TitleDirect single-cell biomass estimates for marine bacteria via Archimedes' principle.
Publication TypeJournal Article
AuthorsCermak N, Becker JW, Knudsen SM, Chisholm SW, Manalis SR, Polz MF
JournalISME J
Date2017 Mar

Microbes are an essential component of marine food webs and biogeochemical cycles, and therefore precise estimates of their biomass are of significant value. Here, we measured single-cell biomass distributions of isolates from several numerically abundant marine bacterial groups, including Pelagibacter (SAR11), Prochlorococcus and Vibrio using a microfluidic mass sensor known as a suspended microchannel resonator (SMR). We show that the SMR can provide biomass (dry mass) measurements for cells spanning more than two orders of magnitude and that these estimates are consistent with other independent measures. We find that Pelagibacterales strain HTCC1062 has a median biomass of 11.9±0.7 fg per cell, which is five- to twelve-fold smaller than the median Prochlorococcus cell's biomass (depending upon strain) and nearly 100-fold lower than that of rapidly growing V. splendidus strain 13B01. Knowing the biomass contributions from various taxonomic groups will provide more precise estimates of total marine biomass, aiding models of nutrient flux in the ocean.

Alternate JournalISME J
PubMed ID27922599
PubMed Central IDPMC5322313
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