Cassava Starch-Agar Blend as Alternative Gelling Agent for Mycological Culture Media

Abstract:

Cassava starch has been used successfully in plant tissue culture media, and its potential in culturing fungi was evaluated for cost reduction since agar is expensive. Starch was extracted from blended-peeled cassava var. Dokudwoade paste and sun-dried for 48 hours. The cassava starch alone and its blend with different amounts of agar were used to prepare culture media, and medium with 5g agar/250ml was used as the standard. Each amount of agar and/or cassava starch was added separately to 250ml potato broth prepared from scratch and then autoclaved. Media were dispensed into Petri plates and left over night under ambient conditions and observed for media characteristics. Plugs of 5mm diameter of Aspergillus niger and Fusarium oxysporum placed at the centre of each Petri plate were used to assess growth and sporulation. It was observed that media with higher concentration of cassava starch had difficulty in dispensing. Clarity of the media was generally good. The mycelial growth and sporulation of A. niger on all media were reasonably good. However, growth was profuse on the cassava starch-blend media and this was probably due to additional form of carbon in starch. There was no significant difference (P > 0.05) between colony diameters and sporulation. The aerial growth of F. oxysporum was generally characterised by loose fluffy mycelia. Colony diameter and number of spores of F. oxysporium were significantly (P < 0.05) different. The different growth and sporulation characteristics of A. niger and F. oxysporum may be due to their different nutritional requirements. In general, all the media in the study supported growth and sporulation of the test fungi. The use of cassava starch-agar blend in mycological culture media preparation is therefore recommended after more studies to validate the present results.

 

Authors:

Kwoseh, C.K. (Department of Crop and Soil Sciences, Lecturer, ckwoseh@hotmail.com, 0322060332)

Asomani-Darko, M., Adubofour, K.


Place of Publication:

This article was published in Bots. J. Agric. Appl. Sci. Vol. 8 No. 1 2012.

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