حذف آنتي بيوتيك نورفلوكساسين از محلول آلوده بوسيله ريزجلبك كلرلا

Removal of Norfloxacin Antibiotic from Contaminated Solution by Microalgae Chlorella sp

در اﯾﻦ ﭘﮋوﻫﺶ ﺗﻮاﻧﺎﯾﯽ ﺣﺬف آﻧﺘﯽﺑﯿﻮﺗﯿﮏ ﻧﻮرﻓﻠﻮﮐﺴﺎﺳﯿﻦ از ﻣﺤﻠﻮل آﺑﯽ ﺗﻮﺳﻂ رﯾﺰﺟﻠﺒﮏ ﮐﻠﺮﻻ ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺖ. ﻫﻤﭽﻨﯿﻦ ﭘﯿﺎﻣﺪﻫﺎي ﺳﻤﯽ اﯾﻦ آﻧﺘﯽﺑﯿﻮﺗﯿﮏ ﺑﺮ روي رﯾﺰﺟﻠﺒﮏ ﮐﻠﺮﻻ ﺑﺎ ﻣﻄﺎﻟﻌﻪ وﯾﮋﮔﯽﻫﺎي رﺷﺪي و ﺑﯿﻮﺷﯿﻤﯿﺎﯾﯽ آن ﺷﺎﻣﻞ وزن ﺧﺸﮏ ﺳﻠﻮل، ﮐﻠﺮوﻓﯿﻞ ﮐﻞ و ﻣﺤﺘﻮاي ﮐﺎرﺗﻨﻮﺋﯿﺪ ﺑﺮرﺳﯽ ﺷﺪ. آزﻣﺎﯾﺶ در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼً ﺗﺼﺎدﻓﯽ ﺑﺎ آراﯾﺶ ﻓﺎﮐﺘﻮرﯾﻞ و ﺑﺎ ﺳﻪ ﺗﮑﺮار اﻧﺠﺎم ﺷﺪ. ﻓﺎﮐﺘﻮرﻫﺎي آزﻣﺎﯾﺶ ﺷﺎﻣﻞ ﭘﻨﺞ ﺳﻄﺢ آﻧﺘﯽﺑﯿﻮﺗﯿﮏ )ﺻﻔﺮ، 20، 50، 80، 120 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( و ﺷﺶ زﻣﺎن ﻧﻤﻮﻧﻪﺑﺮداري )ﺻﻔﺮ، 1، 6 ،3، 9 و 14 روز( ﺑﻮد. وزن ﺧﺸﮏ ﺳﻠﻮﻟﯽ رﯾﺰﺟﻠﺒﮏ ﺑﺎ اﻓﺰاﯾﺶ ﻏﻠﻈﺖ ﻧﻮرﻓﻠﻮﮐﺴﺎﺳﯿﻦ ﺑﻪ ﻃﻮر ﻣﻌﻨﯽداري ﮐﺎﻫﺶ ﯾﺎﻓﺖ و در ﭘﺎﯾﺎن 14 روز اﻧﮑﻮﺑﺎﺳﯿﻮن در ﻏﻠﻈﺖﻫﺎي 50، 80 و 120ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ آﻧﺘﯽﺑﯿﻮﺗﯿﮏ در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﺷﺎﻫﺪ ﺑﻪ ﺗﺮﺗﯿﺐ 21/61، 42/41 و 55/23 درﺻﺪ ﮐﺎﻫﺶ ﻧﺸﺎن داد. ﻣﻘﺎدﯾﺮ ﮐﻠﺮوﻓﯿﻞ ﮐﻞ و ﮐﺎرﺗﻨﻮﺋﯿﺪ ﺑﺎ اﻓﺰاﯾﺶ زﻣﺎن اﻧﮑﻮﺑﺎﺳﯿﻮن ﺑﻪ ﻃﻮر ﻣﻌﻨﯽداري ﺑﻪ دﻟﯿﻞ ﺗﻨﺶ ﻧﺎﺷﯽ از ﻧﻮرﻓﻠﻮﮐﺴﺎﺳﯿﻦ اﻓﺰاﯾﺶ ﭘﯿﺪا ﮐﺮدﻧﺪ. ﻏﻠﻈﺖ ﻣﺆﺛﺮ )EC50( ﻧﻮرﻓﻠﻮﮐﺴﺎﺳﯿﻦ ﺑﺮاي رﯾﺰﺟﻠﺒﮏ ﮐﻠﺮﻻ 453/71 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ در ﭘﺎﯾﺎن 14 روز اﻧﮑﻮﺑﺎﺳﯿﻮن ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﮐﻠﺮﻻ ﺗﻮاﻧﺴﺖ ﭘﺲ از دو ﻫﻔﺘﻪ اﻧﮑﻮﺑﺎﺳﯿﻮن ﺑﻪ ﺗﺮﺗﯿﺐ 69/15، 51/78، 28/41 و 18/18 درﺻﺪ آﻧﺘﯽﺑﯿﻮﺗﯿﮏ ﻧﻮرﻓﻠﻮﮐﺴﺎﺳﯿﻦ را از ﻣﺤﻠﻮل آﺑﯽ داراي ﻏﻠﻈﺖﻫﺎي 80 ،50 ،20 و 120 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ ﺣﺬف ﮐﻨﺪ.

In this study, the removal potential of norfloxacin antibiotic from water was investigated using Chlorella sp. microalga. Also, the toxicological effects of norfloxacin on Chlorella sp. was examined by studying the growth and biochemical characteristics of the microalga including cell dry weight, total chlorophyll and carotenoid content. A multi-level factorial experiment with complete randomized design was performed with three replications. The experimental factors included 5 levels of antibiotic (0, 20, 50, 80 and 120 mg L-1) and 6 sampling times (0, 1, 3, 6, 9 and 14 day). The cell dry weight of Chlorella sp. was significantly reduced at increased concentrations of norfloxacin, showing 12.61, 42.41 and 55.23% reduction at 50, 80 and 120 mg L−1 norfloxacin, respectively, as compared to the control treatment after 14 days of incubation. The total chlorophyll and carotenoid contents were significantly increased by prolonging incubation time as a result of norfloxacine stress. The effective concentration (EC50) of norfloxacin was calculated to be 453.71 mg L−1 for Chlorella sp. at the end of day 14. Chlorella sp. was able to eliminate norfloxacine up to 69.15, 51.78, 28.41 and 18.18% from 20, 50, 80 and 120 mg L−1 water solutions, respectively, after 14 days of incubation.