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Njehie nje bacteria (MIC) bụ nsogbu dị oke njọ n'ọtụtụ ụlọ ọrụ n'ihi na ọ nwere ike ibute nnukwu mfu akụ na ụba. Ejirila ígwè anaghị agba nchara super duplex (2707 HDSS) mee ihe n'akụkụ mmiri n'ihi ezigbo nguzogide kemịkalụ ya. Agbanyeghị, egosighi n'ụzọ nnwale na iguzogide MIC. N'ọmụmụ ihe a, a nyochachara omume MIC nke 2707 HDSS nke nje bacteria aerobic mmiri Pseudomonas aeruginosa kpatara. Nyocha elektrọnik gosiri na n'ihu Pseudomonas aeruginosa biofilm na 2216E medium, enwere mgbanwe dị mma na ikike ire ere na mmụba na njupụta ugbu a nke ire ere. Nyocha X-ray photoelectron spectroscopy (XPS) gosiri mbelata na ọdịnaya Cr n'elu ihe nlele dị n'okpuru biofilm. Nyocha onyonyo nke olulu ndị ahụ gosiri na biofilm P. aeruginosa mepụtara omimi olulu kachasị nke 0.69 μm n'ime ụbọchị 14 nke incubation. Ọ bụ ezie na nke a dị obere, ọ na-egosi na 2707 HDSS anaghị alụso MIC ọgụ kpamkpam. nke ihe nkiri ndụ P. aeruginosa.
A na-eji ígwè Duplex anaghị agba nchara (DSS) eme ihe n'ọtụtụ ụlọ ọrụ dị iche iche maka njikọta ha zuru oke nke ihe ndị dị mma na iguzogide nchara1,2. Agbanyeghị, olulu mmiri dị n'ógbè ka na-eme ma ọ na-emetụta iguzosi ike n'ezi ihe nke ígwè a3,4.DSS anaghị eguzogide nje bacterial corrosion (MIC)5,6.N'agbanyeghị ọtụtụ ojiji nke DSS, enwere ebe ndị iguzogide nchara nke DSS ezughị ezu maka ojiji ogologo oge.Nke a pụtara na ihe ndị dị oke ọnụ karịa nwere nguzogide nchara dị elu chọrọ.Jeon et al7 chọpụtara na ọbụna ígwè anaghị agba nchara super duplex (SDSS) nwere ụfọdụ mmachi n'ihe gbasara nguzogide nchara.Ya mere, a chọrọ ígwè anaghị agba nchara super duplex (HDSS) nwere nguzogide nchara dị elu na ụfọdụ ngwa.Nke a butere mmepe nke HDSS nke nwere ngwakọta dị elu.
Nguzogide nchara nke DSS dabere na oke nke usoro alpha na gamma yana mpaghara Cr, Mo na W nke dara ada 8, 9, 10 dị n'akụkụ nkebi nke abụọ. HDSS nwere nnukwu ọdịnaya nke Cr, Mo na N11, yabụ ọ nwere ezigbo nguzogide nchara na ọnụ ahịa dị elu (45-50) Pitting Resistance Equivalent Number (PREN), nke a chọpụtara site na wt.% Cr + 3.3 (wt.% Mo + 0.5 wt% W) + 16 wt% N12. Nguzogide nchara ya dị mma dabere na nhazi kwesịrị ekwesị nke nwere ihe dị ka ferrite (α) na 50% austenite (γ), HDSS nwere ihe onwunwe igwe ka mma na nguzogide dị elu karịa DSS13 nkịtị. Njirimara nkpuchi chloride. Nguzogide nchara ka mma na-agbasa ojiji nke HDSS na gburugburu chloride na-emebi emebi, dịka gburugburu mmiri.
MIC bụ nnukwu nsogbu n'ọtụtụ ụlọ ọrụ dịka mmanụ na gas na ụlọ ọrụ mmiri14. MIC na-akpata 20% nke mmebi nchara niile15. MIC bụ mmebi bioelectrochemical nke enwere ike ịhụ n'ọtụtụ gburugburu. Ihe nkiri biofim ndị na-etolite n'elu ígwè na-agbanwe ọnọdụ electrochemical, si otú a na-emetụta usoro nchara. A kwenyere na ọ bụ biofilms na-akpata MIC corrosion. Microorganisms electrogenic na-emebi ọla iji nweta ike na-adịgide adịgide iji dị ndụ17. Ọmụmụ MIC na-adịbeghị anya egosila na EET (nkwụnye elektrọn mpụga sel) bụ ihe na-egbochi ọnụego na MIC nke microorganisms electrogenic kpatara. Zhang et al. 18 gosipụtara na ndị na-eme ihe n'etiti elektrọn na-eme ka nnyefe elektrọn dị ngwa n'etiti mkpụrụ ndụ Desulfovibrio sessificans na ígwè anaghị agba nchara 304, na-eduga na mwakpo MIC siri ike karị. Enning et al. 19 na Venzlaff et al. 20 gosiri na biofilm ndị na-ebelata sulfate (SRB) bacteria nwere ike ịmịkọrọ elektrọn ozugbo site na ihe ndị dị n'ime ígwè, na-ebute nnukwu corrosion pitting.
A maara na DSS nwere ike ibute MIC n'ebe nwere SRB, nje bacteria na-ebelata iron (IRB), wdg. 21. Nje bacteria ndị a na-akpata oghere dị n'elu DSS n'okpuru biofilms22,23. N'adịghị ka DSS, a maghị MIC nke HDSS24 nke ọma.
Pseudomonas aeruginosa bụ nje bacteria dị ka gram-negative motile rod nke gbasaara nke ukwuu n'okike25. Pseudomonas aeruginosa bụkwa otu nnukwu nje bacteria na gburugburu mmiri, na-eme ka MIC bụrụ ígwè. Pseudomonas na-etinye aka nke ọma na usoro nchara ma a maara ya dị ka onye mbụ na-achịkwa mmiri n'oge e guzobere biofilm. Mahat et al. 28 na Yuan et al. 29 gosipụtara na Pseudomonas aeruginosa nwere ike ịbawanye ọnụego nchara nke ígwè dị nro na alloys na gburugburu mmiri.
Isi ihe mere e ji rụọ ọrụ a bụ inyocha ihe ndị dị na MIC nke 2707 HDSS nke nje bacteria aerobic nke mmiri Pseudomonas aeruginosa kpatara site na iji usoro electrochemical, usoro nyocha elu na nyocha ngwaahịa corrosion. E mere ọmụmụ ihe electrochemical gụnyere Open Circuit Potential (OCP), Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS), na Potential Dynamic Polarization iji mụọ omume MIC nke 2707 HDSS. E mere nyocha nke Energy dispersive spectrometer (EDS) iji chọta ihe kemịkalụ dị na elu ahụ gbajiri agbaji. Na mgbakwunye, e jiri nyocha X-ray photoelectron spectroscopy (XPS) chọpụta nkwụsi ike nke oxide film passivation n'okpuru mmetụta nke gburugburu mmiri nwere Pseudomonas aeruginosa. A tụrụ omimi olulu ahụ n'okpuru microscope nyocha laser confocal (CLSM).
Tebụl 1 depụtara ihe mejupụtara kemịkalụ nke 2707 HDSS. Tebụl 2 na-egosi na 2707 HDSS nwere njirimara igwe dị mma yana ike mmepụta nke 650 MPa. Foto 1 na-egosi obere nhazi anya nke mmiri ọkụ 2707 HDSS. Enwere ike ịhụ eriri austenite na ferrite ndị dị ogologo na-enweghị usoro nke abụọ na obere nhazi ahụ nwere ihe dị ka 50% austenite na 50% ferrite.
Foto nke 2a na-egosi ike sekit mepere emepe (Eocp) ma e jiri ya tụnyere oge ikpughe maka 2707 HDSS na abiotic 2216E medium na P. aeruginosa broth ruo ụbọchị 14 na 37 °C. Ọ na-egosi na mgbanwe kachasị na nke dị mkpa na Eocp na-eme n'ime awa 24 mbụ. Ọnụọgụ Eocp n'ọnọdụ abụọ ahụ ruru elu na -145 mV (vs. SCE) ihe dị ka awa 16 wee daa nke ukwuu, ruo -477 mV (vs. SCE) na -236 mV (vs. SCE) maka ihe nlele abiotic na P, n'otu n'otu). Kupọns Pseudomonas aeruginosa, n'otu n'otu. Mgbe awa iri abụọ na anọ gachara, uru Eocp nke 2707 HDSS maka P. aeruginosa kwụsiri ike na -228 mV (vs. SCE), ebe uru kwekọrọ na ya maka ihe nlele ndị na-abụghị nke bayoloji bụ ihe dị ka -442 mV (vs. SCE). Eocp n'ihu P. aeruginosa dị obere.
Nnwale elektrọnik nke ihe nlele 2707 HDSS n'ime ihe na-adịghị mma na ofe Pseudomonas aeruginosa na 37 °C:
(a) Eocp dịka ọrụ nke oge ikpughe, (b) usoro polarization n'ụbọchị nke 14, (c) Rp dịka ọrụ nke oge ikpughe na (d) icorr dịka ọrụ nke oge ikpughe.
Tebụl nke atọ depụtara ụkpụrụ paramita corrosion electrochemical nke ihe nlele HDSS 2707 nke e kpughere na abiotic medium na Pseudomonas aeruginosa inoculated medium ruo ụbọchị 14. E wepụtara tangent nke anodic na cathodic curves iji ruo na njikọ ndị na-enye corrosion current density (icorr), corrosion potential (Ecorr) na Tafel slopes (βα na βc) dịka usoro ọkọlọtọ si dị30,31.
Dịka egosiri na Foto 2b, mgbanwe elu nke usoro P. aeruginosa mere ka mmụba na Ecorr ma e jiri ya tụnyere usoro abiotic. Uru icorr, nke dabara na ọnụego nchara, mụbara ruo 0.328 μA cm-2 na ihe nlele Pseudomonas aeruginosa, okpukpu anọ nke ihe nlele na-abụghị nke bayoloji (0.087 μA cm-2).
LPR bụ usoro electrochemical ochie nke na-anaghị emebi emebi maka nyocha nchara ngwa ngwa. E jikwa ya mụọ MIC32. Foto nke 2c na-egosi nguzogide polarization (Rp) dịka ọrụ nke oge ikpughe. Uru Rp dị elu pụtara obere nchara. N'ime awa 24 mbụ, Rp nke 2707 HDSS ruru uru kachasị elu nke 1955 kΩ cm2 maka ihe nlele abiotic na 1429 kΩ cm2 maka ihe nlele Pseudomonas aeruginosa. Foto nke 2c na-egosikwa na uru Rp belatara ngwa ngwa mgbe otu ụbọchị gasịrị wee nọgide na-agbanweghị agbanwe maka ụbọchị 13 sochirinụ. Uru Rp nke ihe nlele Pseudomonas aeruginosa dị ihe dị ka 40 kΩ cm2, nke dị ala karịa uru 450 kΩ cm2 nke ihe nlele na-abụghị nke bayoloji.
Uru icorr ahụ kwekọrọ na ọnụego nchara otu. Enwere ike ịgbakọ uru ya site na nha Stern-Geary ndị a,
Mgbe Zou na ndị otu ya gasịrị, e chere na uru nkịtị nke mkpọda Tafel B n'ọrụ a bụ 26 mV/dec. Foto nke 2d na-egosi na icorr nke ihe nlele 2707 na-abụghị nke bayoloji nọgidere na-akwụsi ike, ebe ihe nlele P. aeruginosa gbanwere nke ukwuu mgbe awa 24 mbụ gasịrị. Uru icorr nke ihe nlele P. aeruginosa dị elu karịa njikwa ndị na-abụghị bayoloji. Usoro a kwekọrọ na nsonaazụ iguzogide polarization.
EIS bụ usoro ọzọ na-anaghị emebi emebi nke e ji akọwa mmeghachi omume electrochemical na njikọ ndị mebiri emebi. Spectra impedance na ụkpụrụ capacitance agbakọrọ nke ihe atụ ndị e kpughere na abiotic media na ngwọta Pseudomonas aeruginosa, Rb resistance nke passive film/biofilm nke e guzobere n'elu ihe nlele ahụ, Rct charge transfer resistance, Cdl electric double layer capacitance (EDL) na QCPE Constant Phase Element (CPE). E nyochakwara paramita ndị a site na itinye data ahụ site na iji ihe nlereanya sekit nhata (EEC).
Foto nke 3 na-egosi nhazi Nyquist (a na b) na nhazi Bode (a' na b') nke ihe nlele HDSS 2707 na ihe dị n'ime mmiri na ofe P. aeruginosa maka oge mmalite dị iche iche. Dayameta nke mgbanaka Nyquist na-ebelata ma ọ bụrụ na Pseudomonas aeruginosa dị. Nhazi Bode (Fig. 3b') na-egosi mmụba na oke nke mgbochi zuru oke. Enwere ike inye ozi gbasara oge ezumike site na usoro kachasị elu. Foto nke 4 na-egosi nhazi anụ ahụ dabere na monolayer (a) na bilayer (b) na EECs ha kwekọrọ. A na-ewebata CPE n'ime ụdị EEC. A na-egosipụta nnabata na mgbochi ya dị ka ndị a:
Ụdị anụ ahụ abụọ na sekit ndị kwekọrọ maka itinye ụdị impedance nke ihe nlele 2707 HDSS:
ebe Y0 bụ nha nke CPE, j bụ ọnụọgụ echiche ma ọ bụ (-1) 1/2, ω bụ ugboro angular, na n bụ CPE ike index erughị unity35. Mgbanwe nke nguzogide nnyefe chajị (ya bụ, 1/Rct) kwekọrọ na ọnụego nchara. Obere Rct pụtara ọsọ nchara ngwa ngwa27. Mgbe ụbọchị 14 nke incubation gasịrị, Rct nke ihe nlele Pseudomonas aeruginosa ruru 32 kΩ cm2, nke pere mpe karịa 489 kΩ cm2 nke ihe nlele na-abụghị nke bayoloji (Tebụl 4).
Foto CLSM na onyonyo SEM dị na Foto nke 5 na-egosi nke ọma na mkpuchi biofilm dị n'elu ihe nlele 2707 HDSS mgbe ụbọchị asaa gasịrị dị oke. Agbanyeghị, mgbe ụbọchị iri na anọ gachara, mkpuchi biofilm ahụ pere mpe ma ụfọdụ mkpụrụ ndụ nwụrụ anwụ pụtara. Tebụl nke 5 na-egosi ọkpụrụkpụ biofilm na ihe nlele 2707 HDSS mgbe ekpughere ya na P. aeruginosa maka ụbọchị 7 na 14. Oke ọkpụrụkpụ biofilm gbanwere site na 23.4 μm mgbe ụbọchị 7 gachara ruo 18.9 μm mgbe ụbọchị 14 gachara. Oke ọkpụrụkpụ biofilm kwadoro usoro a. O belatara site na 22.2 ± 0.7 μm mgbe ụbọchị 7 gachara ruo 17.8 ± 1.0 μm mgbe ụbọchị 14 gachara.
(a) Foto CLSM 3-D mgbe ụbọchị asaa gachara, (b) Foto CLSM 3-D mgbe ụbọchị iri na anọ gachara, (c) Foto SEM mgbe ụbọchị asaa gachara na (d) Foto SEM mgbe ụbọchị iri na anọ gachara.
EDS kpughere ihe ndị dị na biofilm na ngwaahịa nchara na ihe nlele e gosiri na P. aeruginosa ruo ụbọchị iri na anọ. Foto nke 6 na-egosi na ọdịnaya nke C, N, O, na P na biofilm na ngwaahịa nchara dị elu karịa nke dị na metal efu, n'ihi na ihe ndị a jikọtara ya na biofilm na metabolites ha. Microbes chọrọ naanị obere chromium na iron. Oke Cr na Fe dị elu na biofilm na ngwaahịa nchara dị n'elu ihe nlele ahụ na-egosi na matrix metal ahụ efuola ihe ndị dị n'ihi nchara.
Mgbe ụbọchị iri na anọ gachara, a hụrụ olulu mmiri na na-enweghị P. aeruginosa na 2216E. Tupu a gbanye ya, elu ihe nlele ahụ dị ire ụtọ ma nwee ntụpọ (Foto 7a). Mgbe a kpọchiri ya ma wepụ ngwaahịa biofilm na corrosion, a lere olulu ndị kacha omimi n'elu ihe nlele ahụ n'okpuru CLSM, dịka egosiri na Foto 7b na c. A hụghị olulu doro anya n'elu ihe nlele ndị na-abụghị ihe ndị dị ndụ (omimi olulu kachasị 0.02 μm). Omimi olulu kachasị nke Pseudomonas aeruginosa kpatara bụ 0.52 μm mgbe ụbọchị asaa gasịrị na 0.69 μm mgbe ụbọchị iri na anọ gachara, dabere na nkezi omimi olulu kachasị nke ihe nlele atọ (a họọrọ ụkpụrụ omimi olulu kachasị 10 maka ihe nlele ọ bụla) ruru 0.42 ± 0.12 μm na 0.52 ± 0.15 μm, n'otu n'otu (Tebụl 5). Ụkpụrụ omimi olulu ndị a dị obere mana dị mkpa.
(a) Tupu e kpughee ya, (b) ụbọchị iri na anọ n'ime ihe na-adịghị mma na (c) ụbọchị iri na anọ n'ime ofe Pseudomonas aeruginosa.
Foto nke 8 na-egosi ụdị XPS nke elu ihe nlele dị iche iche, a chịkọtara ihe mejupụtara kemịkalụ nke a tụlere maka elu ọ bụla na Tebụl nke 6. Na Tebụl nke 6, pasentị atọm nke Fe na Cr n'ihu P. aeruginosa (ihe nlele A na B) dị ala karịa nke ihe nlele njikwa na-abụghị nke bayoloji (ihe nlele C na D). Maka ihe nlele P. aeruginosa, etinyere usoro spectral ọkwa isi nke Cr 2p na akụkụ elu anọ nwere uru ike njikọ (BE) nke 574.4, 576.6, 578.3 na 586.8 eV, nke enwere ike ịkọwa na Cr, Cr2O3, CrO3 na Cr(OH)3, n'otu n'otu (Foto nke 9a na b). Maka ihe nlele na-abụghị bayoloji, ụdị spectrum ọkwa isi nke Cr 2p nwere isi elu abụọ maka Cr (573.80 eV maka BE) na Cr2O3 (575.90 eV maka BE) na Fig. 9c na d, n'otu n'otu. Ihe dị iche n'etiti ihe nlele abiotic na P. aeruginosa bụ ọnụnọ nke Cr6+ na obere akụkụ dị elu nke Cr(OH)3 (BE nke 586.8 eV) n'okpuru ihe nkiri biofilm ahụ.
Oke XPS nke elu nke ihe nlele 2707 HDSS n'ime mgbasa ozi abụọ ahụ bụ ụbọchị asaa na ụbọchị iri na anọ, n'otu n'otu.
(a) ụbọchị asaa nke ikpughe na P. aeruginosa, (b) ụbọchị iri na anọ nke ikpughe na P. aeruginosa, (c) ụbọchị asaa na abiotic medium na (d) ụbọchị iri na anọ na abiotic medium.
HDSS na-egosi oke iguzogide nchara n'ọtụtụ ebe. Kim na ndị otu ya 2 kọrọ na a kọwara UNS S32707 HDSS dị ka DSS nwere ngwakọta dị elu nke nwere PREN karịa 45. Uru PREN nke ihe atụ 2707 HDSS n'ọrụ a bụ 49. Nke a bụ n'ihi oke ọdịnaya chromium ya na ọkwa molybdenum na Ni dị elu, nke bara uru na gburugburu acidic na nnukwu chloride. Na mgbakwunye, nhazi nke ọma na obere nhazi enweghị ntụpọ bara uru maka nkwụsi ike nhazi na iguzogide nchara. Agbanyeghị, n'agbanyeghị oke iguzogide kemịkalụ ya, data nnwale dị na ọrụ a na-egosi na 2707 HDSS anaghị alụso MIC nke biofilms P. aeruginosa ọgụ kpamkpam.
Nsonaazụ electrochemical gosiri na ọnụego nchara nke 2707 HDSS na ofe P. aeruginosa mụbara nke ukwuu mgbe ụbọchị 14 gasịrị ma e jiri ya tụnyere nke na-abụghị nke bio. Na Foto 2a, a hụrụ mbelata na Eocp na ofe abiotic na ofe P. aeruginosa n'ime awa 24 mbụ. Mgbe nke ahụ gasịrị, biofilm ekpuchiela elu nke ihe nlele ahụ wee bụrụ nke kwụsiri ike36. Agbanyeghị, ọkwa nke Eocp bayọlọji dị elu karịa nke Eocp na-abụghị nke bio. E nwere ihe mere a ga-eji kwere na ọdịiche a bụ n'ihi nhazi biofilm P. aeruginosa. Na Foto 2d, n'ihu P. aeruginosa, uru icorr nke 2707 HDSS ruru 0.627 μA cm-2, nke bụ usoro nke ịdị elu karịa nke njikwa abiotic (0.063 μA cm-2), nke kwekọrọ na uru Rct nke EIS tụrụ. N'ime ụbọchị ole na ole mbụ, uru impedance dị na Ofe P. aeruginosa mụbara n'ihi njikọ nke mkpụrụ ndụ P. aeruginosa na mmepụta nke biofilms. Agbanyeghị, mgbe biofilm kpuchiri elu nke ihe nlele ahụ kpamkpam, impedance ahụ na-ebelata. A na-ebu ụzọ wakpo oyi akwa nchebe ahụ n'ihi mmepụta nke biofilms na biofilm metabolites. Ya mere, iguzogide nchara belatara ka oge na-aga, njikọta nke P. aeruginosa kpatara nchara mpaghara. Usoro dị na mgbasa ozi abiotic dị iche. Nguzogide nchara nke njikwa na-abụghị nke bayoloji dị elu karịa uru kwekọrọ na ihe nlele ndị e kpughere na ofe P. aeruginosa. Ọzọkwa, maka ihe nlele abiotic, uru Rct nke 2707 HDSS ruru 489 kΩ cm2 n'ụbọchị nke 14, nke bụ ugboro 15 uru Rct (32 kΩ cm2) n'ihu P. aeruginosa. Ya mere, 2707 HDSS nwere ezigbo nguzogide nchara na gburugburu ebe na-adịghị ọcha, mana ọ naghị eguzogide mwakpo MIC site na biofilms P. aeruginosa.
Enwere ike ịhụ nsonaazụ ndị a site na usoro polarization na Fig. 2b. E kwuru na njikọta anodic sitere na nhazi biofilm Pseudomonas aeruginosa na mmeghachi omume oxidation metal. N'otu oge ahụ mmeghachi omume cathodic bụ mbelata oxygen. Ọnụnọ nke P. aeruginosa mụbara njupụta ugbu a nke ukwuu, ihe dị ka usoro nke ịdị elu karịa njikwa abiotic. Nke a na-egosi na biofilm P. aeruginosa na-eme ka nchara dị n'ógbè nke 2707 HDSS dịkwuo elu. Yuan na ndị otu ya chọpụtara na njupụta ugbu a nke 70/30 Cu-Ni alloy mụbara n'okpuru ihe ịma aka nke biofilm P. aeruginosa. Nke a nwere ike ịbụ n'ihi biocatalysis nke mbelata oxygen site na biofilm Pseudomonas aeruginosa. Ihe a chọpụtara nwekwara ike ịkọwa MIC nke 2707 HDSS n'ọrụ a. Biofilm Aerobic nwekwara ike inwe obere oxygen n'okpuru ha. Ya mere, ọdịda iji oxygen weghachite elu ígwè nwere ike ịbụ ihe na-enye aka na MIC n'ọrụ a.
Dickinson na ndị otu ya 38 tụrụ aro na ọnụego mmeghachi omume kemịkalụ na electrochemical nwere ike imetụta ozugbo site na ọrụ metabolic nke nje bacteria sessile n'elu ihe nlele ahụ na ọdịdị nke ngwaahịa nchara. Dịka egosiri na Foto 5 na Tebụl 5, ma ọnụọgụ sel na ọkpụrụkpụ biofilm belatara mgbe ụbọchị 14 gasịrị. Nke a nwere ike ịkọwa nke ọma na mgbe ụbọchị 14 gasịrị, ọtụtụ sel sessile dị n'elu 2707 HDSS nwụrụ n'ihi mbelata nri na 2216E medium ma ọ bụ ntọhapụ nke ion metal na-egbu egbu site na matrix 2707 HDSS. Nke a bụ mmachi nke nnwale ogbe.
N'ọrụ a, ihe nkiri P. aeruginosa kwalitere mbelata mpaghara nke Cr na Fe n'okpuru ihe nkiri biofilm dị na elu 2707 HDSS (Foto 6). Na Tebụl 6, mbelata nke Fe na Cr na ihe nlele D ma e jiri ya tụnyere ihe nlele C, na-egosi na Fe na Cr agbazere agbaze nke ihe nkiri P. aeruginosa kpatara nọgidere karịa ụbọchị 7 mbụ. A na-eji ihe nkiri 2216E eme ihe dị ka gburugburu mmiri. O nwere 17700 ppm Cl-, nke yiri nke a hụrụ na mmiri mmiri eke. Ọnụnọ nke 17700 ppm Cl- bụ isi ihe kpatara mbelata na Cr na ihe nlele abiotic ụbọchị 7 na 14 nke XPS nyochachara. Ma e jiri ya tụnyere ihe nlele P. aeruginosa, mgbasa nke Cr na ihe nlele abiotic dị obere n'ihi ike Cl− nke 2707 HDSS na gburugburu abiotic. Foto 9 na-egosi ọnụnọ nke Cr6+ na ihe nkiri passivation. Ọ nwere ike itinye aka na mwepụ nke Cr site na elu ígwè site na ihe nkiri ndụ P. aeruginosa, dịka Chen na Clayton tụrụ aro.
N'ihi uto nje bacteria, uru pH nke usoro tupu na mgbe a kụchara ya bụ 7.4 na 8.2, n'otu n'otu. Ya mere, n'okpuru biofilm P. aeruginosa, ọ gaghị ekwe omume na ọ ga-abụ ihe na-akpata ọrụ a n'ihi pH dị elu na usoro buru ibu. pH nke usoro njikwa na-abụghị nke bayoloji agbanweghị nke ukwuu (site na 7.4 mbụ ruo 7.5 ikpeazụ) n'oge ule ụbọchị 14. Mmụba na pH na usoro ịgba ọgwụ mgbe a kụchara ya bụ n'ihi ọrụ metabolic nke P. aeruginosa ma achọpụtara na ọ nwere otu mmetụta ahụ na pH na enweghị mpempe ule.
Dịka egosiri na Foto nke 7, omimi olulu kachasị nke P. aeruginosa biofilm kpatara bụ 0.69 μm, nke buru ibu karịa nke abiotic medium (0.02 μm). Nke a kwekọrọ na data electrochemical akọwara n'elu. Omimi olulu 0.69 μm dị obere karịa uru 9.5 μm akọpụtara maka 2205 DSS n'otu ọnọdụ ahụ. Data ndị a na-egosi na 2707 HDSS na-egosipụta nguzogide MIC ka mma ma e jiri ya tụnyere 2205 DSS. Nke a ekwesịghị iju anya, ebe ọ bụ na 2707 HDSS nwere ọdịnaya chromium dị elu, na-enye passivation na-adịgide adịgide ogologo oge, n'ihi nhazi usoro nhazi na-enweghị ihe ndị na-emerụ emerụ nke abụọ, na-eme ka ọ sie ike maka P. aeruginosa iwepụ ma malite eclipse isi.
Na mmechi, a hụrụ MIC pitting n'elu 2707 HDSS na ofe P. aeruginosa ma e jiri ya tụnyere obere pitting na abiotic media. Ọrụ a na-egosi na 2707 HDSS nwere MIC resistance ka mma karịa 2205 DSS, mana ọ bụghị MIC zuru oke n'ihi biofilm P. aeruginosa. Nchọpụta ndị a na-enyere aka na nhọrọ nke ígwè anaghị agba nchara kwesịrị ekwesị na atụmatụ ndụ ọrụ maka gburugburu ebe obibi mmiri.
Ụlọ Akwụkwọ nke Metallurgy nke Mahadum Northeastern (NEU) dị na Shenyang, China nyere kupọnu maka 2707 HDSS. E gosiri ihe mejupụtara 2707 HDSS na Tebụl 1, nke Ngalaba Nyocha na Nnwale Ihe NEU nyochachara. E jiri mmiri gwọọ ihe nlele niile na 1180 °C ruo otu awa. Tupu nnwale nchara, e jiri akwụkwọ silicon carbide mee ka ọ dị ka mkpụrụ ego 2707 HDSS nke nwere mpaghara elu ekpughere nke 1 cm2 ruo grit 2000 ma jiri ntụ ntụ Al2O3 0.05 μm mee ka ọ dị mma. Agba na-adịghị arụ ọrụ na-echebe akụkụ na ala. Mgbe ọ kpọchara nkụ, e ji mmiri dị ọcha nke a na-ewepụ ion sachaa ihe nlele ahụ ma jiri ethanol 75% (v/v) sachaa ha ruo awa 0.5. E mesịa, e jiri ikuku kpọọ ha nkụ n'okpuru ọkụ ultraviolet (UV) ruo awa 0.5 tupu e jiri ya.
A zụtara ụdị Pseudomonas aeruginosa MCCC 1A00099 nke mmiri mmiri site na Xiamen Marine Culture Collection Center (MCCC), China. A kụrụ Pseudomonas aeruginosa n'ọkụ na 37°C n'ime karama 250 ml na mkpụrụ ndụ iko electrochemical 500 ml site na iji mmiri mmiri Marine 2216E (Qingdao Hope Biotechnology Co., Ltd., Qingdao, China). Ọkara (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, 0.08 SrBr2, 0.022 H3BO3, 0.004 NaSiO3, 0016 NH3, 0016 NH3, 0016 NH3, 0016 NaH2PO4, peptone 5.0, ihe e si na yist wepụta 1.0 na 0.1 ferric citrate. Autoclave na 121°C maka nkeji iri abụọ tupu a gbaa ya ọgwụ. Jiri hemocytometer gụọ mkpụrụ ndụ sessile na planktonic n'okpuru obere microscope na mmụba 400X. Mgbakwunye mkpụrụ ndụ mbụ nke planktonic Pseudomonas aeruginosa ozugbo a gbasịrị ya ọgwụ bụ ihe dị ka mkpụrụ ndụ 106/ml.
E mere ule electrochemical na sel iko atọ-electrode ochie nke nwere olu dị ọkara nke 500 ml. E jikọtara mpempe akwụkwọ platinum na electrode calomel juru eju (SCE) na reactor site na capillaries Luggin jupụtara na àkwà mmiri nnu, na-eje ozi dị ka elektrọd counter na ntụaka, n'otu n'otu. Iji mee elektrọd ndị na-arụ ọrụ, e jikọtara waya ọla kọpa a kpuchiri rọba na ihe nlele ọ bụla ma kpuchie ya na epoxy, na-ahapụ ihe dị ka 1 cm2 nke mpaghara elu otu akụkụ ekpughere maka elektrọd na-arụ ọrụ. N'oge nha elektrọchemical, e tinyere ihe nlele na 2216E medium ma nọgide na-enwe okpomọkụ incubation mgbe niile (37 °C) na bat mmiri. E jiri Autolab potentiostat tụọ OCP, LPR, EIS na data polarization dynamic dynamic data (Reference 600TM, Gamry Instruments, Inc., USA). E dekọrọ ule LPR na ọnụego nyocha nke 0.125 mV s-1 n'elu oke -5 na 5 mV na Eocp na ugboro nlele nke 1 Hz. EIS mere ya na ebili mmiri sine na ugboro ole Oke 0.01 ruo 10,000 Hz site na iji voltaji etinyere 5 mV na steeti kwụsiri ike Eocp. Tupu e jiri ike ehichapụ elektrọd ndị ahụ, elektrọd ndị ahụ nọ n'ọnọdụ sekit mepere emepe ruo mgbe e ruru uru ike nchara na-enweghị nchara kwụsiri ike. E wee jiri usoro polarization mee ihe site na -0.2 ruo 1.5 V vs. Eocp na ọnụego nyocha nke 0.166 mV/s. E mere ule ọ bụla ugboro atọ na P. aeruginosa na enweghị ya.
E jiri akwụkwọ SiC dị 2000 grit wet tee ihe nlele maka nyocha metallographic n'ụzọ igwe, wee jiri ntụ ntụ Al2O3 0.05 μm mee ka ọ dị mma maka ilele anya. E jiri igwe microscope anya mee nyocha metallographic. E ji mmiri potassium hydroxide 10 wt.% 43 tee ihe nlele ndị ahụ.
Mgbe a kụchara ya, a sachara ihe nlele ahụ ugboro atọ na mmiri saline phosphate-buffered (PBS) (pH 7.4 ± 0.2) wee dozie ya na glutaraldehyde 2.5% (v/v) ruo awa iri iji dozie biofilms. E mechara jiri usoro ethanol (50%, 60%, 70%, 80%, 90%, 95% na 100% v/v) tee ya mmiri tupu ikuku akpọọ nkụ. N'ikpeazụ, a na-awụsa elu nke ihe nlele ahụ na ihe nkiri ọlaedo iji nye ike maka nlele SEM. E lebara anya na onyonyo SEM na ntụpọ ndị nwere mkpụrụ ndụ P. aeruginosa kachasị adịkarị n'elu ihe nlele ọ bụla. Mee nyocha EDS iji chọta ihe kemịkalụ. Ejiri Zeiss Confocal Laser Scanning Microscope (CLSM) (LSM 710, Zeiss, Germany) tụọ omimi olulu ahụ. Iji hụ olulu nchara n'okpuru ihe nkiri biofilm ahụ, e buru ụzọ hichaa ihe nnwale ahụ dịka ọkọlọtọ mba China si dị. (CNS) GB/T4334.4-2000 iji wepụ ngwaahịa nchara na ihe nkiri biofilm n'elu ihe nnwale ahụ.
E jiri isi iyi X-ray monochromatic (aluminum Kα ahịrị na ike eV 1500 na ike eV 150 W) mee nyocha X-ray photoelectron spectroscopy (XPS, sistemụ nyocha elu ESCALAB250, Thermo VG, USA) n'elu oke ike njikọ 0 n'okpuru ọnọdụ ọkọlọtọ -1350 eV. E jiri ike ngafe eV 50 na nha nzọụkwụ eV 0.2 dekọọ spectra mkpebi dị elu.
E wepụrụ ihe ndị a kpọchiri akpọchi ma jiri PBS (pH 7.4 ± 0.2) sachaa ha nke ọma ruo awa 15. Iji hụ na ihe ndị a kpọchiri akpọchi nwere ike ibute nje bacteria na ihe ndị a tụrụ atụ, e ji ihe eji eme ka ihe ndị a dị ndụ (Invitrogen, Eugene, OR, USA) mee ka ihe ndị a dị ndụ tee ihe ndị ahụ. Ngwa a nwere agba fluorescent abụọ, agba SYTO-9 akwụkwọ ndụ akwụkwọ ndụ na agba fluorescent propidium iodide (PI) uhie. N'okpuru CLSM, ntụpọ nwere akwụkwọ ndụ fluorescent na ọbara ọbara na-anọchite anya mkpụrụ ndụ dị ndụ na ndị nwụrụ anwụ, n'otu n'otu. Maka agba, e tinyere ngwakọta 1 ml nwere 3 μl SYTO-9 na 3 μl PI ngwọta maka nkeji iri abụọ na okpomọkụ ụlọ (23 oC) n'ọchịchịrị. Mgbe nke ahụ gasịrị, a hụrụ ihe ndị a kpọchiri akpọchi na ogologo ebili mmiri abụọ (488 nm maka mkpụrụ ndụ dị ndụ na 559 nm maka mkpụrụ ndụ nwụrụ anwụ) site na iji igwe Nikon CLSM (C2 Plus, Nikon, Japan). A tụrụ ọkpụrụkpụ ihe ndị a kpọchiri akpọchi na ụdị nyocha 3-D.
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