Note
Most isolates recovered from marine environments are Gram-negative proteobacteria, even with the use of various media and media additions to enhance recoverability. Cultivation studies with two genera of deep-water sponges yielded nine isolates that demonstrated bulbous branching rod morphology, which is usually associated with microorganisms staining Gram-positive. Gram reactions indicated that the isolates were Gram-negative, which was confirmed by partial 16S rDNA sequencing. All nine isolates were shown to be α-proteobacteria most closely related to other α-proteobacteria isolated from various sponges.