توليد بيوسورفاكتانت با استفاده از ملاس توسط يك باكتري بومي و شناسايي نسبي بيوسورفاكتانت توليد شده

Biosurfactant Production Using Molasses by a Local Bacterium and Partial Characterization of Biosurfactants

ﻋﻠﯽرﻏﻢ ﻣﺰﯾﺖﻫﺎي ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖﻫﺎ در ﻣﻘﺎﺑﻞ ﺳﻮرﻓﺎﮐﺘﺎﻧﺖﻫﺎي ﺷﯿﻤﯿﺎﯾﯽ، ﺑﻪدﻟﯿﻞ ﻫﺰﯾﻨﻪﻫﺎي ﺑﺎﻻي ﺗﻮﻟﯿﺪ اﺳﺘﻔﺎده ﮔﺴﺘﺮده از آﻧﻬﺎ ﻣﺤﺪود ﺷﺪه اﺳﺖ. اﺳﺘﻔﺎده ﻣﻮاد اوﻟﯿﻪ ﺗﺠﺪﯾﺪﭘﺬﯾﺮ، ﭘﺎﯾﺪار و ارزانﻗﯿﻤﺖ ﻣﺎﻧﻨﺪ ﻣﺤﺼﻮﻻت ﺟﺎﻧﺒﯽ و ﺿﺎﯾﻌﺎت ﮐﺎرﺧﺎﻧﺠﺎت و ﺻﻨﺎﯾﻊ ﻣﺨﺘﻠﻒ ﻣﻤﮑﻦ اﺳﺖ ﺗﺎ ﺣﺪ زﯾﺎدي ﺑﺎﻋﺚ ﮐﺎﻫﺶ ﻫﺰﯾﻨﻪﻫﺎي ﺗﻮﻟﯿﺪ ﺷﻮد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺗﻨﻮع و ﻓﺮاواﻧﯽ ﻣﺨﺘﻠﻒ ﻣﺤﺼﻮﻻت ﺟﺎﻧﺒﯽ و ﺿﺎﯾﻌﺎت در ﮐﺸﻮرﻫﺎي ﻣﺘﻔﺎوت ﻣﻮاد اوﻟﯿﻪ اﺳﺘﻔﺎدهﺷﺪه ﻣﺘﻨﻮع ﻫﺴﺘﻨﺪ. در اﯾﺮان ﻋﻼوه ﺑﺮ ﺗﺮﮐﯿﺒﺎت ﻫﯿﺪروﮐﺮﺑﻨﯽ، ﻣﻼس ﻧﯿﺰ از ﻋﻤﺪهﺗﺮﯾﻦ ﻣﺤﺼﻮﻻت ﺟﺎﻧﺒﯽ ﺑﻪ ﺷﻤﺎر ﻣﯽرود. در ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ، از ﻣﯿﺎن 16 ﺑﺎﮐﺘﺮي ﺗﺠﺰﯾﻪﮐﻨﻨﺪه ﻧﻔﺖ ﺑﺎ ﺗﮑﻨﯿﮏﻫﺎي ﻣﻘﺪﻣﺎﺗﯽ ﺗﺸﺨﯿﺺ ﺗﻮﻟﯿﺪﮐﻨﻨﺪهﻫﺎي ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ، ﺳﻮﯾﻪ Pseudomonas aeruginosa sp. ZN ﺑﻪﻋﻨﻮان ﮐﺎراﺗﺮﯾﻦ ﺳﻮﯾﻪ ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪ. ﺑﺮاي ﺗﻌﯿﯿﻦ ﺑﻬﺘﺮﯾﻦ ﻏﻠﻈﺖ ﻣﻼس ﺑﺮاي رﺷﺪ ﺑﺎﮐﺘﺮي و ﺗﻮﻟﯿﺪ ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ ﻏﻠﻈﺖﻫﺎي 2-12% ﺣﺠﻤﯽ/ﺣﺠﻤﯽ ﺑﻪ ﮐﺎر ﮔﺮﻓﺘﻪ ﺷﺪ. ﺑﺎﮐﺘﺮي ﻗﺎدر ﺑﻪ رﺷﺪ و ﺗﻮﻟﯿﺪ ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ در ﺗﻤﺎم ﻏﻠﻈﺖﻫﺎي ﺗﺴﺖﺷﺪه ﺑﻮد، اﻣﺎ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان رﺷﺪ و ﺗﻮﻟﯿﺪ در ﻏﻠﻈﺖﻫﺎي 4-6% ﺣﺠﻤﯽ/ﺣﺠﻤﯽ اﺗﻔﺎق اﻓﺘﺎد. ﻏﻠﻈﺖﻫﺎي ﺑﺎﻻﺗﺮ از 6% اﺛﺮ ﻣﻬﺎري روي رﺷﺪ ﺑﺎﮐﺘﺮي و ﺗﻮﻟﯿﺪ ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ دارﻧﺪ. ﺑﺮاي ﺷﻨﺎﺳﺎﯾﯽ ﻧﺴﺒﯽ ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ ﺗﻮﻟﯿﺪﺷﺪه ﻋﻤﻠﯿﺎت ﺑﺎزﯾﺎﺑﯽ ﺑﺎ روشﻫﺎي رﺳﻮبدﻫﯽ ﺑﺎ اﺳﯿﺪ و اﺳﺘﺨﺮاج ﺑﺎ ﺣﻼل )اﺗﯿﻞاﺳﺘﺎت: ﻫﮕﺰان( اﻧﺠﺎم ﮔﺮﻓﺖ و روشﻫﺎي ﻣﺨﺘﻠﻒ رﻧﮓآﻣﯿﺰي ﮐﺎﻏﺬﻫﺎي TLC و ﻣﺎﯾﻊﻫﺎي روﯾﯽ ﻣﺤﯿﻂ ﮐﺸﺖ ﻓﺎﻗﺪ ﺑﺎﮐﺘﺮي ﻧﺸﺎن داد ﮐﻪ دو ﺑﯿﻮﺳﻮرﻓﺎﮐﺘﺎﻧﺖ ﺗﻮﻟﯿﺪﺷﺪه از ﺟﻨﺲ ﮔﻠﯿﮑﻮﻟﯿﭙﯿﺪ ﻫﺴﺘﻨﺪ.

Although biosurfactants have great advantages over chemical surfactants, their wider industrial applications have been constrained by their relatively high production cost. Using renewable, sustainable, and cheap substrates such as different industrial by-products and wastes maybe decrease biosurfactant production costs. Since in different countries, there are a variety of by-products and wastes so variable substrates are used in different countries. In addition, to hydrocarbon compounds, molasses has been considered as a dominant by-product in Iran. In the current study, among 16 crude oil-degrading isolates, Pseudomonas aeruginosa sp. ZN was selected as the most efficient biosurfactant producer by preliminary methods for detection of biosurfactant producing bacteria. For investigation of the best concentrations of molasses for bacterial growth and biosurfactant production, a wide range of molasses concentrations from 2-12% (v/v) were used. This strain was able to grow and produce biosurfactant in all range of molasses concentrations while the best concentrations were 4-6% (v/v). The concentrations more than 6% decreased the growth and production process. Acid precipitation and solvent extract (ethyl acetate: hexane) methods were carried out for recovery of biosurfactant from the culture broth, then results of spraying on developed TLC and staining fermentation broth without bacterial cells showed the two produced biosurfactants were glycolipid.