文章基本信息

标题：Copper-Induced Morphological, Physiological and Biochemical Responses in the Cyanobacterium Nostoc muscorum Meg 1
本地全文：下载
作者：Rabbul Ibne A. Ahad ; Mayashree B. Syiem
期刊名称：Nature, Environment and Pollution Technology
印刷版ISSN：0972-6268
出版年度：2018
卷号：17
期号：4
页码：1077-1086
语种：English
出版社：Technoscience Publications
摘要：The cyanobacterium Nostoc muscorum Meg 1 was exposed to Cu2+ for seven days to assess its Cu2+ removal potential and the changes brought about in its morphology, physiology and biochemistry on Cu2+ exposure. Cu2+ binding was established by the EDX study. Identification of various functional groups on the cell surface involved in Cu2+ binding was done by FTIR analysis. AAS study showed that the organism was able to remove 96.3% Cu2+ from the medium supplemented with 3 ppm Cu2+. Cellular distribution analysis indicated internalization of 6.1% Cu2+. Another study showed that the maximum Cu2+ removal was a surface phenomenon that did not require energy. The IC50 value for Cu2+ was determined to be 9 ppm as growth was compromised by 50.5%. We used a sub-lethal dose of 3 ppm for all the experiments which are 3-fold higher than the WHO recommended value for Cu2+ (1 ppm) in drinking water. At this concentration, various photosynthetic pigments were reduced by 35.3% (chlorophyll a), 31.3% (phycocyanin), 17% (allophycocyanin), 21.3% (phycoerythrin) and 16% (carotenoids). Photosynthetic PSII activity and respiration rate were also compromised by 45% and 46.2%. Heterocyst frequency, nitrogenase and glutamine synthetase activities were declined by 18.5%, 14.8% and 16.2%. Bright field and SEM images showed distinct morphological changes, where there was filament breakage, disintegration and degradation of individual cells as well as cell elongation, distortion and shriveling. The cyanobacterium generated 436.4% more ROS compared to the control cells.
关键词：Nostoc muscorum Meg 1;Cu2+removal;Bright field microscopy;Biochemical characteristics;EDX-SEM;FTIR