Biochemical and morphological changes in Escherichia coli irradiated by coherent and non-coherent 632.8 nm light.

Irradiation of Escherichia coli cells with either coherent or non-coherent 632.8 nm light (4 J cm-2) causes a transient acceleration of cell proliferation, which is maximal about 60 min after the end of the phototreatment. The stimulatory effect is dose dependent and is especially evident in the case of defective E. coli strains which are in the logarithmic phase of growth, while it becomes less important when cells are exposed to non-coherent 600-700 nm light. Stimulated cells exhibit biochemical and morphological changes, such as an intensified synthesis of cytoplasmic membrane proteins, increased cell volume and ribosomal content, which are suggestive of an enhanced cell metabolism.

[1]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.

[2]  V. S. Letokhov,et al.  Stimulation of E. coli growth by laser and incoherent red light , 1983 .

[3]  J. Basford.  Low-energy laser treatment of pain and wounds: hype, hope, or hokum? , 1986, Mayo Clinic proceedings.

[4]  V S Letokhov,et al.  Comparison of the effects of visible femtosecond laser pulses and continuous wave laser radiation of low average intensity on the clonogenicity of Escherichia coli. , 1991, Journal of photochemistry and photobiology. B, Biology.

[5]  Govindjee.  Energy conversion by plants and bacteria , 1982 .

[6]  Tiina I. Karu,et al.  Photobiological fundamentals of low-power laser therapy , 1987 .

[7]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[8]  R. Munson,et al.  Outer membrane protein profiles of Haemophilus pleuropneumoniae , 1986, Infection and immunity.

[9]  V. Rossetti,et al.  Biochemical effects of helium-neon laser irradiation in the rat brain. , 1991, Journal of photochemistry and photobiology. B, Biology.

[10]  J. Ghuysen,et al.  Membrane-bound DD-carboxypeptidase and LD-transpeptidase of Streptococcus faecalis ATCC 9790. , 1974, European journal of biochemistry.

[11]  C. Woldringh,et al.  Changes in cell diameter during the division cycle of Escherichia coli , 1980, Journal of bacteriology.

[12]  N. V. Paramonov,et al.  Photoreactivation of superoxide dismutase by intensive red (laser) light. , 1988, Free radical biology & medicine.

[13]  Olga Tiphlova,et al.  STIMULATION OF Escherichia coli DIVISION BY LOW‐INTENSITY MONOCHROMATIC VISIBLE LIGHT , 1988, Photochemistry and Photobiology.