Aims: To evaluate the production of biosurfactants by fungi isolated from the Amazonian species Piper hispidum (Piperaceae), and to determine the physico-chemical properties of the crude biosurfactant obtained from the most promising fungi.
Methods and results: A total of 117 endophytic fungi were isolated, and 50 were used to verify the production of biosurfactants. Of these, eight presented positive results in the drop collapse test, and emulsification index ranging from 20 to 78%. The most promising fungi, Ph III 23L and Ph II 22S (identified as Aspergillus niger and Glomerella cingulata, respectively) were recultivated for extraction and analysis of the biosurfactant's physico-chemical characteristics. The cultivation broth that presented the greatest decrease in surface tension (36%) was that of the A. niger, which reduced it from 68·0 to 44·0 mN m-1 . The lowest critical micellar concentration value was found for the same endophyte (14·93 mg ml-1 ).
Conclusions: Endophytes of P. hispidum proved to be interesting producers of biosurfactants and presented promising physico-chemical characteristics for applications in diverse industrial sectors.
Significance and impact of the study: Piper hispidum endophytic fungi can be used as a new source of biosurfactants, as these molecules present a significant market due to their wide industrial applications.
Keywords: biosurfactant; biotechnology; endophytic fungi; fermentation biotechnology; surface tension.
© 2019 The Society for Applied Microbiology.