Northern analysis of the aspB3 transcript level. The upper panel represents 16S and 23S rRNA bands on a 1% agarose gel after ethidium bromide staining. The lower panel displays detected transcripts (1107 kb; marked by an arrow) using a probe against aspB3. H. salinarum R1 wild type cells were grown either in complex (A) or synthetic media (B) and harvested at the indicated OD-values. Cells of ΔlrpA1 grown in synthetic media were harvested at indicated OD-values (C). Synthetic media (B1-4; C) was supplemented with aspartate and/or glutamate as indicated (+/-). Growth curve of H. salinarum R1 grown in synthetic medium with an amino acid composition as indicated (D).