Preparation, characterisation and cell viability of encapsulated Trichoderma asperellum in alginate beads

Abstract

Aim: The encapsulation of Trichoderma asperellum BRM-29104 using Ca-alginate matrix was evaluated.

Methods: Intact and freeze-dried beads containing submerged conidia and microsclerotia (MS) of T. asperellum grown in liquid culture were prepared and characterised. Beads were stored at 8, 25, and 35 °C over 120 days.

Results: The mean sizes of beads before and after freeze-drying were 2.5 ± 0.2 mm and 1.5 × 1.1 mm (± 0.1 mm), respectively. Freeze-dried beads stored at 8 °C were more effective in maintaining conidia concentration, while MS concentrations yielded 10² MS/g for both beads at 8 and 25 °C. The concentration of viable cells in freeze-dried beads stored at 8 °C attained 3.0 × 10⁸ CFU/g after 120 days. FIRT analysis showed an interaction between the alginate and the cell wall of the fungus.

Conclusion: These findings support the use of alginate beads followed by freeze drying and cold storage for maintenance of viability of T. asperellum.

Keywords:

• Alginate
• biocontrol
• fungi
• encapsulation
• microsclerotia

Acknowledgements

The authors are grateful to the Department of Materials Engineering (DEMat) and Department of Pharmacy, both at Federal University of Rio Grande do Norte for the SEM and FTIR analyses, respectively. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).