Leucocytes show improvement growth on PHA polymer surface

Polyhydroxyalkanoate [PHA] from one fermentation process shows diverse physical properties when extracted using different methods. Pseudomonas aeruginosa strain has been previously isolated from the Egyptian ecosystem was cultivated on olive oil as a carbon source under PHA accumulation conditions. PHA was extracted using four different extraction methods and the polymer give different biological properties. Leucocytes grown in different rate on each preparation. RBCs haemolysis test was used to determine the polymers toxicity. PHA isolated directly with chloroform give the highest leucocytes number [19.4 10 4 Cells/48 hr] and the lowest Haemolytic index [2.28]. Bioassays used in this study are recommended for evaluating the in vitro polymer biocompatibility aiming to in vivo application or as a cell line-supporting matrix

Plant crude extracts could be the solution: extracts showing in vivo antitumorigenic activity

Screening active compounds from plants lead to discover new medicinal drugs which have efficient protection and treatment roles against various diseases including cancer. In our study, extracts from different plants represent seeds of: Gossypium barbadense, Ricinus communis, Sesamum indicum, Nigella sativa, Vinca rosea and Melia azedarah; fruits of: Xanthium occidental; flowers of: Atriplex nummularia; barks of: Cinnamomum zeylanicum; latex of: Ficus carica and rhizomes of: Curcuma longa and Zingiber officinale were tested in vivo using three subsequent bioassays: the BST [Brine Shrimp Toxicity bioassay], AWD [Agar well diffusion antimicrobial bioassay] and AtPDT [Agrobacterium tumefaciens Potato Disc Tumor bioassay]. AWD technique omitted any extracts have antimicrobial activities while BST omitted any extract did not has physiological activity and determined the various LC50 of each plant extract. For the first time, using a range of concentrations in the AtPDT modified protocol allowed the detection of tu mor promotion caused by extract represented by A. nummularia. Using cluster analysis leads to classifying the different plant extracts activities to six groups regarding to their toxicity, antitumor activities and both of them. The extracts from edible plants represent 50% of the first and the second group which have the highest antitumor activities represented in F. caraica [group 1] and C. longa [group 2] as well as the non-edible plant extracts of Gossypium barbadense and Ricinus communis. A comparison study between the edible and herbaceous plants different extracts for their antitumor activities was performed. We recommended using the modified protocols used in this study for investigating more plants and using crude plant extracts which have antitumor activities in cancer treatment. Edible plants, which show in vivo antitumor activities, are recommended as save sources for antitumor compounds

Biosynthesis of biodegradable polyhydroxyalkanotes biopolymers in genetically modified yeasts

In the recent decade, biosynthesis of the degradable biopolymers polyhydroxyalkanotes in transgenic yeasts became an important research task. Most research strategies depend on either metabolic engineering or molecular approaches. In the present work, research compared PHA biosynthesis in two types of yeasts; Saccharomyces cerevisiae and a non-convenient Kloeckera spp. Yeast strains were equipped in their cytoplasm with thephaABCRe operon containing genes phbA, phbB and phbC of the PHA biosynthetic pathway of Ralstonia eutropha, which encode p-ketothiolase, NADPH-linked acetoacetyl-CoA reductase and PHA synthase, respectively. The transgenic strains Saccharomyces cerevisiae and Kloeckera sp. were able to produce PHA. The maximum content of the polymer detected in the recombinant strain INVScl/PHAl was 2.68% and only poly-3-hydroxybutyrate [PHB] accumulated. However, the non-conventional transgenic strain KY1/PHA was able to accumulate as maximum of 7.06% of the copolymer poly-[3-hydroxybutyrate-co-poly-3-hydroxyvalerate[[PHV]. Western blot analysis confirmed expression of the phaABC[RE] operon in the transgenic yeast strains. The nature of the PHA thus produced by all tested strains was analyzed by [1]H and [13]C nuclear magnetic resonance [NMR] spectroscopy

Chemical nature of antibiotic produced by pseudomonas fluorescens strain a inhibiting azospirillum spp growth

The antagonistic activity of three Pseudomonas fluorescens strains against Azospirillum spp. was investigated. Data revealed that Pseudomonas fluorescens strain A was the most potent against Azospirillum lipoferum when grown on 523 agar medium, with initial pH of 7.0 and incubation for one day at 30C. Extraction of Pseudomonas fluorescens strain A active ingredient was achieved by using acetone followed by diethyl ether. Using paper chromatography technique, an antibiotic was obtained as purified yellowish brown amorphous powder. It is soluble in methanol, acetone, ethyl acetate, n-butanol, diethyl ether and chloroform. The physicochemical characteristics, i.e., melting point, ultraviolet spectra [UV], infrared spectra [IR], color reactions, the 1H nuclear magnetic resonance [1H-NMR], mass spectra and elemental analysis are given. The purified antibiotic exerted a sharp melting point at 126C, the UV absorption spectra was maximum at 245 [sh] nm in ethylacetate, the molecular weight was found to be 279. Relative abundance [RA], 9.9% and elemental analysis of the antibiotic revealed that the antibiotic substance contains carbon 81.7%, hydrogen 7.5%, oxygen 5.7% and nitrogen 5.0%. The molecular formula of the antibiotic was proposed to C19H21NO based on the MS spectra and elemental analysis