Detection and Expression of Biosynthetic Genes in Actinobacteria ...

BERVANAKIS, G.Chapter 3: RESULTS3.2.5 Bioautography of Antimicrobial MetabolitesEnvironmental actinobacterial isolates exhibiting antimicrobial activity were furtheranalysed using bioautography to identify the active fractions. Figure 34 showsantibacterial activity of the broth supernatant of isolates A0350 and A1113 (lanes 1and 3). These results indicate that partial extractions of fermentation brothsupernatants of isolates were achieved with EtAc require further extractions tocompletely extract all the active metabolites. For culture A2381 the active fractionsfrom the fermented broth supernatant were extracted completely with EtAc, asindicated by the absence of clear zones in the broth supernatant. The active fractionswithin the extract were clearly visible and correlated with the R f values obtained byTLC separation (Table 54). The remaining cultures in table 54 were not tested usingbioautography due to lack of time, however bioassays indicate that the majoritycontain antimicrobial activity and the banding profiles indicate that metabolites wereproduced.Figure 34. Bioautogram of Extracted Metabolites from Fermented ActinobacteriaCultures. Lane 1: Broth supernatant media#153m with A0350 isolate., Lane 2:Mycelial extract of A0350 isolate., Lane 3: Broth supernatant media#153m withA1113 isolate., Lane 4: Mycelial extract of A1113 isolate., Lane 5: Broth supernatantDextrin media with A2381 isolate., Lane 6: Mycelial extract of A2381 isolate._____________________________________________________________________105