RESUMO

The agricultural activity has generated a progressive amount of waste, which needs a proper treatment to avoid negative environmental impacts. At the same time, values can be added to such waste, as its use in animal feed. This research was conducted at the laboratory of Animal Nutrition, State University of Southwestern Bahia, campuses of Vitória da Conquista and Itapetinga. The objective of this study was to evaluate the effect of coffee husks on ruminant feeds by increasing doses of fibrolytic enzymes, evaluating their effects on in vitro ruminal degradability of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (FDA) of the coffee husk (CH). The experiment was a completely randomized design in a 2x4 factorial scheme. It compounded the following treatments: Coffee husk (CH1): 1.5% enzymes (E) and 24 h enzymatic action (EA); CH2: 3.0% (E) and 24h (EA); CH3: 4.5% (E) and 24 h (EA); CH4: 6% (E) and 24 h (EA); CH5: 1.5% (E) 48 h (EA); CH6: 3% (E) and 48h (EA); CH7: 4.5% (E) and 48h (EA); and CH8: 6% (E) and 48 h (EA), all based on dry matter. An improvement in the degradability of the nutritional parameters MS, NDF, and FDA occurred with the addition of enzymes, with 3% enzyme addition being the best level, and 24 hours, as the best action time. In addition to that, as the EA on coffee husk increased, the degradation rate decreased. Therefore, the use of enzymes can improve the digestibility of the fibrous fraction, enabling the use of the coffee husk andpossibly other agroindustrial residues, thus minimizing their adverse effects on nature.

A atividade agrícola tem gerado uma quantidade progressiva de resíduos, os quais necessitam serem tratados de forma adequada para que não promovam impactos ambientais negativos e que, ao mesmo tempo, sejam agregados valores a estes para que possam ser utilizados na alimentação animal. A pesquisa foi conduzida no laboratório de Nutrição Animal da Universidade Estadual do Sudoeste da Bahia, campus de Vitória da Conquista e Itapetinga. Objetivou-se o aproveitamento da casca de café na alimentação de ruminantes através do tratamento com doses crescentes de enzimas fibrolíticas avaliando seus efeitos sobre a degradabilidade ruminal in vitro da matéria seca (MS), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) da casca de café (CC). O delineamento experimental utilizado foi inteiramente casualisado, com esquema fatorial 2x4, constituindo os seguintes tratamentos Casca de café (CC1): 1,5% de Enzimas (E) e 24h de Ação Enzimática (AE); CC2: 3% (E) e 24h (AE); CC3: 4,5%(E) e 24 h(AE); CC4:6 % (E) e 24 h(AE); CC5: 1,5% (E) 48 h(AE); CC6: 3% (E) e 48h(AE); CC7:4,5% (E) e 48h(AE); CC8: 6% (E) e 48 h(AE), com base na matéria seca. Constatou-se que com adição de enzimas, ocorreu uma melhora na degradabilidade dos parâmetros nutricionais MS, FDN e FDA, sendo 3% de enzimas o melhor nível e 24 horas o melhor tempo de ação. Além disso, à medida que a ação enzimática na casca de café aumentou, a taxa de degradação diminuiu. Portanto, o uso de enzimaspode melhorar a digestibilidade da fração fibrosa, possibilitando o uso da casca de café e possivelmenteoutros resíduos agroindustriais, minimizando assim seus efeitos adversos sobre a natureza.

Assuntos

RESUMO

The agricultural activity has generated a progressive amount of waste, which needs a proper treatment to avoid negative environmental impacts. At the same time, values can be added to such waste, as its use in animal feed. This research was conducted at the laboratory of Animal Nutrition, State University of Southwestern Bahia, campuses of Vitória da Conquista and Itapetinga. The objective of this study was to evaluate the effect of coffee husks on ruminant feeds by increasing doses of fibrolytic enzymes, evaluating their effects on in vitro ruminal degradability of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (FDA) of the coffee husk (CH). The experiment was a completely randomized design in a 2x4 factorial scheme. It compounded the following treatments: Coffee husk (CH1): 1.5% enzymes (E) and 24 h enzymatic action (EA); CH2: 3.0% (E) and 24h (EA); CH3: 4.5% (E) and 24 h (EA); CH4: 6% (E) and 24 h (EA); CH5: 1.5% (E) 48 h (EA); CH6: 3% (E) and 48h (EA); CH7: 4.5% (E) and 48h (EA); and CH8: 6% (E) and 48 h (EA), all based on dry matter. An improvement in the degradability of the nutritional parameters MS, NDF, and FDA occurred with the addition of enzymes, with 3% enzyme addition being the best level, and 24 hours, as the best action time. In addition to that, as the EA on coffee husk increased, the degradation rate decreased. Therefore, the use of enzymes can improve the digestibility of the fibrous fraction, enabling the use of the coffee husk andpossibly other agroindustrial residues, thus minimizing their adverse effects on nature.(AU)

A atividade agrícola tem gerado uma quantidade progressiva de resíduos, os quais necessitam serem tratados de forma adequada para que não promovam impactos ambientais negativos e que, ao mesmo tempo, sejam agregados valores a estes para que possam ser utilizados na alimentação animal. A pesquisa foi conduzida no laboratório de Nutrição Animal da Universidade Estadual do Sudoeste da Bahia, campus de Vitória da Conquista e Itapetinga. Objetivou-se o aproveitamento da casca de café na alimentação de ruminantes através do tratamento com doses crescentes de enzimas fibrolíticas avaliando seus efeitos sobre a degradabilidade ruminal in vitro da matéria seca (MS), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) da casca de café (CC). O delineamento experimental utilizado foi inteiramente casualisado, com esquema fatorial 2x4, constituindo os seguintes tratamentos Casca de café (CC1): 1,5% de Enzimas (E) e 24h de Ação Enzimática (AE); CC2: 3% (E) e 24h (AE); CC3: 4,5%(E) e 24 h(AE); CC4:6 % (E) e 24 h(AE); CC5: 1,5% (E) 48 h(AE); CC6: 3% (E) e 48h(AE); CC7:4,5% (E) e 48h(AE); CC8: 6% (E) e 48 h(AE), com base na matéria seca. Constatou-se que com adição de enzimas, ocorreu uma melhora na degradabilidade dos parâmetros nutricionais MS, FDN e FDA, sendo 3% de enzimas o melhor nível e 24 horas o melhor tempo de ação. Além disso, à medida que a ação enzimática na casca de café aumentou, a taxa de degradação diminuiu. Portanto, o uso de enzimaspode melhorar a digestibilidade da fração fibrosa, possibilitando o uso da casca de café e possivelmenteoutros resíduos agroindustriais, minimizando assim seus efeitos adversos sobre a natureza.(AU)

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Coffee is native to shady environments but often grows better and produces higher yields without shade, though at the expense of high fertilization inputs, particularly nitrogen (N). Potted plants were grown under full sunlight and shade (50%) conditions and were fertilized with nutrient solutions containing either 0 or 23 mM N. Measurements were made in southeastern Brazil during winter conditions, when relatively low night temperatures and high diurnal insolation are common. Overall, the net carbon assimilation rate was quite low, which was associated with diffusive, rather than biochemical, constraints. N deficiency led to decreases in the concentrations of chlorophylls (Chl) and total carotenoids as well as in the Chl/N ratio. These conditions also led to qualitative changes in the carotenoid composition, e.g., increased antheraxanthin (A) and zeaxanthin (Z) pools on a Chl basis, particularly at high light, which was linked to increased thermal dissipation of absorbed light. The variable-to-maximum fluorescence ratio at predawn decreased with increasing A+Z pools and decreased linearly with decreasing N. We showed that this ratio was inadequate for assessing photoinhibition under N limitation. Expressed per unit mass, the activities of superoxide dismutase and glutathione reductase were not altered with the treatments. In contrast, ascorbate peroxidase activity was lower in low N plants, particularly under shade, whereas catalase activity was lower in shaded plants than in sun-grown plants, regardless of the N level. Glutamine synthetase activity was greater in sun-grown plants than in shaded individuals at a given N level and decreased with decreasing N application. Our results suggest that the photoprotective and antioxidant capacity per amount of photons absorbed was up-regulated by a low N supply; nevertheless, this capacity, regardless of the light conditions, was not enough to prevent oxidative damage, as judged from the increases in the H(2)O(2) and malondialdehyde concentrations and electrolyte leakage. We demonstrated that N fertilization could adequately protect the coffee plants against photodamage independently of the anticipated positive effects of N on the photosynthetic capacity.

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A cDNA clone (designated CaIRL) encoding an isoflavone reductase-like protein from coffee (Coffea arabica) was retrieved during a search for genes showing organ/tissue-specific expression among the expressed sequence tags (EST) of the Brazilian coffee EST database. The CaIRL cDNA contains a single open reading frame of 946 nucleotides (nt) encoding 314 amino acids (predicted molecular weight of 34 kDa). Several features identified the predicted CaIRL protein as a new member of the PIP family of NADPH-dependent reductases. Expression studies demonstrated that CaIRL is expressed exclusively in coffee leaves and its transcript level is markedly increased in response to fungal infection and mechanical injury. Analysis of transgenic tobacco plants harboring a CaIRL 5'-flanking region (862 nt) fused to uidA reporter gene (GUS) confirmed the responsiveness of the putative promoter to abiotic stress in wounded leaves. In turn, a 5' deletion to -404 completely abolished promoter activation by abiotic stimulus in transgenic plants. The lack of GUS expression in non-wounded leaf tissues in transgenic tobacco was in contrast to the basal level of CaIRL expression observed in non-stressed healthy coffee leaves.

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We examined the role of phenolic compounds, and the enzymes peroxidase and polyphenol oxidase, in the expression of resistance of coffee plants to Leucoptera coffeella (Lepidoptera: Lyonetiidae). The concentrations of total soluble phenols and chlorogenic acid (5-caffeoylquinic acid), and the activities of the oxidative enzymes peroxidase (POD) and polyphenol oxidase (PPO), were estimated in leaves of Coffea arabica, C. racemosa, and progenies of crosses between these species, which have different levels of resistance, before and after attack by this insect. The results indicate that phenols do not play a central role in resistance to the coffee leaf miner. Differences were detected between the parental species in terms of total soluble phenol concentrations and activities of the oxidative enzymes. However, resistant and susceptible hybrid plants did not differ in any of these characteristics. Significant induction of chlorogenic acid and PPO was only found in C. racemosa, the parental donator of the resistance genes against L. coffeella. High-performance liquid chromatography (HPLC) analysis also showed qualitative similarity between hybrids and the susceptible C. arabica. These results suggest that the phenolic content and activities of POD and PPO in response to the attack by the leaf miner may not be a strong evidence of their participation in direct defensive mechanisms.

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RESUMO

In plants, PPO has been related to defense mechanism against pathogens and insects and this role was investigated in coffee trees regarding resistance against a leaf miner and coffee leaf rust disease. PPO activity was evaluated in different genotypes and in relation to methyl-jasmonate (Meja) treatment and mechanical damage. Evaluations were also performed using compatible and incompatible interactions of coffee with the fungus Hemileia vastatrix (causal agent of the leaf orange rust disease) and the insect Leucoptera coffeella (coffee leaf miner). The constitutive level of PPO activity observed for the 15 genotypes ranged from 3.8 to 88 units of activity/mg protein. However, no direct relationship was found with resistance of coffee to the fungus or insect. Chlorogenic acid (5-caffeoylquinic acid), the best substrate for coffee leaf PPO, was not related to resistance, suggesting that oxidation of other phenolics by PPO might play a role, as indicated by HPLC profiles. Mechanical damage, Meja treatment, H. vastatrix fungus inoculation and L. coffeella infestation caused different responses in PPO activity. These results suggest that coffee resistance may be related to the oxidative potential of the tissue regarding the phenolic composition rather than simply to a higher PPO activity.

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The adverse side effects of caffeine have increased the market for decaffeinated coffee to about 10% of coffee consumption worldwide (http://www.ncausa.org), despite the loss of key flavour compounds in the industrial decaffeinating process. We have discovered a naturally decaffeinated Coffea arabica plant from Ethiopia, a species normally recognized for the high quality of its beans. It should be possible to transfer this trait to commercial varieties of arabica coffee plants by intraspecific hybridization--a process likely to be simpler than an interspecific hybridization strategy, which could require more than 30 years of breeding to fix the decaffeinated trait and would probably result in an inferior cup of coffee.

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Polyphenol oxidase (PPO) was characterized in partially purified extracts of leaves (PPO-L) and fruit endosperm (PPO-E) of coffee (Coffea arabica L.). PPO activity was higher in early developmental stages of both leaves and endosperm of fruits. Wounding or exposure of coffee leaves to methyl jasmonate increased PPO activity 1.5-4-fold. PPO was not latent and was not activated by protease treatment. PPO activity was stimulated 10-15% with sodium dodecyl sulphate (SDS) at 0.35-1.75 mM, but at higher concentrations activities were similar to the control samples, without detergent. Prolonged incubation of extracts with trypsin or proteinase K inhibited PPO activity but pepsin had no effect. Inhibition of PPO with proteinase K was increased in the presence of SDS. PPO activity from both tissues was optimal at pH 6-7 and at an assay temperature of 30 degrees C. Activity was highest with chlorogenic acid as substrate with a Km of 0.882 mM (PPO-L) and 2.27 mM (PPO-E). Hexadecyl trimethyl-ammonium bromide, polyvinylpyrrolidone 40. cinnamic acid and salicylhydroxamic acid inhibited PPO from both tissues. Both enzymes were inactivated by heat but the activity in endosperm extracts was more heat labile than that from leaves. The apparent Mr determined by gel filtration was 46 (PPO-L) and 50 kDa (PPO-E). Activity-stained SDS polyacrylamide gel electrophoresis (PAGE) gels and western blots probed with PPO antibodies suggested the existence of a 67 kDa PPO which is susceptible to proteolytic cleavage that generates a 45 kDa active form.

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