Substrate (biology)

Abstract: Five species of rumen bacteria with overlapping substrate fermentative capabilities were tested for substrate preferences and evidence of catabolite regulatory mechanisms. All five bacteria showed evidence of some type of catabolite regulatory mechanism. In the six-substrate test system that was used, utilization of every substrate was inhibited by another substrate in at least one of the bacteria. Inhibited versus noninhibited substrate data suggest that the five bacteria have different strategies of substrate utilization and thus occupy separate niches in the rumen. The significance of these observations to understanding the rumen ecosystem is discussed.

Abstract: Marine hard-substrate communities are important ecological and evolutionary resources for paleontologists and neontologists, yet their study is handicapped by numerous terms that are used inconsistently. A rationalized nomenclature system is proposed for plants and animals that encrust or bore natural marine hard substrates. The terms describe the identity of the colonizing organism, the nature of the substrate, and the location of the colonist (on the surface or within the substrate). These terms follow simple principles, making them easy to construct and interpret. A new collective term also is introduced: a sclerobiont is any organism (animal or plant) fouling any kind of hard substrate.