In situ detection of antibiotic amphotericin B produced in Streptomyces nodosus using Raman microspectroscopy.
The study of spatial distribution of secondary metabolites within microbial cells facilitates the screening of candidate strains from marine environments for functional metabolites and allows for the subsequent assessment of the production of metabolites, such as antibiotics. This paper demonstrates the first application of Raman microspectroscopy for in situ detection of the antifungal antibiotic amphotericin B (AmB) produced by actinomycetes-Streptomyces nodosus. Raman spectra measured from hyphae of S. nodosus show the specific Raman bands, caused by resonance enhancement, corresponding to the polyene chain of AmB. In addition, Raman microspectroscopy enabled us to monitor the time-dependent change of AmB production corresponding to the growth of mycelia. The Raman images of S. nodosus reveal the heterogeneous distribution of AmB within the mycelia and individual hyphae. Moreover, the molecular association state of AmB in the mycelia was directly identified by observed Raman spectral shifts. These findings suggest that Raman microspectroscopy could be used for in situ monitoring of antibiotic production directly in marine microorganisms with a method that is non-destructive and does not require labeling.
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. r-miyaoka@ruri.waseda.jp.
Rimi
R
Miyaoka
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. m.hosokawa@aoni.waseda.jp.
Masahito
M
Hosokawa
Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513, Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan. mando@aoni.waseda.jp.
Masahiro
M
Ando
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. moritets@aoni.waseda.jp.
Tetsushi
T
Mori
Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513, Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan. hhama@nctu.edu.tw.
Hiro-O
HO
Hamaguchi
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. haruko-takeyama@waseda.jp.
Haruko
H
Takeyama
D000666:Amphotericin B / Q000096:biosynthesis / Q000737:chemistry*; D000935:Antifungal Agents / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D005285:Fermentation; D005658:Fungi / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D012997:Solvents; D013059:Spectrum Analysis, Raman / Q000379:methods; D013302:Streptomyces / Q000378:metabolism*
D000935:Antifungal Agents; D012997:Solvents; D000666:Amphotericin B; D004121:Dimethyl Sulfoxide