油茶炭疽病拮抗细菌Y13主要抑菌物质分离纯化及作用方式

油茶内生拮抗细菌Y13是一株对油茶炭疽病菌有较强抑制作用的枯草芽胞杆菌。为了确定其抑菌物质的成分组成及其对油茶炭疽病菌的作用方式，本文通过乙醇沉淀、固相萃取、反相高效液相色谱法及LC MS对抑菌物质进行分离鉴定。一共分离纯化出16个活性组分，保留时间在10.5~26.0 min的8个组分对于油茶炭疽病菌产生明显的抑菌圈，其中保留时间为11.0 min处的色谱峰抑菌效果最强，经质谱初步鉴定确定该化合物的分子量为1 042.56 u；保留时间在27.5~39.5 min的8个组分导致油茶炭疽病病原菌菌丝颜色加深，其中以保留时间37.5 min处的色谱峰效果最为明显，质谱鉴定该化合物的分子量为1 480.85 u。显微观察发现它们通过导致菌丝断裂、畸形、原生质凝集的方式抑制菌丝生长；通过使孢子畸形、膨大、消融而抑制孢子萌发。

Isolation and purification of antimicrobial substance produced by endophytic bacteria Y13 in the Camelliaand its inhibitory effect on Camellia anthracnose

Bacillus subtilis strain Y13 isolated from Camellia has strong inhibitory activity against Colletotrichum gloeosporioides. In order to identify the antimicrobial compounds and the inhibition mechanism against C.gloeosporioides, the antimicrobial substances were isolated and purified by ethanol precipitation, solid phase extraction and reversed phase high performance liquid chromatography. Antifungal activity assay indicated that 16 main peak fractions had inhibition activity. The 16 main peak fractions can be divided in two groups. One group at retention time from 10.5 min to 26.0 min showed inhibition activity. The peak fraction at retention time 11.0 min showed the strongest activity and the molecular weight was 1 042.56 u identified by LC MS. The other group at retention time from 27.5 min to 39.5 min dark the mycelia of C.gloeosporioides. The compound at retention time 37.5 min showed the strongest activity and the molecular weight was 1 480.85 u. Microscope observation revealed that the 2 compounds could break up and enlarge the mycelia, deform and swell the spores, and inhibit the spore germination.