嗅觉是动物的一个重要感官功能，而一项最新研究显示，细菌这种单细胞生物也有类似的“嗅觉”，它可以感知空气中的气味，并由此对周边环境做出判断。
英国纽卡斯尔大学１６日发布公报说，该校研究人员利用土壤中常见的地衣杆菌和枯草杆菌进行实验。结果显示，它们都能“嗅出”空气中氨气的气味，并集体做出向气味来源方向扩张的反应。
研究人员说，这是因为氨气是细菌消耗食物时常释放的副产品，对其他细菌而言，这意味着气味来源方向有食物，以及已有细菌竞争者。实验中，“嗅到”气味的细菌会集体结成一种生物膜，既便于向食物靠近，也有助于和其他细菌竞争。
领导研究的奈兰博士说，这是首次发现细菌也有能闻气味的“鼻子”。实际上，细菌作为单细胞生物，并没有“鼻子”这样的器官，下一步研究将关注细菌体内哪些分子承担了“嗅觉”工作。如果能由此找到抑制细菌形成生物膜的方法，将有助于在医疗等领域阻止细菌在器械上形成有破坏性的生物膜。
该研究报告发表在新一期《生物技术杂志》上。（生物谷Bioon.com）
生物谷推荐原文出处：
Biotechnology Journal DOI: 10.1002/biot.201000174
Bacterial Olfaction
Reindert Nijland1,2, J. Grant Burgess Professor1,*
Sensing their environment is a crucial ability of all life forms. In higher eukaryotes the sensing of airborne volatile compounds, or olfaction, is well developed. In plants, slime moulds and yeast there is also compelling evidence that these organisms can smell their environment and respond accordingly. Here we show that bacteria are also capable of olfaction. Bacillus licheniformis was able to sense airborne volatile metabolites produced by neighbouring bacterial cultures and cells could respond to this chemical information in a coordinated way. When Bacillus licheniformis was grown in a microtitre plate adjacent to a bacterial culture of the same or a different species, growing in complex medium, biofilm formation and pigment production were elicited by volatile molecules. A weaker response occurred in increasingly distant wells. The emitted volatile molecule was identified as ammonia. These data demonstrate that B. licheniformis has evolved the ability collect information about its environment from the surrounding air and physiologically respond to it in a manner similar to olfaction. This is the first time that a behavioural response triggered by odorant molecules received through the gas phase is described in bacteria.
