Adeiubigbe, E.Y. & Odunfa, S.A. 1990. Growth and extracellular enzyme production by strains of Bacillus species isolated from fermenting African locust bean, iru. Journal of Applied Bacteriology69, 662–671. Seven strains of Bacillus subtilis group, isolated from fermented African locust bean (iru), were screened for proteolytic activity. Three strains (BS2, BL2 and BP2), which were found to be highly proteolytic, were compared on the basis of growth and extracellular enzyme production in media with and without locust bean. AH had their optimum pH for growth between 7.0 and 9.0. The three strains produced varied amounts of amylase, polygalacturonase, galac‐lanase and sucrase. The amounts of amylase and polygalacturonases produced by strain BS2 were significantly higher (at α= 0.5) than those of strains BL2 and BP2. None of the strains produced pectinmethylesterase in nutrient broth with or without African locust bean. Although the three strains were lipolytic on tributyrin agar plates, only trace amounts of lipase were detected titrimetrically in broth medium containing African locust bean. The three strains produced varying levels of sucrase and galactanases. Phytase activity was not detected in the broth culture of strain BS2. The presence of African locust bean in culture medium generally enhanced the production of extracellular enzymes significantly (at α= 0.05) in the three strains.

Wood samples of red pine (Pinus resinosa) were subjected to freezing for 60 h at a temperature of -20°C and then thermally modified in soy oil at a temperature of 220°C for 2 and 4 h. The pH, acid buffering capacities, alkali buffering capacities, surface energy and resistance to termite attack were determined. Wood, subjected to pre-freezing as a pre-treatment method, has lower surface energy, pH values and acid buffering capacity. The effects on pH and acid buffering capacity were only significant during the 2-h treatment. The effect of pre-freezing on the alkali buffering becomes noticeable only after 4 h of thermal modification. The effect of this pre-treatment method varies largely with the treatment temperature. After 2-h thermal modification, the unfrozen wood showed higher susceptibility than the frozen wood while the reverse was the case as the treatment time was increased to 4 h.

Proteinases were excreted by strains of Bacillus subtilis during fermentation of African locust bean cotyledons. Those excreted by one strain were purified and characterized by ammonium sulphate precipitation, ion‐exchange chromatography (IEC), gel filtration, inhibition tests and polyacrylamide gel electrophoresis (PAGE). Three proteinases and an esterase without proteolytic activity were identified. A serine proteinase which showed a high degree of hydrophobicity and a neutral proteinase were present. The third proteinase showed both proteolytic and esterolytic activities, and had multiple electrophoretic mobilities on polyacrylamide gel.

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