Abstract
Two galactanases (galactanase S-2 and S-39) were purified to homogeneous states from culture filtrates of alkalophilic Bacillus sp. S-2 and S-39, respectively. The galactanase from Bacillus sp. S-2 were purified by ammonium sulfate precipitation, chromatography on DEAE-Cellulofine, and by gel filtration on Cellulofine GC-200 m. The enzyme had a molecular weight (SDS-PAGE) of 40, 000 and isoelectric point of 8.6. It was most active at pH 10 and 50°C, and was stable between pH 7 and 12 (at 20°C for 15 hr), and below 45°C (at pH 10 for 15min). The galactanase from Bacillus sp. S-39 was purified by ammonium sulfate precipitation and chromatographies on DEAE-Toyopearl 650M and CM-Toyopearl 650M. The enzyne had a molecular weight (SDS-PAGE) of 36, 000 and isoelectric point of 7.1. It was most active at pH 4 and 40°C, and was stable between pH 5 and 12 (at 20°C for 15 hr), and below 60°C (at pH 4 for 15 min). Both enzymes hydrolyzed soybean galactan to produce galactooligosaccharides with very little galactose, but did not attack larch wood arabinogalactan. These enzymes were both referred to as endo-β-1, 4-galactanases (EC 3.2.1.89).
