Study On Preparation And Properties Of Lasiodiplodia Theobromae Dyed With Rubberwood (Hevea Brasiliensis)

Wood stain is generally considered to be a defect of wood properties,reducing the economic values of wood.Few researchers use microorganisms to make wood color phenomenon to increase the decorative effect of wood surface,to achieve the reverse use of wood stain.Compared with the traditional physical and chemical dyeing methods,biological dyeing method is a green wood processing method with low energy consumption,no pollution,and flexible and diverse dyeing effects.Blue stain of rubberwood?Hevea brasiliensis?is a common stain phenomenon.In this paper,the common blue stain fungi?Lasiodiplodia theobromae?was used as“dye”to prepare rubberwood dyed with L.theobromae.In this paper,the optimum growth environment of L.theobromae was studied by using improved Czapek–dox medium.To investigate the effect of L.theobromae on the surface properties of rubber wood in Czapek–dox medium and the effect of L.theobromae on physical and mechanical properties of rubber wood in PDA medium.The mechanism of coloration of rubber wood by fungi was studied.The results showed that the optimum growth environment of L.theobromae was glucose 20 g/L,yeast extract 9g/L,p H 4,KCl 0.3g/L,Mg SO₄1.0g/L,Fe SO₄0.02g/L and Agar 15g/L.The growth rate of L.theobromae in the improved Czapek–dox medium was 1.5 times that in the PDA medium.The secretions in the Czapek–dox medium were spotty or clumpy,with uneven secretion and easy to be contaminated by bacteria in the later growth period.The secretions in the PDA medium were secreted radially to the surrounding areas,and the growth was more stable.Fungi can both produce better decorative effect on rubber wood under the conditions of two kinds of medium,the color mixing efficiency in Czapek–dox medium is higher,and the growth state in PDA medium is stable,and the influence of fungi on physical and mechanical properties of rubber wood is not changed much.EDS,XRD and FTIR analysis shows the relative crystallinity of rubber wood was increased by the fungi,and the cellulose,hemicellulose and extract were degraded,but the lignin was not affected.L.theobromae can produce better color mixing effect on rubber wood,and can be used in the production and manufacture of interior decoration materials,furniture and other wood products.