بررسی ویژگی‌های پروبیوتیکی و ضدمیکروبی levilactobacillus brevis nkn55 جداسازی شده از ماست محلی

زﻣﯿﻨﻪ ﻣﻄﺎﻟﻌﺎﺗﯽ: در اﯾﻦ ﭘﮋوﻫﺶ آزﻣﺎﯾﺸﮕﺎﻫﯽ وﯾﮋﮔﯽﻫﺎی ﭘﺮوﺑﯿﻮﺗﯿﮑﯽ و ﺿﺪﻣﯿﮑﺮوﺑﯽ ﺳﻮﯾﻪlevilactobacillus brevis nkn55ﺟﺪاﺳﺎزی ﺷﺪه از ﻣﺎﺳﺖ ﻣﺤﻠﯽ ﺑﺮرﺳﯽ ﺷﺪ. ﻫﺪف: اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﭘﺘﺎﻧﺴﯿﻞ ﻋﻤﻠﮑﺮدی و ﻓﻌﺎﻟﯿﺖ ﺿﺪﻣﯿﮑﺮوﺑﯽ ﺳﻮﯾﻪ lev. brevis nkn55ﺟﺪاﺳﺎزی ﺷﺪه از ﻣﺎﺳﺖ ﻣﺤﻠﯽ اﻧﺠﺎم ﺷﺪ، ﺗﺎ در ﺻﻮرت دارا ﺑﻮدن وﯾﮋﮔﯽ ﻫﺎی ﻋﻤﻠﮑﺮدی و ﺿﺪﻣﯿﮑﺮوﺑﯽ ﻣﻄﻠﻮب،در ﺗﻮﻟﯿﺪ ﻣﺤﺼﻮﻻت ﻟﺒﻨﯽ ﺑﻪ ﻋﻨﻮان ﮐﺸﺖ ﻣﮑﻤﻞ و ﯾﺎ ﺑﻪ ﻋﻨﻮان ﻧﮕﻬﺪارﻧﺪه ﻃﺒﯿﻌﯽ ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار ﮔﯿﺮﻧﺪ روش ﮐﺎر: اﺑﺘﺪا ﺳﻮﯾﻪ، از ﻧﻈﺮ وﯾﮋﮔﯽﻫﺎی ﭘﺮوﺑﯿﻮﺗﯿﮑﯽ از ﻗﺒﯿﻞ ﻣﻘﺎوﻣﺖ ﺑﻪ اﺳﯿﺪ ) ph 2/5، 3/5و 4/5(، ﺧﺎﺻﯿﺖ ﻫﯿﺪروﻓﻮﺑﯿﺴﯿﺘﯽ، ﻣﻘﺎوت ﺑﻪ ﺻﻔﺮا ) 0/3، 0/5و0/7 ( و ﺟﺬب ﮐﻠﺴﺘﺮول ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺳﭙﺲ ﺗﻮﻟﯿﺪ آﻣﯿﻦ ﺑﯿﻮژﻧﯿﮏ، ﻋﺪم ﻓﻌﺎﻟﯿﺖ ﻫﻤﻮﻟﯿﺘﯿﮏ و dnaseﻧﯿﺰ ﺑﺮرﺳﯽ ﺷﺪ. ﻇﺮﻓﯿﺖ آﻧﺘﯽاﮐﺴﯿﺪاﻧﯽ ﺳﻮﯾﻪ ﺟﺪاﺳﺎزی ﺷﺪه )dpphو abts( ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ و وﯾﮋﮔﯽ ﺿﺪﻣﯿﮑﺮوﺑﯽ )روش دﯾﺴﮏ دﯾﻔﯿﻮژن آﮔﺎر و ﭼﺎﻫﮏ آﮔﺎر( ﺳﻮﯾﻪ، در ﻣﻘﺎﺑﻞ 6 ﺑﺎﮐﺘﺮی ﺑﯿﻤﺎریزای ﻏﺬازاد )klebsiella aerogenes ،staphylococcus aureus ،escherichia coli، salmonella typhimurium ،listeria monocytogenes و bacillus cereus( ﺑﺮرﺳﯽ ﺷﺪ. ﭘﺘﺎﺳﯿﻞ ﭼﺴﺒﻨﺪﮔﯽ ﺑﻪ ﺳﻠﻮل 2-caco، ﺿﺪﭼﺴﺒﻨﺪﮔﯽ، ﺗﺠﻤﯿﻊ ﺧﻮدﮐﺎر و اﻧﺒﺎﺷﺘﮕﯽ ﻧﯿﺰ ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ: ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﮐﺎﻫﺶ ﺗﻌﺪاد ﺳﻮﯾﻪ ﻣﺮﺑﻮط ﺑﻪ ﻣﺎﻧﺪﮔﺎری 3ﺳﺎﻋﺖ در phﺑﺮاﺑﺮ ﺑﺎ 2/5ﺑﻮد. ﺑﺎ ﮐﺎﻫﺶph از 4/5ﺑﻪ 2/5، ﮐﺎﻫﺶ ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ در ﺗﻌﺪاد ﺳﻠﻮل ﻫﺎی زﻧﺪه ﻣﺸﺎﻫﺪه ﺷﺪ و از 7/8ﺑﻪ log cfu/ml 6/90ﮐﺎﻫﺶ ﯾﺎﻓﺖ. lev. brevis nkn55در ﻏﻠﻈﺖ ﻫﺎی ﻣﺨﺘﻠﻒ ﻧﻤﮏ ﻫﺎی ﺻﻔﺮاوی ﻣﻘﺎوﻣﺖ ﺧﻮﺑﯽ از ﺧﻮد ﻧﺸﺎن داد. در اﯾﻦ ﭘﮋوﻫﺶ رﺷﺪ ﺳﻮﯾﻪ ﻣﻮرد ﺑﺮرﺳﯽ ﺑﺎ اﻓﺰاﯾﺶ درﺻﺪ ﻧﻤﮏ ﺻﻔﺮاوی، در 0/7% ﻣﺘﻮﻗﻒ ﺷﺪ. ﺧﺎﺻﯿﺖ ﻫﯿﺪروﻓﻮﺑﯽ، 58/40درﺻﺪ ﺑﻮد. ﺗﻮﻟﯿﺪ آﻣﯿﻦ ﺑﯿﻮژﻧﯿﮏ، dnase، و ﻓﻌﺎﻟﯿﺖ ﻫﻤﻮﻟﯿﺘﯿﮏ ﻣﻨﻔﯽ ﺑﻮد. ﻣﯿﺰان ﺟﺬب ﮐﻠﺴﺘﺮول 39/10، ﻣﯿﺰان ﻣﻬﺎر رادﯾﮑﺎل آزاد dpph وabts ﺑﻪ ﺗﺮﺗﯿﺐ 33/46 و 38/50درﺻﺪ، ﭘﺘﺎﻧﺴﻞ ﺗﺠﻤﯿﻊ ﺧﻮدﮐﺎر و اﻧﺒﺎﺷﺘﮕﯽ ﺑﻪ ﺗﺮﺗﯿﺐ 33/8و 21/45درﺻﺪ ﺑﻪ دﺳﺖ آﻣﺪ. ﭘﺘﺎﻧﺴﯿﻞ ﭼﺴﺒﻨﺪﮔﯽ ﺑﻪ ﺳﻠﻮل 2-caco، 10 /50و ﭘﺘﺎﻧﺴﯿﻞ ﺿﺪﭼﺴﺒﻨﺪﮔﯽ در ﺑﺮاﺑﺮ k. aerogenes در رﻗﺎﺑﺖ 38/90، در ﻣﻬﺎر 31/20و در ﺟﺎﺑﻪ ﺟﺎﯾﯽ 19/8درﺻﺪ ﺑﻪ دﺳﺖ آﻣﺪ ﻧﺘﯿﺠﻪ ﮔﯿﺮی: ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ ﺑﻪدﺳﺖ آﻣﺪه، ﺳﻮﯾﻪ دارای ﭘﺘﺎﻧﺴﯿﻞ ﭘﺮوﺑﯿﻮﺗﯿﮑﯽ و ﺿﺪﻣﯿﮑﺮوﺑﯽ ﻗﺎﺑﻞ ﻗﺒﻮﻟﯽ اﺳﺖ و ﻣﯽﺗﻮاﻧﺪ ﭘﺲ از ﭘﮋوﻫﺶﻫﺎی ﺑﯿﺸﺘﺮ ﺑﺮای ﻣﺼﺎرف اﻧﺴﺎﻧﯽ ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار ﮔﯿﺮد.

evaluation of probiotic and antimicrobial properties of levilactobacillus brevis nkn55 isolated from local yogurt

background: this laboratory study investigated the probiotic and antimicrobial properties of the levilactobacillus brevis nkn55 strain isolated from local yogurt. aims: the aim of this study was to evaluate the functional potential and antimicrobial activity of the lev. brevis nkn55 strain isolated from local yogurt. if the strain exhibits desirable functional and antimicrobial properties, it could be used as a supplementary culture or natural preservative in dairy products.methods: initially, the strain was assessed for probiotic characteristics such as acid resistance (at ph levels 2.5, 3.5, and 4.5), hydrophobicity, bile resistance (at concentrations of 0.3%, 0.5%, and 0.7%), and cholesterol absorption. the production of biogenic amines, hemolytic activity, and dnase activity were also examined. the antioxidant capacity of the isolated strain was determined using dpph and abts assays. the antimicrobial properties (disc diffusion agar and well diffusion agar methods) of the strain were tested against six foodborne pathogenic bacteria (escherichia coli, staphylococcus aureus, klebsiella aerogenes, listeria monocytogenes, salmonella typhimurium, and bacillus cereus). additionally, the potential for adhesion to caco-2 cells, anti-adhesion, auto-aggregation, and co-aggregation capabilities were evaluated. results: the highest reduction in the number of viable cells occurred after 3 hours at ph 2.5, with a reduction to 2.5. a significant decrease in viable cell count was observed when the ph was lowered from 4 to 2, decreasing from 7.8 to 6.90 log cfu/ml. the lev. brevis nkn55 strain demonstrated good resistance to different concentrations of bile salts, with growth ceasing at 0.7% bile salts. hydrophobicity was measured at 58.40%. the strain showed negative results for biogenic amine production, dnase activity, and hemolytic activity. cholesterol absorption was 39.10%, and the inhibition rates of dpph and abts free radicals were 33.46% and 38.5%, respectively. auto-aggregation and co-aggregation potentials were 33.8% and 21.45%, respectively. the adhesion potential to caco-2 cells was 10.50%, and the anti-adhesion potential against k. aerogenes was 38.90% in competition, 31.20% in exclusion, and 19.8% in displacement assays. conclusion: the results showed that the lev. brevis nkn55 strain possesses acceptable probiotic and antimicrobial potential and could be considered for human consumption after further research.