Adaptation of soil nitrifiers to very low nitrogen level jeopardizes the efficiency of chemical fertilization in west african moist savannas.

The moist savanna zone covers 0.5 × 10 km in West Africa and is characterized by very low soil N levels limiting primary production, but the ecology of nitrifiers in these (agro)ecosystems is largely unknown. We compared the effects of six agricultural practices on nitrifier activity, abundance and diversity at nine sites in central Ivory Coast.

Characterisation of a highly saturated Irvingia gabonensis seed kernel oil with unusual linolenic acid content.

The search for new sources of oil with improved characteristics has focused our attention on the characterisation of Irvingia gabonensis seed kernel oil. Physicochemical analysis have revealed the following assets: refractive index (1.42 ± 0.

Alpha-mannosidases from the digestive fluid of Rhynchophorus Palmarum larvae as novel biocatalysts for transmannosylation reactions.

Two biological fluids, namely hemolymph and digestive fluid from the larval stage of Rhynchophorus palmarum Linneaus, a serious pest in agroecosystem exploiting oil palm, were screened for hydrolytic activities, by the use of synthetic and natural glycoside substrates. Several exo and endoglycosidase activities were observed but, the interesting alpha-mannosidase activity (0.41 +/- 0.

Purification, kinetic properties and physicochemical characterization of a novel acid phosphatase (AP) from germinating peanut (Arachis hypogaea) seed.

Acid phosphatase activity was detected in peanut (Arachis hypogaea) cotyledons during germination. Four (4) to six (6) days of germination was the meantime corresponding to maximum hydrolytic activity of this enzyme. The understanding of the role of acid phosphatase activity during germination led to purify this enzyme by successive chromatography separations on DEAE-Sepharose CL-6B, Sephacryl S-100 HR and Phenyl-Sepharose HP to apparent homogeneity from germinated peanut cotyledon five days old.