Biomass production by Arthrospira platensis under different culture conditions

In biotechnological processes, the culture media components are responsible for high costs and exert a strong influence on the cyanobacteria behavior. The objective of this study was to evaluate the Arthrospira platensis growth potential for biomass production under different cultivation conditions using an experimental design. Three factors that are important for cyanobacteria growth were evaluated: sodium bicarbonate (9 to 18 g/l), sodium nitrate (1.25 to 2.5 g/l), and irradiance (20 to 120 µmol photons/m2.s–1). The results showed that the concentration of NaNO3 in the A. platensis medium can be reduced, resulting in increased concentrations of biomass produced. There was a higher biomass production due to the increase in the concentration of NaHCO3 and irradiance, mainly when these two factors varied tending towards the highest values studied. The results demonstrate the potential to produce Arthrospira platensis with lower costs and effluent generation without affecting cultivation performance.

Production of phycobiliproteins by Arthrospira platensis under different lightconditions for application in food products

There has been an increase in investment in research on new sources of natural pigments for food application. Some cyanobacteria can change the structures responsible for light harvesting and cellular processes according to the wavelength and light intensity. This phenomenon has been described as complementary chromatic adaptation. The present study aimed to investigate the growth of Arthrospira platensis using different light qualities, irradiance, and wavelength by evaluating the production of biomass, proteins, and phycobiliproteins. The occurrence of the chromatic adaptation phenomenon in this cyanobacterium was also investigated. The microorganism used in this study, A. platensis, was grown in a Zarrouk medium under three irradiance levels, 50, 100, and 150 μmol fotons.m–2.s–1 with illumination provided by white and green fluorescent lamps. The condition of 150 µmol fotons.m–2.s–1 white light was the one that promoted the highest biomass production of A. platensis cultures (2115.24 mg.L–1). There was no difference in the production of total protein and total phycobiliproteins under the studied conditions. It is likely that the large supply of nitrogen in the Zarrouk medium was sufficient for cell growth and maintenance, and it supplied the production of accessory pigments composed of protein. Finally, there was no evidence of the complementary chromatic adaptation phenomenon in A. platensis cultivated under green light. Moreover, this condition did not increase phycocyanin production.

Composition and color stability of anthocyanin-based extract from purple sweet potato

AbstractPurple sweet potato (PSP) can provide products with attractive color besides nutritious benefits in food processing. So, the compositions and color stability of an aqueous anthocyanin-based PSP extract were investigated in order to promote its wide use in food industry. PSP anthocyanins were extracted with water, and nine individual anthocyanins (48.72 ug mL–1 in total, 24.36 mg/100 g fresh PSP in yield) were found by HPLC analysis. The PSP extract also contained 17.11 mg mL–1 of protein, 0.44 mg mL–1 of dietary fiber, 2.82 mg mL–1 of reducing sugars, 4.02 ug mL–1 of Se, 54.21 ug mL–1 of Ca and 60.83 ug mL–1 of Mg. Changes in color and stability of the PSP extract, as affected by pH, heat, light and extraction process, were further evaluated. Results indicated that PSP anthocyanins had good stability at pH 2.0-6.0, while the color of PSP extract kept stable during 30 days of storage at 20 °C in dark. Both UV and fluorescent exposure weakened the color stability of PSP extract and UV showed a more drastic effect in comparison. A steaming pretreatment of fresh PSP is beneficial to the color stability.

Lime and fertilizer recommendation system for coconut trees

Fertilizer recommendation to most agricultural crops is based on response curves. Such curves are constructed from field experimental data, obtained for a particular condition and may not be reliable to be applied to other regions. The aim of this study was to develop a Lime and Fertilizer Recommendation System for Coconut Crop based on the nutritional balance. The System considers the expected productivity and plant nutrient use efficiency to estimate nutrient demand, and effective rooting layer, soil nutrient availability, as well as any other nutrient input to estimate the nutrient supply. Comparing the nutrient demand with the nutrient supply the System defines the nutrient balance. If the balance for a given nutrient is negative, lime and, or, fertilization is recommended. On the other hand, if the balance is positive, no lime or fertilizer is needed. For coconut trees, the fertilization regime is divided in three stages: fertilization at the planting spot, band fertilization and fertilization at the production phase. The data set for the development of the System for coconut trees was obtained from the literature. The recommendations generated by the System were compared to those derived from recommendation tables used for coconut crop in Brazil. The main differences between the two procedures were for the P rate applied in the planting hole, which was higher in the proposed System because the tables do not pay heed to the pit volume, whereas the N and K rates were lower. The crop demand for K is very high, and the rates recommended by the System are superior to the table recommendations for the formation and initial production stage. The fertilizer recommendations by the System are higher for the phase of coconut tree growth as compared to the production phase, because greater amount of biomass is produced in the first phase.

Broccoli yield in response to top-dressing fertilization with green manure and biofertilizer

The objective of this work was to evaluate the productive performance of broccoli under different top-dressing organic fertilizations. The experiment was conducted under protected cultivation, in a completely randomized design with four replications, with two plants per experimental unit. Broccoli seedlings were produced in a commercial substrate in styrofoam trays. The seedlings were transplanted to plastic pots containing 10.0 L of substrate made up of subsoil and organic compost at the ratio of 3:1 (v/v), respectively, which is equivalent to about 20.0 t ha-1 of organic compost at planting. After seedling establishment, the top-dressing fertilization treatments were applied: gliricidia biomass associated or not with liquid biofertilizer of cattle manure to the soil and bokashi. Two control treatments were established: one with mineral fertilization recommended for the crop and the other without top-dressing fertilization. The broccoli production was evaluated (commercial standard). Plants that received mineral fertilizer were more productive, however, they were not significantly different (p>0.05), by Dunnet test, from the plants fertilized with 2.5 t ha-1 gliricidiabiomass (dry mass) associated with liquid biofertilizer (2.0 L m-2) applied to soil. Top-dressing fertilizations with only gliricidia, at 2.5 and 5.0 t ha-1 of biomass (dry mass), resulted in no significant increase in production of broccoli inflorescence. The use of bokashi in addition to gliricidia biomass and liquid biofertilizer reduced the efficiency of the fertilization compared with plants that received only gliricidia and liquid biofertilizer.

Close relationship between diameters at 30cm height and at breast height (DBH)

This paper proposes the establishment of a second diameter measuring standard at 30cm shoot extension ('diam30') as input variable for allometric biomass estimation of small and mid-sized plant shoots. This diameter standard is better suited than the diameter at breast height (DBH, i.e. diameter at 1.30m shoot extension) for adequate characterization of plant dimensions in low bushy vegetation or in primary forest undergrowth. The relationships between both diameter standards are established based on a dataset of 8645 tree, liana and palm shoots in secondary and primary forests of central Amazonia (ranging from 1-150mm dbh). Dbh can be predicted from the diam(30) with high precision, the error introduced by diameter transformation is only 2-3% for trees and palms, and 5% for lianas. This is well acceptable for most field study purposes. Relationships deviate slightly from linearity and differ between growth forms. Relationships were markedly similar for different vegetation types (low secondary regrowth vs. primary forests), soils, and selected genera or species. This points to a general validity and applicability of diameter transformations for other field studies. This study provides researchers with a tool for the allometric estimation of biomass in low or structurally heterogeneous vegetation. Rather than applying a uniform diameter standard, the measuring position which best represents the respective plant can be decided on shoot-by-shoot. Plant diameters measured at 30cm height can be transformed to dbh for subsequent allometric biomass estimation. We recommend the use of these diameter transformations only for plants extending well beyond the theoretical minimum shoot length (i.e., >2m height). This study also prepares the ground for the comparability and compatability of future allometric equations specifically developed for small- to mid-sized vegetation components (i.e., bushes, undergrowth) which are based on the diam(30) measuring standard.

Daldinia eschscholtzii (Ascomycota, Xylariaceae) isolated from the Brazilian Amazon: taxonomic features and mycelial growth conditions

The Amazon has a high diversity of fungi, including species of the genus Daldinia (Ascomycota, Xylariaceae), which produce secondary metabolites with recognized nematicidal and antimicrobial activity. The ecological role of Daldinia is important, as stromata serve as refuges to many insects and arthropodes, and the fungi contribute to the degradation of vegetable organic matter. The aim of this study was to analyze the taxonomic features and mycelial growth conditions in vitro of a Daldinia specimen collected in the Brazilian Amazon. Morphological and molecular studies of the fungus identified it as D. eschscholtzii. To evaluate mycelial growth, we cultivated the fungus at 20, 25, 30, 35, and 40 °C in malt extract-peptone agar (MEPA), malt extract-peptone (MEP), potato dextrose (PD), and minimum medium (MM). The best mycelial growth occurred at 35 °C, although the greatest amount of biomass was obtained at 25 °C and 30 °C. PD proved to be the best medium for biomass production.

Organic material decomposition and nutrient dynamics in a mulch system enriched with leguminous trees in the Amazon

The new techniques proposed for agriculture in the Amazon region include rotational fallow systems enriched with leguminous trees and the replacement of biomass burning by mulching. Decomposition and nutrient release from mulch were studied using fine-mesh litterbags with five different leguminous species and the natural fallow vegetation as control. Samples from each treatment were analyzed for total C, N, P, K, Ca, Mg, lignin, cellulose content and soluble polyphenol at different sampling times over the course of one year. The decomposition rate constant varied with species and time. Weight loss from the decomposed litter bag material after 96 days was 30.1 % for Acacia angustissima, 32.7 % for Sclerolobium paniculatum, 33.9 % for Iinga edulis and the Fallow vegetation, 45.2 % for Acacia mangium and 63.6 % for Clitoria racemosa. Immobilization of N and P was observed in all studied treatments. Nitrogen mineralization was negatively correlated with phenol, C-to-N ratio, lignin + phenol/N ratio, and phenol/phosphorus ratios and with N content in the litterbag material. After 362 days of field incubation, an average (of all treatments), 3.3 % K, 32.2 % Ca and 22.4 % Mg remained in the mulch. Results confirm that low quality and high amount of organic C as mulch application are limiting for the quantity of energy available for microorganisms and increase the nutrient immobilization for biomass decomposition, which results in competition for nutrients with the crop plants.

Winter pasture and cover crops and their effects on soil and summer grain crops

The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

Determinação dos hidrocarbonetos saturados e policíclicos aromáticos presentes no material particulado da atmosfera amazônica

It was identified and quantified several organic compounds in the atmosphere of a site into Amazon Basin with high impact of biomass burning emission. It was important to know the particulate matter composition with respect to n-alkanes and PAH associated with the particulate matter because they provided indication on the main sources contributing to airborne particles, the contribution of natural vs. man-made emission and the aging of the particles. The main classes of compounds observed were n-alkanes, PAH and nitro-PAH. It was observed the formation of nitro-PAH from photochemical reactions. The aerosol mass concentration is mainly associated with fluoranthene, pyrene and benzo(ghi)perylene. Environmental and direct emissions samples (flaming and smoldering) were collected and analysed.

Utilização do resíduo líquido de indústria de processamento de suco de laranja como meio de cultura de Penicillium citrinum: depuração biológica do resíduo e produção de enzima

Penicillium citrinum grown in orange juice processing wastes medium under continuous agitation was studied in order to establish optimal conditions (incubation period, incubation temperature, initial pH and nitrogen addition) for biomass and ribonuclease production, as well as, biological depuration of the wastes. Nitrogen addition to wastes medium increased the biomass and ribonuclease production and provides COD reduction. The soy meal shows to be the best nitrogen source. The conditions for a more favorable enzyme and biomass production and COD reduction were initial pH 6.0 and temperature of 27°C. The maximum value obtained for these parameters on optimal conditions of cultivation was 11 U/mL of enzyme, 4 mg/mL of biomass (dry matter) and 55% of COD reduction, in 96 hours of incubation.

A indústria petroquímica no próximo século: como substituir o petróleo como matéria-prima?

The world reserves of petroleum will finish in about 100 years. For a tropical country like Brazil, biomass will be the natural substitute for petroleum. For the best utilization of biomass, it first needs to be separated into its principal components: cellulose, hemicelluloses, lignins, vegetable and essential oils, non-structural carbohydrates, bark and foliage. All feedstocks for the chemical industry can be obtained from these biomass components, as shown in the first part of this paper. In the second part we discuss how the major products from petrochemicals can be obtained from the different biomass components. We show that Brazil can use different strategies, compared to other countries, to obtain petrochemical products, which could result in innovations. However, it is necessary that the government starts to invest immediately in order to keep the petrochemical industries competitive with foreign industries, so that they continue to be one of Brazil's major employers.

Uso de frascos de polipropileno descartáveis no pré-tratamento de amostras de água para determinação de chumbo, cobre e mercúrio por voltametria de onda quadrada

In this work a simple and versatile procedure is described for treating water samples using small polypropylene (PP) vials (4 mL) for determining heavy metals by square wave voltammetry (SWV). This procedure involves treatment with nitric acid (0.2 mol L-1) and boiling in a water-bath (~ 100 ºC). This process is completed after one hour and allows the pretreatment of several samples simultaneously. The accuracy was estimated using addition/recovery studies and certified water sample analysis, yielding an agreement near to 100%.

Desempenho de biomassas na adsorção de hidrocarbonetos leves em efluentes aquosos

Removal of hydrocarbons from aqueous effluents using biosorbents was investigated. The effluent was simulated by a dispersion of gasoline (simple hydrocarbons) in water. Corn-cob, wood powder, coconut mesocarp and sugar-cane bagasse were used as adsorbents and their performance verified by means of batch experiments performed in an agitated vessel. The influence of input variables such as hydrocarbon concentration, mass of biomass and agitation level on the adsorbents' capacity was studied by means of factorial design. The results indicated that, among the materials studied, coconut mesocarp and sugar-cane bagasse can be considered promising biomasses for treating aqueous effluents contaminated by hydrocarbons.

Transformação de triglicerídeos em combustíveis, materiais poliméricos e insumos químicos: algumas aplicações da catálise na oleoquímica

The use of biomass as raw-material for obtaining chemicals, polymers and fuels is emerging as a clever alternative solution for the increasing energy demand, environmental awareness and petroleum shortage. In this work, some attempts in order to develop catalytic systems suitable for triglyceride transformation into fuels, polymers and intermediates are reviewed.