Detoxification of cyanides in cassava flour by linamarase of Bacillus subtilis KM05 isolated from cassava peel

Abstract

Defensive cyanogenic glucoside linamarin accounts for 80% cyanide content of cassava and is known to cause severe diseases upon continual consumption. Detoxification of this cyanide would enhance the nutritive quality and hence market value of cassava flour. We isolated cyanogenic glucoside utilizing indigenous bacteria from cyanide rich cassava peel waste and exploited their potential for detoxification. Among the isolates, Bacillus subtilis KM05 utilized cyanogenic glycoside through assimilatory degradation with the release of hydrogen cyanide and ammonia. The partially purified linamarase (53 KDa) enzyme from this organism showed considerable activity (9.6 U/ml) and effected rapid cyanide reduction in cassava flour. The results indicate scope for enzymatic detoxification of cassava cyanide without compromising nutrients in sago industries.

Key words: Cyanogenic glucoside, enzymatic treatment, linamarin, linamarase.