Commensal relationship between a sheath-forming bacterium, Sphaerotilus natans, and a sheath-degrading bacterium, Paenibacillus sp.
Paenibacillus sp. strain TB is capable of degrading the sheath prepared from a sheathed bacterium, Sphaerotilus natans. S. natans was able to grow alone on casamino acids but strain TB was not. Cocultivation of strain TB and S. natans was examined in a medium supplemented with casamino acids as a growth substrate. The growth of strain TB was observed when the sheath was supplied to the medium or in cocultivation with S. natans. The phospholipid amount reached a maximum after 24 h of cocultivation and subsequently kept almost the same level for 96 h. The sheath amount also reached a maximum after 24 h and then gradually declined. The cell concentration of strain TB increased throughout the cocultivation. By competitive PCR targeted for amplification of a part of 16S rDNA, the abundance ratio (S. natans/strain TB) of 6.7 was obtained at 72 h. Almost no growth of strain TB was detected in a coculture with a sheath-less mutant of S. natans. The evidence allows the conclusion that strain TB grew by utilizing the intact sheath in coculture with S. natans.
Takeda
Minoru
M
Division of Materials Science and Chemical Engineering, Faculty of Engineering, Yokohama National University, Hodogaya, Japan. mtake@ynu.ac.jp
Nishiyama
Toshiharu
T
Nomoto
Shogo
S
Shinmaru
Sachie
S
Suzuki
Ichiro
I
Koizumi
Jun-ichi
J
D001407:Bacillus / Q000502:physiology*; D001483:Base Sequence; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D020560:Proteobacteria / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S