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Transposon Tn917-LTV1 was used to produce a collection of Lactococcus lactis strains with fusion of a promoterless lacZ gene to chromosomal loci. Screening 2,500 Tn917-LTV1 integrants revealed 222 that express beta-galactosidase on plates at 30 degrees C. Pulsed-field gel electrophoresis revealed Tn917-LTV1 insertions in at least 13 loci in 15 strains(More)
Nonparticipation of the bacterial dnaA gene in plasmid replication has been assumed to be the general rule. In conditional dnaA mutants of Escherichia coli, only plasmid pSC101 has been shown to have a dnaA requirement. Experiments with dnaA null mutants of E. coli, presented here, show that dnaA plays a critical and direct role in the replication of(More)
Chlorophyll, organic (citric and malic acids) and abscisic acid (ABA) contents and stem water potential were measured to indicate possible physiological effects of heavy metal deposition on Empetrum nigrum L. (crowberry). The leaves and stems of E. nigrum were collected at distances of 0.5 and 8 km from the Cu-Ni smelter at Harjavalta, south-west Finland.(More)
Tumor spheroids of HT-29 human colon adenocarcinoma and A375 melanoma were established to investigate the uptake and clearance kinetics of TNT-1, a monoclonal antibody that targets necrotic cells of tumors. Our data reveal that there was rapid uptake of TNT-1 and its F(ab')2 fragment in both spheroid models, whereas an antibody of irrelevant specificity,(More)
Enzymatic milk coagulation for cheese manufacturing involves the cleavage of the scissile bond in kappa-casein by an aspartic acid protease. Bovine chymosin is the preferred enzyme, combining a strong clotting activity with a low general proteolytic activity. In the present study, we report expression and enzymatic properties of recombinant camel chymosin(More)
Empetrum nigrum L. (crowberry) is one of the plants surviving near the Cu-Ni smelters in Finland and Russia. According to field observations, the fine roots of E. nigrum are situated below 40 cm depth and the root biomass is reduced in the polluted sites. This could cause a reduced root uptake of macronutrients and trace elements in the field and,(More)
Two transposition vectors, pTV32 and pLTV1, containing transposon Tn917 derivatives TV32 and LTV1, respectively, were introduced into Lactococcus lactis subsp. lactis MG1614. It was found that pTV32 and pLTV1 replicate and that TV32 and LTV1 transpose in this strain. A protocol for production of a collection of Tn917 insertions in L. lactis subsp. lactis(More)
Nonsense suppressor strains of Lactococcus lactis were isolated using plasmids containing nonsense mutations or as revertants of a nonsense auxotrophic mutant. The nonsense suppressor gene was cloned from two suppressor strains and the DNA sequence determined. One suppressor is an ochre suppressor with an altered tRNA(gln) and the other an amber suppressor(More)
Two genes, hom and thrB, involved in threonine biosynthesis in Lactococcus lactis MG1614, were cloned and sequenced. These genes, which encode homoserine dehydrogenase and homoserine kinase, were initially identified by the homology of their gene products with known homoserine dehydrogenases and homoserine kinases from other organisms. The identification(More)
A generalized sinusoidal model for speech signal processing is studied. The main feature of the model is that the amplitude of each sinusoidal component is allowed to vary exponentially with time. We propose to use the model in transitional speech segments such as speech onsets and voiced/un-voiced transitions. Computer simulations with natural speech(More)