Influence of the Environment on the Morphological and Biochemical Characteristics of Different Aspergillus niger Wild Type Strains

The present work studied the differences in accumulation, transformation and volatilization of different heavy metals ions on molecular and macromorphological features of Aspergillus niger wild type strains. Four different strains of A. niger (An) were used. Three strains (An-P, An-N, An-S) were isolated from acid and ultra acid mining regions with higher concentration of As and Sb. The fourth strain (An-G) was used as the comparative one. Environmental burden strongly affected biochemical, macro and micromorphological characteristics of studied strains. The RAMP profiles showed 90 % similarity among the studied strains. The strain An-S showed its own characteristic RAMP profile, different to the others ones. Analyzed strains can be clustered into two groups on the basis of the changes in gene expression and morphological parameters. Differences were found in both acid beta-1,3-glucanases and peroxidases. Main quantitative and qualitative differences by A-PAGE and SDS-PAGE were registered for proteins with Mr similar to 50; 34; 28-27 and 11 kDa. Presence of living mutants of A. niger strains in old environmental burden indicate on the adaptation and mutation processes of soil microorganisms from the point of long-term effect.