MUDANÇAS CLIMÁTICAS: DESAFIOS E OPORTUNIDADES PARA A CONSERVAÇÃO DA BIODIVERSIDADE BRASILEIRA

A realidade das mudanças climáticas pelas quais o planeta está passando é inequívoca, assim como a influência humana nesse processo. O Painel Intergovernamental sobre Mudanças Climáticas das Nacões Unidas prevê mudanças climáticas substanciais para a região Neotropical. De fato, os impactos dessas mudanças climáticas sobre a biodiversidade da região já estão sendo sentidos: colapso de ecossistemas de corais no Caribe, retração de glaciares nos Andes e eventos extremos de seca na Amazônia. Embora haja um corpo substancial de conhecimento em torno dos possíveis impactos das mudanças climáticas sobre as formações florestais brasileiras, sobretudo as amazônicas, estudos dos impactos sobre elementos da biodiversidade do país são praticamente inexistentes. Nos últimos 20 anos foram publicados apenas dois artigos científicos em periódicos indexados na base do Thompson Institute for Scientific Information (ISI). Essa lacuna de conhecimento impossibilita a elaboração de quaisquer estratégias de adaptação às mudanças climáticas visando à conservação da biodiversidade brasileira. A comunidade científica e as agências de fomento à pesquisa, portanto, devem começar a priorizar estudos dessa natureza. O Brasil, no entanto, não deve se concentrar apenas em estratégias de ‘adaptação', pois existe grande potencial no país para ações de ‘mitigação' das mudanças climáticas em andamento. Apesar da sua matriz energética limpa, o país figura entre os maiores emissores mundiais de gases de efeito estufa, devido às enormes emissões associadas ao desmatamento. Uma questão de primeira ordem é a histórica oposição do país à incorporação de ‘desmatamento evitado' como um dos Mecanismos de Desenvolvimento Limpo do Protocolo de Kyoto. É importante que a comunidade científica brasileira ligada à conservação participe ativamente desse debate, cujas conseqüências para a biodiversidade são bastante graves

Decolorization of aqueous effluents using agro waste

In this study, the potential of agrowaste for a food dye sequestration from aqueous effluents was investigated. Initially, four local agrowaste waste namely pumpkin seed hull, bean null, oat straw and nut shells, were tested in natural condition. Bean hull (BH) revealed the best uptake capacity for Food Red 14 (FR14). The agro waste was characterised before and after dye sorption process using SEM and FTIR techniques. Those analyses were conducted in order to identify the principal connections contributing to the sorption process. The point of zero charge of BH surface, pHpzc was assessed at 4.6, which indicated a mostly acidic surface, favorable for dye adsorption at pH<6, when the sorbent is positively charged. The dye removal efficiency of the adsorbent has been established in relation to some factors, such as: pH, amount of adsorbent, dye initial concentration, contact time and temperature. In order to make the sorption process predictable, four empirical isotherms and four kinetics models were applied to the experimental data so as to enact the nature of the sorption process. Attempts have also been made for sorbent viability by testing different solvents for FR14 desorption. FTIR spectra reveal the main bands in FR14 sorption process: that at 1450 cm-1 corresponding to C=C bond from the aromatic ring appears greatly diminished for FR14-BH after the sorption process and suggests a horizontal orientation of the molecules. The movement of the band at 3442 cm-1, corresponding to -OH groups, to lower wave number suggests lower involvement of these groups in the sorption process. The others band movement from BH spectra after the sorption process is due to physical interactions (hydrogen bond, van der Waals force) that occur between functional groups of sorbent and dye. The present study shows that the agro-waste bean hull is very effective as biosorbent for Food Red 14 removal from aqueous solutions, from a large range of dye concentration in aqueous solutions (5-400 mg L-1) in batch system. Since the agricultural wastes used in this study are friendly, abundantly and locally available, the sorbents are economically viable for aqueous effluents decolorization

Effect of ferulic acid on the performance of soy protein isolate-based edible coatings applied to fresh-cut apples

The economic importance of fresh-cut fruit market is becoming progressively more significant, while the food industry shows increased interest in innovation of products bringing health benefits. The objective of this work was to assess the potential of incorporating ferulic acid (antioxidant with reported bioactivity that can act as cross-linking agent) in soy protein-based edible coating formulations in order to increase the quality and shelf life of fresh-cut apples (cv. Golden). Glycerol was used as plasticizer and ferulic acid was incorporated in concentrations between 1.0 and 4.0 g L?1. The properties of fresh-cut apples were analysed during seven days of storage at 10 °C. A common commercial antioxidant (sodium ascorbate at 10 g L?1) was tested for comparison. Uncoated apples and apples dipped into antioxidants solution were used as controls. The results emphasized the need to incorporate this phenolic antioxidant in a biopolymer matrix, due to its hydrophobic characteristics and consequently a poor dispersion along the surface of the fruit. They also indicate that the efficiency of the coatings incorporating ferulic acid is highly dependent on pH. The formulation with ferulic acid at 4.0 g L?1 and pH 7.0 has demonstrated potential application in extending the shelf life of fresh-cut apples.Thanks are due to the European Community's Seventh Framework Programme (SusFoFlex, collaborative project number 289829, KBBE.2011.2.3-03). LAQV/REQUIMTE received financial support from FCT/MEC through national funds and FEDER, under the Partnership Agreement PT2020 (reference UID/QUI/50006/2013 - POCl/01/0145/FEDER/007265).info:eu-repo/semantics/publishedVersio

Effect of pH and pressure on syngas fermentation by anaerobic mixed cultures

Syngas fermentation by mesophilic anaerobic mixed cultures was studied, regarding the effect of initial medium pH (5.8, 6.9 and 7.6) and total initial syngas pressure (1.0, 1.75 and 2.5 atm) in methane production and other alternative products (acids and alcohols). Complete consumption of CO and H2 was achieved in less than 72 h at 1.0 atm syngas, and within 240 h for higher syngas pressures. The highest specific CH4 production (normalized to the initial syngas concentration, CO+H2) was 0.89 mol CH4/mol syngas, and was obtained for pH 5.8 and 1.0 atm syngas. Volatile fatty acids (VFA) were produced in methanogenic-inhibited assays, with 0.92 mol VFA/mol syngas as the best conversion yield (at pH 6.9 and 1.0 atm). Only residual concentrations of alcohols (< 0.005 mol alcohols/mol syngas) were produced by methanogenic-inhibited sludge. Syngas pressure had a major effect on conversion yields, which might be related to the susceptibility of microbial communities to the higher CO partial pressures

Traceability statement for the determination of total chromium fraction in serpentine soils by atomic absorption spectrometry

The purpose of this work is to contribute for the metrological traceability statement of chemical measurements. Traceability statement for total chromium mass fraction in serpentine soils was developed. Accordingly, the quantity values requiring a high degree of control are calibration and quality control standard solutions, matrix certified reference material and the calibration curve model fit

Anaerobic microbial LCFA degradation in bioreactors

This paper reviews recent results obtained on long-chain fatty acids (LCFA) anaerobic degradation. Two LCFA were used as model substrates: oleate, a mono-unsaturated LCFA, and palmitate, a saturated LCFA, both abundant in LCFA-rich wastewaters. 16S rRNA gene analysis of sludge samples submitted to continuous oleate- and palmitate-feeding followed by batch degradation of the accumulated LCFA demonstrated that bacterial communities were dominated by members of the Clostridiaceae and Syntrophomonadaceae families. Archaeal populations were mainly comprised of hydrogen-consuming microorganisms belonging to the genus Methanobacterium, and acetate-utilizers from the genera Methanosaeta and Methanosarcina. Enrichment cultures growing on oleate and palmitate, in the absence or presence of sulfate, gave more insight into the major players involved in the degradation of unsaturated and saturated LCFA. Syntrophomonas-related species were identified as predominant microorganisms in all the enrichment cultures. Microorganisms clustering within the family Syntrophobacteraceae were identified in the methanogenic and sulfate-reducing enrichments growing on palmitate. Distinct bacterial consortia were developed in oleate and palmitate enrichments, and observed differences might be related to the different degrees of saturation of these two LCFA. A new obligately syntrophic bacterium, Syntrophomonas zehnderi, was isolated from an oleatedegrading culture and its presence in oleate-degrading sludges detected by 16S rRNA gene cloning and sequencing.Fundação para a Ciência e a Tecnologia (FCT)Fundo Social Europeu (FSE) - SFRH/BD/8726/2006, SFRH/BPD/14591/200

Enrichment and microbial characterization of syngas converting anaerobic cultures

Bioconversion of recalcitrant biomass/waste into bulk chemicals or biofuels is often not feasible. By gasification of these materials, syngas (mainly composed of CO2, CO and H2) is generated and can be used for the production of high value compounds by thermochemical or biotechnological processes. Here, three thermophilic cultures enriched with syngas mixtures or pure CO (T-Syn, T-Syn-CO and T-CO) were studied. Stable enriched cultures obtained by subsequent transfers for over a year, convert syngas/CO to mainly acetate and hydrogen (CO partial pressure up to 0.88 bar). 16S rRNA based techniques (PCR-DGGE) showed that predominant microorganisms in the cultures belonged to Desulfotomaculum, Caloribacterium, Thermincola and Thermoanaerobacter genera. Moreover, from the syngas- and CO-degrading cultures, a novel Thermoanaerobacter sp. (strain PCO) and a novel Moorella sp. (strain E3-O) were isolated