Development Of Rapid Detection Methods For Sulfate-reducing Bacteria

Sulfate-reducing bacteria (SRB) are the most widely studied marine corrosivemicroorganisms. Since common SRB detection methods are time-consuming, thispaper focus on development and fabrication of fast SRB detection methods. Detectionmethods based on concanavalin A, cell-mediated bioimprinted films, and SRBcharacteristic metabolic process as the recognizing strategies were established forselective, sensitive and fast SRB quantitative analysis. The specific results of thethesis are as follows:1. A biosensor based on biomaterial recognition was established for rapid SRBdetection. Concanavalin A was chosen as bio-recognition element, and square wavevoltammetry was used for bacterial detection. Concanavalin A and signalingmolecules, ferrocene, were conjugated onto the surface of Fe3O4@MnO2nanomaterials with the help of dopamine enhanced polymerization process. Thiselectrochemical biosensor could shorten bacterial detection time to less than2h.Besides, the detection sensitivity enhancement was on the order of340%, and thelimit of detection would be decreased to40cfu mL-1.2. A sensor based on bioimprinted films was developed for rapid SRB detection.Bioimprinted films were synthesized by bacteria-mediated approach for selectivebacteria recognition, and electrochemical impedance spectroscopy was used for fastSRB population quantitative analysis. Graphene was introuced into bacterialattachment platform to obtain good electrochemical signals for bacterial detection.This bacterial detection method based on cell-mediated bioimprinted films couldavoid the use of biological bio-recognition elements, which are easily lost specificbinding abilities, and the bacterial population could be obtained within1h.3. Detection protocols based on SRB characteristic bacterial metabolic processwere constructed for rapid SRB quantitative analysis. Since sulfide is thecharacteristic metabolite of SRB, SRB detection methods based on chemical conversion from ZnO nanorods arrays to ZnS arrays, the photocatalytic property ofmicrobial synthesized ZnS nanoparticles, Thiobacillus thioparus microbial biosensor,inhibition of cysteine protease activity, and reduced graphene sheets were establishedby taking advantage of this SRB characteristic metabolite. The detection sensitivitywas greatly enhacned with the help of nanomaterials and enzymes, and the time forselective SRB detection was greatly shortened as a result.