Non-reducing polyketide synthase involved in the biosynthesis of bifonsecin B, a dimeric gamma-naphthopyrone (PubMed:31067027). The first step in the biosynthesis of bifonsecin B is the production of gamma-naphthopyrone precursor YWA1 by the non-reducing polyketide synthase albA, via condensation of one acetyl-CoA starter unit with 6 malonyl-CoA units (PubMed:31067027). YWA1 is then methylated by bfoE at position C-6 to yield foncesin which is further methylated at position C-8 by bfoD to produce fonsecin B (Probable). A key enzyme in the biosynthetic pathway is the cytochrome P450 monooxygenase bfoB which catalyzes the oxidative dimerization of fonsecin B to bifonsecin B (PubMed:31067027). Bfob also catalyzes the oxidative dimerization of rubrofusarin B into nigerone (PubMed:31067027). The stereoselectivity of bfoB is influenced by the two natural monomeric substrates; homodimerization of fonsecin B yields a stereochemically pure biaryl, M-foncerine B, while rubrofusarin B yields a mixture of enantiomers M- and P-nigerone (PubMed:31067027). acetyl-CoA + 6 H(+) + 6 malonyl-CoA = 6 CO2 + 7 CoA + H2O + YWA1 Secondary metabolite biosynthesis. Multidomain protein; including a starter unit:ACP transacylase (SAT) that selects the starter unit; a ketosynthase (KS) that catalyzes repeated decarboxylative condensation to elongate the polyketide backbone; a malonyl-CoA:ACP transacylase (MAT) that selects and transfers the extender unit malonyl-CoA; a product template (PT) domain that controls the immediate cyclization regioselectivity of the reactive polyketide backbone; and 2 acyl-carrier protein (ACP) domains that serve as the tethers of the growing and completed polyketide via their phosphopantetheinyl arm. The C-terminal region is involved in Claisen-type cyclization of the second ring of naphthopyrone.