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Phenylpropionic Acid (phenylpropionic + acid)
Selected AbstractsMetabolism of phenylpropionic acid in enteropathogenic Escherichia coli belonging to serogroup O111 and its application for diagnosisFEMS MICROBIOLOGY LETTERS, Issue 1 2001Kinue Irino Abstract We evaluated a biochemical assay based on the ability to metabolise ,-phenylpropionic acid (PPA) as a diagnostic aid in the identification of typical enteropathogenic Escherichia coli (EPEC) strains. A total of 1061 E. coli strains of serogroups O55, O111, and O119 were initially characterised regarding their H types (serotypes) and the presence of EPEC DNA sequences, eae, EAF, and bfpA. In case of the serogroup O111 strains, 84.6% carried the typical EPEC markers, and the great majority of those (98.1%) were PPA-positive. In contrast, only 0.9% of the serogroups O55 and O119 strains carrying the typical EPEC markers (53.6% and 75.4%, respectively) were PPA-positive. We conclude that the PPA test is a useful method to detect typical EPEC strains only among strains of the O111 serogroup. [source] Alterations in Taxol Production in Plant Cell Culture via Manipulation of the Phenylalanine Ammonia Lyase PathwayBIOTECHNOLOGY PROGRESS, Issue 6 2002Michelle C. Brincat One approach to increasing secondary metabolite production in plant cell culture is to manipulate metabolic pathways to utilize more resources toward production of one desired compound or class of compounds, such as diverting carbon flux from competing secondary pathways. Since phenylalanine provides both the phenylisoserine side chain and the benzoyl moiety at C-2 of Taxol, we speculated that blockage of the phenylpropanoid pathway might divert phenylalanine into Taxol biosynthesis. We used specific enzyme inhibitors to target the first enzyme in the phenylpropanoid pathway, phenylalanine ammonia lyase (PAL), the critical control point for conversion of l -phenylalanine to trans -cinnamic acid. Cinnamic acid acted quickly in reducing PAL activity by 40,50%, without affecting total protein levels, but it generally inhibited the taxane pathway, reducing Taxol by 90% of control levels. Of the taxanes produced, 13-acetyl-9-dihydro-baccatin III and 9-dihydrobaccatin III doubled as a percentage of total taxanes in C93AD and CO93P cells treated with 0.20 and 0.25 mM cinnamic acid, when all other taxanes were lowered. The PAL inhibitor ,-aminooxyacetic acid (AOA) almost entirely shut down Taxol production at both 0.5 and 1.5 mM, whereas l -,-aminooxy-,-phenylpropionic acid (AOPP) had the opposite effect, slightly enhancing Taxol production at 1 ,M but having no effect at 10 ,M. The discrepancy in the effectiveness of AOA and AOPP and the lack of effect with addition of phenylalanine or benzoic acid derivatives further indicates that the impact of cinnamic acid on Taxol is related not to its effect on PAL but rather to a specific effect on the taxane pathway. On the basis of these results, a less direct route for inhibiting the phenylpropanoid pathway may be required to avoid unwanted side effects and potentially enhance Taxol production. [source] Novel microbial diversity adherent to plant biomass in the herbivore gastrointestinal tract, as revealed by ribosomal intergenic spacer analysis and rrs gene sequencingENVIRONMENTAL MICROBIOLOGY, Issue 4 2005Ross Larue Summary It is well recognized that a dynamic biofilm develops upon plant biomass in the herbivore gastrointestinal tract, but this component of the microbiome has not previously been specifically sampled, or directly compared with the biodiversity present in the planktonic fraction of digesta. In this study, the digesta collected from four sheep fed two different diets was separated into three fractions: the planktonic phase, and the microbial populations either weakly or tightly adherent to plant biomass. The community DNA prepared from each fraction was then subjected to both ribosomal intergenic spacer analysis (RISA) and denaturing gradient gel electrophoresis (DGGE). Both types of analysis showed that dietary factors influence community structure, and that the adherent fractions produced more complex profiles. The RIS-clone libraries prepared from the planktonic and adherent populations were then subjected to restriction fragment length polymorphism (RFLP) and DNA sequence analyses, which resulted in a far greater degree of discrimination among the fractions. Although many of the sequenced clones from the adherent populations were assigned to various clusters within the low G+C Gram-positive bacteria, the clone libraries from animals consuming an all-grass diet were largely comprised of novel lineages of Clostridium, while in animals consuming the starch-containing diet, Selenomonas and Ruminococcus spp. were the dominant low G+C Gram-positive bacteria. Additionally, the libraries from hay-fed animals also contained clones most similar to asaccharolytic Clostridia, and other Gram-positive bacteria that specialize in the transformation of plant phenolic compounds and the formation of cinnamic, phenylacetic and phenylpropionic acids. These results reveal, for the first time, the phylogeny of adherent subpopulations that specialize in the transformation of plant lignins and other secondary compounds, which potentiate polysaccharide hydrolysis by other members of the biofilm. [source] | ||||||||||