Catalyzes the NAD(P)(+)-dependent oxidation of alpha-ketoglutaric semialdehyde (alphaKGSA) to alpha-ketoglutarate. Is involved in a degradation pathway of L-arabinose that allows A.brasilense to grow on L-arabinose as a sole carbon source. Prefers NAD(+) to NADP(+) as a cosubstrate. Displays broad substrate specificity: exhibits the highest activity with alphaKGSA and succinic semialdehyde as substrates, but to a lesser extent, is also active with glutaraldehyde, benzaldehyde, and a number of aldehydes from C3 to C8. 2,5-dioxopentanoate + H2O + NADP(+) = 2-oxoglutarate + 2 H(+) + NADPH 2,5-dioxopentanoate + H2O + NAD(+) = 2-oxoglutarate + 2 H(+) + NADH H2O + NAD(+) + succinate semialdehyde = 2 H(+) + NADH + succinate The catalytic efficiency with alphaKGSA in the presence of NAD(+) is 5.2- and 6.2-fold higher than with succinic semialdehyde and glutaraldehyde, respectively. When NADP(+) is used as a cosubstrate, the catalytic efficiency with alphaKGSA drops 6-fold compared with that in the presence of NAD(+). Homotetramer. Induced by L-arabinose, and to a lesser extent by D-glucose or a nutrient-rich medium. Cells lacking this gene are unable to grow on L-arabinose as a sole carbon source but grow on a nutrient-rich medium or D-glucose at the same growth rate as the wild-type strain. Moreover, both the wild-type and the mutant strains can grow on D-glucarate or D-galactarate as a sole carbon source. A.brasilense possesses two isozymes of alphaKGSA dehydrogenase with essential physiological roles for the L-arabinose and D-glucarate/D-galactarate metabolisms, respectively. The L-arabinose isozyme was isolated in PubMed:16835232 and is described in this entry. The other NAD(+)-preferring isozyme of alphaKGSA dehydrogenase is induced dramatically by D-glucarate or D-galactarate but not by L-arabinose. Belongs to the aldehyde dehydrogenase family.