Screening of filamentous fungi for lipase production: Hypocrea pseudokoningii a new producer with a high biotechnological potential

Abstract

Filamentous fungi isolated from soil samples were screened for extracellular lipase production. The best producer was Hypocrea pseudokoningii identified by taxonomical criteria, and by rDNA sequencing of the variable internal transcribed spacers (ITS I and II) and the intervening 5.8S gene. The fungus was grown in a complex medium supplemented with 1% Tween 80 and 0.2% yeast extract, for 4 days. The optimum pH for extracellular and intracellular lipases was 7.0 and 8.0, respectively. Both enzymes exhibited maximum activity at 40°C. Extracellular and intracellular lipase activities were highly stable in the pH range 3.0–8.0 at room temperature. The intracellular lipase was thermostable up to 60°C, for 15 min and the extracellular, for 107 min, at the same temperature. The intracellular lipase was stimulated by silver ions. Extracellular lipase was stable in organic solvents, such as DMSO, alcohols, acetone, and acetonitrile, for 24 hours. Lipase activity increased around 80% when detergents were added to the enzymatic assay, such as Tween 80, Triton X-100, and SDS.

Keywords::

• Screening
• Hypocrea pseudokoningii
• lipase
• molecular characterization
• ITS

Acknowledgments

JAJ and MLTMP are Research Fellows of CNPq. APT, FDAF were recipient FAPESP Fellowship. MGP and ACV are supported by CNPq. We thank Ricardo F. Alarcon, Mariana Cereia and Mauricio de Oliveira for technical assistance.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

This work was supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho de Desenvolvimento Científico e Tecnológico (CNPQ) and National System for Research on Biodiversity (Sisbiota-Brazil, CNPq 563260/2010-6/FAPESP n° 2010/52322-3).