African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

In vitro larvicidal action of Paecilomyces marquandii crude extract

  Filippe E. F. Soares1, Fabio R. Braga2,  Hugo L. A. Geniêr1, Jackson V. Araújo2, Lucas B. Campos1 and José H. Queiroz1*
  1Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil. 2Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil.  
Email: [email protected]

  •  Accepted: 26 August 2011
  •  Published: 09 October 2011



The aim of this present work is to produce Paecilomyces marquandii crude extract and its in vitro larvicidal action. Saccharose, glucose, coffee residue, soluble starch, insoluble starch, soybean meal and wheat bran were the carbon sources tested. NaNO3, NH4Cl, soybean meal, (NH4)2SO4, yeast extract, casein peptone, tryptone and NH4NO3 were the nitrogen sources tested. Central composite design was applied to determine the optimal concentration of the tested significant variables. The best carbon sources were glucose and soybean meal, while the best nitrogen source observed was tryptone. The greatest value for proteolytic activity was 246.58 U/ml due to the concentration of tryptone and pH value. Results showed that the optimum pH was 8.0, while the optimum temperature was 60°C. The optimized extract obtained from P. marquandii exhibited in vitro larvicidal activity with 60.1% reduction. Tryptone and pH optimized the production of proteases by fungus P. marquandii.


Key words: Nematophagous fungi, Paecilomyces marquandii, crude extract, larvicidal action, surface response.