Abstract:

Mould, stain and decay fungi are the common microorganisms that can damage bamboo. Scanning electron microscope (SEM) was used in this study to investigate the macro- and micro-structural changes in bamboo after attack by these three types of fungi. The results showed that the mycelia of the mould and stain fungi were found only on the surfaces of the bamboo specimens and no hyphae were detected inside. The hyphae of the stain fungi were found to penetrate into bamboo and grew in metaxylem vessels, and then expand through the pits between cells; the stain fungi caused blue, brown and black discolorations from deep inside of the bamboo specimens. Similar to the stain fungi, the hyphae of the brown-rot fungus was also found to intrude from cell to cell through pits between cells; moreover, they gradually became denser and thicker causing very visible boreholes in the cell walls which then led to large-area cell wall rupture and collapse. It was observed from the vertical sections of the bamboo specimens under SEM that the brown-rot fungus firstly attacked the cell walls of the metaxylem vessels, followed by the parenchyma cells, and finally the fiber cells in bamboo.

Key words: scanning electron microscope (SEM), mould, stain fungi, decay fungi, bamboo