I was once told by my supervisor that cloudiness in an actinomycete broth culture indicates contamination. Recently, I inoculated an actinomycete, which I had previously isolated from a marine snail, in ISP2 broth. Since I am not able to tell if it's contaminated by merely observing the broth culture, I decided to make a smear. In the smear, I was able to observe some actinomycete hyphae along with some round cell-like things. I am unsure if this is indicative of contamination.