Fourier transform infrared reflectance microspectroscopy study of Bacillus subtilis engineered without dipicolinic acid: the contribution of calcium dipicolinate to the mid-infrared absorbance of Bacillus subtilis endospores.
Mid-infrared spectra of spores of two strains of Bacillus subtilis, PS832 (wild-type) and FB122 (sleB spoVF), that are isogenic except for the two mutations in FB122 were obtained by Fourier transform infrared (FT-IR) reflectance microspectroscopy. The mutations in FB122 cause the spores of this strain to be devoid of dipicolinic acid (pyridine-2,6-dicarboxylic acid; DPA), a biomarker characteristic of bacterial spores. Analysis of these two strains by difference spectroscopy revealed a spectrum similar to that of calcium dipicolinate (CaDPA), a chelate salt of DPA. This difference spectrum was compared to mid-infrared spectra of both DPA and CaDPA, and was attributed to CaDPA only. This is the first report known to the authors of a genetically engineered organism being used to identify the spectral contribution of a particular cellular component.
Perkins
D L
DL
Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St. Columbia, South Carolina 29208, USA.
Lovell
C R
CR
Bronk
B V
BV
Setlow
B
B
Setlow
P
P
Myrick
M L
ML
D001412:Bacillus subtilis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017610:Calcium Compounds / Q000032:analysis* / Q000737:chemistry; D005818:Genetic Engineering / Q000379:methods*; D016297:Mutagenesis, Site-Directed; D010848:Picolinic Acids / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D013045:Species Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013171:Spores, Bacterial / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D017610:Calcium Compounds; D010848:Picolinic Acids; C004860:dipicolinic acid