New and effective entrapment of polyelectrolyte-enzyme-complexes in LentiKats

Amyloglucosidase EC 3.2.1.3 was used as model for the immobilisation of enzymes in poly(vinylalcohol) hydrogel (LentiKats) lenses. The entrapment of the enzyme in PVA-hydrogel based on a two-step procedure, firstly its coupling to polyelectrolytes increased the structure level of the enzyme, and subsequently, the resulting complex was entrapped in LentiKats. The immobilised enzyme retained 45% of its original activity and lost no activity over five repeated batch runs.     

Ecdysteroid resistant subclones of the epithelial cell line from Chironomus Tentans (insecta, diptera). I. Selection and characterization of resistant clones

Summary Chironomus tentans cells were cultured in the presence of gradually increasing concentrations of 20-OH-ecdysone or a nonsteroidal molting hormone agonist, the benzoylhydrazine RH 5992, for a period of about 2 yr. From these cultures, subclones were selected, which are resistant to up to 25 μM 20-OH-ecdysone according to morphological (changes in cell shape and cell arrangement) and physiological criteria (acetylcholinesterase induction, secretion of chitinolytic enzymes, thymidine incorporation). Some subclones, selected in the presence of 20-OH-ecdysone, are resistant only to molting hormone, but still respond to RH 5992 morphologically and biochemically, whereas subclones selected in the presence of the benzoylhydrazine showed no reaction neither to 20-OH-ecdysone nor to the hormone agonist. Hormone resistance is stable; 3 mo. after hormone withdrawal, resistant clones still do not respond to renewed exposure to 20-OH-ecdysone or RH 5992, respectively. Because in all resistant subclones tested so far all hormonally regulated responses known from sensitive cells were no longer detectable, it is assumed that the hormone signaling pathway itself is interrupted. Possible mechanisms of hormone resistance were discussed.     

Influence of microorganism and plant oils on the structure of mannosylerythritol lipid (MEL) biosurfactants revealed by a novel thin layer chromatography mass spectrometry method

Journal of Industrial Microbiology & Biotechnology - Mannosylerythritol lipids (MEL) are microbial glycolipid biosurfactants with great potential for application in cosmetics and household...     

Poly(carbamoylsulphonate) as a matrix for whole cell immobilization - biological characterization

Summary Poly(carbamoylsulphonate) (PCS), a hydrogel matrix of low toxicity for the immobilization of microorganisms was characterized with respect to physiological properties. The survival rates of immobilized Paracoccus denitrificans in PCS were greater than 99 %, the initial division rate of the bacterium inside the gel was the same as of free suspended cells and decreases with increasing cell density within the first days. The polymer has good resistance to microbial degradation and excellent mechanical stability. First results of long term behaviour and kinetic data of nitrifying bacteria entrapped within PCS gel beads are shown.