Screening for endophytic fungi with antibacterial efficiency from Moringa oleifera and Withania somnifera

Abstract

Plants have a great potential to grow while carrying inside them fungi and bacteria known as endophytes. These endophytes have a potential to produce bioactive molecules which are of immense pharmaceutical importance. In the current study, plants having medicinal properties such as Moringa oleifera and Withania somnifera were explored for studying endophytic fungi associated with them. Moringa oleifera and Withania somnifera are widely known for their nutritional and medicinal values. The endophytic fungal associations of these plants have revealed their efficacy in therapeutic field. In the current study, endophytic fungal strains were extracted by incubating the dried plant samples on potato dextrose agar media, supplemented with streptomycin at 28 �C for 5-10 days. A total of 21 and 24 endophytes were isolated from herbal plant Moringa oleifera and Withania somnifera, respectively. Microscopic study revealed four active strains of M. oleifera i.e. Colletotrichum sp. (MO-S2), Cladosporium sp. (MO-S4, MO-L3) and Fusarium sp. (MO-R1), and two active strains of W. somnifera i.e. Alternaria sp. (WS-S8) and Fusarium sp. (WS-R5). Active strains of endophytic fungi were further screened for their antibacterial activity against pathogenic gram negative bacterial strain of Escherichia coli (ATCC 25922) and gram positive strain of Staphylococcus aureus (ATCC25323). Our results showed that fungal isolates of M. oleifera (MO-S2) and W. somnifera (WS-S8) had antibacterial activity against both the bacterial strains. However, three fungal strains of M. oleifera (MO-L3, MO-S4, and MO-R1) and one of W. somnifera (WS-R5) showed antibacterial activity against gram negative bacterial strain of E. coli.