TABLE 1.
Screening of α-acetolactate-producing mutants of L. lactis subsp. lactis biovar diacetylactis
| Parent straina | No. of colonies screenedb | Brown colonies
|
α-Acetolactate-producing mutantsc
|
|||
|---|---|---|---|---|---|---|
| No. | % (relative to colonies screened) | No. | % relative to:
|
|||
| Colonies screened (10−3) | Brown colonies | |||||
| Y8 | 380,000 | 300 | 0.08 | 5 | 1.3 | 1.7 |
| MR3 | 120,000 | 258 | 0.22 | 14 | 11.7 | 5.4 |
| NO8 | 140,000 | 110 | 0.08 | 26 | 18.6 | 23.6 |
a
Parent strains were deficient in ALDC.
b
Screening was performed on LDHA-20 agar.
c
Mutants that formed brown colonies on LDHA-20 agar and that produced more than 0.2 mM α-acetolactate when cultivated in modified MRS medium, containing no citrate.