No abstract

No abstract

Pseudomonas aeruginosa AT10 produced a mixture of surface-active rhamnolipids when cultivated on mineral medium with waste free fatty acids as carbon source. The development of the production process to an industrial scale included the design of the culture medium. A 2 4 full factorial, central composite rotational design and response surface modelling method (RSM) was used to enhance rhamnolipid production by Pseudomonas aeruginosa AT10. The components that are critical for the process medium were the carbon source, the nitrogen source (NaNO 3 ), the phosphate content (K 2 HPO 4 /KH 2 PO 4 2:1) and the iron content (FeSO 4 Á 7H 2 O). Two responses were measured, biomass and rhamnolipid production. The maximum biomass obtained was 12.06 g dm À3 DCW, when the medium contained 50 g dm À3 carbon source, 9 g dm À3 NaNO 3 , 7 g dm À3 phosphate and 13.7 mg dm À3FeSO 4 Á 7H 2 O. The maximum concentration of rhamnolipid, 18.7 g dm À3

e food additive named polyglycerol polyricinoleate (PGPR) and identi�ed with the code E-476 (PGPR) is used as emulsi�er in tin-greasing emulsions for the baking trade and for the production of low-fat spreads. However, the main application of PGPR is in the chocolate industry, where, besides its action as an emulsi�er, it also has important properties as a viscosity modi�er and thus improves the moulding properties of the molten chocolate. An additional property of PGPR in chocolate is its ability to limit fat bloom. �nown chemical methods for preparing this emulsi�er involve long reaction times and high operating temperatures, which adversely affect the quality of the �nal product leading to problems of coloration and odors that could make it inadvisable for the food industry. As an alternative, the enzymatic synthesis of PGPR by the catalytic action of two lipases has been developed. e enzymes act in mild reaction conditions of temperature and pressure, neutral pH, and in a solvent-free system, which makes the process environmentally friendly and avoids side reaction, so that the product has a higher purity and quality.

The common effect of NH4+, NO3-, KH2PO4 and sucrose on the biosynthesis of galanthamine by a Leucojum aestivum shoot culture was studied. Polynominal regression models were elaborated for the description of the galanthamine biosynthesis as a consequence of variation of the investigated variables (NH4+ between 0.20 and 0.54 g/L; NO3- between 1.44 and 3.44 g/L; KH2PO4 between 0.10 and 0.24 g/L, and sucrose between 30.00 and 60.00 g/L). Optimization procedures allowed us to establish the optimal concentrations of the investigated variables and to propose the modified MS nutrient medium, with 4.50 g/L KNO3, 0.89 g/L NH4NO3, 1.25 g/L (NH4)2SO4, 0.10 g/L KH2PO4 and 60 g/L sucrose, for the galanthamine production by a Leucojum aestivum shoot culture. The proposed modified MS medium provided considerable increase of both the production yield and the relative content of the target alkaloid in the alkaloid mixture.

In the alkaloid galanthamine, the plant family Amaryllidaceae has endowed the pharmaceutical community with a potent and selective inhibitor of the enzyme acetylcholinestersae (AChE), of prominence in the chemotherapeutic approach towards motor neuron diseases. Following on the commercial success of this prescription drug in the treatment of Alzheimer's disease, it is anticipated that other drug candidates will in future emerge from the family. In this regard, the phenanthridones, exemplified by narciclasine and pancratistatin, of the lycorine series of Amaryllidaceae alkaloids have shown much promise as remarkably potent and selective anticancer agents, with a drug target of the series destined for the clinical market within the next decade. Given these interesting biological properties and their natural abundance, plants of the Amaryllidaceae have provided a diverse and accessible platform for phytochemical-based drug discovery. The crinane series of Amaryllidaceae alkaloids are also enriched with a significant array of biological properties. As a consequence of their close structural similarity to the anticancer agents of the lycorine series, the cytotoxic potential of crinane alkaloids has been realized through structure-activity relationship (SAR) studies involving targets of both semi-synthetic and natural origin, which has identified several members as leads with promising antiproliferative profiles. As the first of its kind, this review seeks to collate such information from the past few decades in advancing the crinane group as a viable platform for anticancer drug discovery.

No abstract

Molasses can be regarded as a useful resource for biotechnological applications, such as the production of lichenysin. The use of agro-industrial substrates has an important role in the sustainable and competitive development of several industrial sectors, as well as in industrial residues management. Additionally, lichenysin is particularly effective in preventing biofilm formation by strains problematic for the food industry and in the hospital environment. Lichenysin also efficiently disrupts biofilm.