10 min. Current intensities around 103 ± 13 nA with the sensors and good stability was obtained for both immobilization procedures. Detection limits, calculated using 10% inhibition were 31.5 µg L-1 and 35 µg L-1 for maneb and zineb, respectively. Results obtained with other MBRS-modified electrodes consisting of mono and bi-enzymic sensors were compared. The ability to catalyze NADH oxidation by MB was also highlighted.