Bacterial utilization of dissolved free amino acids, dissolved combined amino acids and ammonium in the Delaware Bay estuary:effects of carbon and nitrogen limitation

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 128:109-120 (1995) - doi:10.3354/meps128109 Bacterial utilization of dissolved free amino acids, dissolved combined amino acids and ammonium in the Delaware Bay estuary: effects of carbon and nitrogen limitation Middelboe M, Borch NH, Kirchman DL The contribution of dissolved free amino acids (DFAA), dissolved combined amino acids (DCAA) and ammonium to the C and N requirements of bacterioplankton was examined in batch cultures enriched with various sources of C and N. DFAA sustained up to 14 and 34% of the C and N requirements, respectively, during exponential growth. DCAA constituted less than 10% of the C demand in all cultures during exponential growth and up to 24% of the N demand in N-limited cultures. In C-limited cultures DFAA, DCAA, and NH4+ constituted 37 to 62%, 4 to 10% and 27 to 59% of total N uptake (DFAA + DCAA + NH4+) during exponential growth. In nitrogen-limited cultures the corresponding values were 78, 14, and 8% of total N uptake. During the stationary phase the importance of DCAA as a C and N source increased as DFAA and NH4+ concentrations decreased. In addition to allowing us to examine the contribution of various compounds to supporting bacterial production, our data on uptake and concentrations suggest that bacteria release free and combined amino acids, especially during the stationary phase. DCAA . DFAA . Ammonium . Bacterial utilization . C- and N-limitation Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 128. Publication date: November 23, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.