Complex sentence: New species have been cultured since 1987, when Woese's review paper was published, that are sufficiently different to warrant a new phylum, mostly thermophiles and often also chemolithoautotrophs, such as Aquificae, which oxidises hydrogen gas.
Split into simpler sentences: New species have been cultured since 1987, when Woese's review paper was published, that are sufficiently different that they warrant a new phylum. Most of these are thermophiles and often also chemolithoautotrophs, such as Aquificae, which oxidises hydrogen gas.