Resumo Em condições de estresse salino, o crescimento das plantas é reduzido, em virtude, do desequilíbrio osmótico, nutricional e oxidativo. Contudo, o ácido salicílico atua na mitigação desse estresse abiótico por promover incremento no crescimento, fotossíntese, metabolismo do nitrogênio, síntese de osmorreguladores e enzimas antioxidantes. Nesse contexto, objetivou-se avaliar o efeito de doses de ácido salicílico sobre o crescimento e alterações fisiológicas de mudas de berinjela sob estresse salino. O experimento foi conduzido em casa de vegetação, onde os tratamentos foram distribuídos em blocos ao acaso utilizando uma matriz composta central Box com cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,50; 1,08; 2,50; 3,92 e 4,50 dS m-1), associada a cinco doses de ácido salicílico (AS) (0,00; 0,22; 0,75; 1,28 e 1,50 mM), com quatro repetições e cada parcela composta por três plantas. Aos 40 dias após a semeadura, foram determinados a altura da planta, diâmetro do caule, número de folhas, área foliar, vazamento de eletrólito, teor relativo de água e massa seca total. A CEa e a aplicação de AS influenciaram no crescimento e nas alterações fisiológicas das mudas de berinjela. O aumento da CEa reduziu o crescimento na ausência de AS. O dano de membrana com o uso de AS manteve-se estável até 3,9 dS m-1 de CEa. O conteúdo relativo de água independentemente da CEa aumentou com 1 mM de SA. O uso de AS na concentração de 1 mM mitigou o efeito deletério da salinidade no crescimento das mudas até 2,50 dS m-1 de CEa.

Abstract Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.

Abstract Sugarcane cultivation stands out in Brazilian agribusiness, covering more than eight million hectares for the production of sugar, ethanol, and by-products. Fertilization is one of the limiting factors in sugarcane yield, for which filter cake is a viable solution to meet plant nutritional needs. This study aimed to assess the effect of enriched filter cake on gas exchange and yield in RB041443 sugarcane, cultivated in soils of the coastal tablelands of Paraíba, Brazil. The experiment was conducted in the Monte Alegre S/A sugarcane mill, in the municipality of Mamanguape, using a randomized blocks experimental design, with 12 treatments (T1- cake, T2- cake + MAP, T3- cake + gypsum, T4 - cake + phosphate, T5- cake + bagasse, T6- cake + MAP + gypsum, T7- cake + MAP + phosphate, T8- cake + MAP + bagasse, T9- cake + gypsum + phosphate, T10- cake + gypsum + bagasse, T11- cake + phosphate + bagasse, and T12- control (only MAP)), and 4 replications, totaling 48 plots. A significant effect (5% probability) was also observed for the variables number of leaves and tons of stem per hectare (TSH). T1- cake, T4- cake + phosphate, T6- cake + MAP + gypsum and T10- cake + gypsum + bagasse, had the best results for TSH, with yields greater than 140 t ha-1. Regarding stomatal conductance, the highest values were obtained in T6 and T8, which, together with T11, had the highest gs values. Concerning the internal carbon concentration, T1, T2, T6, and T8 stood out. T6 also had a significant effect on transpiration. From this study, it was concluded that the use of enriched filter cake as a base fertilizer in sugarcane culture contributes to increasing the yield of the RB041443 variety, generating positive responses for plant gas exchange, being T1 and T10 indicated to increase the production in the sugar-energy sector.

Resumo A cultura da cana-de-açúcar ocupa uma posição de destaque para o agronegócio brasileiro, abrangendo mais de oito milhões de hectares na produção de açúcar, etanol e subprodutos. Um dos fatores limitantes na produtividade da cana-de-açúcar é a questão da adubação, sendo a torta de filtro uma solução viável para suprir as necessidades nutricionais da planta. Com esse estudo, objetivou-se avaliar o efeito do uso da torta de filtro enriquecida sob as trocas gasosas e produtividade da variedade de cana-de-açúcar RB041443 cultivada em solos dos tabuleiros costeiros da Paraíba. O experimento foi conduzido na Usina Monte Alegre S/A, no município de Mamanguape-PB, utilizando o delineamento experimental em blocos casualizados com 12 tratamentos (T1- Torta, T2- Torta + MAP, T3- Torta + Gesso, T4 - Torta + Fosfato, T5- Torta + Bagaço, T6- Torta + MAP + Gesso, T7- Torta + MAP + Fosfato, T8- Torta + MAP + Bagaço, T9- Torta + Gesso + Fosfato, T10- Torta + Gesso + Bagaço, T11 - Torta + Fosfato + Bagaço, e T12 - Testemunha (Apenas MAP)), 4 repetições, totalizando 48 parcelas. Efeito significativo a 5% também foi observado para a variável número de folhas e tonelada de colmo por hectare. Para a variável TCH, os melhores resultados foram obtidos nos tratamentos T1- Torta, T4-Torta + Fosfato, T6- Torta + MAP + Gesso e T10- Torta + Gesso + Bagaço, com produtividades superiores a 140 t ha-1. Para a condutância estomática, resultados superiores foram obtidos no T6 e T8, que, junto ao T11, agruparam-se com os maiores valores de gs. Em relação a concentração interna de carbono, destacaram-se os tratamentos T1, T2, T6 e T8. Para a variável transpiração, o T6 apresentou influência significativa da torta de filtro. Com o referido estudo, concluiu-se que a utilização da torta de filtro enriquecida como adubação de fundação na cultura da cana-de-açúcar possibilita aumento no rendimento produtivo da variedade RB 041443, bem como respostas positivas para as trocas gasosas da planta, sendo os tratamentos T1 e T10 indicados para aumentar a produção do setor sucroenergético.

This study aims to assess a new approach for concomitant valorization of two industrial wastes - raw glycerin and spent brewer’s yeast - for the bioproduction of valuable carotenoids. Microbial pigments have numerous applications in the food and cosmetic industries. First, four cultures of yeasts were screened using pure glycerol and either (NH4)2SO4 or urea as carbon and nitrogen sources, respectively. The ability of the best performing culture to accumulate carotenoids was investigated in a medium in which only wastes were supplemented as carbon and nitrogen sources. All the fermentations were carried out in 500 mL-Erlenmeyer flasks containing 150 mL of the medium. Microbial culture was incubated at 30 °C and 150 rpm for 120 h. Particularly, R. marina was the strain with the biggest potential to produce total carotenoids (up to 420 μg g-1). The four major carotenoid pigments identified by LCAPCI-MS were β-carotene, γ-carotene, torulene, and torularhodin. All fermentation assays and all the determinations were performed in triplicate. Results show that the bioprocess proposed in this work is technically and environmentally feasible, and sustainable. The simultaneous use of raw glycerin and spent brewer’s yeast for the production of carotenoids by R. marina is reported for the first time.

Abstract The performance of an in-situ capacitance sensor for on-line monitoring of biomass concentration was evaluated for some of the most important microorganisms in the biotechnology industry: Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris and Bacillus megaterium. A total of 33 batch and fed-batch cultures were carried out in a bench-scale bioreactor and biomass formation trends were followed by dielectric measurements during the growth phase as well as the induction phase, for 5 recombinant E. coli strains. Permittivity measurements and viable cellular concentrations presented a linear correlation for all the studied conditions. In addition, the permittivity signal was further used for inference of the cellular growth rate. The estimated specific growth rates mirrored the main trends of the metabolic states of the different cells and they can be further used for setting-up control strategies in fed-batch cultures.

High cell density cultivations of recombinant E. coli have been increasingly used for the production of heterologous proteins. However, it is a challenge to maintain these cultivations within the desired conditions, given that some variables such as dissolved oxygen concentration (DOC) and feed flow rate are difficult to control. This paper describes the software SUPERSYS_HCDC, a tool developed to supervise fed-batch cultures of rE. coli with biomass concentrations up to 150 gDCW/L and cell productivities up to 9 gDCW.L-1.h-1. The tool includes automatic control of the DOC by integrated action of the stirrer speed as well as of the air and oxygen flow rates; automatic start-up of the feed flow of fresh medium (system based on a neural network committee); and automatic slowdown of feeding when oxygen consumption exceeds the maximum capacity of the oxygen supply.

This paper reports the results of applying anaerobic sequencing batch biofilm reactors (AnSBBR) for treating sulfate-rich wastewater. The reactor was filled with polyurethane foam matrices or with eucalyptus charcoal, used as the support for biomass attachment. Synthetic wastewater was prepared with two ratios between chemical oxygen demand (COD) and sulfate concentration (COD/SO4(2-)) of 0.4 and 3.2. For a COD/SO4(2-) ratio of 3.2, the AnSBBR performance was influenced by the support material used; the average levels of organic matter removal were 67% and 81% in the reactors filled with polyurethane foam and charcoal, respectively, and both support materials were associated with similar levels of sulfate reduction (above 90%). In both reactors, sulfate-reducing bacteria (SRB) represented more than 65% of the bacterial community. The kinetic model indicated equilibrium between complete- and incomplete-oxidizing SRB in the reactor filled with polyurethane foam and predominantly incomplete-oxidizing SRB in the reactor filled with charcoal. Methanogenic activity seems to have been the determining factor to explain the better performance of the reactor filled with charcoal to remove organic matter at a COD/SO4(2-) ratio of 3.2. For a COD/SO4(2-) ratio of 0.4, low values of sulfate reduction (around 32%) and low reaction rates were observed as a result of the small SRB population (about 20% of the bacterial community). Although the support material did not affect overall performance for this condition, different degradation pathways were observed; incomplete oxidation of organic matter by SRB was the main kinetic pathway and methanogenesis was negligible in both reactors.

Foram estudados os efeitos do cultivo contínuo da cana-de-açúcar por meio da análise micromorfológica de Latossolos Amarelos argilosos da região dos tabuleiros costeiros do estado de Alagoas, Brasil. Quatro talhões foram selecionados na Usina Caeté, município de São Miguel dos Campos, AL, em janeiro de 1995, sendo um com vegetação nativa (Tn), e os demais cultivados por períodos de dois (T2), dezoito (T18) e vinte e cinco (T25) anos. Os solos foram morfologicamente caracterizados, sendo coletadas amostras indeformadas dos horizontes A, AB e BA de cada perfil, em caixas de Kubiena, para análises micromorfológicas. Foram coletadas amostras para análises de densidade do solo, macroposidade, carbono orgânico e condutividade hidráulica saturada. Os resultados evidenciam que o uso agrícola dos solos causou mudanças na morfologia do horizonte superficial, com o desenvolvimento de um horizonte Ap, com sensível perda de estrutura. Após um evidente impacto negativo nas propriedades físicas com o primeiro plantio da cana-de-açúcar, o manejo adotado promoveu uma recuperação parcial da macroporosidade no horizonte superficial após 18 e 25 anos de cultivo. Além da formação inicial de uma camada compactada nos horizontes Ap e AB, foi observado um adensamento pedogenético natural do solo no BA, acelerado com o cultivo da cana-de-açúcar, pelo preenchimento de poros com argila iluvial. A porosidade total obtida pelo analisador de imagem nas fotografias das lâminas delgadas corrobora uma sensível redução da porosidade no horizonte superficial com a introdução do cultivo. Mostra também que a porosidade do horizonte BA é baixa no perfil com vegetação nativa, comprovando o caráter pedogenético do adensamento desse horizonte. Apesar de não ter sido observado nenhum revestimento nas unidades estruturais em campo, a micromorfologia mostrou pedofeições morfológicas com revestimentos argilosos nos agregados e enchimento de poros com argila iluvial, o que indica a tendência à formação de horizonte B textural com o tempo.

The effects of continuous sugarcane cropping on the properties of a clayey Yellow Latosol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, AL, involving a native forest (Tn) and sugarcane fields cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized and undisturbed samples of the A, AB, and BA horizons of each profile were collected for micromorphological analysis. The results showed that agricultural use promoted morphological changes with the development of an Ap horizon with loss of original structure. After an evident negative impact on physical properties after the first crop (profile T2), management practices promoted a partial increase in the macroporosity of the surface horizon after 18 and 25 years. Besides the development of compaction in the Ap and AB horizon with cultivation, a natural pedogenetic dense layer was observed in the BA horizon. This densification is increased with agricultural use, due to the filling of pores with illuvial clay. Total porosity measurements obtained by image analysis of thin sections revealed decreasing porosity at the surface horizon with the first cultivation. This reduction, however, did not increase with continuous cropping. The image analysis also showed that the natural porosity of the BA horizon is very small even in the profile under native forest, indicating pedogenic origin of the densification of this horizon. Although clay coatings were not observed in the field, micromorphology showed pedofeatures with clay coatings in peds and filling of pores with illuvial clay. This observation and the significant increase of the textural gradient all suggest a tendency to the formation of an argillic horizon with time.

Foram estudados os efeitos do cultivo contínuo da cana-de-açúcar nas principais propriedades químicas de um Latossolo Amarelo argiloso da região dos tabuleiros costeiros do estado de Alagoas, Brasil. Quatro talhões foram selecionados na Usina Caeté, município de São Miguel dos Campos, sendo um com vegetação nativa (Tn), e os demais cultivados por períodos de 2 (T2), 18 (T18) e 25 (T25) anos. Os solos foram morfologicamente caracterizados e, nas amostras de cada horizonte, determinados pH (H2O e KCl), carbono orgânico, fósforo disponível, bases trocáveis, capacidade de troca catiônica, saturação por bases e saturação por alumínio. Os resultados mostraram que o manejo adotado no cultivo da cana-de-açúcar melhorou a fertilidade dos solos estudados, proporcionando aumentos no pH, nos teores de cálcio, de magnésio, de fósforo, de bases trocáveis e diminuição da saturação por alumínio. Observou-se também a movimentação de cálcio e de magnésio para os horizontes inferiores.

The effects of continuous sugarcane cropping on the chemical properties of a clayey Yellow Latosol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, State of Alagoas, Brazil, involving a native forest (Tn) and sugarcane fields, cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized and samples were taken from each horizon to determine pH (H2O and KCl), organic carbon, extractable phosphorus, exchangeable bases, cation exchange capacity, base saturation and aluminum saturation. The results indicated that the sugarcane cropping system improved soil fertility, leading to significant increases in pH, calcium, magnesium, phosphorus and base saturation, and a decrease in aluminum saturation. A downward translocation of calcium and magnesium to deeper horizons was also observed.

Foram estudados os efeitos do cultivo contínuo da cana-de-açúcar nas principais propriedades físicas e morfológicas de um latossolo amarelo argiloso da região dos tabuleiros costeiros do estado de Alagoas. Quatro talhões foram selecionados na Usina Caeté, município de São Miguel dos Campos (AL), em janeiro de 1995; um com vegetação nativa (Tn) e os demais cultivados por períodos de dois (T2), dezoito (T18) e vinte e cinco (T25) anos. Os solos foram caracterizados morfologicamente e, nas amostras de cada horizonte, foram determinados granulometria, grau de floculação, umidade a -0,034 MPa e -1,52 MPa, densidade do solo e das partículas, macroporosidade e porosidade total. Foram coletadas amostras indeformadas dos horizontes A, AB e BA de cada perfil para determinação de condutividade hidráulica saturada, microporosidade e densidade do solo. Os resultados mostraram que o uso agrícola dos solos causou mudanças na morfologia do horizonte superficial com o desenvolvimento de um horizonte Ap, apresentando transição abrupta para o horizonte AB subjacente e perda de estrutura. Em relação às propriedades físicas, os resultados indicaram que o cultivo contínuo causou diminuição no conteúdo de argila, nos horizontes superficiais, e um aumento significativo, nos horizontes subsuperficiais. Após evidente impacto negativo nas propriedades físicas com o primeiro plantio da cana-de-açúcar, o manejo adotado promoveu novo equilíbrio, com recuperação parcial da porosidade total e sensível aumento no conteúdo de água disponível. Por outro lado, o uso agrícola promoveu significativa redução na condutividade hidráulica saturada do horizonte superficial, quando comparado com o solo sob vegetação nativa.

The effects of continuous sugarcane cropping on the physical and morphological properties of a clayey xanthic ferralsol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, State of Alagoas, Brazil, involving a native forest (Tn), and sugarcane fields, cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized, and samples were taken from each horizon to determine particle size distribution, degree of floculation, moisture at - 0.034 MPa and - 1.52 MPa, soil bulk and particle densities, macroporosity and calculated total porosity. Undisturbed samples of the A, AB and BA horizons of each profile were collected to determine microporosity, saturated hydraulic conductivity and soil bulk density. The results showed that the agricultural use promoted morphological changes with the development of an Ap horizon showing abrupt transition to the underlying AB horizon and lack of structure. In relation to physical properties, the results indicated that the cultivation decreased the clay content of the surface horizon and increased significantly that of the sub-surface horizon. After an evident negative impact on physical properties after the first crop, the management practices promoted a new equilibrium, with increases in total porosity and water availability. On the other hand, the agricultural use resulted in a significant reduction of the saturated hydraulic conductivity in the surface horizon, when compared to the virgin forest site.