Investigations on the influence of wood‐inhabiting bacteria on the pH‐value in trees

Regardless of their isolation origin, bacteria from wetwood of fir and poplar, from polluted beech and spruce trees, and from discoloured timber of Ilomba, acidified aerobically glucose‐rich substrates by organic acid production and increased the pH of protein media by ammonia. The pH‐changes occurred in laboratory nutrient media and also in the physiologically characterized capillary liquids and wood flours of fir, poplar and spruce.