Derby Melissa L, Galliano Michael, Krzanowski Joseph J, Martin Dean F
Department of Chemistry, Institute for Environmental Studies, University of South Florida, SCA 400, 4202 E. Fowler Avenue, Tampa, FL 33620, USA.
Toxicon. 2003 Feb;41(2):245-9. doi: 10.1016/s0041-0101(02)00285-4.
Studies were conducted on the conditions under which the red tide organism, Karenia brevis (a.k.a., Gymnodinium breve), was treated with Nannochloris sp. The latter organism is known to produce cytolytic agents called Apparent Oceanic Naturally Occurring Cytolin (APONINs). Conventional wisdom might suggest that brevetoxins would be released upon destruction of the single-celled dinoflagellate K. brevis and that efforts to treat red tide outbreaks would lead to release of brevetoxins and enhanced toxicity toward marine species. Earlier studies described conditions by which K. brevis cells were converted to a non-motile form when cultures of K. brevis were treated with an isolate (Psi-APONIN) produced by Nannochloris sp. but when centrifuged only a small amount of the toxin was released. The present study confirms that the toxin is not released when the K. brevis is undisturbed, however, when the culture is stressed (stirred with a magnetic stirring bar for 24, 48, and 72h) toxin was released, and the toxicity could be measured using a Microtox analyzer. In the study, it was found that at as few as eighty cells of K. brevis produced a toxic effect of 20% as measured by the effect on Vibrio fischeri. Nannochloris sp. had no effect on the bacteria used in the Microtox analyzer, nor did interaction of Nannochloris sp. with K. brevis in the short term. This effect is presumed to be due to the production of Psi-APONIN and conversion of K. brevis to a non-motile or resting form.
开展了关于用微绿球藻处理赤潮生物短裸甲藻（又称海洋裸甲藻）的条件的研究。已知后一种生物会产生一种名为表观海洋天然存在细胞溶素（APONINs）的细胞溶解剂。传统观点可能认为，单细胞甲藻短裸甲藻被破坏时会释放短裸甲藻毒素，而且处理赤潮爆发的努力会导致短裸甲藻毒素的释放，并增强对海洋物种的毒性。早期研究描述了用微绿球藻产生的一种分离物（Psi - APONIN）处理短裸甲藻培养物时，短裸甲藻细胞会转变为非游动形式的条件，但离心时仅释放出少量毒素。本研究证实，当短裸甲藻未受干扰时毒素不会释放，然而，当培养物受到胁迫（用磁力搅拌棒搅拌24、48和72小时）时毒素会释放，并且可以使用微毒性分析仪测量毒性。在该研究中发现，仅80个短裸甲藻细胞就能产生20%的毒性效应（以对费氏弧菌的影响来衡量）。微绿球藻对微毒性分析仪中使用的细菌没有影响，短期内微绿球藻与短裸甲藻之间也没有相互作用。这种效应据推测是由于Psi - APONIN的产生以及短裸甲藻转变为非游动或静止形式所致。
