Biomass production and essential oil yield in Ageratum conyzoides L. - Asteraceae in different stages of development

An experiment was carried out at Sâo Manuel Experimental Farm, FCA-UNESP, Botucatu-SP, in 1994 and 1995, aiming to determine the biomass production and essential oil yield of mentrasto (Ageratum conyzoides L. - Asteraceae) in different stages of development. The statistical design used was a complete randomized block with 8 replications and 3 treatments (pre-flowering, flowering and post-flowering). The spacing was 70 cm between rows and 50 cm between plants, with 70 plants/parcel. The seedlings were transplanted 40 days after sowing. After harvesting, the fragments (roots, stems, leaves, flowers) and whole plants were washed, separated and weighted. The extractions of essential oil were done by hydrodistillation, using Clevenger apparatus, for two hours. There were statistic differences (Tukey 5%) in fresh weight of all vegetal parts w'hen harvested in different development stages. About essential oil yield, statistic differences were not verified among the treatments.

Feeding ecology, density and biomass of the freshwater turtle, Phrynops geoffroanus, inhabiting a polluted urban river in south-eastern Brazil

This study examines the ecology of a population of Geoffroy's side-necked turtle Phrynops geoffroanus inhabiting a polluted urban river in Ribeirão Preto city, São Paulo state, south-eastern Brazil. Adult turtles fed mainly on Chironomidae larvae and pupae (Chironomus cf. plumosus, 100% of occurrence frequency) and domestic waste, but they also consumed terrestrial items (cockroach, snails) and carrion. Juvenile turtles showed more feeding diversity than the adults and exhibited a trend for predation on Chironomidae pupae, but this is not reflected in resource partitioning. The elevated number of turtles (170-230 turtles/ha of river) and biomass (255-345 kg/ha of river) inhabiting this urban river is probably the result of the abundance of sewage and organic waste produced by humans, the absence of predators, and increased availability of nesting areas. Such factors convert this area into an environment highly advantageous for the survival of Geoffroy's side-necked turtle.

Periphyton on natural substratum in jurumirim reservoir (São Paulo, Brazil): Community biomass and primary productivity

Seasonal variation in the biomass and primary productivity of the periphyton on natural substratum (internodes of Echiiwchloa polystaclya HBK Hitch.) was studied during one year (from August 1993 to July 1994) in a lagoon with permanent connection with a river. We also analysed the relationships between the hydrological regime, climatic conditions and physico-chemical variables of water with the biological compounds of the periphyton. Values of dry mass, ash-free dry mass, chlorophyll a and phaeophytin of periphyton ranged from 0.55±0.24 g m-2 to 7.86±4.93 g m-2; 0.28±0.18 g m-2 to 3.72±2.23 g m-2; 0.57±0.09 mg m-2 to 15.57±4.52 mg m-2; 0.03±0.03 mg m-2 to 4.74±3.46 mg m-2, respectively. The primary productivity of periphytic algae measured by C14 method ranged from 6.45±1.29 mg C m-2 h-1 to 52.88± 7.55 mg C m-2 h-1. The biomass showed a peak in October 1993, February and April 1994. Higher value of primary productivity was recorded in December 1993 and January 1994 and was due to the peculiar light and nutrition conditions during this period. We conclude that biomass and productivity of the community are controlled mainly by hydrological regime (fluctuations of water level). © INTERNATIONAL SCIENTIFIC PUBLICATIONS.

Diurnal variation of zooplankton biochemical composition and biomass in plankton production tanks

The nutritional value of zooplankton (lipid and phosphorus contents) was analyzed in outdoor, plankton-culture tanks, to monitor the effects of diurnal variation and fertilization. Total lipid contents were significantly higher (average values of about 14% DW) for the treatment fertilized during the sampling week. A significantly highher total lipid concentrations generally coincided with high biomass of Moina sp. (Cladocera) and Thermocyclops sp. nauplii (Copepoda), which is probably related to zooplankton filtration rates. The values tended to be higher during the afternoon and the night. Phosphorus contents in the zooplanktonic population varied from 0.15 to 0.91% DW, with significant differences among the tanks. The zooplankton nutritional quality was greatly influenced by fertilization, which also determined the species composition in the tanks.

Study of biosorption of rare earth metals (La, Nd, Eu, Gd) by Sargassum sp. biomass in batch systems: Physicochemical evaluation of kinetics and adsorption models

This work evaluated kinetic and adsorption physicochemical models for the biosorption process of lanthanum, neodymium, europium, and gadolinium by Sargassum sp. in batch systems. The results showed: (a) the pseudo-second order kinetic model was the best approximation for the experimental data with the metal adsorption initial velocity parameter in 0.042-0.055 mmol.g -1.min-1 (La < Nd < Gd < Eu); (b) the Langmuir adsorption model presented adequate correlation with maximum metal uptake at 0.60-0.70 mmol g-1 (Eu < La < Gd < Nd) and the metal-biomass affinity parameter showed distinct values (Gd < Nd < Eu < La: 183.1, 192.5, 678.3, and 837.3 L g-1, respectively); and (c) preliminarily, the kinetics and adsorption evaluation did not reveal a well-defined metal selectivity behavior for the RE biosorption in Sargassum sp., but they indicate a possible partition among RE studied. © (2009) Trans Tech Publications.

Optimal energy generation with biomass of sugarcane harvest

The aim of this work is the application of the Interior Point and Branch and Bound methods in multiobjective optimization models related to sugarcane harvest residual biomass. These methods showed their viability to help on choosing the sugarcane planting varieties, searching to optimize cost and energy balance of harvest residual biomass, which have conflitant objectives. These methods provide satisfactory results, with fair computing performance and reliable and consistent solutions to the analyzed models. © 2011 IEEE.

Biomass production and chemical composition of essential oil of Piper callosum as affected by spacing in Manaus, Amazonas State, Brazil

The family Piperaceae contains nearly 2000 species, most of them distributed in two genera, Piper and Peperomia. In Brazil circa 170 Piper species are found, mainly in tropical areas Their use ranges from flavoring and culinary to raw material for pharmaceutical and cosmetic industry. One of these species, Piper callosum, is used in folk medicine in the Amazon area. The objective of this study was to evaluate the production of biomass (aerial parts) as well as yield and composition of the essential oil from the leaves, according to different spacing between cultivated plants at Embrapa Western Amazon, in Manaus, State of Amazonas, Brazil. The experimental design was randomized blocks, with four treatments and seven replicates with six plants. Biomass production was inversely proportional to the spatial arrangements, with the greatest biomass production (1034.93 kg/ha) in the shortest spacing (E1), although no statistical difference was verified between E3 and E4. The same response was observed for the production of essential oil. The chemical composition of the oil was not affected by spacing, and major compounds found were safrole (59.1%), beta-pinene (8.3%), alpha-pinene (6.5%), methyl eugenol (6.3%) and 1,8-cineole (4.1).

Biomass and yield of peanut grown on tropical soil amended with sewage sludge contaminated with lead

Application of sewage sludge with high lead (Pb) contents may pollute soils and contaminate crops. The objective of this work was to evaluate peanut responses to application of sewage sludge with varying Pb contents in order to supply phosphorus (P) to the plant. A greenhouse experiment was carried out with peanut grown on soil sample from a medium-textured Haplustox. Treatments were arranged in 3 × 2 + 2 factorial scheme, replicated three times, distributed in randomized block design, and consisted of: three Pb rates applied to soil with sewage sludge (3, 21, and 42 mg kg-1) × two times of sewage sludge application (30 days before peanut sowing and at the day of the sowing) + mineral fertilization + control (without sewage sludge and mineral fertilization). Sewage sludge was efficient to supply P to peanut. Sewage sludge containing high rates of Pb, when applied, did not harm biomass and yield of the plant, but increased HCl-extractable Pb in soil and Pb content in shoot, roots, and pod husks. Increase of Pb content in pod husks may represent contamination risk of kernels and their products with fragments from husks detached during manipulation or industrial processing of peanuts. © 2012 Fábio Camilotti et al.

Above- and below-ground biomass and carbon dynamics in Brazilian Cerrado wet grasslands

Questions: Grasslands are usually neglected as potential carbon stocks, partially due to the lack of studies on biomass and carbon dynamics in tropical grasslands. What is the importance of Brazilian tropical wet grasslands as carbon sinks? Does fire frequency and season affect biomass and carbon allocation in Brazilian wet grasslands? Location: Wet grasslands, tropical savanna, Jalapão, Tocantins, northern Brazil. Methods: We determined biomass above- and below-ground, estimated carbon stocks in biennially burned plots (B2) and plots excluded from fire for 4 yr (B4). Moreover, we determined biomass in both rainy and dry seasons. Samples were 0.25 m × 0.25 m × 0.2 m (eight samples per treatment, applying a nested design, total of 48 samples). The biomass was classified in above-ground graminoids, forbs and dead matter, and below-ground roots and other below-ground organs. We used ANOVA to compare variables between treatments and seasons. Results: More than 40% of the total biomass and carbon stocks were located below-ground, mostly in roots. A high proportion of dead biomass (B4) was found in the above-ground material, probably due to low decomposition rates and consequent accumulation over the years. Although these grasslands do not experience water stress, we found significant evidence of resource re-allocation from below-ground organs to the above-ground biomass in the rainy season. Conclusions: We found more dead biomass in the rainy season, probably due to low decomposition rates, which can increase fire risk in these grasslands during the following dry season. These tropical wet grasslands stored high amounts of carbon (621 to 716 g C.m-2), mostly in the roots. Thus, policymakers should consider tropical grasslands as potential carbon stocks, since they are one of the most threatened and unprotected ecosystems in Brazil. © 2012 International Association for Vegetation Science.

Biomass-to-bio-products application of feruloyl esterase from Aspergillus clavatus

The structural polysaccharides contained in plant cell walls have been pointed to as a promising renewable alternative to petroleum and natural gas. Ferulic acid is a ubiquitous component of plant polysaccharides, which is found in either monomeric or dimeric forms and is covalently linked to arabinosyl residues. Ferulic acid has several commercial applications in food and pharmaceutical industries. The study herein introduces a novel feruloyl esterase from Aspergillus clavatus (AcFAE). Along with a comprehensive functional and biophysical characterization, the low-resolution structure of this enzyme was also determined by small-angle X-ray scattering. In addition, we described the production of phenolic compounds with antioxidant capacity from wheat arabinoxylan and sugarcane bagasse using AcFAE. The ability to specifically cleave ester linkages in hemicellulose is useful in several biotechnological applications, including improved accessibility to lignocellulosic enzymes for biofuel production. © 2012 Springer-Verlag Berlin Heidelberg.

Influence of specimen size, tray inclination and air flow rate on the emission of gases from biomass combustion

Experiments of biomass combustion were performed to determine whether specimen size, tray inclination, or combustion air flow rate was the factor that most affects the emission of carbon dioxide, carbon monoxide, and methane. The chosen biomass was Eucalyptus citriodora, a very abundant species in Brazil, utilized in many industrial applications, including combustion for energy generation. Analyses by gas chromatograph and specific online instruments were used to determine the concentrations of the main emitted gases, and the following figures were found for the emission factors: 1400 ± 101 g kg-1 of CO2, 50 ± 13 g kg-1 of CO, and 3.2 ± 0.5 g kg-1 of CH4, which agree with values published in the literature for biomass from the Amazon rainforest. Statistical analysis of the experiments determined that specimen size most significantly affected the emission of gases, especially CO2 and CO. •Statistical analysis to determine effects on emission factors.•CO2, CO, CH4 emission factors determined for combustion of Eucalyptus.•Laboratory results agreed with data for Amazonian biomass combustion in field tests.•Combustion behavior under flaming and smoldering was analyzed. © 2013 Elsevier Ltd.

Partitioning of net primary production in Eucalyptus and Acacia stands and in mixed-species plantations: Two case-studies in contrasting tropical environments

The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition.Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total belowground carbon flux (TBCF), net primary production (NPP) and its partitioning between above- and belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood productions.Annual soil CO2 efflux (FS) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual FS was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to belowground production, leading to a one third higher wood biomass at harvest in the mixed-species stand.A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations. © 2012 Elsevier B.V.

An analysis of diurnal cycles in the mass of ambient aerosols derived from biomass burning and agro-industry

Strong diurnal cycles in ambient aerosol mass were observed in a rural region of Southeast Brazil where the trace composition of the lower troposphere is governed mainly by emissions from agro-industry. An optical particle counter was used to record size-segregated aerosol number concentrations between 13 May 2010 and 15 March 2011. The data were collected every 10 min and used to calculate aerosol mass concentrations. Aerosol samples were also collected onto filters during daytime (10:00-16:00 local time) and nighttime (20:00-06:00) periods, for subsequent analysis of soluble ions and water-soluble organic carbon. Biomass burning aerosols predominated during the dry winter, while secondary aerosols were most important in the summer rainy season. In both seasons, diurnal cycles in calculated aerosol mass concentrations were due to the uptake of water by the aerosols and, to a lesser extent, to emissions and secondary aerosol formation. In neither season could the observed mass changes be explained by changes in the depth of the boundary layer. In the summer, nighttime increases in aerosol mass ranged from 2.7-fold to 81-fold, depending on particle size, while in the winter, the range was narrower, from 2.2-fold to 9.5-fold, supporting the possibility that the presence of particles derived from biomass burning reduced the overall ability of the aerosols to absorb water. Key Points Diurnal cycle of agro-industrial aerosol mass governed by humidity Biomass burning emissions act to suppress particle growth Need to consider diurnal mass cycles in aerosol dry deposition models ©2013. American Geophysical Union. All Rights Reserved.

Biosorption of cadmium (II) and lead (II) from aqueous solution using exopolysaccharide and biomass produced by Colletotrichum sp.

The biosorption of Cd(II) and Pb(II) ions on biomass and exopolysaccharide (EPS) produced by Colletotrichum sp. fungus has been investigated as a function of contact time, initial pH, initial metal ion concentration, and initial adsorbent concentration in a batch system. Adsorption equilibrium was described by Freundlich and Langmuir isotherms. Adsorption was characterized through granulometry, SEM and EDX analysis. Then, studies were performed to regenerate the adsorbent. Biosorption of metals by biomass and EPS were best described by the Langmuir and Freundlich isotherm, respectively. Results of thermodynamic investigations showed that adsorption reactions were spontaneous (ΔG° < 0), exothermal, and mainly physical. The EPS was able to remove 79 and 98% of cadmium and lead, respectively, and the biomass removed 85 and 84% of cadmium and lead, respectively, in a solution with initial concentration 100 mg L-1, and the four adsorption-desorption cycles of all adsorbents showed up with great regenerative capacity and relative stability after these four cycles, the high potential of these biological materials in sorption has been shown. © 2013 Copyright Balaban Desalination Publications.