Improvement of cloned [alpha]-amylase gene expression in fed-batch culture of recombinant Saccharomyces cerevisiae by regulating both glucose and ethanol concentrations using a fuzzy controller

Journal Article · Sat Nov 05 00:00:00 EST 1994 · Biotechnology and Bioengineering; (United States)

DOI:https://doi.org/10.1002/bit.260440906· OSTI ID:6899878

Shiba, Sumihisa; Nishida, Yoshio; Park, Y S; Iijima, Shinji; Kobayashi, Takeshi ^[1]

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1. Nagoya Univ. (Japan). Dept. of Biotechnology

The effect of ethanol concentration on cloned gene expression in recombinant Saccharomyces cerevisiae strain 20B-12 containing one of two plasmids, pNA3 and pNA7, was investigated in batch cultures. Plasmids pNA3 and pNA7 contain the [alpha]-amylase gene under the control of the SUC2 or PGK promoter, respectively. When the ethanol concentration was controlled at 2 to 5 g/L, the gene expressions were two times higher than those at 20 g/L ethanol. To increase the gene expression by maintaining both the ethanol and glucose concentrations at low levels, a fuzzy controller was developed. The concentrations of glucose and ethanol were controlled simultaneously at 0.15 and 2 g/L, respectively, in the production phase using the fuzzy controller in fed-batch culture. The synthesis of [alpha]-amylase was induced by the low glucose concentration and maintained at a high level of activity by regulating the ethanol concentration at 2 g/L. The secretory [alpha]-amylase activities of cells harboring plasmids pNA3 and pNA7 in fed-batch culture were 175 and 392 U/mL, and their maximal specific activities 7.7 and 12.4 U/mg dry cells, respectively. These values are two to three times higher in activity and three to four times higher in specific activity than those obtained when glucose only was controlled.

• OSTI ID: 6899878
• Journal Information: Biotechnology and Bioengineering; (United States), Vol. 44:9; ISSN 0006-3592
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMYLASE
BIOSYNTHESIS
GENES
ETHANOL
BIOLOGICAL EFFECTS
SACCHAROMYCES CEREVISIAE
GENE REGULATION
ENZYME INDUCTION
RECOMBINANT DNA
ALCOHOLS
DNA
ENZYMES
EUMYCOTA
FUNGI
GLYCOSYL HYDROLASES
HYDROLASES
HYDROXY COMPOUNDS
MICROORGANISMS
NUCLEIC ACIDS
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
PLANTS
PROTEINS
SACCHAROMYCES
SYNTHESIS
YEASTS
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