發(fā)布時(shí)間：2018-11-26 17:35

【摘要】：本研究選取誘導(dǎo)型重組菌E.coli DPD2794、E.coli TV1061及組成型重組菌E.coliTop10-P.luxCDABE、E.coli DH5α-P.luxCDABE為作用菌株,通過(guò)山梨酸納米微粒對(duì)重組發(fā)光菌生長(zhǎng)、發(fā)光情況影響,及場(chǎng)發(fā)射掃描電鏡(SEM)成像結(jié)果,對(duì)山梨酸納米微粒的抑菌活性進(jìn)行評(píng)價(jià),對(duì)其作用機(jī)理進(jìn)行了初步探究。試驗(yàn)得到以下結(jié)論:1.誘導(dǎo)型重組菌E.coli DPD2794、E.coli TV1061最適發(fā)光溫度分別為27℃、28℃,對(duì)數(shù)中后期達(dá)到最大發(fā)光強(qiáng)度255、422,最大耐受發(fā)光的溫度為33℃、32℃。E.coli DPD2794在pH 6時(shí)菌體生長(zhǎng)良好、發(fā)光強(qiáng)度最大。山梨酸納米微粒對(duì)誘導(dǎo)型重組菌E.coli DPD2794、E.coli TV1061的最小抑菌濃度(MIC)分別為60μg/mL和64μg/mL,對(duì)組成型重組菌E.coli Top10-P.luxCDABE和E.coli DH5α-P.luxCDABE的MIC分別為52μg/mL和40μg/mL。2.加入的山梨酸納米微粒,對(duì)兩株組成型重組菌,隨著濃度增加,最大發(fā)光強(qiáng)度顯著降低(P0.05);加入各菌株MIC濃度的山梨酸納米微粒,菌體生長(zhǎng)被完全抑制,不產(chǎn)生發(fā)光。對(duì)于誘導(dǎo)型重組發(fā)光菌,E.coli DPD2794僅對(duì)有毒化合物的基因毒性產(chǎn)生響應(yīng),高濃度山梨酸納米微粒抑制菌體發(fā)光;當(dāng)濃度≤3.75μg/mL(即1/16 MIC)對(duì)菌體發(fā)光有促進(jìn)作用。E.coli TV1061能夠?qū)Χ喾N引起代謝變化的有毒化合物產(chǎn)生響應(yīng)。高濃度(≥1/4 MIC)處理菌體不發(fā)光,低濃度抑制菌體發(fā)光,山梨酸納米微粒對(duì)E.coli TV1061的發(fā)光無(wú)促進(jìn)作用。根據(jù)兩株誘導(dǎo)型重組發(fā)光菌的發(fā)光機(jī)制,推測(cè)山梨酸納米微粒是通過(guò)對(duì)菌體細(xì)胞造成DNA損傷進(jìn)行抑菌作用。誘導(dǎo)型重組菌和組成型重組菌經(jīng)山梨酸納米微粒處理后的場(chǎng)發(fā)射掃描電鏡(SEM)成像顯示,細(xì)胞膜被破壞,菌體破裂,胞內(nèi)物質(zhì)溶出,部分破損菌體有山梨酸納米微粒附著。根據(jù)SEM成像結(jié)果及殼聚糖納米微粒、山梨酸的抑菌作用機(jī)理,推斷山梨酸納米微粒的作用機(jī)制為利用殼聚糖納米微粒的粘膜粘附性,使山梨酸納米微粒與膜蛋白結(jié)合,改變膜蛋白的結(jié)構(gòu)進(jìn)而影響菌體生理結(jié)構(gòu);山梨酸納米微粒釋放的部分山梨酸分子進(jìn)入菌體內(nèi)部,與微生物中酶的巰基結(jié)合,破壞菌體酶系結(jié)構(gòu),從而抑制微生物生長(zhǎng)繁殖。
[Abstract]:In this study, the recombinant bacteria E.coli DPD2794,E.coli TV1061 and E. coli DH5 偽-P.luxCDABE, E. coli, E. coli and E. coli, respectively, were selected as the acting strains. The growth and luminescence of the recombinant luminescent bacteria were influenced by sorbic acid nanoparticles. The bacteriostatic activity of sorbic acid nanoparticles was evaluated by field emission scanning electron microscopy (SEM) imaging and the mechanism of its action was preliminarily explored. The results are as follows: 1. The optimum luminescence temperature of inducible recombinant strain E.coli DPD2794,E.coli TV1061 was 27 鈩，

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