Fig 1.
Map showing sampling sites.
Fig 2.
Schematics of small-scale (A) and large-scale (B) TFF systems for the concentration and separation of microbes from water samples.
Abbreviations are as follows: Ret, retentate; Perm, permeate; kDa, kiloDalton; BC, bacterial concentration; BF, bacterial filtration; VC, viral concentration; VF, viral filtration; 30 kDa filter1, 30 kDa cut-off filter with regenerated cellulose material produced by Millipore; 30 kDa filter2, 30 kDa cut-off filter with polyethersulfone material produced by Millipore; 30 kDa filter3; 30 kDa cut-off filter with polyethersulfone material produced by Pall.
Fig 3.
Efficiencies of 0.22 μm and 1000 kDa membranes filtration of bacteria (A) and viruses (B) with small-scale TFF system for contrasting marine environments.
Error bars depict the standard error of the mean expressed in percentage. *, p < 0.05; **, p < 0.01.
Fig 4.
Efficiencies of filtration by bacteria-size membranes for bacteria (A) and viruses (B), and bacterial concentration by Millipore 0.22 μm membrane for samples from contrasting marine environments (C) in large-scale TFF system.
Error bars depict the standard error of the mean expressed in percentage. *, p < 0.05; **, p < 0.01.
Fig 5.
The relationships between bacterial abundance and the efficiency of bacterial recovery
Fig 6.
Efficiencies of viral filtration by three 30 kDa membranes for samples from contrasting marine environments in small-scale TFF(A). Comparison of viral filtration by Millipore and Pall 30 kDa cut-off membranes (B) and for samples from contrasting marine environments using Millipore 30 kDa cut-off membrane (C) in large-scale TFF.
Error bars depict the standard error of the mean expressed in percentage. *, p <0.05; **, p<0.01.
Fig 7.
Comparison of samples from Station N2 in Xiamen coastal water (A) and Station WP5 in the western Pacific Ocean (B) in virus-like particle's Side Scatter (C) by flow cytometry.