Proteomic evaluation of free fatty acid biosynthesis in Jatropha curcas L. (physic nut) kernel development

Jatropha curcas L. is one of the economic crops that are cultivated for biodiesel production. Here, the fatty acid and protein profiles of J. curcas kernels were evaluated during their development. The fruits were divided into eight developmental stages (stages I to VIII) based on their age and morphology. The fatty acid content was analyzed at each stage using gas chromatography after conversion to methyl esters. Fatty acid levels were found to differ between all eight developmental stages, although the major fatty acid in each stage was oleic acid followed by linoleic, palmitic and stearic acids, respectively, except in stage I where linoleic acid was more common than oleic acid. All fatty acids showed a maximum content at stage III, a rapid decline at stage IV and another peak at stage VII before declining. Significant changes were found in the relative abundance of 22 proteins during seed development, of which the expression levels for transcripts encoding for four of these proteins, acetyl CoA carboxylase, phosphoenolpyruvate carboxylase, mercaptopyruvate sulfurtransferase and 4-coumarate: coenzyme A ligase, as evaluated by quantitative RT-PCR, were altered between the developmental stages of the kernels in a broadly similar pattern as the level of most fatty acids.Keywords: Jatropha curcas L., FAME, ACCase, PEPC, MST, 4CL, quantitative real time PCRAfrican Journal of Biotechnology Vol. 12(21), pp. 3132-314

NirK and nirS Nitrite reductase genes from non-agricultural forest soil bacteria in Thailand

The genetic heterogeneity of the nitrite reductase gene (nirK and nirS) fragments from denitrifying prokaryotes in a non-agricultural forest soil in Thailand was investigated using soil samples from the Plant Germplasm-Royal Initiation Project area in Kanchanaburi Province, Thailand. Soil bacteria were screened for denitrification activity and 13 (from 211) positive isolates were obtained and further evaluated for their ability to reduce nitrate and to accumulate or reduce nitrite. Three species with potentially previously unreported denitrifying activities were recorded. Analysis of the partial nirK and nirS sequences of these 13 strains revealed a diverse sequence heterogeneity in these two genes within the same environment and even potentially within the same host species, the potential existence of lateral gene transfer and the first record of both nirK and nirS homologues in one bacterial species. Finally, isolates of two species of bacteria (Corynebacterium propinquum and Micrococcus lylae) are recorded as denitrifiers for the first time