A screening programme of soil bacteria for antagonism toward mould and wood stain fungi was undertaken on 8 types of agar-based media by application of several bacteria to each plate. The rapid screening method was subsequently verified by testing antagonism of the most promising bacteria on Scots pine sapwood. Most of the 64 bacterial showed antagonistic effects on certain media against individual fungi after 8 weeks incubation. Bacterial antagonism toward fungi and growth rates of fungi and bacteria were media specific. Greatest total antagonistic effect by bacteria against fungi develeoped on yeast malt agar, and least on tryptone soya agar. The most effective bacteria were not particularly antagonistic toward fungi on low nutrient media but were nevertheless effective on wood. Bacterial colonies which grew only slightly during the incubation period produced the greatest mean fungal inhibition. One unidentified bacterial isolate demonstrated antagonism toward 9 of 10 fungi tested and was the most effective antagonist against both Ceratocystis pilifera and Aspergillus niger on agar media. A total of 10 bacteria showed antagonism to 5 or more of the tested fungi. Selected bacteria along 8 Trichoderma strains and 5 yeast species were subsequently tested for antagonism in wood-based trials under high humidity. The most effective bacterial isolate from the screening programme was also highly effective against mould and stain develepment on wood. Other bacteria were successful against either mould or stain development. Further screening programmes are recommended to test potentially antagonistic bacteria against serveral fungi, including Paecilomyces variotii and Sclerophoma pityophila, on yeast malt agar.

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