Nandakumar Kanavillil, Obika Hideki, Shinozaki Tatsuya, Ooie Toshihiko, Utsumi Akihiro, Yano Tetsuo
Marine Eco-materials Research Group, Marine Resources and Environment Research Institute (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan.
Water Res. 2003 May;37(10):2311-6. doi: 10.1016/S0043-1354(03)00007-1.
The ability of pulsed laser irradiations to cause damage on the biofouling organisms is recently being investigated. If this technique is employed in industries such as power generation wherein a large quantity of water is being used for the cooling purpose, many organisms other than the targeted would get affected. In this study, we have investigated the damage caused by the pulsed laser irradiations from an Nd:YAG laser (fluence 0.1J/cm(2)) for varying durations such as 2, 5, 10, 30, 60 and 300 s on two marine diatom species namely Skeletonema costatum and Chaetoceros gracilis. Upon exposure to low power laser irradiations, these diatom species showed mortalities between 52.6+/-9.3% to 97.7+/-3.1% in the case of S. costatum and 57.8+/-2.5% to 98.9+/-0.6% in the case of C. gracilis for 2 and 300 s of irradiations, respectively. The mortality increased with the increase in the duration of laser irradiation. The estimation of the chlorophyll a concentration in the irradiated samples showed a considerable reduction varying between 9.8% and 57% in C. gracilis and 3% and 70.3% in S. costatum for 2 and 300 s of irradiations, respectively. The laser-survived cells grew as the non-irradiated (control) samples. C. gracilis frustules were broken by the laser whilst, the cell materials were drained out of the frustules in the case of S. costatum. The study therefore showed that the low power pulsed laser irradiations could cause significant damage on the two species of planktonic diatoms.
脉冲激光辐照对生物污损生物造成损伤的能力最近正在被研究。如果这项技术应用于诸如发电等行业，其中大量的水被用于冷却目的，那么除了目标生物之外的许多生物都会受到影响。在本研究中，我们研究了Nd:YAG激光（能量密度0.1J/cm(2)）的脉冲激光辐照在2、5、10、30、60和300秒等不同持续时间下对两种海洋硅藻物种，即中肋骨条藻和纤细角毛藻造成的损伤。在暴露于低功率激光辐照后，对于中肋骨条藻，在2秒和300秒辐照情况下，这些硅藻物种的死亡率分别在52.6±9.3%至97.7±3.1%之间；对于纤细角毛藻，在2秒和300秒辐照情况下，死亡率分别在57.8±2.5%至98.9±0.6%之间。死亡率随着激光辐照持续时间的增加而增加。对辐照样品中叶绿素a浓度的估计表明，在纤细角毛藻中，对于2秒和300秒的辐照，叶绿素a浓度分别有相当大的降低，在9.8%至57%之间；在中肋骨条藻中，叶绿素a浓度分别在3%至70.3%之间。激光照射后存活的细胞与未照射（对照）样品一样生长。纤细角毛藻的壳片被激光打破，而在中肋骨条藻的情况下，细胞物质从壳片中排出。因此，该研究表明低功率脉冲激光辐照会对这两种浮游硅藻造成显著损伤。
