Growth Inhibition of Sulfate-Reducing Bacteria during Gas and Oil Production Using Novel Schiff Base Diquaternary Biocides: Synthesis, Antimicrobial, and Toxicological Assessment

Abstract

Upstream crude oil production equipment is always exposed to destruction damagingly which is caused by sulfate-reducing bacterium (SRB) activities that produce H 2 S gas, which leads to increased metal corrosion (bio-fouling) rates and inflicts effective infrastructure damage. Hence, oil and gas reservoirs must be injected with biocides and inhibitors which still offer the foremost protection against harmful microbial activity. However, because of the economic and environmental risks associated with biocides, the oil and gas sectors improve better methods for their usage. This work describes the synthesis and evaluation of the biological activities as the cytotoxicity and antimicrobial properties of a series of diquaternary cationic biocides that were studied during the inhibition of microbial biofilms. The prepared diquaternary compound was synthesized by coupling vanillin and 4-aminoantipyrene to achieve the corresponding Schiff base, followed by a quaternization reaction using 1,6-bromohexane, 1,8bromooctane, and 1,12-bromododecane. The increase of their alkyl chain length from 6 to 12 methylene groups increased the obtained antimicrobial activity and cytotoxicity. Antimicrobial efficacies of Q1−3 against various biofilm-forming microorganisms, including bacteria and fungi, were examined utilizing the diameter of inhibition zone procedures. The results revealed that cytotoxic efficacies of Q1−3 were significantly associated mainly with maximum surface excess and interfacial characteristics. The cytotoxic efficiencies of Q1−3 biocides demonstrated promising results due to their comparatively higher efficacies against SRB. Q3 exhibited the highest cytotoxic biocide against the gram +ve, gram −ve, and SRB species according to the inhibition zone diameter test. The toxicity of the studied microorganisms depended on the nature and type of the target microorganism and the hydrophobicity of the biocide molecules. Cytotoxicity assessment and antimicrobial activity displayed increased activity by the increase in their alkyl chain length.

Durian Shell-Mediated Simple Green Synthesis of Nanocopper against Plant Pathogenic Fungi

“…The results showed that the nanocomposites exhibited good antifungal efficacy against both fungal strains. A wide and relatively heterogeneous inhibition zone was detected, which characterizes the antibacterial ring of fungal strains. − The zones of inhibition for Corynespora cassiicola and Neoscytalidium dimidiatum correspond to 22.00 ± 0.52 mm and 18.00 ± 0.58 mm (Figure a,b). And, the extract is not antifungal against both Corynespora cassiicola and Neoscytalidium dimidiatum (Figure c,d).…”

Sulfide-Ion-Responsive Mesoporous Silica/ZIF-8 Nanocapsules to Inhibit Microbiologically Influenced Corrosion

“…7 Traditionally, the alloying method has been used for alleviating the SRB-induced MIC around the world over the past few years, the antibacterial elements have been incorporated into the metals to improve their performance; however, the antibacterial and corrosion resistances of these alloys are often unsatisfactory because the incorporated elements are usually limited by their solid solubility in the alloy matrix. 8 Moreover, excessive incorporation amounts of the alloy elements also have a negative influence on their mechanical properties. 9 Recently, the application of active substances, such as corrosion inhibitors and bactericides, has become an efficient and convenient approach for suppressing MIC induced by SRB.…”