汤谷月 刘朝霞 赵宝梅 刘春菊 韩超

摘 要：从小麦根际土中分离到一株对小麦纹枯病菌拮抗活性较高的菌株X2-3，为进一步利用该菌株，对其进行了鉴定，并对其抗菌特性进行了分析。根据菌落形态和产酶特征及16S rDNA分析，将菌株X2-3鉴定为辣椒溶杆菌（Lysobacter capsici）。平板对峙法测定其抑菌谱发现，X2-3对Rhizoctonia cerealis、Thielaviopsis basicola等多种植物病原真菌和Phytophthora parasitica等卵菌表现明显的抑菌活性，但对Xanthomonas oryzae pv. oryzae和Ralstonia solanacearum等革兰氏阴性细菌没有拮抗活性。抗菌物质稳定性分析结果发现，粗提纯的抗菌物对蛋白酶K和温度不敏感，表明该物质可能属于非线性蛋白，且具有一定的耐热性。

关键词：辣椒溶杆菌； 鉴定； 抗菌物质； 拮抗活性

中图分类号：S482.2+92文献标识号：A文章编号：1001-4942（2016）05-0093-05

Abstract A strain X2-3 that showed higher antifungal activity to Rhizoctonia cerealis was isolated from wheat rhizosphere soil. Then it was identified and its antifungal characteristics were analyzed for further utilization. The strain X2-3 was identified as Lysobacter capsici based on the cultural properties and 16S rDNA sequence. Antimicrobial spectrum analysis indicated that X2-3 showed obvious antimicrobial activities to plant pathogenic fungi Rhizoctonia cerealis， Thielaviopsis basicola and oomycetes Phytophthora parasitica， but not to gram-negative bacteria such as Xanthomonas oryzae pv. oryzae and Ralstonia solanacearum. The stability analysis results showed that the antimicrobial substance crudely purified from strain X2-3 were not sensitive to protease K and high temperature， which indicated that it might be nonlinear protein and had certain heat resistance.

Key words Lysobacter capsici；Identification； Antifungal substance； Antimicrobial activity

溶杆菌属（Lysobacter）在自然环境中多见于土壤和水体等，由于该类细菌生长较慢，与芽孢杆菌、假单孢杆菌等细菌相比，其分离纯化较为困难，分离出现的比例相对较低[1]。溶杆菌为革兰氏阴性菌，菌体杆状，无鞭毛，可滑行，基因组G+C含量较高，在NA培养基菌落乳白色或淡黄色，圆形，表面光滑。目前已知的溶杆菌有20个种，包括产酶溶杆菌（Lysobacter enzymogenes）、抗生素溶杆菌（L. antibioticus）和胶状溶杆菌（L. gummosus）等[2]。溶杆菌属因具有如下特性而备受关注：（1）溶杆菌可产生蛋白酶、几丁质酶和纤维素酶等多种胞外酶，这些酶类对多种病原真菌、细菌和线虫具有溶菌活性；（2）可产生β-内酰胺类、大环肽类和缩肽类等多种抗生素，在抗生素的研制和开发中有重要价值[3]。溶杆菌在植物病害防治中已有一些研究和报道，其中研究较多的为L. enzymogenes，研究发现，L. enzymogenes菌株C3对小麦赤霉病、高羊茅叶斑病和菜豆锈病等都有较好的防治效果[4，5]。……