TABLE 1.

Nitrite accumulation in Pseudomonas strain M19 and mutant cells after growth for 68 h at room temperature

Strain	Amt (mM) of nitrite accumulateda
	Peptoneb	Ammoniumc	Nitrated	Nitrate + peptonee
M19	0.03 ± 0.00 (HETN)	0.02 ± 0.00 (HETN)	4.40 ± 0.43 (NAP/NAR)	17.16 ± 2.32 (HETN/NAP/NAR)
mt54	0	0	0.05 ± 0.00 (NAP)	0
mt97	0	0	0.04 ± 0.00 (NAP)	0
mt105	0	0	NGf	0

^aNitrite accumulated in cultures grown with nitrogen sources. Values are the mean ± standard deviation for three cultures. Proposed pathways for nitrite production are indicated in parentheses. Pathway abbreviations: HETN, heterotrophic nitrification; NAP, periplasmic nitrate reductase; NAR, membrane-bound nitrate reductase.

^bNitrification broth with peptone (22).

^cMinimal medium with succinate and ammonium (10).

^dMinimal medium with succinate (10) supplemented with 10 mM sodium nitrate.

^eNitrification broth with peptone (22) supplemented with 10 mM sodium nitrate.

^fNG, no growth.