Biotechnological potential of actinobacteria isolated from rhizosphere of the medicinal plant, Ipomoea pes-caprae (L.) R. Br.

The aim of the present study was to evaluate the antimicrobial activity and the production of L-asparaginase by actinobacteria isolated from the rhizosphere of the medicinal plant, Ipomoea pes-caprae (L.) R. Br., and to conduct a comparative chemical characterization of the methanolic extract from leaves and the most active micro-organism. After isolation, the antimicrobial activity of actinobacteria from rhizosphere were evaluated against Candida albicans UFPEDA 1007, Bacillus subtilis UFPEDA 86, Escherichia coli UFPEDA 224, Staphylococcus aureus UFPEDA 02 and clinically isolated S. aureus UFPEDA 705. The chemical characterization was conducted by thin layer chromatography for the following groups: triterpenes, steroids, mono- and sesquiterpenes, alkaloids, saponin, coumarin, flavonoids, phenylpropanoids, cinnamic acid derivatives. Finally, a qualitative assay was carried out to evaluate the production of L asparaginase. Among all isolated actinobacteria, the strain Nocardia sp. A94 was the most active against Gram positive bacteria, including the clinical isolate (inhibition diameter zone of 23 mm). Additionally, mono/sesquiterpene groups were detected in its methanolic extract, as well in the extract from I. pes-caprae. On the other hand, the production of the L-asparaginase was confirmed in 55.17% of tested actinobacteria. The results show the biotechnological potential of actinobacteria from the rhizosphere of I. pes-caprae as producers of antimicrobial compounds and L-asparaginase, both activities can be explored for pharmaceutical, cosmetic and food industries.