توليد بيوسورفكتانت توسط باكتري Pseudomonas putida1694 در منابع مختلف كربن

Biosurfactant Production by Pseudomonas putida1694 in Various Carbon Sources

بيوسورفكتانت ها تركيبات فعال سطحي هستند كه توسط ميكروارگانيسم ها توليد ميشوند. در اين مطالعه توليد بيوسورفكتانت توسط باكتري‌ putida1694 Pseudomonasدر منابع مختلف كربن )نفت سفيد، گلوكز و ملاس نيشكر( تحت تأثير دماهاي 30 و 37 درجه سلسيوس و زمان گرماگذاري 48 و 168 ساعت مورد ارزيابي قرار گرفت. به­ منظور تشخيص توليد بيوسورفكتانت از روشهاي كمي و كيفي غربالگري مانند، آزمون هموليز، آزمون فروپاشي، پراكنش نفت، درصد امولسيون كنندگي ، كاهش كشش سطحي و آبگريزي سطح سلول استفاده شد. نتايج نشان داد P.putida1694 ﺗﻮاﻧﺎﯾﯽ رﺷﺪ در ﻫﺮ ﺳﻪ ﻣﻨﺒﻊ ﮐﺮﺑﻦ را دارد. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ ﻏﺮﺑﺎﻟﮕﺮي ﺗﻮﻟﯿﺪ ﺑﯿﻮﺳﻮرﻓﮑﺘﺎﻧﺖ، ﺳﻮﯾﻪ ﺑﻪﮐﺎر رﻓﺘﻪ در اﯾﻦ ﭘﮋوﻫﺶ داراي ﻫﻤﻮﻟﯿﺰ ﻣﺜﺒﺖ ﯾﺎ β در ﻣﺤﯿﻂ آﮔﺎر ﺧﻮندار ﺑﻮد. ﺗﺮﮐﯿﺒﺎت ﺗﻮﻟﯿﺪ ﺷﺪه ﺗﻮﺳﻂ ﺑﺎﮐﺘﺮي P.putida1694 در ﺗﻤﺎم ﻣﻨﺎﺑﻊ ﮐﺮﺑﻦ در زﻣﺎنﻫﺎ و دﻣﺎﻫﺎي اﻋﻤﺎل ﺷﺪه ﺑﻪ ﺗﻪ ﭼﺎﻫﮏ ﺳﻘﻮط ﮐﺮدﻧﺪ، ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد اﯾﻦ ﺑﺎﮐﺘﺮي ﺑﯿﺸﺘﺮﯾﻦ ﮐﺎﻫﺶ ﮐﺸﺶ ﺳﻄﺤﯽ را در ﻣﻨﺒﻊ ﮐﺮﺑﻦ ﻧﻔﺖ ﺳﻔﯿﺪ ﭘﺲ از 168 ﺳﺎﻋﺖ و در دﻣﺎي ﮔﺮﻣﺎﮔﺬاري 37 درﺟﻪ ﺳﻠﺴﯿﻮس داﺷﺖ و ﺗﻮاﻧﺴﺖ ﮐﺸﺶ ﺳﻄﺤﯽ آنرا ﺗﺎ 20/33 ﻣﯿﻠﯽﻧﯿﻮﺗﻮن ﺑﺮ ﻣﺘﺮ ﮐﺎﻫﺶ دﻫﺪ. ﺑﯿﺸﺘﺮﯾﻦ درﺻﺪ اﻣﻮﻟﺴﯿﻮنﮐﻨﻨﺪﮔﯽ در ﻣﻨﺒﻊ ﮐﺮﺑﻦ ﻣﻼس)28 درﺻﺪ( ﺑﻪدﺳﺖ آﻣﺪ. ﻫﻤﭽﻨﯿﻦ ﺑﯿﺸﯿﻨﻪ درﺻﺪ آﺑﮕﺮﯾﺰي ﺳﻄﺢ ﺳﻠﻮل ﺑﻪ ﻣﻨﺒﻊ ﮐﺮﺑﻦ ﻧﻔﺖ ﺳﻔﯿﺪ )70 درﺻﺪ( اﺧﺘﺼﺎص داﺷﺖ. ﻣﯿﺰان ﺑﯿﻮﺳﻮرﻓﮑﺘﺎﻧﺖ ﺗﻮﻟﯿﺪ ﺷﺪه در ﻣﻨﺎﺑﻊ ﮐﺮﺑﻦ ﻧﻔﺖ ﺳﻔﯿﺪ، ﮔﻠﻮﮐﺰ و ﻣﻼس ﺑﻪﺗﺮﺗﯿﺐ 10/2، 1/7 و 5/5 ﮔﺮم ﺑﺮ ﻟﯿﺘﺮ ﺑﻮد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺗﻮﻟﯿﺪ ﺑﯿﺸﺘﺮ ﺑﯿﻮﺳﻮرﻓﮑﺘﺎﻧﺖ در ﺣﻀﻮر ﻧﻔﺖ ﺳﻔﯿﺪ، ﺑﻪﻧﻈﺮ ﻣﯽرﺳﺪ از اﯾﻦ ﺑﺎﮐﺘﺮي ﺑﺮاي ﭘﺎﻻﯾﺶ ﺧﺎكﻫﺎي آﻟﻮده ﺑﻪ ﻧﻔﺖ ﻣﯽﺗﻮان اﺳﺘﻔﺎده ﻧﻤﻮد.

Bio-surfactants as surface active compounds are produced by microorganisms. In this study bio-surfactant production by Pseudomonas putida1694 were evaluated in different carbon sources (kerosene, sugar cane molasses and glucose) at 30 and 37 °C within the incubation periods of 48 and 168 hours. For screening bio-surfactant production, hemolysis, and oil collapse and emulsification index, surface tension reduction and cell surface hydrophobicity tests were done. Results showed that P. putida1694 was able to grow in all carbon sources. Based on bio-surfactant production, this strain had a positive or β hemolysison blood agar medium. The Compounds produced by this strain in each of carbon sources at both temperatures and incubation periods collapsed down. The maximum surface tension reduction was recorded in the samples containing kerosene as carbon source incubated at 37 ° C for 168 hours, in which bacterium reduced surface tension to 20.33 mNm-1. Themaximum emulsifying and cell hydrophobicitywere recorded in molasses (28%) and kerosene(70%) respectively. Bio-surfactant production amounts by P. putida1694 in kerosene, glucose and molasses as carbon sources were 10.2, 1.7 and 5.5 g L-1, respectively. Due to higher production of bio-surfactant in the presence of kerosene, it seems that the bacteria can be used for refining oil-contaminated soils.