Medium density fibreboard production by hot pressing without adhesive using Triarrhena sacchariflora residue bio-pretreated by white-rot fungus Coriolus versicolor.

AIMS: To produce fibreboard with Triarrhena sacchariflora residue (TSR) without adhesive and understand the relationship between bio-pretreatment and mechanical property of fibreboard. METHODS AND RESULTS: White-rot fungus Coriolus versicolor was used to pretreat TSR, and biochemical and physical analysis were investigated by ultraviolet spectrophotometry, Fourier transform infrared spectroscopy and environmental scanning electron microscopy method. CONCLUSIONS: TSR was suitable to produce fibreboard without adhesive by bio-pretreatment with C. versicolor. The property of fibreboard became stronger by optimization of bio-pretreatment parameters, and the moduli of rupture and elasticity of fibreboard were increased to 18·12 MPa and 4·3 GPa, respectively, which were close to national standard of medium-density fibreboard with adhesive. Bio-pretreated TSR increased the mechanical properties of fibreboard because of 1·4-fold content of polysaccharide and 1·15 U g(-1) laccase, more hydroxyl group and more porous surface structure than that of untreated TSR. SIGNIFICANCE AND IMPACT OF THE STUDY: TSR-based fibreboard production without adhesive eliminated potential formaldehyde gas emission.

[Serological typing of the somatic antigens of Pasteurella multocida strains isolated from poultry and mammals]. / Serologichno tipizirane vurkhu somatichnite antigeni na shtamove Pasteurella multocida, izolirani ot ptitsi i bozainitsi.

Somatic antigens were used for the serotyping of a total of 80 Pasteurella multocida strains isolated from birds with acute and chronic form of cholera as well as from mammals with bronchopneumonia. The investigations made use of the agglutination reaction between factorial sera (0:1, 0:2, 0:3, 0:5, 0:6, 0:8, 0:9, and 0:11) and antigens treated with 1 n HCl. The O-factorial sera behaved specifically after absorption with the respective reference antigens. They showed titers of 1:640 or higher than these with homologous antigens through cross-agglutination reaction. Sixty-nine strains (86.25 per cent) were typed, and 61 per cent of those isolated from birds were shown to belong to groups 0:5 and 0:9, while as many as 62 per cent of the strains isolated from pigs were referred to groups 0:1 and 0:2, and 62 per cent of those isolated from calves--to groups 0:2 and 0:9.

[Passive hemagglutination test with capsular and somatic antigens of Pasteurella multocida strains isolated from birds]. / Pasivna khemaglutinatsionna reaktsiia s kapsulni i somatichni antigeniot shtamove Pasteurella multocida, izolirani ot ptitsi.

Comparative investigations were carried out with the passive hemagglutination reaction in the serotyping of 14 reference and 34 P. multocida strains isolated from birds with three types of antigens obtained from one and the same bacterial mass: capsular extracts obtained by Carter's method (1), thermostable capsular extracts obtained after Carter and additionally heated at 100 C degrees for one hour (2), thermostable somatic extracts obtained after the additional heading of the depot of bacterial mass, treated after Carter at 100 C degrees for one hour (3). The results obtained with the three extracts correlated fully with each other as established with the passive hemagglutination test. Out of 34 strains 76.47 per cent were typed with the use of two of the capsular extracts, and 97.05 per cent--with the thermostable somatic extracts. Thermostable somatic extracts obtained from reference and field strains of P. multocida showed type specificity according to the classification of Carter. Of the P. multocida strains isolated from birds that succumbed to acute or chronic form of fowl cholera 97.06 per cent were typed as serotype A, and 2.94 per cent--chiefly in the chronic form of the disease--as serotype B. It was found that immunodiffusion conducted with capsular extracts was the most suitable method for the detection of antibodies in the sera of rabbits against P. multocida prior to the animals' hyperimmunization with type cultures.