Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Journal of Invertebrate Pathology
Vol.
105, No. 1, 2010; Pages: 16 - 23

Preservation of aerial conidia and biomasses from entomopathogenic fungi Beauveria brongniartii and Metarhizium anisopliae during lyophilization

Stefan Toegel, Sharareh Salar-Behzadi, Andrea Horaczek-Clausen, Helmut Viernstein

Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.

Abstract

In this study, we assessed the stability provided by different formulations to aerial conidia or biomasses (conidia, blastospores, and mycelia) of Beauveria brongniartii and Metarhizium anisopliae subjected to lyophilization. First, the impact of the freezing and drying processes on spore survival was evaluated. Whereas unprotected B. brongniartii spores showed high cryosensitivity, those of M. anisopliae were markedly harmed by the drying process. Then, the protective efficiency of 14 excipients was systematically evaluated and optimized regarding required concentrations. Fructose, glucose, and saccharose significantly enhanced viabilities for B. brongniartii and M. anisopliae spores following lyophilization, especially as a result of their cryoprotective effects. In addition, the effect of various bulking agents on spore survival was studied and dextran 4 was selected to enhance the physical properties of the lyophilized products. The combination of fructose and dextran 4 was further applied to prepare lyophilized biomasses of both fungi. In comparison to freshly harvested biomasses, the lyophilized products showed similar growth rates and a comparable production of virulent secondary metabolites such as destruxin A, destruxin B, or oosporein, suggesting their applicability as biological control agents.

Keywords: Metarhizium anisopliae; Beauveria brongniartii; Cryoprotection; Lyoprotection; Imbibitional damage; Formulation


 

 

 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution