title: Application of pyrolysis-gas chromatography-mass spectrometry and multivariate analysis to study bacteria and fungi in biofilms used for bioremediation.
abstract: Biofilms are communities of microorganisms adhering to a surface and embedded in an extracellular polymeric matrix, frequently associated with disease and contamination, and also used for engineering applications such as bioremediation. A mixed biofilm formed by bacteria and fungi may provide an optimal habitat for addressing contaminated areas. To exploit the potential of natural microbial communities consisting of bacteria and fungi, it is essential to understand and control their formation. In this work, a method to discriminate among bacteria of genera Bacillus, Pseudomonas, Rhodococcus with respect to the fungus Pleorotus in a biofilm by means of pyrolysis-gaschromatography-mass spectrometry and multivariate analysis is reported. Methylated fatty acids were chosen as biomarkers of microorganisms in the pyrolysates. In situ thermal hydrolysis and methylation was applied. Pyrograms were used as fingerprints, thus allowing for the characterization of whole cells analyzed without any sample pretreatment. Normalized pyrographic peak areas were chosen as variables for chemometric data processing. Principal components analysis was applied as a data exploration tool. Satisfactory results were obtained in analyzing a real biofilm. The influence of growth medium on whole bacteria fatty acid cell composition was also explored.
authors.affiliation: Department of Chemistry "Giacomo Ciamician", University of Bologna, Italy. dora.melucci@unibo.it
authors.forename: Dora
authors.initials: D
authors.lastname: Melucci
authors.forename: Stefano
authors.initials: S
authors.lastname: Fedi
authors.forename: Marcello
authors.initials: M
authors.lastname: Locatelli
authors.forename: Clinio
authors.initials: C
authors.lastname: Locatelli
authors.forename: Simona
authors.initials: S
authors.lastname: Montalbani
authors.forename: Martina
authors.initials: M
authors.lastname: Cappelletti
mesh_terms: D001407:Bacillus / Q000254:growth & development; D001419:Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D018441:Biofilms; D005227:Fatty Acids / Q000032:analysis / Q000737:chemistry; D005658:Fungi / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D011549:Pseudomonas / Q000254:growth & development; D012240:Rhodococcus / Q000254:growth & development
chemical_list: D005227:Fatty Acids