Bradyrhizobium japonicum

[Eric Johansen]

Mike O'Hara (mjohara at pacbell.net) wrote:
: icurkovic at HWCN.ORG wrote:
: > 
: > Hello,
: > 
: > I've never tried a newgroup before so this is all kind of new to me.
: > 
: > Anyway, I was wondering if there is anyone who could help me out. I'm a
: > 3rd year university student taking a intro microbiology course. I just
: > finished a lab where we have to identify an unknown bacteria.
: > 
: > I have narrowed it down to 2 choices: Bradyrhizobium japonicum and
: > Serratia marcescens. I am pretty sure it is the latter, but I want to know
: > if someone could answer a question for me: Are most colonies of B.
: > japonicum red or white?
: > 

B. japonicum colonies are usually white although some strains produce
a brown pigment that could look reddish.
S. marcescens is red.

: > I am also in some dire need of some biochemical test results for this
: > species...indole test, urea, lead acetate, Vogues Proskauer & methyl red
: > test. Bergey's Manual of Bacteriology has been pretty useless for this
: > species.
: > 
: > I would appreciate any kind of help. Thanks!
: > 
: > Ivan
:   An unusual but very appropriate differentiation would be to find out
: if the organism causes nodules to form on soyabeans.....

Excellent suggestion although lab strains often lose the
ability to nodulate.
: Mike