Monitoring the mode of action of synthetic and natural biocides against Aeromonas hydrophila by Raman spectroscopy and chemometrics

Abstract

We have investigated the mode of action of synthetic biocides, (2-(thiocyanomethylthio) benzothiazole(TCMTB), dichlorophen, (commonly used in leather industry for preservation) and natural biocides, oregano and eucalyptus oils, on Aeromonas hydrophila using Raman spectroscopy in collaboration with multivariate analysis and 2D correlation spectroscopy to evaluate whether Raman spectra acquired contained valuable information to study the action of biocides on bacterial cells. The growth of A. hydrophila in clear and outer edge zone of inhibition differ in their reaction with different biocides, which allows us to highlight the differences as a characteristic of two kinds of bacteria. Such classification helps identify oregano oil as the most effective biocide by altering clear and outer edge zone of bacteria. Standard disk diffusion assay method was used for screening biocide bacteria interactions and later analysed by Raman spectroscopy. The paper also presents the introduction of TCMTB and oregano oil into leather processing stages to examine and determine the antimicrobial effect as an application to real-world setting. Therefore, we conclude that Raman spectroscopy with appropriate computational tools constitutes a powerful approach for screening biocides, which provide solutions to all the industries using biocides including leather industry, considering the potentially harmful effect of biocides to humans and the environment. Graphical abstract

Ecotoxicity Study of New Composite Materials Based on Epoxy Matrix DER-331 Filled with Biocides Used for Industrial Applications

“…The first series of experiments aimed to a create two-component biofilm: heterophilic Escherichia coli, Klebsiella pneumonia, isolated from an aquatic environment. Based on scientific data on the composition of marine microflora [20], 18 h test cultures of microorganisms were used as an inoculum for biofilms. The first series of experiments aimed to create a two-component biofilm: heterophilic Escherichia coli, Klebsiella pneumoniae, isolated from an aquatic environment.…”

“…As mentioned above, the regression equation adequately describes the composition. When converting the elements of the regression equation according to (14), we obtained the following equation using the natural value of the variable parameters (20).…”

“…At the same time, the practical use of any chemical intensifies the issues of their environmental toxicity and impact on ecosystems in the long run. Numerous studies on the bioaccumulation of anthropogenic chemical pollutants indicate that biocides have a long half-life and can accumulate in the environment [20][21][22][23][24][25][26][27]. Changes in the chemical composition of the aquatic environment threaten the species diversity of ecosystems [28,29].…”

Sensing of Antibiotic–Bacteria Interactions

“…Raman spectroscopy can provide native and rich chemical information on microbial compositions; thus, it is suitable for phenotypic screening. Recent examples of studying chemical stresses for bacteria include the investigation of the effects of biocides on Aeromonas hydrophila [ 41 ]. SERS was also employed for the evaluation of various inactivation methods on Pseudomonas syringae [ 42 ].…”