Quantitative spectroscopy analysis of prokaryotic cells: vegetative cells and spores

• Published in: Biosensors & bioelectronics Vol. 19; no. 8; pp. 893 - 903
• Main Authors: Alupoaei, Catalina E, Olivares, Jose A, Garcı́a-Rubio, Luis H
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.03.2004; Elsevier Science
• Subjects: Absorbance; Algorithms; Bacillus globigii; Biological and medical sciences; Biosensor; Biosensors; Biotechnology; Escherichia coli - chemistry; Escherichia coli - isolation & purification; Feasibility Studies; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Microorganisms; Models, Biological; Multiwavelength spectroscopy; Optical properties; Reproducibility of Results; Scattering; Sensitivity and Specificity; Spectrum Analysis - methods; Spores, Bacterial - chemistry; Spores, Bacterial - isolation & purification; Statistics as Topic; Various methods and equipments; Multiwavelength spectroscopy; Absorbance; Microorganisms; Biosensor; Scattering; Optical properties; Spectrometry; Microorganism; Spores; Quantitative analysis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2003.08.021

Multiwavelength ultraviolet/visible (UV-Vis) spectra of microorganisms and cell suspensions contain quantitative information on properties such as number, size, shape, chemical composition, and internal structure of the suspended particles. These properties are essential for the identification and classification of microorganisms and cells. The complexity of microorganisms in terms of their chemical composition and internal structure make the interpretation of their spectral signature a difficult task. In this paper, a model is proposed for the quantitative interpretation of spectral patterns resulting from transmission measurements of prokaryotic microorganism suspensions. It is also demonstrated that different organisms give rise to spectral differences that may be used for their identification and classification. The proposed interpretation model is based on light scattering theory, spectral deconvolution techniques, and on the approximation of the frequency dependent optical properties of the basic constituents of living organisms. The quantitative deconvolution in terms of the interpretation model yields critical information necessary for the detection and identification of microorganisms, such as size, dry mass, dipicolinic acid concentration, nucleotide concentration, and an average representation of the internal scattering elements of the organisms. E. coli, P. agglomerans, B. subtilis spores, and vegetative cells and spores of Bacillus globigii are used as case studies. It is concluded that spectroscopy techniques coupled with effective interpretation models are applicable to a wide range of cell types found in diverse environments.