A passive dosimeter designed to measure exposure to hydrogen fluoride was tested under laboratory conditions over the concentration range of 0.56 – 4.47 mg HF/m. The lowest concentration was chosen to be close to the Polish TLV (0.5 mg HF/m). The dosimeter consists of a Whatman No.1 filter paper impregnated with K2HPO4 placed in a polyethylene holder protected by a polyethylene screen. After ex...

among the ways of pigment production, microbial synthesis has gained more interest for high growth rate, easy extraction and high yield. pigments are used in the food industry as natural colorants and preservatives; they also have pharmaceutical applications. in this study, fungus monascus purpureus ptcc 5303 was used to produce red, orange and yellow pigments. at first, significant variables w...

Optimization of submerged culture conditions for the production of mycelial growth and exopolysaccharides (EPSs) by Collybia maculata was investigated. The optimum temperature and the initial pH for EPS production in a shake-flask culture of C. maculata were found to be 20°C and 5.5, respectively. Among the various medium’s constituents examined, glucose, Martone A-1, K2HPO4, and CaCl2 were the...

A survey was carried out to select an antibiotic producing Streptomyces strain isolated from garden soil in Alexandria, Egypt. Streptomyces violatus showed the highest antimicrobial activity in static cultures after 7 days incubation at 30°C. The antibacterial substance was more active against Bacillus subtilis and Staphyllococcus aureus than Escherichia coli or Sarcina lutea. Growth of S. viol...

Dextran a bacterial exopolysaccharide and a polymer of glucose is produced by different microorganisms like Leuconostoc mesenteroides, Lactobacillus spp, Streptococcus mutans, Weissella confusa etc. It has a wide range of applications in the food, pharmaceutical and other industries. Dextran and its derivatives like iron dextran, clinical dextran, food grade dextran are rapidly emerging as new ...

In this paper, the efficiency of an aqueous two-phase system (ATPS) for purification of nanometer-sized bioparticles, plasmid DNA (pDNA), was studied. Polymer-salt ATPS consisting of polyethylenglycol (PEG)-K2HPO4 was used for the purification of 7 kb and 14 kb plasmid vectors. PEG-300 and PEG-1450 were applied to investigate the influence of different molecular mass of PEG on partitioning beha...

The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi’s orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3...