The aged wine consumed 49% of all available nitrogen.Although this proportion is similar to that of the unaged wine, the aged wine used a smaller amount of nitrogen (approximately 4 mmol/L versus 5 mmol/L), i.e., total nitro-gen consumption was less marked in the aged wine, which contained less available nitrogen for the bacteria. The individ-ual compounds preferentially used included l-proline (59.4% of all nitrogen consumed), l-leucine (8.61%), urea (7.51%)and ammonium ion (7.06%). These four substances jointly accounted for 82.6% of all nitrogen used by the bacteria