TABLE 1.

Half-lives of nifH transcripts in the presence of rifampin or chloramphenicol during the L period (1000 to 2200) in Trichodesmium sp. strain IMS 101 culture^a

Time when inhibitor added	Half-life (min) with:
	Rifampin	Chloramphenicol
1000	60	35
1600	74	52
1800	45	NAb

^aThe final concentration for both rifampin and chloramphenicol was 50 μg/ml. See Fig. 8 for corresponding Northern blot analysis of nifH transcripts. 

^bNA, not analyzed.