{"title":"酸性化Pediococcus acilactii UL5连续游离和固定化细胞培养中Pediocin 5的产生和质粒稳定性","authors":"J Huang, C Lacroix, H Daba, R E Simard","doi":"10.1111/j.1365-2672.1996.tb03268.x","DOIUrl":null,"url":null,"abstract":"<p><p>Continuous production of pediocin 5 from Pediococcus acidilactici UL5 was investigated in MRS medium at different pH and dilution rates during continuous free cell (FC) and immobilized cell (IC) fermentations. Pediocin 5 activity from FC operated at a dilution rate of 0.31 h-1 largely increased from 128 to 2048 AU mL-1 as pH decreased from 7.0 to 5.0. Pediocin 5 activity in IC at a dilution rate of 0.93 h-1 was much less affected by pH, varying from 256 AU mL-1 at pH 7.0 to 512 AU mL-1 at pH 5.0. At the optimum pH 5.0, the dilution rate greatly influenced pediocin 5 activity both in FC and IC. Pediocin 5 production during continuous FC culture decreased with time for all dilution rates tested except 0.31 h-1 and average activity over 144 h cultures reached a maximal value of 4915 AU mL-1 at a dilution rate of 0.26 h-1. For IC, pediocin 5 production was stable with time and increased with the dilution rate from 256 to 1024 AU mL-1 in the range of 0.47-2.28 h-1. Three Listeria strains were tested for their ability to screen low bacteriocin-producing variants (Bac+v) of Bac+ cells in FC and IC cultures by using a modified deferred antagonism method. Ten to 28% of Bac+v cells appeared after 144 h of FC cultures at dilution rates in the range 0.09-0.42 h-1 and pH control set points of 5.0-7.0 while almost no Bac+v cell was detected during 192 h IC culture in the same pH range and for dilution rates varying from 0.47 to 2.28 h-1. The Bac+v cells isolated produced eight- to 64-fold less pediocin 5 than the Bac+ cells. Although electrophoresis analysis showed no apparent difference in the plasmid profiles of Bac+v and Bac+ cells, the Bac- mutant obtained by acriflavine treatment had lost the pMJ5 plasmid encoding for bacteriocin production. The decreased quantity of plasmid DNA in Bac+v cells suggests that the decreased pediocin 5 activity of Bac+v cells resulted from a decrease in plasmid copy number.</p>","PeriodicalId":22599,"journal":{"name":"The Journal of applied bacteriology","volume":"80 6","pages":"635-44"},"PeriodicalIF":0.0000,"publicationDate":"1996-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/j.1365-2672.1996.tb03268.x","citationCount":"43","resultStr":"{\"title\":\"Pediocin 5 production and plasmid stability during continuous free and immobilized cell cultures of Pediococcus acidilactici UL5.\",\"authors\":\"J Huang, C Lacroix, H Daba, R E Simard\",\"doi\":\"10.1111/j.1365-2672.1996.tb03268.x\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Continuous production of pediocin 5 from Pediococcus acidilactici UL5 was investigated in MRS medium at different pH and dilution rates during continuous free cell (FC) and immobilized cell (IC) fermentations. Pediocin 5 activity from FC operated at a dilution rate of 0.31 h-1 largely increased from 128 to 2048 AU mL-1 as pH decreased from 7.0 to 5.0. Pediocin 5 activity in IC at a dilution rate of 0.93 h-1 was much less affected by pH, varying from 256 AU mL-1 at pH 7.0 to 512 AU mL-1 at pH 5.0. At the optimum pH 5.0, the dilution rate greatly influenced pediocin 5 activity both in FC and IC. Pediocin 5 production during continuous FC culture decreased with time for all dilution rates tested except 0.31 h-1 and average activity over 144 h cultures reached a maximal value of 4915 AU mL-1 at a dilution rate of 0.26 h-1. For IC, pediocin 5 production was stable with time and increased with the dilution rate from 256 to 1024 AU mL-1 in the range of 0.47-2.28 h-1. Three Listeria strains were tested for their ability to screen low bacteriocin-producing variants (Bac+v) of Bac+ cells in FC and IC cultures by using a modified deferred antagonism method. Ten to 28% of Bac+v cells appeared after 144 h of FC cultures at dilution rates in the range 0.09-0.42 h-1 and pH control set points of 5.0-7.0 while almost no Bac+v cell was detected during 192 h IC culture in the same pH range and for dilution rates varying from 0.47 to 2.28 h-1. The Bac+v cells isolated produced eight- to 64-fold less pediocin 5 than the Bac+ cells. Although electrophoresis analysis showed no apparent difference in the plasmid profiles of Bac+v and Bac+ cells, the Bac- mutant obtained by acriflavine treatment had lost the pMJ5 plasmid encoding for bacteriocin production. The decreased quantity of plasmid DNA in Bac+v cells suggests that the decreased pediocin 5 activity of Bac+v cells resulted from a decrease in plasmid copy number.</p>\",\"PeriodicalId\":22599,\"journal\":{\"name\":\"The Journal of applied bacteriology\",\"volume\":\"80 6\",\"pages\":\"635-44\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1996-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1111/j.1365-2672.1996.tb03268.x\",\"citationCount\":\"43\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Journal of applied bacteriology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1111/j.1365-2672.1996.tb03268.x\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of applied bacteriology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1111/j.1365-2672.1996.tb03268.x","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 43
摘要
在不同pH和稀释率的MRS培养基中,研究了由嗜酸Pediococcus acidilactii UL5在连续游离细胞(FC)和固定化细胞(IC)发酵过程中连续生产pediocin 5的情况。在0.31 h-1稀释率下,当pH从7.0降低到5.0时,FC的Pediocin 5活性从128 AU mL-1增加到2048 AU mL-1。当稀释率为0.93 h-1时,IC中的Pediocin 5活性受pH的影响较小,从pH 7.0时的256 AU mL-1到pH 5.0时的512 AU mL-1。在最佳pH 5.0时,稀释率对FC和IC中pediocin 5的活性都有很大影响。除0.31 h-1外,FC连续培养过程中,所有稀释率的pediocin 5产量都随着时间的推移而下降,在0.26 h-1的稀释率下,培养144 h的平均活性达到最大值4915 AU mL-1。在0.47 ~ 2.28 h-1范围内,稀释率为256 ~ 1024 AU mL-1时,弓形虫素5的产量随时间稳定而增加。采用改进的递延拮抗方法,对三株李斯特菌菌株在FC和IC培养物中筛选Bac+细胞的低产菌素变体(Bac+v)的能力进行了测试。在0.09-0.42 h-1的稀释率和5.0-7.0的pH控制设定值范围内,FC培养144小时后出现10 - 28%的Bac+v细胞,而在相同的pH范围和0.47 - 2.28 h-1的稀释率范围内,IC培养192小时后几乎没有检测到Bac+v细胞。分离的Bac+v细胞产生的pediocin 5比Bac+细胞少8 - 64倍。虽然电泳分析显示Bac+v和Bac+细胞的质粒谱没有明显差异,但经吖啶黄碱处理获得的Bac-突变体失去了编码细菌素产生的pMJ5质粒。Bac+v细胞的质粒DNA数量减少,表明Bac+v细胞的pediocin 5活性降低是由于质粒拷贝数减少所致。
Pediocin 5 production and plasmid stability during continuous free and immobilized cell cultures of Pediococcus acidilactici UL5.
Continuous production of pediocin 5 from Pediococcus acidilactici UL5 was investigated in MRS medium at different pH and dilution rates during continuous free cell (FC) and immobilized cell (IC) fermentations. Pediocin 5 activity from FC operated at a dilution rate of 0.31 h-1 largely increased from 128 to 2048 AU mL-1 as pH decreased from 7.0 to 5.0. Pediocin 5 activity in IC at a dilution rate of 0.93 h-1 was much less affected by pH, varying from 256 AU mL-1 at pH 7.0 to 512 AU mL-1 at pH 5.0. At the optimum pH 5.0, the dilution rate greatly influenced pediocin 5 activity both in FC and IC. Pediocin 5 production during continuous FC culture decreased with time for all dilution rates tested except 0.31 h-1 and average activity over 144 h cultures reached a maximal value of 4915 AU mL-1 at a dilution rate of 0.26 h-1. For IC, pediocin 5 production was stable with time and increased with the dilution rate from 256 to 1024 AU mL-1 in the range of 0.47-2.28 h-1. Three Listeria strains were tested for their ability to screen low bacteriocin-producing variants (Bac+v) of Bac+ cells in FC and IC cultures by using a modified deferred antagonism method. Ten to 28% of Bac+v cells appeared after 144 h of FC cultures at dilution rates in the range 0.09-0.42 h-1 and pH control set points of 5.0-7.0 while almost no Bac+v cell was detected during 192 h IC culture in the same pH range and for dilution rates varying from 0.47 to 2.28 h-1. The Bac+v cells isolated produced eight- to 64-fold less pediocin 5 than the Bac+ cells. Although electrophoresis analysis showed no apparent difference in the plasmid profiles of Bac+v and Bac+ cells, the Bac- mutant obtained by acriflavine treatment had lost the pMJ5 plasmid encoding for bacteriocin production. The decreased quantity of plasmid DNA in Bac+v cells suggests that the decreased pediocin 5 activity of Bac+v cells resulted from a decrease in plasmid copy number.