Production Of Active Compounds Research Articles

Biochemical activities of Iranian Mentha piperita L. and Myrtus communis L. essential oils

GC–MS analysis of essential oils of Iranian Mentha piperita and Myrtus communis extracted by hydrodistillation lead to identification of 26 and 32 compounds, respectively. The oils had good to excellent antimicrobial activities against Escherichia coli, Staphylococcus aureus and Candida albicans with the oil of M. piperita being more active. The findings suggest feasibility of application of M. piperita oil in treatment of the infections caused by C. albicans and E. coli. D-values on exposure to M. piperita and Myrtus communis oils were (2.14 and 2.8 min), (1.4 and 12.8 min) and (4.3 and 8.6 min) for E. coli, S. aureus and C. albicans , respectively. The oils were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and β-carotene/linoleic acid systems. M. piperirta oil exerted greater antioxidant activity than that of M. communis. Phytochemical and phytobiological characteristics of these oils may lead to extraction and production of active compounds in single or combined forms with useful applications.

Endophytic bacterial communities of field-grown potato plants and their plant-growth-promoting and antagonistic abilities.

To study the effect of plant growth on potato-associated bacteria, the composition and properties of bacteria colonizing the endosphere of field-grown potato were analyzed by a multiphasic approach. The occurrence and diversity of potato-associated bacteria were monitored by a cultivation-independent approach, using terminal restriction fragment length polymorphism analysis of 16S rDNA. The patterns obtained revealed a high heterogeneity of community composition and suggested the existence of plant-specific communities. However, endophytic populations correlated to a certain extent with plant growth performance. Endophytes were also isolated from plants that grew well or grew poorly and were identified by partial sequencing of the 16S rRNA genes. A broad phylogenetic spectrum was found among isolates and differently growing plants hosted different bacterial populations. In an approach to investigate the plant-growth-promoting potential of potato-associated bacteria, a total of 35 bacteria were screened by dual testing for in vitro antagonism towards (i) the fungal pathogens Verticillium dahliae, Rhizoctonia solani, Sclerotinia sclerotiorum, and Phytophthora cactorum and (ii) the bacterial pathogens Erwinia carotovora, Streptomyces scabies, and Xanthomonas campestris. The proportion of isolates with antagonistic activity was highest against Streptomyces sp. (43%) followed by those against Xanthomonas sp. (29%). As all plants showed more or less severe disease symptoms of scab disease caused by Streptomyces scabies, we assume that the presence of the pathogen induced the colonization of antagonists. The antifungal activity of the isolates was generally low. The biotechnological potential of endophytic isolates assessed by their antagonistic activity and by in vitro production of enzymes, antibiotics, siderophores, and the plant growth hormone indole-1,3-acetic acid was generally high. Overall, seven endophytes were found to antagonize fungal as well as bacterial pathogens and showed a high production of active compounds and were therefore considered promising biological control agents.

Photobioreactor Stability by Phase Plane Technique Applied to Spirulina Maxima Growth

Spirulina maxima is a worthy multicellular filamentous micro-algae used as a food supplement and raw material for fine chemicals and biologically active compounds production. Intensive approach consisting of cultivating pure strains of this photoautotroph microorganism in photobioreactors is more desirable than extensive ones, largely incontrollable with regard to production stability. Determining the best reaction conditions to reach a steady state in the runway events is often needed in biological systems. For a biochemical engineer, knowing the system stability for an optimal bioreactor configuration is crucial to estimate the rate at which dependent variables grow or decay with the time reaction. The stability analysis becomes important in recycle processes in which possibility that these systems influence themselves exists. The aim of this work deals with the 1) description of the growth kinetics by a logistic and unstructured model based on Monod kinetics taking into account the maintenance in life of viable cells; 2) establishment of a dynamic growth model for Spirulina maxima cultivated in continuous lamellar photobioreactors using industrial manures as macro-nutrients; 3) determination of optimal culture conditions sustaining a stable growth of S. maxima in a system of two bioreactors in series; and 4) investigation of the dynamic stability of this multivariable system with nonlinear dynamics using phase plane technique (PPT). Although good mixing of the culture is essential for ensuring adequate supply of nutrients and prevention of the accumulation of toxic metabolites. Excessive agitation causes mechanical damage to Spirulina cells. An air flow rate of 2.5 L/min for airlift agitation represented a balance between the need to provide good mixing and to avoid cell damage. A stable steady state was achieved corresponding to a productivity of 10.8 g. m2/day when the system was supplied with 0.2 g N/L of minerals, at a dilution rate of 0.1 1/day, temperature of 30 °C under light intensity of 18 Klux. PPT as a powerful procedure successfully predicts the stability of such a complex system very well.

Inter‐population variability of secondary metabolites in Hypericum spp. (Hypericaceae) of the Northern Apennines, Italy

Hypericum spp. flowers were collected from different sites of Northern Apennines in Italy and were analysed by HPTLC technique to determine their contents in flavonoids (rutin, hyperosid, quercitrin, isoquercitrin and quercetin) and hypericins (pseudohypericin and hypericin). The H. perforatum and H. richeri composition was evaluated in order to investigate the influence of ecological conditions on secondary metabolites production. The species studied showed some differences in the amounts of investigated metabolites and high variability was observed in populations gathered in different places. No significant effects of environmental factors on active compound production were observed, except for the rutin content which is in positive correlation with the altitude of the growing site. Interesting informations are also given about the morphology of secretory structures found in Hypericum richeri.

Vaccine cornucopia. Transgenic vaccines in plants: new hope for global vaccination?

Vaccine cornucopia. Transgenic vaccines in plants: new hope for global vaccination?

Modeling synergistic and antagonistic interactions in xenobiotic compounds.

Over time, synergistic/antagonistic interactions between pairs of compounds has been examined from a variety of viewpoints that impose difficulties in comparative studies. The increasing importance of potentiated activity in plant–organism interfaces mediated by secondary phytometabolites and also of inter- and intraspecific animal interactions, and their ecological impact in terms of increased cost effectiveness and organism fittness in the production of active compounds, demands that a standard methodology be designed to ascertain the amount of synergism/antagonism of A + [B, C, ..., Z] mixtures. Here we preface one such method, based on the comparison of theoretically predicted addition of dose–response (D/R) curves of pairs of compounds mixed in 0–100% relative proportions and constant added dosage, examined at various total dosages, with experimental results of similarly composed mixtures. It is shown that large effects in the activity prediction curves occur as a consequence of minor changes in the D/R profiles of individual compounds. These changes may lead to equivocal assessment of potentiation by application of coactivity coefficients without close examination of predicted curves. Evaluation of this method with literature from the data surveyed illustrated its potentially general application in studies of compound synergism.

Plant biotechnologies for the production of active compounds by cell cultures and whole plants: [formula omitted] (Centre de Recherche Nestlé - 101 avenue Gustave Eiffel - 37390 Notre Dame d'Oé - France)

Plant biotechnologies for the production of active compounds by cell cultures and whole plants: [formula omitted] (Centre de Recherche Nestlé - 101 avenue Gustave Eiffel - 37390 Notre Dame d'Oé - France)

Optically active compound production using immobilized enzymes in organic solvents

Optically active compound production using immobilized enzymes in organic solvents