Effects of mutations of genes encoding several putative glycosyltransferases on biofilm formation and EPS production in <i>Xoc</i> wild-type and <i>ΔrpfG</i> mutant backgrounds.

<p>(A) Elevated biofilm formation in <i>Xoc ΔrpfG</i> was reduced to the wild-type level when <i>xagA</i>, <i>xagB</i> and <i>gumD</i>, but not <i>pgaA</i> or <i>pgaC</i> was deleted singly in the <i>ΔrpfG</i> genotype. The full length <i>xagA</i> and <i>gumD</i> genes restored the ability of biofilm formation in <i>ΔrpfG/xagA</i> and <i>ΔrpfG/gumD</i> mutants, respectively. (B) The ability of <i>ΔgumD</i> to form biofilm was greatly attenuated in the wild-type background, but was restored by complementation. Biofilm formation in the <i>ΔpgaA</i>, <i>ΔpgaC, ΔxagA</i> and <i>ΔxagB</i> single mutants was not altered compared to the wild-type strain. (C) EPS production was significantly reduced in the <i>ΔgumD</i> mutant, but not in <i>ΔpgaA</i>, <i>ΔpgaC, ΔxagA</i> and <i>ΔxagB</i> mutants compared to the wild-type. These experiments were repeated at least three times with similar results.