Catalyzes methylation of the sphingoid base component of glucosylceramides (GluCers) at the C9-position. Sphingolipid C9-methylation requires 4,8-desaturated ceramides as substrates. Glucosylceramides play important roles in growth, differentiation and pathogenicity. The methyl group at the C9-position distinguishes fungal glucosylceramides from those of plants and animals, and may thus play a role in host-pathogen interactions enabling the host to recognize the fungal attack and initiate specific defense responses. Not necessary for vegetative growth at low temperatures, but plays a role in hyphal formation on solid medium. a (4E,8E)-4-sphinga-4,8-dienine ceramide + S-adenosyl-L-methionine = a 9-methyl-(4E,8E)-sphinga-4,8-dienine ceramide + H(+) + S-adenosyl-L-homocysteine Lipid metabolism; sphingolipid metabolism. Produces only non-methylated glucosylceramides. Has a decreased hyphal growth rate. Belongs to the CFA/CMAS family.