ABSTRACT
We report on theoretical and experimental considerations on bacteria capturing and enrichment via magnetic separation enabling integrated diagnosis and treatment of blood stream infections. We show optimization of carrier-pathogen interactions based on a mathematical model followed by an experimental proof-of-concept study along with investigations on the process safety.
ABSTRACT
Lactic acid bacteria (LAB) are used widespread in the food industry as traditional starters for various fermented foods. For recombinant protein production, LAB would be superior with view from the food safety demands since most of them are Generally Recognized As Safe organisms. We investigated the two pSIP expression systems, pSIP403 and pSIP409 (Sørvig et al. 2005), to produce a hyper-thermophilic ß-glycosidase (CelB) from Pyrococcus furiosus in Lactobacillus plantarum NC8 and Lactobacillus casei as hosts, respectively. Both lactobacilli harboring the pSIP409-celB vector produced active CelB in batch bioreactor cultivations (MRS medium) while the specific CelB activity of the cell free extract was about 44 % higher with L. plantarum (1,590 ± 90 nkat/mg(protein)) than with L. casei (1,070 ± 66 nkat/mg(protein)) using p-nitrophenyl-ß-galactoside (pNPGal) as the substrate. A fed-batch bioreactor cultivation of L. plantarum NC8 pSIP409-celB resulted in a specific CelB activity of 2,500 ± 120 nkat ( pNPGal)/mg(protein) after 28 h. A repeated dosage of the inducer spp-IP did not increase the enzyme expression further. As alternative for the cost intensive MRS medium, a basal whey medium with supplements (yeast extract, Tween 80, NH(4)-citrate) was developed. In bioreactor cultivations using this medium, about 556 ± 29 nkat ( pNPGal)/mg(protein) of CelB activity was achieved. It was shown that both LAB were potential expression hosts for recombinant enzyme production. The pSIP expression system can be applied in L. casei.
Subject(s)
Archaeal Proteins/metabolism , Cellulase/metabolism , Gene Expression , Lactobacillus/metabolism , Pyrococcus furiosus/enzymology , Archaeal Proteins/chemistry , Archaeal Proteins/genetics , Cellulase/chemistry , Cellulase/genetics , Enzyme Stability , Hot Temperature , Lactobacillus/genetics , Pyrococcus furiosus/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolismABSTRACT
By inoculation of embryonating chicken eggs via the yolk sac route Chlamydia psittaci was grown from 11 lungs of 45 pigs with pneumonia (24.4%). From the lungs of 55 pigs with other diseases the organism was isolated in five cases (9.1%). Chlamydiae were not detectable by cultural methods in the uterine mucosa of 87 sows, arthritic joints of 30 store pigs and in aborted fetuses. A commercial available enzyme amplified immunoassay indicated the presence of chlamydial antigen in mucosal scrapings from the uterus of two sows and in the fetal membranes as well as fetal organs in one case of porcine abortion.
