In the course of searching for more suitable
medium substrates for the isolation of actinomycetes,
we found that humic acid extracted
from soil was more effective than the normally
used nutrients. Therefore, we developed
HV agar containing humic acid as the sole
source of carbon and nitrogen. On this
agar plates, not only streptomycete colonies
but also many other actinomycetes belonging
to Micromonospora, Microbispora, Streptosporangiurn,
Dactylosporangium genera and other
related ones appeared and developed quite
abundantly, whereas the development of
true bacteria was restricted. In this paper,
we report on the new medium, HV agar, as
weU as on the results obtained when using it.
The media was also compared with other
currently used media for the isolation of
actinomycetes.