Bacterial growth kinetics on diphenylmethane and naphthalene-heptamethylnonane mixtures.

Experiments were carried out to determine if diphenylmethane is utilized by a species of Pseudomonas (Hydrogenomonas) in the dissolved state regardless of the physical state (liquid or solid) of the undissolved diphenylmethane suspended in the medium. Bacterial growth rates in the presence of various amounts of solid or liquid diphenylmethane indicate that liquid diphenylmethane is utilized at the aqueous-diphenylmethane interface but that solid diphenylmethane is not. A Pseudomonas sp. that was isolated on naphthalene (solid), but could not utilize heptamethylnonane, was grown in the presence of various amounts of a naphthalene-heptamethylnonane mixture (liquid). The growth rates indicate that the bacterium could utilize naphthalene at the aqueous-hydrocarbon interface, which is not the case in the absence of the heptamethylnonane.