Es made use of (F .; df , P ), too as substantial Nenrichment by Nsubstrate variations in utilization by bacteria isolates (F .; df , P ) (Fig).Substrate utilizations have been lowest on recalcitrant nucleic acid and humic matter substrates for bacteria from all enrichments, followed by peptidoglycan.Es used (F .; df , P ), too as significant Nenrichment by Nsubstrate differences in utiliz