جداسازی اگزوپلی‌ساکاریدهای باسیلوس‌های خاک مناطق‌کویری و اثر آنها بر کیفیت ماست قالبی طی زمان نگهداری در سرما

ﯾﮑﯽ از ﻣﻬﻤﺘﺮﯾﻦ ﮐﺎرﺑﺮدﻫﺎی ﺑﯿﻮﺗﮑﻨﻮﻟﻮژی درﺻﻨﺎﯾﻊ ﻏﺬاﯾﯽ، ﺗﻮﻟﯿﺪ ﻣﻮاد اﻓﺰودﻧﯽ ﻣﺨﺘﻠﻒ ﻣﯽﺑﺎﺷﺪ. از ﺟﻤﻠﻪ ﻣﻮاد اﻓﺰودﻧﯽ ﺗﻮﻟﯿﺪی ﺑﻪ روش ﺑﯿﻮﺗﮑﻨﻮﻟﻮژی ﻣﯽ ﺗﻮان ﺑﻪ ﺗﻮﻟﯿﺪ اﮔﺰوﭘﻠﯽﺳﺎﮐﺎرﯾﺪﻫﺎی ﺗﻮﻟﯿﺪ ﺷﺪه ﺗﻮﺳﻂ ﺑﺎﮐﺘﺮیﻫﺎ در ﻣﺤﺼﻮﻻت ﻟﺒﻨﯽ اﺷﺎره ﻧﻤﻮد. ﺗﻨﻮع در ﺳﺎﺧﺘﺎر و ﺗﺮﮐﯿﺐ ﺷﯿﻤﯿﺎﯾﯽ اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪﻫﺎی ﻣﯿﮑﺮوﺑﯽ، ﺳﺒﺐ ﺑﺮﺗﺮی آن ﻫﺎ ﻧﺴﺒﺖ ﺑﻪ ﭘﻠﯿﻤﺮﻫﺎی ﺟﺎﻧﻮری و ﮔﯿﺎﻫﯽ ﺷﺪه اﺳﺖ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﯾﻦ ﻣﻮارد، ﻣﯽ ﺗﻮان از اﯾﻦ ﺗﺮﮐﯿﺒﺎت ﺑﻪ ﻋﻨﻮان اﻓﺰودﻧﯽ ﻣﻮاد ﻏﺬاﯾﯽ ﺑﺎ اﺛﺮات ﺳﻼﻣﺘﯽ ﺑﺨﺶ اﺳﺘﻔﺎده ﻧﻤﻮد. در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ، ﺑﺎﮐﺘﺮی ﻫﺎی ﺑﺎﺳﯿﻠﻮس ﺗﻮﻟﯿﺪﮐﻨﻨﺪه اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪﻫﺎ از ﺧﺎکﻫﺎی ﻣﻨﺎﻃﻖ ﮐﻮﯾﺮی ﺟﺪاﺳﺎزی و ﭘﺲ از آن،ﮔﺮوه ﻫﺎی ﺳﺎﺧﺘﺎری و عاملی اگزوپلی ساکاریدی با استفاده از روش ft-ir مشخص گردیدند. وجود پیک های در ناحیه فرکاسن 400-4000 (cm^-1) ﻧﺸﺎن دﻫﻨﺪه ﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪ ﺑﻮدن و ﺧﺎﻟﺺ ﺑﻮدن ﻣﺎده اﺳﺘﺨﺮاج ﺷﺪه اﺳﺖ. ﺳﭙﺲ، اﺛﺮات آنﻫﺎ ﺑﺮ ﮐﯿﻔﯿﺖ ﻣﺎﺳﺖ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ،ﮐﯿﻔﯿﺖ ﻧﻤﻮﻧﻪ ﻫﺎی ﻣﺎﺳﺖ ﺣﺎوی اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪ ﺑﺎﮐﺘﺮی ﻫﺎی k, c, b, a وe در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﮔﺮوه ﺷﺎﻫﺪ ﮐﻪ ﻓﺎﻗﺪ اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪ ﺑﻮد ﺑﻪﻃﻮر ﻣﻌﻨﯽداری اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻨﺪ. اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪ ﺣﺎﺻﻞ از ﺑﺎﮐﺘﺮی e ﻣﯿﺰان آب اﻧﺪازی را در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﺳﺎﯾﺮ ﻧﻤﻮﻧﻪ ﻫﺎ و ﻧﻤﻮﻧﻪ ﺷﺎﻫﺪ ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داری ﮐﺎﻫﺶ داد و ﻫﻤﭽﻨﯿﻦ وﯾﺴﮑﻮزﯾﺘﻪ و ﻇﺮﻓﯿﺖ ﻧﮕﻬﺪاری آب و ﻗﻮام ﻣﺎﺳﺖ را ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داری اﻓﺰاﯾﺶ داد. در ﻧﻬﺎﯾﺖ، ﺑﺮ اﺳﺎس ﺗﻮاﻟﯽ 16s rdna، ﺑﺎﮐﺘﺮی ﮐﻪ اﮔﺰوﭘﻠﯽ ﺳﺎﮐﺎرﯾﺪ آن ﺑﯿﺸﺘﺮﯾﻦ ﺗﺄﺛﯿﺮ در ﺑﻬﺒﻮد ﮐﯿﻔﯿﺖ ﻣﺎﺳﺖ داﺷﺖ، ﺑﺎﺳﯿﻠﻮس وﯾﺪﻣﺎﻧﯽﺳﻮﯾﻪ hbum207173 ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪ.

isolation of bacillus soil exopolysaccharides in desert areas and their effect on the quality of molded yogurt during cold storage

one of the most important applications of biotechnology in the food industry is theproduction of various additives. among the additives produced by biotechnology method isthe production of exopolysaccharides produced by bacteria in dairy products.diversity in thestructure and chemical composition of microbial exopolysaccharides has made them superiorto animal and plant polymers. due to these cases, these compounds can be used as foodadditives with health effects. in the present study, bacillus bacteria producingexopolysaccharides were isolated from the soils of desert areas and then, the structural andfunctional groups of exopolysaccharides were identified using ft-ir method. the presenceof peaks in the frequency range 400-4000 (cm-1)indicates the polysaccharide and purity of theextracted material. then, their effects on the quality of yogurt were investigated. based onthe results, the quality of yogurt samples containing exopolysaccharide of bacteria k, c, b, aand e significantly increased compared to the control group that did not containexopolysaccharide.exopolysaccharide from e bacterium significantly reduced hydrationcompared to other samples and control samples and also significantly increased the viscosityand water holding capacity and consistency of yogurt. finally, based on the 16s rdnasequence, the bacterium whose exopolysaccharide had the greatest effect on improving thequality of yogurt, bacillus wiedmannii strain hbum207173 was identified.