Regulation of Light Output and Identification of Luminous Bacteria from Free-Living and Particle-Associated Bacterial Assemblages.

摘要

Samples from a culture of the marine nitrogen-fixing bacteria Vibrio natriegens were collected from aerobic/combined-nitrogen replete conditions and at regular intervals after shifting the culture to anaerobic/combined-nitrogen absent conditions. RNA and proteins were extracted from the samples for filter-binding assays using a 1.9 kb nifHD probe and antisera to nitrogenase. Results indicated that nifH mRNA and nitrogenase began to appear 100-120 min after shifting the culture from aerobic/combined-nitrogen replete to anaerobic/combined-nitrogen absent conditions. After 6-9 h (early log growth) nifH mRNA disappeared, whereas nitrogenase remained throughout log growth up to 18 h after shift. Additionally, both nifh mRNA and nitrogenase disappeared within 40 min after shifting the culture from nitrogen-fixing to non-nitrogen-fixing conditions; nifh mRNA disappeared within 10 min after the shift in a subsequent experiment. Nitrogenase, Nitrogen-fixing, Vibrio natriegens, Marine bacteria.