engleski

Impact of environmental stress on marine diatoms: insight from AFM study

The impact of heavy metal cadmium and the impact of temperature on lightly silicified marine diatom Cylindrotheca closterium regarding growth dynamics and morphological characteristics were studied. C. closterium cultures were able to sustain positive growth in the tested range of 0–1000 microg Cd l-1 with the observed significant decrease of specific growth rate in the exponential growth phase in the highest tested Cd concentration. Temperature also affected the growth rate with the highest growth rate at the highest tested temperature. In order to gain more insight into the effects on diatoms morphological features, the cell surface of C. closterium was characterized at the nanoscale on a single cell level using atomic force microscopy (AFM). Changes induced by Cd were observed as irregular patterns of silica spheres on more silicified parts of the cell, girdle band and around the raphe. The temperature did not induce any nanomorphological changes in frustule, however, enhanced organic matter production at lower temperatures was observed. This study contributes to better understanding the effects of different environmental stressors on diatoms morphological characteristics on a single cell level.

heavy metal stress ; temperature stress ; atomic force microscopy (AFM)

nije evidentirano