6533b7d8fe1ef96bd12697fd
RESEARCH PRODUCT
Localization of Lactococcus lactis ssp lactis bv diacetylactis in alginate gel beads affects biomass density and synthesis of several enzymes involved in lactose and citrate metabolism
Rémy CachonCharles Divièssubject
Calcium alginatebiologyAcetoinLactococcus lactisbiology.organism_classificationApplied Microbiology and BiotechnologyBiochemistryDiacetylDiacetyl reductasechemistry.chemical_compoundchemistryBiochemistrybiology.proteinFermentationCitric acidAlcohol dehydrogenasedescription
Lactococcus lactis ssp lactis bv diacetylactis, immobilized in calcium alginate beads, was grown in synthetic medium in a continuous flow reactor. Cell distribution inside the gel, as well as the activity of various enzymes, was measured after 30 h of operation. The included biomass tended to concentrate at the periphery of the bead along a section of radius about 100 μm long. ATPase activity was maximal in this zone. The activity of NADH oxidase, alcohol dehydrogenase, diacetyl reductase and acetoin reductase, which are repressed in the presence of citrate, were higher in the deeper zones than at the surface of the beads. This result shows that only the peripheral zone of the bead is responsible for the bioconversion of citrate into flavour compounds (diacetyl and acetoin).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1993-06-01 | Biotechnology Techniques |