INFLUENCE OF TEMPERATURE ON FLAVOUR COMPOUND PRODUCTION FROM CITRATE BY Lactobacillus rhamnosus ATCC 7469.

MEDINA, R.B.; OLIVER, G.; BENITO DE CÁRDENAS, I.L.

MICROBIOLOGICAL RESEARCH

Elsevier

Año: 2001 vol. 155 p. 257 - 262

0944-5013

The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C] citrate rate were observed at 37ºC. At this temperature, maximum citrate lyase activity and the specific diacetyl and acetoin production (YDA%) were observed. The high levels of a-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L- lactate dehydrogenase found at 37ºC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45ºC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increases with increasing culture temperature of 22 at 37ºC. Thus there are greater quantities of pyruvate available for the production of a-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.