TABLE 1.

Hydrogen sulfide production under low- and high-nitrogen conditions in transformed and untransformed strains

Nitrogen concn (mg/liter)	Strain	Maximum fermentation rate (g/h)a	Total H2S (ng)	% Maximum of H2S
433b	UCD522	0.123	3,300	100
	UCD522pVector	0.115	3,100	93
	UCD522pMET17	0.102	5,000	150
	UCD713	0.104	890	100
	UCD713pVector	0.127	850	96
	UCD713pMET17	0.098	210	24
208c	UCD522	0.149	6,800	100
	UCD522pVector	0.144	6,300	93
	UCD522pMET17	0.166	8,000	118
	UCD713	0.146	3,900	100
	UCD713pVector	0.154	3,700	95
	UCD713pMET17	0.106	680	17

^aThe maximum fermentation rate was calculated from the fermentation rate data by using time points corresponding to the steepest decline in weight. 

^bValues represent the average of independent determinations of three replicates. Replicate values varied by less than 3%. 

^cValues represent the average of independent determinations of two replicates. Replicates varied by less than 5%.