A method for polyethylene glycol-induced protoplast transformation of glutamate-producing bacteria with plasmid DNA was established. Protoplasts were prepared from cells grown in the presence of penicillin by treatment with lysozyme in a hypertonic medium. The concentration of penicillin during growth affected the efficiency of formation, regeneration, and polyethylene glycol-induced DNA uptake of protoplasts. Regeneration of protoplasts was accomplished on a hypertonic agar medium containing sodium succinate and yeast extract. The spectinomycin and streptomycin resistance plasmid pCG4, originally from Corynebacterium glutamicum T250, could transform various glutamate-producing bacteria such as C. glutamicum, Corynebacterium herculis, Brevibacterium flavum, and Microbacterium ammoniaphilum. The plasmid was structurally unchanged and stably maintained in new hosts. The transformation frequency of most competent protoplasts with pCG4 DNA isolated from primary transformants was high (ca. 10(6) transformants per microgram of covalently closed circular DNA) but was still two orders of magnitude below the frequency of transfection with modified DNA of the bacteriophage phi CGI. The difference was ascribed to the involvement of regeneration in transformation.

Hybrid plasmids were constructed by combining in vitro the Escherichia coli plasmid pGA22, which carries the genes determining resistance to kanamycin, tetracycline, chloramphenicol and ampicillin, with the cryptic plasmids, pCG1 and pCG2, of Corynebacterium glutamicum. The hybrid plasmids were introduced into C. glutamicum and E. coli and replicated in both hosts. They expressed all the E. coli resistance phenotypes except ampicillin resistance in C. glutamicum. The levels of antibiotic inactivating enzymes encoded on these plasmids were about four to ten times lower in C. glutamicum than in E. coli. Despite the lack of expression of ampicillin resistance, beta-lactamase activity was detected in C. glutamicum carrying hybrid plasmids.

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Ferroelectric capacitors using SrBi2(Ta1−xNbx)2O9 (SBTN) were compositionally altered varying Nb concentration from 0 to 1, the corresponding I–V and P–E electrical characteristics evaluated from room temperature to 145 °C. These temperature evaluations reveal that the leakage current will increase with larger Nb concentration and the dominant conduction mechanism changes from Schottky to Frenkel–Poole emission. The ferroelectric hysteresis curve shifts in the direction of negative polarization as the temperature or the concentration of Nb increases. Concentration increases in Nb reduces the temperature dependence of remnant polarization and coercive field. Film resistance to imprint and degradation from elevated temperature improves. Substituting b-site Nb for Ta allows imprinted capacitors to recover by application of either bipolar fatigue pulses at room temperature (RT) or, cycling P–E measurement pulses at elevated temperature. Due to this asymmetrical tradeoff of film ferroelectric properties, there is an optimum identifiable range of Nb concentrations (0.25–0.5) capable of achieving memory performance. Optimized SBTN ferroelectric films will suitably perform in integrated circuit memory function applications provided that the leakage current incurred at higher Nb concentrations can be reduced.