title: Invertase production by Saccharomyces cerevisiae protoplasts immobilized in strontium alginate gel beads.
abstract: The invertase productivity of Saccharomyces cerevisiae IFO 0309 protoplasts in a static culture was 35 times (extracellular) and 9 times (extracellular + intracellular) higher than those of cells. When S. cerevisiae protoplasts were immobilized in 1.0% strontium alginate gel as an artificial cell wall, the protoplasts could be cultivated in a shake flask without disruption, and invertase was secreted into the broth. However, cell wall regeneration in the immobilized protoplasts was detected at about 24 h of cultivation. This implies that prevention of cell wall regeneration is a prerequisite for long term process with protoplasts. When 0.5 microg/ml aculeacin A (inhibitor of beta-1,3 glucan synthesis) was added to the broth, active protoplasts were maintained without cell wall regeneration for more than 24 h and invertase was produced extracellularly. Immobilized S. cerevisiae T7 protoplasts (this strain produces twice as much invertase as S. cerevisiae IFO 0309) were used for invertase production in a bubble column reactor, and a high and stable level of invertase (45 U/ml) was maintained for 72 h.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Kamogawa
authors.forename: H
authors.initials: H
authors.lastname: Aoyagi
authors.forename: I
authors.initials: I
authors.lastname: Kato
authors.forename: R
authors.initials: R
authors.lastname: Nakajima