Atrazine-induced chlorosis in Synechococcus elongatus cells.
نویسندگان
چکیده
The effects of a widely used herbicide, atrazine, on the freshwater cyanobacterium Synechococcus elongatus were studied. The cyanobacteria were exposed to varying concentrations of atrazine (0.025, 0.05, 0.1, 0.25, and 0.75 microM) for 96 h. Different parameters such as growth, autofluorescence of chlorophyll a, pigment content, volume, and internal granularity of the cells were determined daily. Differences were detected between cultures with and cultures without atrazine for the parameters analyzed. Atrazine exposure induced the process of chlorosis in cyanobacterial cells, given that this herbicide has an effect on photosynthesis, chlorotic subpopulations having low values of chlorophyll a autofluorescence. More unpigmented subpopulations (chlorotic) appeared as the atrazine concentration increased and better growth rates resulted. Atrazine also induced changes in cell volume and internal granularity, these being most apparent after 48 h of exposure and in cultures with higher atrazine concentrations (0.25 and 0.75 microM).
منابع مشابه
Effect of salinity on some physiological and biochemical responses in the cyanobacterium Synechococcus elongatus
In this study, some physiological and biochemical responses of Synechococcus elongatus to salt stress were investigated. The cyanobactrium was grown in BG-11 medium under different concentrations of NaCl (0, 0.5, 1 M). The results indicated that the growth of S. elongatus was significantly inhibited under salt stress on days 5, 9 and 12. Protein content increased in S. elongatus on day 12 in pr...
متن کاملRemoval of triazine herbicides from freshwater systems using photosynthetic microorganisms.
The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioco...
متن کاملNitrogen Starvation Acclimation in Synechococcus elongatus: Redox-Control and the Role of Nitrate Reduction as an Electron Sink
Nitrogen starvation acclimation in non-diazotrophic cyanobacteria is characterized by a process termed chlorosis, where the light harvesting pigments are degraded and the cells gradually tune down photosynthetic and metabolic activities. The chlorosis response is governed by a complex and poorly understood regulatory network, which converges at the expression of the nblA gene, the triggering fa...
متن کاملمطالعه خواص ضدباکتریایی عصاره های متانولی، اتری و آبی برخی از گونه های سیانوباکتری ها در شرایط آزمایشگاهی
Background and purpose: Cyanobacteria are rich sources of secondary metabolites. Antibiotic resistant pathogens are rising and people are more interested in using natural products these days. Hence, identifying competent cyanobacteria for the extraction of antimicrobial compounds is of great benefit. The main objective of this study was to investigate the in vitro antibacterial activity of ...
متن کاملبررسی اثر دماهای مختلف بر خصوصیات فیزیولوژیکی سیانوباکتری Synechococcus elongatus بهعنوان کاندید تولید بیودیزل
یکی از منابع بیولوژیک برای تولید بیودیزل سیانوباکتریها میباشند. هدف از این تحقیق مطالعه اثر دما در میزان بقاء، رنگیزههای فتوسنتزی، محتوای و کیفیت چربی Synechococcus elongatusبهعنوان مواد خام برای تولید بیودیزل بود. در این تحقیق نمونهبرداری از جزیره خارک انجام شد. بعد از خالص سازی، نمونه درمحیط کشت BG11 در دمای 25 درجه سانتیگراد تحت نور دائمی و 7 pH نگهداری شدند. شناسایی نمونه با...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Archives of environmental contamination and toxicology
دوره 46 3 شماره
صفحات -
تاریخ انتشار 2004