Isolation and Screening of Extracellular Lipase-Producing Endophytic Fungi from Handroanthus impetiginosus

Aims: This study aimed to screen extracellular lipase-producing endophytic fungi isolated from Handroanthus impetiginosus (H. impetiginosus).

Study Design: Endophytic fungi were isolated and screened for extracellular lipase production. The best strains obtained were tested for lipase production, via submerged fermentation, using two different carbon sources.

Place and Duration of Study: Institute of Chemistry, Federal University of Alfenas, between June 2016 and December 2017.

Methodology: Healthy and mature leaves were collected from H. impetiginosus in Alfenas/Minas Gerais, Brazil. Endophytic fungi were isolated from leaves by following standard microbiological methods. All isolated fungi (122) were used in the screening for potential lipase production. Submerged fermentation cultivations, using two different carbon sources, were carried out based on the previous screening results obtained. The best lipase-producing endophytic fungus was identified using molecular biology techniques. The produced lipase by submerged fermentation was purified by organic solvent precipitation and characterized by SDS-PAGE analysis.

Results: A total of 122 isolates of endophytic fungi were obtained. Two isolated fungi showed high lipase activity in the plate screening and were chosen for submerged fermentation cultivations using glucose and cottonseed oil as carbon sources. A maximum lipase activity of 5.9 U/mL was obtained for one strain after 48 h of fermentation for the culture medium using cottonseed oil as a carbon source. This strain was genetically identified as Preussia africana. A single protein band with an apparent molecular mass of 64 kDa was detected by SDS-PAGE analysis after lipase purification (purification factor of 18.5).

Conclusion: A potential microorganism, able to produce an extracellular lipase in submerged fermentation, was isolated from H. impetiginosus. To date, this is the first report of extracellular lipase production by Preussia africana. The potential for this new lipase should be evaluated through a full characterization of these lipase properties in further studies.