2-D Wavelet Packet Analysis of Structural Self-Organisation and Morphogenic Regulation in Filamentous Fungal Colonies

		/vol03/cljones4/	© Copyright 1996
		Volume 03	Received: Accepted:	---- ----

2-D Wavelet Packet Analysis of Structural Self-Organisation and Morphogenic Regulation in Filamentous Fungal Colonies Cameron L. Jones
Abstract
	Fungal colonies are composed of filaments called hyphae which self-organise into an interconnected, branching mycelium during growth. These organisms display species-specific branching behaviour and secrete exo-enzymes in response to nutrient assimilation. This paper details a new image analysis software routine called 2-D Wavelet Packet Analysis (2-D WPA) which quantifies the global fractal dimension and provides a unique index of fungal branching morphology. The global fractal dimension is an overall estimate of scaling complexity. This contrasts with a multifractal approach which looks for scaling at different resolution levels. The 2-D WPA is superior to alternative global analytical methods since it estimates scaling in the horizontal, vertical and diagonal directions at multiple spatial resolutions by mapping pixel points onto wavelet coefficients. The logarithmic decay of wavelet packet coefficient energy versus position provides an unbiased estimate of fractal scaling. A full source code is provided. The fungus Pycnoporus cinnabarinus secretes the phenol-oxidase exo-enzyme, laccase, which is of use industrially for the bleaching of recycled paper/Kraft pulps and in other areas which use peroxidase chemistry. The fractal dimension was enumerated for fungi grown on basal Newspaper Only media and on media supplemented with the paramorphogen, cellobiose. This compound caused profuse hyphal branching and a reduction in radial expansion. These changes in morphology were accompanied by an exponential increase in the expression of laccase into the extracellular medium in liquid culture. Hypersecretion was stimulated approximately 7070% over the control at 5 days. This study shows that the fractal dimension is a useful indicator of future enzyme yield and demonstrates a strong correlation between spatial pattern phenomena and physiological function.

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