Studying of the Bacterial Growth Phases Using Fourier Transform Infrared Spectroscopy and Multivariate Analysis (original) (raw)
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Monitoring of bacterial growth and structural analysis as probed by FT-IR spectroscopy
Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1994
Fourier-transform infrared spectroscopy was used to explore structural changes in bacteria under different incubation conditions. In particular, differences between Bradyrhizobium japonicum (BRJ) grown in liquid and on solid media were investigated, as well as the rearrangement of BRJ after transfer from one medium to the other. The FT-IR absorption bands located between 1200 and 900 cm-1 region, vary in spectral shape and intensity when BRJ were suspended in solution medium or plated on solid medium. In agreement with the electronic micrograph data, these spectroscopic changes are due to the changes involving the bacterial wall (peptidoglycan) when BRJ are plated in agar medium. By means of this FT-IR ultrastructural study of Bradyrhizobium japonicum bacteria, it has been possible to follow and to evaluate the rate of the molecular change in bacteria without any destructive interference. This indicates that FT-IR spectroscopy can prove to be a valuable technique in the monitoring of metabolic events in bacterial cells relevant to agriculture as well as environmental and health sciences.
Fourier transform infrared (FT-IR) spectroscopy is a physico-chemical method based on measurement of vibration of a molecule excited by IR radiation at a specific wavelength range. FT-IR spectra of bacterial cells can be used to analyze their total composition, including proteins, fatty acids, carbohydrates, nucleic acids, and lipopolysacharides. FT-IR techniques coupled with different chemometrics analyses of the spectra offer a wide range of applications for food microbiology, including detection, differentiation, quantification, and taxonomic level classification of bacteria from culture broth or food matrices. FT-IR spectroscopy is a reliable, rapid, and economic technique which could be explored as a routine diagnostic tool for bacterial analysis by the food industry, diagnostic laboratories, and public health authorities. This chapter highlights the principles of FT-IR spectroscopic analysis of bacteria, the advantages and disadvantages of FT-IR applied to bacterial analysis, various sampling techniques, spectral manipulation, statistical analysis of spectra, and applications in pathogen detection.
Differentiation of Mesophilic and Thermophilic Bacteria with Fourier Transform Infrared Spectroscopy
Applied Spectroscopy, 2007
In the present study the characterization and differentiation of mesophilic and thermophilic bacteria were investigated by using Fourier transform infrared (FT-IR) spectroscopy. Our results showed significant differences between the FT-IR spectra of mesophilic and thermophilic bacteria. The protein-to-lipid ratio was significantly higher for thermophiles compared to mesophiles. The absorption intensity of the CH 3 asymmetric stretching vibration was higher in thermophilic bacteria, indicating a change in the composition of the acyl chains. The higher intensity/area observed in the CH 2 symmetric stretching mode at 2857 cm À1 , and the CH 2 bending vibration band at 1452 cm À1 , indicated a higher amount of saturated lipids in thermophilic bacteria. The lipid C¼O stretching vibration at 1739 cm À1 , which was observed in the mesophilic group, was not observed clearly in the thermophilic group, indicating a difference in packing that is presumably due to the decreased proportion of unsaturated acyl chains in thermophilic bacteria. In addition, the carbonyl groups become hydrogen bonded and the cellular DNA content was lower in thermophilic bacteria. Moreover, in the 1000-400 cm À1 frequency region, the spectra of each bacterial species belonging to both the mesophilic and thermophilic bacterial groups, showed characteristic differences that were discriminated via dendrogram using cluster analysis. The curent study implies that FT-IR spectroscopy could be succesfuly applied for the rapid comparison of bacterial groups and species to establish either similarities or discrepencies, as well as to confirm biochemical or physiological characteristics.
Fourier Transform Infrared (FT-IR) Spectroscopy for Biological Studies (REVIEW)
Gazi University Journal of …, 2010
In the recent years, vibrational spectroscopies (infrared spectroscopy) have been developed for all sorts of analysis in microbiology. Important features of these methods are the relative ease with which measurements can be performed. Fourier transform infrared spectroscopy (FT-IR) is a technique that has been used over the years in chemical analysis for the identification of substances and is one that may be applied to the characterization of microorganisms. Infrared spectroscopy is based on the measurement of the molecular bond vibration compounds, excited by radiation of a suitable frequency, when given the conditions for energy absorption by the molecules. Here, we review the potential application of vibrational spectroscopies for use in biology. It can be concluded that vibrational spectroscopy show high potential as novel methods.
Evaluation of FT-IR spectroscopy as a tool to quantify bacteria in binary mixed cultures
Journal of Microbiological Methods, 2011
Fourier-transform infrared (FT-IR) spectroscopy is known as a high-resolution method for the rapid identification of pure cultures of microorganisms. Here, we evaluated FT-IR as a method for the quantification of bacterial populations in binary mixed cultures consisting of Pseudomonas putida and Rhodococcus ruber. A calibration procedure based on Principal Component Regression was developed for estimating the ratio of the bacterial species. Data for method calibration were gained from pure cultures and artificially assembled communities of known ratios of the two member populations. Moreover, to account for physiological variability, FT-IR measurements were performed with organisms sampled at different growth phases. Measurements and data analyses were subsequently applied to growing mixed cultures revealing that growth of R. ruber was almost completely suppressed in co-culture with P. putida. Population ratios obtained by fatty acid analysis as an independent reference method were in high agreement with the FT-IR derived ratios.
International Journal of Food Microbiology, 2010
It was previously established that Lactobacillus fermentum ACA-DC 179, Lactobacillus plantarum ACA-DC 287 and Lactobacillus plantarum ACA-DC 2350 exhibit antimicrobial activity against Salmonella enterica serovar Typhimurium. In order to further investigate the killing effect of these microorganisms against Salmonella cells, we employed Fourier transform infrared spectroscopy (FT-IR). Salmonella cells were incubated with different concentrated lactobacilli supernatants and their FT-IR spectra were recorded. The second derivative transformation of the original spectra revealed changes in spectral regions corresponding to absorptions of major cellular constituents (e.g. cell wall, cell membrane, and proteins of the cell) among the Salmonella cells treated with the supernatants and those treated with the control samples. Principal component analysis of the second derivative transformed spectra showed that the yet unidentified antimicrobial compound(s) produced by the lactobacilli tested clearly interfered with the fatty acids of the cell membrane, as well as the polysaccharides of the cell wall in Salmonella cells, pointing towards a dual killing mode. Our study shed light for the first time in the anti-Salmonella activity of the particular Lactobacillus strains.
Frontiers in Microbiology, 2023
Microorganisms play pivotal roles in shaping ecosystems and biogeochemical cycles. Their intricate interactions involve complex biochemical processes. Fourier Transform-Infrared (FT-IR) spectroscopy is a powerful tool for monitoring these interactions, revealing microorganism composition and responses to the environment. This review explores the diversity of applications of FT-IR spectroscopy within the field of microbiology, highlighting its specific utility in microbial cell biology and environmental microbiology. It emphasizes key applications such as microbial identification, process monitoring, cell wall analysis, biofilm examination, stress response assessment, and environmental interaction investigation, showcasing the crucial role of FT-IR in advancing our understanding of microbial systems. Furthermore, we address challenges including sample complexity, data interpretation nuances, and the need for integration with complementary techniques. Future prospects for FT-IR in environmental microbiology include a wide range of transformative applications and advancements. These include the development of comprehensive and standardized FT-IR libraries for precise microbial identification, the integration of advanced analytical techniques, the adoption of high-throughput and single-cell analysis, real-time environmental monitoring using portable FT-IR systems and the incorporation of FT-IR data into ecological modeling for predictive insights into microbial responses to environmental changes. These innovative avenues promise to significantly advance our understanding of microorganisms and their complex interactions within various ecosystems.
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj Napoca Veterinary Medicine, 2013
Fourier transform infrared spectroscopy was used as a tool for identifying spectral markers representing differences between Escherichia coli and Borrelia Burgdorferi sensu stricto. In order to prescribe an effective treatment it is important to identify the pathogenic agent as fast as possible. Among the existing methods based on the vibrational spectroscopy that can provide a real time detection of microorganisms, there is also the Fourier transform infrared spectroscopy. We obtained main differences in spectral range 3250-3650 cm-1 (region dominated by hydroxy or amino groups), 1500-1200 cm-1 (mixed region) and 1200-900 cm-1 (polysaccharide region). Our results suggest that FT-IR spectroscopy can be used for the detection of the biochemical differeces between Escherichia coli and Borrelia Burgdorferi sensu stricto.
Application of Mid-infrared and Raman Spectroscopy to the Study of Bacteria
Food and Bioprocess Technology, 2011
Infrared spectroscopy and Raman spectroscopy provide complementary technologies for rapid and precise detection of microorganisms and are emerging methods in food analysis. It is possible to use either of these techniques to differentiate and quantify microorganisms in relatively simple matrices such as liquid media and simple solutions with determinations taking less than an hour. Vibrational spectroscopy, unlike other techniques used in microbiology, is a relatively simple method for studying structural changes occurring within a microbial cell following environmental stress and applications of food processing treatments. Vibrational spectroscopy provides a wide range of biochemical properties about bacteria in a single spectrum, most importantly characteristics of the cell membrane. These techniques are especially useful for studying properties of bacterial biofilms on contact surfaces, the presence and viability of bacterial vegetative cells and spores, the type and degree of bacterial injury, and assessment of antibiotic susceptibility. Future trends in food analysis will involve combining vibrational spectroscopy with microscopy, mass spectroscopy, or DNA-based meth-ods to comprehensively study bacterial stress. Further advances in selectivity, sensitivity, and improved chemometric methods, along with reduction in the cost of instrumentation, may lead to the development of fieldready and real-time analytical systems.