TABLE 1.

Production of clavulanic acid and the 5S clavams by pah1 mutants

Medium and mutant or wild- type straina	Concn (μg/ml)b
	Clavulanic acid	Alanyl- clavam	Clavam-2- carboxylic acid	2-Hydroxy- methylclavam
SA medium
M-5A	13.0	0	0	0
M-5B	16.0	0	0	0
WT-5	5.6	0	0	0
M-6Ac	10.7	0	0	0
M-6Bc	13.1	0	0	0
WT-6	9.6	0	0	0
M-11A	18.6	0	0	0
M-11B	25.4	0	0	0
M-11E	22.9	0	0	0
M-11F	19.9	0	0	0
WT-11	15.2	0	0	0
Soy medium
M-5A	145	42	79	49
M-5B	180	40	60	34
WT-5	441	0.5	66	121
M-6Ac	151	0.1	1	0
M-6Bc	155	0.4	3	0
WT-6	132	0.9	3	0
M-11A	113	45	114	65
M-11B	161	37	87	44
M-11E	188	19	37	20
M-11F	91	45	121	79
WT-11	175	24	75	45

^aMutant strains are designated with the letter M, followed by a number to indicate the primary transformant which gave rise to the mutant, and then the letters A, B, etc., indicate the particular mutant strain. Wild-type strains are plasmid-free (cured) isolates from each primary transformant that gave rise to mutants and are designated WT, followed by a number to indicate the primary transformant. The cultures were grown for 96 h in SA or soy medium before analysis by HPLC.

^bThe levels of production of the 5S clavam metabolites are expressed in clavulanic acid equivalents. Peak areas from HPLC analyses were converted to concentrations by using a clavulanic acid standard with a known concentration.

^cMutants M-6A and M-6B both carried the apramycin cassette in the opposite orientation relative to that in the pah1 gene. All other mutants carried the disruption cassette in the same orientation as that in the pah1 gene.