中文摘要：

枯草芽孢杆菌（Bacillus subtilis）B26分离自白桦林地土壤,对多种变色菌具有抑制效果。经紫外诱变,筛选得到1株抑菌活性更强的突变菌株B26-10。与菌株B26相比,突变菌株B26-10显著提高了对引起木材变色的绿色木霉7258、甘薯长喙壳8430和交链孢5173的抑菌效果,提高幅度分别为60%、46%和25%。菌株B26-10经传代10次后,抑菌效果稳定。对突变菌株B26-10的上清液、发酵液及高温处理后的发酵液进行抑菌活性测定,结果表明,发酵液的抑菌活性略大于上清液抑菌活性,发酵液经高温处理后无抑菌活性。菌株B26-10的抑菌作用可能与其具有抑菌活性的代谢产物有关,代谢产物可能为蛋白类物质。在白桦木片被变色菌侵染之前,利用菌株B26-10对木片进行生防处理,可以有效地控制白桦变色。

英文摘要：

Bacillus subtilis B26 with antifungal activity against wood sapstain was isolated from the soil samples of Betula platyphylla Suk.Cells of Bacillus subtilis B26,as an original strain were mutated by UV irradiation to improve its antifungal activity.The mutant B26-10 was obtained due to enhanced activity in inhibiting Trichoderna viride 7258,Ceratocystis fimbriata 8430,and Alternaria alternata 5173.Compared to the performance of strain B26,the antifungal activity of mutant B26-10 was promoted to 60 % for T.viride 7258,46 % for C.fimbriata 8430,25 % for A.alternata 5173,respectively.Successive sub-culturing of B26-10 for 10 generations did not cause its antifungal activity loss.The antifungal activity of the supernatant,fermentation broth and the broth after treated with heating were also tested.The antifungal activity of fermentation broth was slightly higher than those of the supernatant;the fermentation broth lost antifungal activity after heating.The results indicated that the antifungal activity seems to be related with the production of active metabolites,and the active metabolites could be proteins.The successful control of sapstain can be obtained by the pretreatment of Bacillus subtilis B26-10 before the attack of sapstain.The results indicated that Bacillus subtilis B26-10 could be a potent organism for bio-control agent in the field of wood protection.