Catalyzes the addition of Glc, the second sugar moiety of the O152-antigen repeating unit, to GlcNAc-pyrophosphate-undecaprenol. N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate + UDP-alpha-D-glucose = beta-D-Glc-(1->3)-alpha-D-GlcNAc-di-trans,octa-cis-undecaprenyl diphosphate + H(+) + UDP Optimum pH is 6. Bacterial outer membrane biogenesis; lipopolysaccharide biosynthesis. Belongs to the glycosyltransferase 2 family.