Abstract:
The ability to cure infectious diseases is being threatened by the emergence and global
dissemination of antimicrobial resistance mechanisms. Mix culturing of fungi plays a significant
role in the quest for new antimicrobial compounds and/or enhanced production
of known active compound/s synthesized by either organism. Aspergillus subramanianii,
an endophyte of Gyrinops walla; is known to possess antibacterial activity against
Staphylococcus aureus. In the present study, out of eight endophytic fungi of G. walla
cohabiting with A. subramanianii tested, only two; VEF 4 and VEF 8 showed poor
antibacterial activity against S. aureus in agar plug assay. These two and another
four endophytes (VEF 1, VEF 3, VEF 9, and VEF 10) of G. walla which did not
show any antagonistic activity against A. subramanianii in the dual culture assay were
selected and separately co-cultured with A. Subramanianii in Potato Sucrose Agar. A
significant increase was observed in the zone of inhibition when the ethyl acetate fraction
of 3 week–old mix culture of A. subramanianii and VEF 4, compared to that of the
monocultures of each candidate. The TLC bioautogram showed a single active spot for
both the crude ethyl acetate fractions of mixed culture and the axenic culture of A.
subramaianii. The HPLC-UV profiles of the active spots revealed that both members
produced the same compounds suggesting the increased efficiency may be due to the
total effect of the two members in mixed cultures.
