Using Raman spectroscopy and chemometrics to identify the growth phase of Lactobacillus casei Zhang during batch culture at the single-cell level

Table 1 Raman frequencies and their peak assignments grouped by their time-dependent trace profiles in Fig. 4

Curve	Raman bands (cm⁻¹)	Biological assignment/interpretation
a	668	G ring breathing
b	1575	Guanine, adenine (ring stretching)
c	1100	Polyhydroxybutyrate
d	1484/1482	Amide II
e	783/786	Phosphodiester; cytosine
f	813	Nucleic acids (C–O–P–O–C in RNA backbone)
g	934	Proline, hydroxyproline, v(C–C) skeletal of collagen backbone
h	852	Tyr
i	963	CH₂ rock, C–C_ɑ
j	1032	Phe
k	1550	Tryptophan
l	1003	Phe
m	1437	CH₂ and CH₃ deformation vibrations (lipid)
n	1443	CH₂ bending mode of proteins and lipids

Raman spectroscopy can provide specific markers of DNA, RNA, protein, and lipid, whose ratios in a bacterial cell can be highly dependent on the cell’s metabolic state

ISSN: 1475-2859