FIG. 8.

RNA gel blot analysis of Arsa-7, Aalu-37, Arsa-48, and Aalu-90 during citrate production (10 ppb; pelleted) and noncitrate production (1,000 ppb; filamentous) growth. The blots contained 15 μg of total RNA prepared from the biomass of A. niger cells grown for 0.04, 0.08, 1, 1.5, 2, 3, 4, 4.5, or 5 days after an initial growth period of 12 h with 10 ppb of Mn²⁺. All membranes were stripped and hybridized with an 18S rRNA probe to verify equivalent sample loading and for the estimation of the relative transcription of those genes.