Ultrahigh bacterial production in a eutrophic subtropical Australian river: Does viral lysis short-circuit the microbial loop?

摘要: We studied trophic dynamics in a warm eutrophic subtropical river (Bremer River, Australia) to determine potential sources of dissolved organic carbon (DOC) and the fate heterotrophic bacterial production. Sustained high rates production suggested that exogenous DOC was accessible (labile). Bacterial specific growth (0.2 h21 1.8 h21) were some highest measured for natural aquatic ecosystems, which is consistent with respiration rates. Bacteria consumed 10 times more than supplied by daily algal production, result implies terrestrial driving Viruses (1011 L21) abundant bacteria; viral ratio ranged from 3.5 12 wet summer 11 35 dry spring weather typical environments. Through combination phage lysis, continuous supply lost ecosystem CO2-vented bacterial–viral loop. processing rivers may be contributing disproportionately large amounts CO2 global cycle compared temperate freshwater ecosystems.