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Lalata ƙananan ƙwayoyin cuta (MIC) babbar matsala ce a masana'antu da yawa saboda yana iya haifar da asarar tattalin arziki mai yawa.Super duplex bakin karfe 2707 (2707 HDSS) ana amfani dashi a cikin mahalli na ruwa saboda kyakkyawan juriyar sinadarai.Koyaya, juriyarta ga MIC ba a gwada gwaji ba.Wannan binciken yayi nazarin halin MIC 2707 HDSS wanda kwayar cutar aerobic ta teku ta haifar da Pseudomonas aeruginosa.Binciken Electrochemical ya nuna cewa a gaban Pseudomonas aeruginosa biofilm a cikin 2216E matsakaici, yuwuwar lalata ta canza daidai, kuma ƙarancin lalacewa na yanzu ya karu.Sakamakon binciken X-ray photoelectron spectroscopy (XPS) ya nuna raguwa a cikin abun ciki na Cr a saman samfurin a ƙarƙashin biofilm.Binciken hotunan ramin ya nuna cewa Pseudomonas aeruginosa biofilms sun samar da matsakaicin zurfin rami na 0.69 µm bayan kwanaki 14 na al'ada.Kodayake wannan ƙarami ne, yana nuna cewa 2707 HDSS ba su da cikakkiyar kariya ga tasirin P. aeruginosa biofilms akan MIC.
Duplex bakin karfe (DSS) ne yadu amfani a daban-daban masana'antu saboda da cikakken hade da kyau kwarai inji Properties da lalata juriya1,2.Koyaya, rami na gida na iya faruwa har yanzu, wanda zai iya shafar amincin wannan ƙarfe 3, 4.Ba a kiyaye DSS daga lalatawar ƙananan ƙwayoyin cuta (MIC) 5,6.Kodayake kewayon aikace-aikacen DSS yana da faɗi sosai, har yanzu akwai wuraren da juriya na lalata DSS bai isa ba don amfani na dogon lokaci.Wannan yana nufin cewa ana buƙatar kayan da suka fi tsada tare da juriya mafi girma.Jeon et al.7 ya gano cewa ko da super duplex bakin karfe (SDSS) yana da wasu iyakoki dangane da juriya na lalata.Don haka, akwai buƙatar super duplex bakin karfe (HDSS) tare da juriya mai girma a wasu aikace-aikace.Wannan ya haifar da haɓaka HDSS mai ƙarfi sosai.
Juriya na lalata DSS an ƙaddara ta hanyar rabon α-phase zuwa γ-phase da yankunan da aka ƙare a cikin Cr, Mo da W kusa da matakan sakandare8,9,10.HDSS ya ƙunshi babban abun ciki na Cr, Mo da N11, wanda ke ba shi kyakkyawan juriya na lalata da ƙima mai girma (45-50) daidai da ƙimar juriya na pitting (PREN), wanda aka ayyana ta wt.% Cr + 3.3 (wt.% Mo). + 0, 5 wt % W) + 16 wt %.N12.Kyakkyawan juriya na lalata ya dogara da daidaitaccen abun da ke ƙunshe da kusan 50% ferritic (α) da 50% austenitic (γ).HDSS ya inganta ingantattun kaddarorin inji da mafi girman juriya na chlorine idan aka kwatanta da DSS13 na al'ada.Halayen lalata sinadarai.Ingantattun juriya na lalata yana ƙara amfani da HDSS a cikin ƙarin mahalli na chloride mai ƙarfi kamar yanayin ruwa.
MIC babbar matsala ce a masana'antu da yawa, gami da mai da iskar gas da samar da ruwa14.MIC yana da kashi 20% na duk lalacewar lalacewa15.MIC lalata ce ta bioelectrochemical wacce za'a iya lura da ita a yawancin mahalli16.Samuwar biofilms akan saman karfe yana canza yanayin electrochemical kuma don haka yana tasiri tsarin lalata.An yarda gabaɗaya cewa lalatawar MIC ta haifar da biofilms14.Electrogenic microorganisms suna cinye karafa don samun kuzari don rayuwa17.Nazarin MIC na baya-bayan nan sun nuna cewa EET (canja wuri na lantarki na waje) shine ƙayyadaddun abu don MIC da ƙwayoyin cuta na lantarki suka haifar.Zhang et al.18 ya nuna cewa masu shiga tsakani na lantarki suna hanzarta canja wurin lantarki tsakanin Desulfovibrio vulgaris sessile sel da 304 bakin karfe, wanda ya haifar da mummunan harin MIC.Anning et al.19 da Wenzlaff et al.20 sun nuna cewa biofilms na ƙwayoyin cuta masu rage sulfate (SRBs) na iya ɗaukar electrons kai tsaye daga abubuwan ƙarfe na ƙarfe, yana haifar da rami mai tsanani.
DSS an san yana da saukin kamuwa da MIC a cikin kafofin watsa labarai da ke dauke da SRBs, ƙwayoyin cuta masu rage baƙin ƙarfe (IRBs), da sauransu 21.Waɗannan ƙwayoyin cuta suna haifar da ramukan gida a saman DSS a ƙarƙashin biofilm22,23.Ba kamar DSS ba, an san kadan game da MIC HDSS24.
Pseudomonas aeruginosa wata kwayar cuta ce ta Gram-korau, mai motsi, kwaya mai siffa ta sanda wacce ta yadu a cikin yanayi25.Pseudomonas aeruginosa kuma shine babban microbiota da ke da alhakin MIC na karfe a cikin yanayin marine26.nau'in Pseudomonas suna da hannu kai tsaye a cikin hanyoyin lalata kuma an gane su azaman masu mulkin mallaka na farko yayin ƙirƙirar biofilm27.Mahat et al.28 da Yuan et al.29 ya nuna cewa Pseudomonas aeruginosa yana kula da haɓaka ƙimar ƙarancin ƙarfe da gami a cikin yanayin ruwa.
Babban makasudin wannan aikin shine yin nazarin abubuwan MIC na 2707 HDSS da ke haifar da kwayar cutar aerobic na ruwa Pseudomonas aeruginosa ta amfani da hanyoyin electrochemical, hanyoyin bincike na sama da kuma nazarin samfuran lalata.Nazarin lantarki da suka haɗa da yuwuwar kewayawa (OCP), juriya na polarization na layi (LPR), ƙirar ƙirar ƙirar lantarki (EIS) da yuwuwar polarization an yi don nazarin halayen MIC 2707 HDSS.Ana gudanar da bincike na tarwatsawar makamashi (EDS) don gano abubuwan sinadarai a saman da suka lalace.Bugu da ƙari, kwanciyar hankali na wucewar fim ɗin oxide a ƙarƙashin rinjayar yanayin ruwa mai dauke da Pseudomonas aeruginosa an ƙaddara ta X-ray photoelectron spectroscopy (XPS).An auna zurfin ramukan a ƙarƙashin na'urar sikelin Laser mai ɗaukar hoto (CLSM).
Shafin 1 yana nuna nau'in sinadarai na 2707 HDSS.Tebur na 2 ya nuna cewa 2707 HDSS yana da kyawawan kaddarorin inji tare da ƙarfin yawan amfanin ƙasa na 650 MPa.A kan fig.1 yana nuna microstructure na gani na maganin zafi da aka bi da 2707 HDSS.Za'a iya ganin tsattsauran ra'ayi na matakan austenitic da ferritic ba tare da matakai na biyu ba a cikin ƙaramin tsarin da ke ɗauke da kusan kashi 50% austenitic da 50% na ferritic.
A kan fig.2a yana nuna yuwuwar buɗewar kewayawa (Eocp) tare da lokacin bayyanarwa don 2707 HDSS a cikin 2216E abiotic matsakaici da Pseudomonas aeruginosa broth na kwanaki 14 a 37°C.An gano cewa sauye-sauyen da aka fi bayyana a Eocp sun faru a cikin sa'o'i 24 na farko.Ƙimar Eocp a cikin waɗannan lokuta biyu sun haura kusan -145 mV (a kan SCE) a cikin kimanin sa'o'i 16 sannan kuma ya ragu sosai zuwa -477 mV (a kan SCE) da -236 mV (a kan SCE) don samfurori marasa halitta da P don dangi. SCE) patina ya fita, bi da bi.Bayan sa'o'i 24, ƙimar Eocp na Pseudomonas aeruginosa 2707 HDSS ya kasance mai inganci a -228 mV (idan aka kwatanta da SCE), yayin da madaidaicin ƙimar samfurin da ba na halitta ya kasance kusan -442 mV (idan aka kwatanta da SCE).Eocp a gaban Pseudomonas aeruginosa ya yi ƙasa sosai.
Gwajin Electrochemical na samfuran 2707 HDSS a cikin kafofin watsa labarai na abiotic da Pseudomonas aeruginosa broth a 37°C:
(a) Canji a cikin Eocp tare da lokacin fallasa, (b) lanƙwan polarization a rana ta 14, (c) canji a cikin Rp tare da lokacin fallasa, (d) canjin corr tare da lokacin fallasa.
Shafin 3 yana nuna ma'auni na lalata electrochemical na samfurori na 2707 HDSS da aka fallasa su zuwa magungunan abiotic da P. aeruginosa inoculated media a cikin tsawon kwanaki 14.Tangential extrapolation na anodic da cathodic masu lankwasa zuwa tsaka-tsakin tsaka-tsakin sun ba da izinin ƙayyade ƙarancin lalacewa na yanzu (icorr), yuwuwar lalata (Ecorr) da gangaren Tafel (β da βc) bisa ga daidaitattun hanyoyin30,31.
Kamar yadda aka nuna a cikin Hoto 2b, hawan hawan P. aeruginosa na sama ya haifar da karuwa a cikin Ecorr idan aka kwatanta da ma'auni na abiotic.Ƙimar icorr na samfurin da ke ɗauke da Pseudomonas aeruginosa, daidai da ƙimar lalata, ya karu zuwa 0.328 µA cm-2, wanda ya ninka sau hudu fiye da na samfurin da ba na halitta ba (0.087 µA cm-2).
LPR hanya ce ta al'ada ta electrochemical don ƙididdigar ƙididdiga mara lahani na lalata.An kuma yi amfani da shi don nazarin MIC32.A kan fig.2c yana nuna canji a cikin juriya na polarization (Rp) dangane da lokacin bayyanarwa.Ƙimar Rp mafi girma yana nufin ƙarancin lalata.A cikin sa'o'i 24 na farko, Rp 2707 HDSS ya kai kololuwa a 1955 kΩ cm2 don samfurori marasa ilimin halitta da 1429 kΩ cm2 don samfuran Pseudomonas aeruginosa.Hoto na 2c kuma ya nuna cewa ƙimar Rp ta ragu da sauri bayan kwana ɗaya sannan ta kasance ba ta canzawa cikin kwanaki 13 masu zuwa.Ƙimar Rp don samfurin gwajin Pseudomonas aeruginosa yana kusan 40 kΩ cm2, wanda ya yi ƙasa da ƙimar 450 kΩ cm2 don samfurin gwajin da ba na halitta ba.
Darajar icorr yayi daidai da daidaitaccen adadin lalata.Ana iya ƙididdige ƙimarta daga ma'aunin Stern-Giri mai zuwa:
A cewar Zoe et al.33 An ɗauki gangaren Tafel B a matsayin ƙimar ƙimar 26 mV/dec a cikin wannan aikin.A kan fig.2d ya nuna cewa icorr na nau'in abiotic 2707 ya kasance da kwanciyar hankali, yayin da icorr na ƙungiyar Pseudomonas aeruginosa ya canza da ƙarfi tare da babban tsalle bayan sa'o'i 24 na farko.Ƙimar icorr na samfurin gwaji na Pseudomonas aeruginosa wani tsari ne mai girma fiye da wanda ba na ilimin halitta ba.Wannan yanayin ya yi daidai da sakamakon juriya na polarization.
EIS wata hanya ce wacce ba ta lalacewa da ake amfani da ita don siffanta halayen halayen lantarki a yanayin lalata34.Impedance spectra da capacitance lissafin tube fallasa su abiotic kafofin watsa labarai da kuma mafita na Pseudomonas aeruginosa, Rb ne juriya na m / biofilm kafa a saman da tsiri, Rct ne cajin canja wurin juriya, Cdl ne lantarki biyu Layer.) da kuma sigogi na QCPE akai-akai (CPE).An kara nazarin waɗannan sigogi ta hanyar kwatanta bayanai tare da samfurin lantarki (EEC).
A kan fig.3 yana nuna makircin Nyquist na al'ada (a da b) da makircin Bode (a' da b') na samfuran HDSS 2707 a cikin kafofin watsa labarai na abiotic da Pseudomonas aeruginosa broth a lokuta daban-daban na shiryawa.A gaban Pseudomonas aeruginosa, diamita na madauki na Nyquist yana raguwa.Makircin Bode (Hoto 3b') yana nuna haɓakar jimlar rashin ƙarfi.Za'a iya samun bayanai game da kullun lokacin hutu daga lokaci maxima.A kan fig.4 yana nuna tsarin jiki da kuma daidaitattun EEC dangane da Layer-Layer (a) da biyu-Layi (b).An gabatar da CPE a cikin samfurin EEC.An bayyana shigar da ita da kuma impedance kamar haka:
Samfuran jiki guda biyu da madaidaitan da'irori masu dacewa don dacewa da 2707 HDSS coupon impedance bakan:
Inda Y0 shine girman CPE, j shine lambar hasashe ko (-1) 1/2, ω shine mitar angular, kuma n shine ƙimar ƙarfin CPE ƙasa da ɗaya35.Juriya juriya na caji (watau 1/Rct) yayi daidai da ƙimar lalata.Ƙananan ƙimar Rct yana nufin ƙimar lalata mafi girma27.Bayan kwanaki 14 na shiryawa, Rct na samfurin gwajin Pseudomonas aeruginosa ya kai 32 kΩ cm2, wanda ya fi ƙasa da 489 kΩ cm2 na samfurin gwajin da ba na halitta ba (Table 4).
Hotunan CLSM da hotunan SEM a cikin fig.5 ya nuna a sarari cewa ɗaukar hoto na biofilm a saman samfurin HDSS 2707 ya kasance mai yawa bayan kwanaki 7.Duk da haka, bayan kwanaki 14 murfin biofilm ya zama maras kyau kuma wasu matattun kwayoyin halitta sun bayyana.Table 5 yana nuna kauri na biofilm na samfuran HDSS 2707 bayan kwanaki 7 da 14 na fallasa zuwa Pseudomonas aeruginosa.Matsakaicin kauri na biofilm ya canza daga 23.4 µm bayan kwanaki 7 zuwa 18.9 µm bayan kwanaki 14.Matsakaicin kauri na biofilm shima ya tabbatar da wannan yanayin.Ya ragu daga 22.2 ± 0.7 μm bayan kwanaki 7 zuwa 17.8 ± 1.0 μm bayan kwanaki 14.
(a) Hoton 3-D CLSM a kwanaki 7, (b) Hoton 3-D CLSM a kwanaki 14, (c) Hoton SEM a kwanaki 7, da (d) Hoton SEM a kwanaki 14.
EMF ya bayyana abubuwan sinadarai a cikin biofilm da samfuran lalata akan samfuran da aka fallasa ga Pseudomonas aeruginosa na kwanaki 14.A kan fig.Hoto na 6 ya nuna cewa abun ciki na C, N, O, P a cikin biofilm da samfurori na lalata sun fi girma fiye da ƙarfe mai tsabta, tun da waɗannan abubuwa suna hade da biofilm da metabolites.Kwayoyin halitta suna buƙatar kawai adadin Cr da Fe.Babban abun ciki na Cr da Fe a cikin biofilm da samfuran lalata a saman samfurin suna nuna asarar abubuwa a cikin matrix na ƙarfe a sakamakon lalata.
Bayan kwanaki 14, an lura da ramuka tare da kuma ba tare da P. aeruginosa a cikin matsakaici 2216E.Kafin incubation, saman samfuran ya kasance santsi kuma ba tare da lahani ba (Fig. 7a).Bayan ƙaddamarwa da kuma cire samfuran biofilm da lalata, an bincika ramuka mafi zurfi a saman samfurin ta amfani da CLSM, kamar yadda aka nuna a cikin siffa 7b da c.Ba a sami fayyace rami a saman abin da ba na halitta ba (mafi girman zurfin rami 0.02 µm).Matsakaicin zurfin rami da Pseudomonas aeruginosa ya haifar shine 0.52 µm bayan kwanaki 7 da 0.69 µm bayan kwanaki 14, dangane da matsakaicin matsakaicin zurfin rami daga samfuran 3 (an zaɓi mafi girman zurfin rami na 10 don kowane samfurin) kuma ya kai 0. 42 ± 0.12 µm. .da 0.52 ± 0.15 µm, bi da bi (Table 5).Waɗannan ƙimar zurfin zurfin ƙanana ne amma mahimmanci.
(a) kafin fallasa;(b) Kwanaki 14 a cikin yanayin abiotic;(c) Kwanaki 14 a cikin P. aeruginosa broth.
A kan fig.Shafin 8 yana nuna nau'in XPS na nau'i-nau'i daban-daban na samfurori, kuma an taƙaita ilimin sunadarai da aka yi nazari akan kowane surface a cikin Tebu 6. A cikin Table 6, adadin atomic na Fe da Cr sun kasance da yawa a gaban P. aeruginosa (samfurori A da B). ) fiye da a cikin nau'ikan sarrafawa marasa ilimin halitta.(misali C da D).Don samfurin Pseudomonas aeruginosa, Cr 2p core level spectral curve an daidaita shi zuwa manyan sassa huɗu tare da ƙarfin ɗaure (BE) na 574.4, 576.6, 578.3 da 586.8 eV, waɗanda aka sanya su zuwa Cr, Cr2O3, CrO3 da Cr. 3, bi da bi (Hoto 9a da b).Don samfuran marasa ilimin halitta, bakan matakin ainihin Cr 2p a cikin ɓangarorin.9c da d sun ƙunshi manyan kololuwa biyu na Cr (BE 573.80 eV) da Cr2O3 (BE 575.90 eV), bi da bi.Bambanci mafi ban mamaki tsakanin coupon abiotic da coupon P. aeruginosa shine kasancewar Cr6 + da ƙananan ƙananan ƙananan Cr (OH) 3 (BE 586.8 eV) a ƙarƙashin biofilm.
Faɗin sararin XPS na samfuran 2707 HDSS a cikin kafofin watsa labarai biyu na kwanaki 7 da 14, bi da bi.
(a) Kwana 7 P. aeruginosa bayyanar, (b) kwana 14 P. aeruginosa fallasa, (c) bayyanar abiotic na kwana 7, (d) bayyanar abiotic na kwana 14.
HDSS yana nuna babban matakin juriya na lalata a yawancin mahalli.Kim et al.2 ya ruwaito cewa an gano HDSS UNS S32707 a matsayin DSS mai doped sosai tare da PREN fiye da 45. Ƙimar PREN na samfurin HDSS 2707 a cikin wannan aikin shine 49. Wannan shi ne saboda babban abun ciki na Cr da manyan matakan Mo da Ni, waɗanda ke da amfani a cikin yanayi na acidic da mahalli tare da babban abun ciki na chlorides.Bugu da ƙari, ma'auni mai ma'auni mai kyau da ƙananan ƙwayoyin cuta marasa lahani suna ba da kwanciyar hankali na tsari da juriya na lalata.Duk da kyakkyawan juriya na sinadarai, bayanan gwaji a cikin wannan aikin sun nuna cewa 2707 HDSS ba ta da cikakkiyar kariya ga Pseudomonas aeruginosa biofilm MICs.
Sakamakon Electrochemical ya nuna cewa yawan lalata na 2707 HDSS a cikin Pseudomonas aeruginosa broth ya karu sosai bayan kwanaki 14 idan aka kwatanta da yanayin da ba na halitta ba.A cikin Hoto 2a, an sami raguwar Eocp duka a cikin matsakaicin abiotic da a cikin P. aeruginosa broth a cikin sa'o'i 24 na farko.Bayan haka, biofilm ya ƙare rufe saman samfurin kuma Eocp ya zama ɗan kwanciyar hankali.Koyaya, matakin biotic Eocp ya kasance sama da matakin abiotic Eocp.Akwai dalilai da za a yi imani da cewa wannan bambanci yana hade da samuwar P. aeruginosa biofilms.A kan fig.2g, darajar icorr na 2707 HDSS ya kai 0.627 µA cm-2 a gaban Pseudomonas aeruginosa, wanda shine tsari na girma fiye da na tsarin kula da kwayoyin halitta (0.063 µA cm-2), wanda ya dace da Rct ƙimar da aka auna ta EIS.A cikin 'yan kwanaki na farko, ƙimar impedance a cikin broth P. aeruginosa ya karu saboda haɗewar sel P. aeruginosa da samuwar biofilm.Duk da haka, impedance yana raguwa lokacin da biofilm ya rufe saman samfurin gaba ɗaya.An kai hari kan Layer na kariya da farko saboda samuwar biofilm da biofilm metabolites.Sabili da haka, juriya na lalata yana raguwa akan lokaci, kuma adibas na Pseudomonas aeruginosa yana haifar da lalata a cikin gida.Abubuwan da ke faruwa a cikin yanayin abiotic sun bambanta.Rashin juriya na lalata tsarin kula da marasa ilimin halitta ya fi girma fiye da daidaitattun samfuran da aka fallasa ga Pseudomonas aeruginosa broth.Bugu da ƙari, don samfuran abiotic, ƙimar Rct 2707 HDSS ta kai 489 kΩ cm2 a ranar 14, wanda ya ninka sau 15 fiye da gaban Pseudomonas aeruginosa (32 kΩ cm2).Don haka, 2707 HDSS yana da kyakkyawan juriya na lalata a cikin yanayi mara kyau, amma ba a kiyaye shi daga harin MIC ta Pseudomonas aeruginosa biofilm.
Hakanan za'a iya lura da waɗannan sakamakon daga maƙallan polarization a cikin figs.2b.Reshen Anodic yana hade da Pseudomonas aeruginosa biofilm samuwar da kuma halayen iskar shaka na karfe.A lokaci guda, halayen cathodic shine rage yawan oxygen.Kasancewar P. aeruginosa yana ƙaruwa da yawa na lalata halin yanzu, wanda shine game da tsari na girma sama da na sarrafa abiotic.Wannan ya nuna cewa Pseudomonas aeruginosa biofilm ya inganta lalacewar gida na 2707 HDSS.Yuan et al.29 sun gano cewa yawan lalata na yanzu na 70/30 Cu-Ni gami ya karu ta hanyar Pseudomonas aeruginosa biofilm.Wannan na iya zama saboda biocatalysis na rage oxygen ta hanyar Pseudomonas aeruginosa biofilm.Wannan abin lura yana iya yin bayanin MIC 2707 HDSS a cikin wannan aikin.Aerobic biofilms kuma na iya rage iskar oxygen da ke ƙarƙashinsu.Don haka, ƙin sake dawo da saman ƙarfe tare da iskar oxygen na iya zama abin da ke ba da gudummawa ga MIC a cikin wannan aikin.
Dickinson et al.38 ya ba da shawarar cewa ƙimar sinadarai da halayen electrochemical kai tsaye ya dogara da aikin rayuwa na ƙwayoyin cuta da ke haɗe zuwa saman samfurin da kuma yanayin samfuran lalata.Kamar yadda aka nuna a cikin Hoto na 5 da Table 5, adadin kwayoyin halitta da kauri na biofilm sun ragu bayan kwanaki 14.Ana iya yin bayanin wannan da kyau ta gaskiyar cewa bayan kwanaki 14 yawancin ƙwayoyin da aka kafa akan 2707 HDSS surface sun mutu saboda raguwar abinci mai gina jiki a cikin matsakaicin 2216E ko sakin ions ƙarfe masu guba daga matrix 2707 HDSS.Wannan iyakance ne na gwaje-gwajen tsari.
A cikin wannan aikin, wani Pseudomonas aeruginosa biofilm ya inganta raguwar gida na Cr da Fe a ƙarƙashin biofilm a saman 2707 HDSS (Fig. 6).A cikin Table 6, Fe da Cr sun ragu a cikin samfurin D idan aka kwatanta da samfurin C, yana nuna cewa Fe da Cr rushewar da P. aeruginosa biofilm ya haifar da ci gaba bayan kwanakin 7 na farko.Ana amfani da yanayin 2216E don daidaita yanayin ruwa.Ya ƙunshi 17700 ppm Cl-, wanda yayi daidai da abin da ke cikin ruwa na teku.Kasancewar 17700 ppm Cl- shine babban dalilin raguwar Cr a cikin 7-day da 14-day samfurori marasa ilimin halitta wanda XPS yayi nazari.Idan aka kwatanta da samfurin gwajin Pseudomonas aeruginosa, rushewar Cr a cikin samfurin gwajin kwayoyin halitta ya ragu sosai saboda ƙarfin juriya na 2707 HDSS zuwa chlorine a cikin yanayin abiotic.A kan fig.9 yana nuna kasancewar Cr6+ a cikin fim ɗin wucewa.Wannan na iya kasancewa yana da alaƙa da cirewar Cr daga saman ƙarfe ta hanyar P. aeruginosa biofilms, kamar yadda Chen da Clayton39 suka ba da shawara.
Saboda haɓakar ƙwayoyin cuta, ƙimar pH na matsakaici kafin da bayan shiryawa sun kasance 7.4 da 8.2, bi da bi.Saboda haka, lalata kwayoyin acid ba zai iya ba da gudummawa ga wannan aikin a ƙarƙashin P. aeruginosa biofilms saboda ƙananan pH a cikin matsakaicin matsakaici.pH na matsakaicin kulawar da ba ilimin halitta bai canza sosai ba (daga farkon 7.4 zuwa 7.5 na ƙarshe) yayin lokacin gwajin kwanaki 14.Haɓakawa a cikin pH a cikin matsakaici na inoculum bayan an haɗa shi tare da aikin rayuwa na Pseudomonas aeruginosa, kuma an sami irin wannan tasiri akan pH a cikin rashin gwajin gwajin.
Kamar yadda aka nuna a cikin fig.7, matsakaicin zurfin rami wanda Pseudomonas aeruginosa biofilm ya haifar shine 0.69 µm, wanda ya fi girma a cikin matsakaicin abiotic (0.02 µm).Wannan ya yarda da bayanan lantarki na sama.A ƙarƙashin yanayi guda, zurfin rami na 0.69 µm ya fi sau goma ƙasa da ƙimar 9.5 µm da aka ƙayyade don 2205 DSS40.Waɗannan bayanan sun nuna cewa 2707 HDSS yana nuna mafi kyawun juriya ga MIC fiye da 2205 DSS.Wannan ba abin mamaki bane tunda 2707 HDSS yana da matakin Cr mafi girma, wanda ke ba da izinin wucewa mai tsayi, yana sa Pseudomonas aeruginosa ya fi wahalar ragewa, kuma yana fara aiwatarwa ba tare da hazo na biyu mai cutarwa Pitting41 ba.
A ƙarshe, an sami MIC pitting a kan 2707 HDSS saman a cikin Pseudomonas aeruginosa broth, yayin da pitting ya kasance mai banƙyama a cikin kafofin watsa labarun.Wannan aikin ya nuna cewa 2707 HDSS yana da mafi kyawun juriya ga MIC fiye da 2205 DSS, amma ba shi da cikakkiyar rigakafi ga MIC saboda Pseudomonas aeruginosa biofilm.Waɗannan sakamakon suna taimakawa wajen zaɓin bakin karfe masu dacewa da tsawon rayuwa don yanayin ruwa.
An samar da samfuran HDSS 2707 ta Makarantar Metallurgy, Jami'ar Arewa maso Gabas (NEU), Shenyang, China.An nuna ainihin abun da ke ciki na 2707 HDSS a cikin Tebu 1, wanda Sashen Nazarin Kayayyaki da Gwaji na Jami'ar Arewa maso Gabas suka yi nazari.Dukkan samfuran an bi da su don ingantaccen bayani a 1180 ° C na awa 1.Kafin gwajin lalata, 2707 HDSS tsabar kudin karfe tare da fallen fili na 1 cm2 an goge shi zuwa 2000 grit tare da sandpaper na silicon carbide sannan kuma ya kara goge shi da 0.05 µm Al2O3 foda slurry.Ana kiyaye tarnaƙi da ƙasa tare da fenti marar amfani.Bayan bushewa, an wanke samfurori tare da ruwa mai tsabta mai tsabta da kuma haifuwa tare da 75% (v / v) ethanol don 0.5 h.Sannan an bushe su da iska a ƙarƙashin hasken ultraviolet (UV) na sa'o'i 0.5 kafin amfani.
Jirgin ruwa Pseudomonas aeruginosa MCCC 1A00099 an sayo shi daga Xiamen Marine Culture Collection (MCCC), China.Marine 2216E ruwa matsakaici (Qingdao Hope Biotechnology Co., Ltd., Qingdao, China) da aka yi amfani da al'ada Pseudomonas aeruginosa a 250 ml flasks da 500 ml electrochemical gilashin Kwayoyin karkashin aerobic yanayi a 37 ° C.Matsakaici ya ƙunshi (g/l): 19.45 NaCl, 5.98 MgCl2, 3.24 Na2SO4, 1.8 CaCl2, 0.55 KCl, 0.16 Na2CO3, 0.08 KBr, 0.034 SrCl2, 0.02, 3034 SrCl, 0.08 SrBr.0, 308 SrBr0. 0.008, 0.008 Na4F0H20PO.1.0 cire yisti da 0.1 citrate baƙin ƙarfe.Autoclave a 121 ° C na minti 20 kafin allurar.Sessile da planktonic sel an ƙidaya su ƙarƙashin na'urar hangen nesa ta amfani da hemocytometer a girman 400x.Matsakaicin farko na ƙwayoyin planktonic P. aeruginosa nan da nan bayan allurar ya kai kusan sel 106/mL.
An gudanar da gwaje-gwajen lantarki a cikin tantanin halitta na gilashin lantarki na yau da kullun tare da matsakaicin girma na 500 ml.An haɗa takardar platinum da cikakken calomel electrode (SCE) zuwa reactor ta wata katuwar Luggin da ke cike da gadar gishiri kuma an yi aiki a matsayin na'urorin lantarki da na'urori, bi da bi.Don ƙirƙirar na'ura mai aiki, an haɗa wayar tagulla mai rufi na roba zuwa kowane samfurin kuma an rufe shi da epoxy, yana barin kusan 1 cm2 na sararin samaniya a gefe ɗaya don lantarki mai aiki.A lokacin ma'auni na electrochemical, an sanya samfurori a cikin matsakaici na 2216E kuma an ajiye su a cikin zafin jiki na yau da kullum (37 ° C) a cikin wanka na ruwa.An auna OCP, LPR, EIS da yuwuwar bayanan polarization mai ƙarfi ta amfani da Autolab potentiostat (Reference 600TM, Gamry Instruments, Inc., Amurka).An yi rikodin gwaje-gwajen LPR a ƙimar sikanin 0.125 mV s-1 a cikin kewayon -5 da 5 mV da Eocp tare da ƙimar samfurin 1 Hz.An yi EIS a daidaitaccen yanayin Eocp ta amfani da wutar lantarki mai aiki na 5 mV tare da sinusoid akan kewayon mitar 0.01 zuwa 10,000 Hz.Kafin yuwuwar sharewar, na'urorin lantarki suna cikin yanayin da'ira a buɗe har sai an kai ga ingantaccen yuwuwar lalatawar 42.Tare daAn maimaita kowace gwaji sau uku tare da kuma ba tare da Pseudomonas aeruginosa ba.
Samfurori don ƙididdigar ƙarfe an goge su da injina tare da 2000 grit rigar takarda SiC sannan kuma an goge su tare da 0.05 µm Al2O3 foda slurry don kallon gani.An gudanar da bincike na metallographic ta amfani da na'urar gani da ido.An kwafe samfurin tare da 10 wt% potassium hydroxide bayani43.
Bayan shiryawa, wanke sau 3 tare da phosphate buffered saline (PBS) (pH 7.4 ± 0.2) sa'an nan kuma gyara tare da 2.5% (v / v) glutaraldehyde na 10 hours don gyara biofilm.Rashin ruwa na gaba tare da ethanol a cikin jerin matakai (50%, 60%, 70%, 80%, 90%, 95% and 100% by volume) kafin bushewar iska.A ƙarshe, an zubar da fim ɗin zinare a saman samfurin don samar da haɓaka don lura da SEM44.Hotunan SEM suna mayar da hankali kan wuri tare da mafi yawan kafa P. aeruginosa Kwayoyin a saman kowane samfurin.An gudanar da bincike na EMF don gano abubuwan sinadaran.Don auna zurfin ramin, an yi amfani da na'urar duba microscope na Zeiss confocal Laser (CLSM) (LSM 710, Zeiss, Jamus).Don lura da ramukan lalata a ƙarƙashin biofilm, samfurin gwajin an fara tsaftace shi bisa ga ka'idar kasa ta Sin (CNS) GB/T4334.4-2000 don cire samfuran lalata da biofilm daga saman samfurin gwajin.
X-ray photoelectron spectroscopy (XPS, ESCALAB250 Surface Analysis System, Thermo VG, Amurka) bincike ta amfani da wani monochromatic X-ray source (Al Kα line tare da wani makamashi na 1500 eV da kuma wani iko na 150 W) a cikin wani m kewayon dauri makamashi. 0 ƙasa da daidaitattun yanayin -1350 eV.Yi rikodin bakan ƙuduri mai ƙarfi ta amfani da ƙarfin wucewar 50 eV da girman matakin 0.2 eV.
Cire samfurin da aka haɗa kuma a hankali a wanke shi da PBS (pH 7.4 ± 0.2) don 15 s45.Don lura da yiwuwar ƙwayoyin cuta na biofilm akan samfurin, an lalatar da biofilm ta amfani da LIVE/DEAD BacLight BacLight Viability Kit (Invitrogen, Eugene, OR, USA).Kit ɗin ya ƙunshi rini mai kyalli guda biyu: SYTO-9 kore mai kyalli da kuma propidium iodide (PI) rini mai kyalli.A cikin CLSM, dige-dige kore da jajayen ɗigo suna wakiltar sel masu rai da matattu, bi da bi.Don tabo, sanya 1 ml na cakuda mai ɗauke da 3 µl na SYTO-9 da 3 µl na maganin PI a zazzabi na ɗaki (23°C) a cikin duhu na mintuna 20.Bayan haka, an lura da samfuran tabo a tsayin raƙuman ruwa biyu (488 nm don sel masu rai da 559 nm don matattun ƙwayoyin cuta) ta amfani da na'urar Nikon CLSM (C2 Plus, Nikon, Japan).Auna kauri na biofilm a yanayin sikanin 3-D.
Yadda za a buga wannan labarin: Li, H. et al.Tasirin Pseudomonas aeruginosa marine biofilm akan lalata microbial na 2707 super duplex bakin karfe.kimiyya.Gidan 6, 20190;doi:10.1038/srep20190 (2016).
Zanotto, F., Grassi, V., Balbo, A., Monticelli, C. & Zucchi, F. Stress lalata fatattaka na LDX 2101 duplex bakin karfe a cikin chloride mafita a gaban thiosulfate.lalata.ilimin kimiyya.80, 205-212 (2014).
Kim, ST, Jang, SH, Lee, IS da Park, YS Tasirin maganin zafi na maganin zafi da nitrogen a cikin garkuwar iskar gas akan juriyar lalatawar super duplex bakin karfe welds.lalata.ilimin kimiyya.53, 1939-1947 (2011).
Shi, X., Avchi, R., Geyser, M. da Lewandowski, Z. Nazarin kwatankwacin sinadarai na microbial da electrochemical pitting a cikin 316L bakin karfe.lalata.ilimin kimiyya.45, 2577-2595 (2003).
Luo H., Dong KF, Li HG da Xiao K. Electrochemical hali na 2205 duplex bakin karfe a alkaline mafita a daban-daban pH dabi'u a gaban chloride.electrochemistry.Jarida.64, 211-220 (2012).
Lokacin aikawa: Janairu-09-2023