Optimization of biomass production with copper bioaccumulation by yeasts in submerged fermentation

The objective of this work was to study the production of biomass with copper bioaccumulation in submerged fermentation using sugarcane molasses. Candida pelliculosa BARU 05 isolated from Baru (Dipteryx alata) was selected for its good capacity to accumulate the copper. Fermentation was carried out using the medium composed by sugarcane molasses at 5 °Brix enriched with (g/L) CuSO4.5H2O 0.1; yeast extract, 10.0; (NH4)2SO4, 5.0 ; KH2PO4, 5.0 MgSO4, 0.5, inoculum 10 percent of total volume (100 ml), pH 6.0, and incubation at 30 °C, 120 rpm for 120 h. After three steps of optimization an uptake of 95.04 percent and 13.397 g/L biomass were obtained. The kinetics of copper bioaccumulation and biomass production was followed in a 10- liter bioreactor in a batch and fed-batch fermentation which showed copper accumulation of 91.98 and 100 percent, respectively, and biomass production of 38.85 g/L (24 h) and 57.54 g/L (48 h), respectively.

Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762) (Culicidae) and Artemia salina (Artemidae)

This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24 h for Na2[EDTA-Cu(II)] and total mortality in 72 h for SAP-Na2[EDTA-Cu(II)].

Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762) (Diptera: Culicidae) and Artemia salina (artemidae)

This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24 h for Na2[EDTA-Cu(II)] and total mortality in 72 h for SAP-Na2[EDTA-Cu(II)].

Aedes aegypti é inseto de grande interesse na Saúde Pública por transmitir o vírus da Dengue, Febre Amarela e Febre Hemorrágica da Dengue. No controle do mosquito utilizam-se inseticidas organoclorados, organofosforados, carbamatos e piretróides que guiam à seleção de insetos resistentes. A combinação de íons metálicos de transição, EDTA, STI e SAP são propostos como estratégia efetiva e persistente para o controle de larvas de Ae. aegypti através de danos ao sistema digestório por radicais livres. A toxicidade dos compostos foi avaliada para Ae. aegypti e A. salina (organismo não alvo). Os bioensaios foram conduzidos para avaliar o efeito tóxico dos compostos e associações após 24 e 72 horas. As CL10, CL50 e CL90 foram obtidas para comparações de toxicidade. Para Ae. aegypti a CL50 foi 32,65 mg L-1 em 24 horas para Na2[EDTA-Cu(II)] e mortalidade total a 62,5 mg.L-1para quelato em polímero acrílico de liberação lenta SAP-Na2[EDTA-Cu(II)] em até 72 horas.

Utilization of the biorreactor of imersion by bubbles at the micropropagation of Ananas comosus L. Merril

The research for new techniques of in vitro cultivation is being object of many studies around the world, in order to optimize and decrease production costs of seedlings with agronomical interest. The main goal of this work was to compare different systems of in vitro cultivations using Ananas comosus L. Merril. So, the in vitro growth of the plantlets was promoted in two different bioreactors: Bioreactor of Immersion by Bubbles (B.I.B.®) and the Reactor of Temporary Immersion (R.I.T.A.®) with immersion cycle every 2 hours for 15 minutes and the traditional system in flasks with 200 mL. All cultivation systems used the MS liquid nutritive solution, supplemented with BAP (1 mgL-1), ANA (0.25 mgL-1), sucrose (30 gL-1) and Tween 20® (0.5 µL). The pH was adjusted to 5.8 and sterilized at 120°C for 15 minutes. The cultures were kept into a growth room during 30 days, with controlled temperature of 25±2°C, under white cold light (46.8 µmol.m-2.s-1), with photoperiod of 16 hours. The experimental design used was randomized, with three treatments, three repetitions and ten plants each stage. Among the evaluated systems, the BIB® presented the best results for the tested variables, mainly the total number of shoots, being 2.3 e 3.1 times superior when compared with the system R.I.T.A.® and the traditional consecutively. So the system of immersion by bubbles turns into an effective equipment to produce seedlings of pineapple in large scale.

A busca por novas técnicas de cultivo in vitro vem sendo amplamente estudadas, visando otimizar e baixar o custo de produção das mudas que tenham interesse agronômico. O objetivo deste trabalho foi comparar diferentes sistemas de cultivo in vitro de Ananas comosus L. Merril. Para tanto, o crescimento in vitro de plântulas foi promovido em sistemas de biorreatores (B.I.B.® e R.I.T.A.®) com ciclo de imersão a cada 2 horas por 15 minutos e o sistema tradicional em frascos de 200 mL. Em todos os sistemas de cultivo, foram utilizadas solução nutritiva líquida MS, suplementado com 1 mg L-1 de BAP, 0,25 mg L-1 de ANA, 30 g L-1 de sacarose e 0,5 µL de Tween® 20, pH ajustado para 5,8 e autoclavagem a 120°C por 15 minutos. As culturas foram mantidas em sala de crescimento durante 30 dias, temperatura controlada de 25±2°C, sob luz branca fria (46,8 µmol.m-2.s-1), com 16 horas de fotoperíodo. O delineamento foi inteiramente casualizado, com três tratamentos, três repetições e dez plantas por estágios. Para os sistemas avaliados, o biorreator de imersão por bolhas apresentou os melhores resultados dentre as variáveis analisadas, com destaque ao número total de brotações, sendo 2,3 e 3,1 vezes superiores quando comparado com o sistema R.I.T.A.® e sistema tradicional respectivamente. Portanto, o sistema de imersão por bolhas torna-se um equipamento eficaz na produção de mudas de abacaxizeiro em larga escala.