Abstract
Lytic infection of bacteria by viruses releases nutrients during cell lysis
and stimulates the growth of primary producers, but the path by which these
nutrients flow from lysates to primary producers has not been traced. This
study examines the remineralisation of nitrogen (N) from Vibrio lysates by heterotrophic bacterioplankton and its transfer to primary
producers. In laboratory trials, Vibrio sp. strain PWH3a was
infected with a lytic virus (PWH3a-P1) and the resulting 36.0 µmol L−1 of dissolved organic N (DON) in the lysate was added to cultures
containing cyanobacteria (Synechococcus sp. strain DC2) and a
natural bacterial assemblage. Based on the increase in cyanobacteria, 74 %
(26.5 µmol L−1 N) of the DON in the lysate was remineralised and
taken up. Lysate from Vibrio sp. strain PWH3a labeled with
15NH4+ was also added to seawater containing natural microbial
communities, and in four field experiments, stable isotope analysis indicated
that the uptake of 15N was 0.09 to 0.70 µmol N µg−1 of
chlorophyll a. The results from these experiments demonstrate that DON from
lysate can be efficiently remineralised and transferred to phytoplankton, and
they provide further evidence that the viral shunt is an important link in
nitrogen recycling in aquatic systems.
Citation
ID:
229776
Ref Key:
shelford2018biogeosciencesvirus-mediated