• KSBB Journal
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• v.23 no.1
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• pp.59-64
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• 2008

Optimum conditions for production of casein phosphopeptides (CPP) from sodium casenate by immobilized cell culture of Streptococcus faecalis var. liquefaciens were investigated. Immobilized cells were made by mixing 60% sodium alginate solution with an equal volume of culture broth at the end of exponential phase and subsequently dropping the mixture into $CaCl_{2}$ solution. Optimum conditions for CPP production by the immobilized cells were the same as those ($50^{\circ}C$, pH 7.0, and 10% substrate concentration) by the crude enzyme solution from the supernatant of culture broth. Optimum loading volume of the immobilized cells into a batch reactor was 30% (w/v). Using a continuous reactor loaded by the immobilized cells under the identified optimal conditions, we were able to produce CPP continuously up to 30 days with a maximum CPP conversion efficiency of 20%.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.417-422
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• 1985

Streptococcus faecalis var. liquefaciens was examined for the presence of plasmid deoxyribonucleic acid. An analysis by agarose gel electrophoresis revealed the presence of at least four plasmids of approxymately 6.8, 5.2, 2.6, and 2.1 Mdal. Two plasmid cured strains were obtained by novobiocin treatment. SKR2, which lost 5.2 mdal plasmid (pSK2) and 2.1 Mdal plasmid(pSK4) was sensitive to lincomycin and erythromycin. However, all cured strains showed identical response as parental strain in sugar fermentation, temperature sensitivity, proteolytic activity, and liquefaction of gelatin. The results imply that pSK2 or pSK4 is associated with antibiotic resistance of Str. faecalis var. liquefaciens.