Effects of Penicillium griseofulvum’s biological dyeing on the properties of Phyllostachys heterocycla

ObjectiveDiscoloration of bamboo is common. However, the functional development for this feature is still insufficient. The discoloration of bamboo affects the use value and economic value of bamboo and its products. At present, the research on biological discoloration of bamboo is mainly aimed at prevention and control. In this study, the biological dyeing of bamboo was realized by inducing Penicillium griseofulvum to infect bamboo, which is easy to change color.

MethodThe bamboo infected by P. griseofulvum was prepared by fungal culture, inoculation, infection, sterilization and drying; the effects of P. griseofulvum infection on the micromorphology, chemical components, surface properties, physical and mechanical properties of Phyllostachys heterocycla were analyzed by SEM, ATR-FTIR, surface color difference test, surface contact angle test, surface roughness test, mass loss rate and 24 hours water absorption, mechanical strength test.

ResultThe red exudate secreted by P. griseofulvum accumulated and permeated to the surface of Phyllostachys heterocycla. P. griseofulvum entered, spread, grew and produced pigment in the interior of bamboo through vessel cells in bamboo vascular bundles. The degradation of cellulose, lignin and hemicellulose mainly occurred in the early stage of infection. The infection behavior made the surface color difference value of Phyllostachys heterocycla increased continuously, the color changed to dark red gradually, forming a unique decorative effect. At the same time, the surface contact angle became smaller, and the surface roughness had no obvious change. The influence of infection behavior on the physical and mechanical properties of Phyllostachys heterocycla was small, the mass loss rate was slightly increased, the water absorption rate decreased in 24 hours, and the decrease of mechanical properties mainly occurred in 10−20 days of infection.

ConclusionThis study proves that the biological dyeing of bamboo can achieve better dyeing effect and has no serious adverse effects to bamboo properties, which provides the theoretical basis for further research of biological dyeing technology of bamboo.