Devi Karunanidhi Kanchana, Kothamasi David
Laboratory of Soil Biology and Microbial Ecology, Centre for Environmental Management of Degraded Ecosystems, University of Delhi, Delhi, India.
FEMS Microbiol Lett. 2009 Nov;300(2):195-200. doi: 10.1111/j.1574-6968.2009.01782.x. Epub 2009 Sep 4.
Pseudomonas fluorescens CHA0 has been shown to suppress the growth of a wide range of microbial plant pathogens as well as invertebrate pests such as root nematodes. Hydrogen cyanide, a secondary metabolite produced by the bacterium, has been credited as being one of the determinants of its biocontrol ability. The use of biocontrol agents against social insect pests such as termite Odontotermes obesus has limitations because of behavioural adaptations that include (1) removal of the pathogen when grooming by the termites and (2) isolation of infested members of the colony. In this study, we show that cyanide of bacterial origin may inhibit cytochrome c oxidase (CCO) of the termite respiratory chain and demonstrate that HCN-producing bacteria such as P. fluorescens can actually kill a macroscopic insect pest by cyanide poisoning. This ability of pseudomonad metabolites such as cyanide, which can bring about pest death by blocking respiration through inhibition of CCO rather than infection or predation, can potentially overcome the behavioural adaptations of social insect pests such as termites and represents an attractive option for insect pest management.
荧光假单胞菌CHA0已被证明能抑制多种微生物植物病原体以及诸如根结线虫等无脊椎害虫的生长。氰化氢是该细菌产生的一种次生代谢产物，被认为是其生物防治能力的决定因素之一。由于行为适应性，使用生物防治剂对付诸如白蚁（黑翅土白蚁）等社会性害虫存在局限性，这些行为适应性包括：（1）白蚁梳理时清除病原体；（2）隔离蚁群中受感染的成员。在本研究中，我们表明细菌来源的氰化物可能抑制白蚁呼吸链中的细胞色素c氧化酶（CCO），并证明产HCN的细菌如荧光假单胞菌实际上可通过氰化物中毒杀死一种大型害虫。假单胞菌代谢产物如氰化物的这种能力，可通过抑制CCO阻断呼吸导致害虫死亡，而非通过感染或捕食，这有可能克服诸如白蚁等社会性害虫的行为适应性，是害虫治理的一个有吸引力的选择。
