** ph : 7.3

** memo : Sterilize solutions A and B separately at 121°C for 15 min., cool to 50°C and then mix aseptically with filter-sterilized solution C and 5.0 ml of filter-sterilized standard vitamin solution (see medium 626).

RBA is an ammonium-free medium which has successfully been used for the isolation, growth and purity check of a broad spectrum of nitrogen fixing bacteria (Ref. 3363). For microaerophilic nitrogen-fixing bacteria use semisolid medium with 0.3% end concentration of agar and incubate the liquid cultures under 10% (v/v) air and 90% (v/v) N

** additional actions :