major lineages of bacteria
... that the number of known major lineages of bacteria has more than quadrupled in the past 20 years but many of them cannot be grown in a lab?
... that the number of known <b id="mwFfE"><a href="./Bacterial_phyla" id="mwFfI" rel="mw:WikiLink" title="Bacterial phyla">major lineages of bacteria</a></b> has more than quadrupled in the past 20 years but many of them cannot be <a href="./Microbiological_culture" id="mwFfM" rel="mw:WikiLink" title="Microbiological culture">grown in a lab</a>?