• Korean Journal of Microbiology
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• v.28 no.2
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• pp.120-127
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• 1990

Intraspecific fusion frequency between Filobasidium capsuligenum CBS6122-2 ade and met trp or met strains was $2.9\times 10^{-3}$ and $8.5\times 10^{-3}$, respectively. And intergeneric fusion frequency between Folobadidium capsuligenum CBS 4318 (cys his) and Saccharomyces cerevisiae 262-12-1 (hom3 thr1) or X2180-1A (ade thr) was $8.8\times 10^{-6}$ and $9.5\times 10^{-4}$, respectively. Nuclear fusion appears to occru in fusants between intraspecies and intergenera as strongly suggested by DNA content, nuclear staining, comparison of survival rate to UV light and mitotic segregation analysis. It was also found that $\alpha$-amylase and glucoamylase activity from intraspecific hybrids was 1.6-2.1 fold increased when compared with that from thier parents.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.31-37
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• 1997

Intergeneric hybrids between Aspergillus niger and Perricillium ch~y.sop~um(Tyr ), hyperlipolytic enzyne-producing fungi, were obtained by nuclear transfer technique:. Optimal conditions for formation of intergeneric hybrids were investigated. Maximum production of protoplasts were obtainrd by 1% Novozym 234 at $30^{\circ}C$ for 3 hrs and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6 M KC]. Frequencies of hybrid formation by nuclear transfer were $1.3{\times}$10^{-3}$$ $-3.8{\times}$10^{-3}$$. From the chervation of genetic stability, conidial size, DNA content, ;md nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed 1.4-2.2 fold higher lipase activities than parental strains. It was strongly supported by results of this study that nuclear transfer technique is much more efficient in the formation of intergeneric hybrids than protoplast fusion and is very useful for the improvement of strains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.779-784
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• 1995

The effective production of 5'-GMP(5'-Guanylic acid) by immobilized 5'-GMP producing fusant RC102(intergeneric protoplast fusion between Brevibacterium ammoniagenes ATCC21263 and Corynebacterium glutamicum ATCC21171) was investigated. The Fusant RC102 was immobilized by entrapping in -carrageenan, agar, polyacrylamide or Ca-alginate. 3% k-carrageenan was selected as the most suitable matrix. In the production of 5'-GMP using the immobilized whole cells of fusant RC102, the optimum conditions were $32^{\circ}C$, pH 8.0, $30\mu\textrm{g}/L\;of\;Mn^{2+},\;1{\times}10^{-6}%\;of\;Zn^{2+}$. In order to use fermentation medium containing CSL(Corn Steep Liquor) plentiful in $Mn^{2+}$, the optimum conditions of penicillin G, D-cycloserine and POESA(polyoxyethylene stearylamine) for production of 5'-GMP were 0.8unit/ml, 0.8unit/ml, 0.8unit/ml and 5mg/ml, respectively. Cationic surfactant, POESA was effective and superior to the antibiotics, penicillin G or D-cyloserine in 5'-GMP productivity. The condinuous fermentation using immobilized fusant RC102 showed that 5'-GMP productivity was stable for more than 15 days.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.143-151
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• 1997

Interspecific hybrids between Aspergillus niger and Penicillium notatum (Tyr-), hyperlipolytic enzyme-producing fungi, were obtained by nuclear transfer technique. Optimal conditions for formation of intergeneric hybrids were investigated. Maximum production of protoplasts was obtained by 1% Novozyme 234 at $30^{\circ}C$ for 3 hrs and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6 M KCl. Frequencies of hybrid formation by nuclear transfer were $3.8{\times}10^{-3}{\sim}1.3{\times}10^{-3}$. From the observation of genetic stability, conidial size, DNA content, and nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed $1.2{\sim}1.7$ fold higher lipase activities than parental strains. It was strongly supported by results of this study that nuclear transfer technique is much more efficient in the formation of intergeneric hybrids than protoplast fusion and is very useful for the improvement of strains.