Oil Palm Tree Elaeis Guineensis Research Articles

Thermal stability of peroxidase from the african oil palm tree Elaeis guineensis.

The thermal stability of peroxidase from leaves of the African oil palm tree Elaeis guineensis (AOPTP) at pH 3.0 was studied by differential scanning calorimetry (DSC), intrinsic fluorescence, CD and enzymatic assays. The spectral parameters as monitored by ellipticity changes in the far-UV CD spectrum of the enzyme as well as the increase in tryptophan intensity emission upon heating, together with changes in enzymatic activity with temperature were seen to be good complements to the highly sensitive but integral method of DSC. The data obtained in this investigation show that thermal denaturation of palm peroxidase is an irreversible process, under kinetic control, that can be satisfactorily described by the two-state kinetic scheme, N -->(k) D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated.

Long-term chemiluminescent signal is produced in the course of luminol peroxidation catalyzed by peroxidase isolated from leaves of african oil palm tree.

Optimal conditions were found for the oxidation of luminol by hydrogen peroxide in the presence of peroxidase isolated from leaves of the African oil palm tree Elaeis guineensis (AOPTP). The pH range for maximal chemiluminescence intensity (8.3-8.6) is similar for AOPTP, horseradish, and Arthromyces ramosus peroxidases and slightly different from that for tobacco peroxidase (9.3). Increasing the buffer concentration decreases the chemiluminescence intensity. As in the case of other anionic peroxidases, the catalytic efficiency of AOPTP does not depend on the presence of enhancers (4-iodophenol and 4-hydroxycinnamic acid) in the reaction medium. The detectable limit of AOPTP assayed by luminol peroxidation is 2.10(-12) M. The long-term chemiluminescence signal produced during AOPTP-dependent luminol peroxidation is a characteristic feature of the African oil palm enzyme. This feature in combination with its very high stability suggests that AOPTP will be a promising tool in analytical practice.

Captura de Rhynchophorus palmarum (L.) pelo uso de feromônio de agregação associado a árvore-armadilha e inseticida

A eficiência do feromônio de agregação do Rhynchophorus palmaram (L.), 2(E)-6-methyl-2-hepten-4-ol, associado com inseticida foi avaliada na captura de adultos desta praga em árvores de dendenzeiros Elaeis guineensis. Entalhes confeccionados em árvores de dendenzeiros atacadas pelo nematóide Rhadinaphelenchus cocophilus Cobb., agente causal da doença do anel-vermelho foram pulverizados com inseticida (Furadan 350 SC) mais 3 ml do feromônio. Outro grupo de árvores foram tratadas somente com inseticida. A captura de R. palmarum nas árvores tratadas com feromônio mais inseticida foi entre 65 e 89 % superior ao tratamento com inseticida.