TY - JOUR
T1 - Screening for Bacillus subtilis group isolates that degrade cyanogens at pH 4.5-5.0.
AU - Abban, Stephen
AU - Brimer, Leon
AU - Abdelgadir, Warda S.
AU - Jakobsen, Mogens
AU - Thorsen, Line
PY - 2013/1/5
Y1 - 2013/1/5
N2 - Cyanogenic food crops abound in nature with important crops like cassava forming the staple food for over half a billion people. Detoxification by hydrolysis of cassava cyanogenic glycosides often involves acid fermentation, and in some of these processes Bacillus species are encountered. Forty Bacillus spp. (20 Bacillus subtilis, 11 Bacillus licheniformis, 7 Bacillus sonorensis, 2 Bacillus cereus) isolated from acid fermented primary starters to produce Gergoush, a Sudanese fermented snack, were screened for their ability to grow and to hydrolyze linamarin, the major cyanogen found in cassava at pH levels below 5.0; also the cyanogen amygdalin was assessed. The B. subtilis isolates grew in both HCl and lactic acid environments from pH. 4.5-6.0 while being able to break down the cyanogenic glycosides. The B. licheniformis and B. sonorensis isolates grew and degraded cyanogens at pH. 5.0 in a HCl environment, while two B. cereus isolates used in the study showed no breakdown reaction under all conditions tested. One B. subtilis isolate was observed to have substrate specificity between the breakdown of linamarin and amygdalin. We conclude that some Bacillus spp. isolates are important in the microbiological breakdown of cyanogens in cassava fermentations even at pH. 4.5-5.0 though further investigations are required.
AB - Cyanogenic food crops abound in nature with important crops like cassava forming the staple food for over half a billion people. Detoxification by hydrolysis of cassava cyanogenic glycosides often involves acid fermentation, and in some of these processes Bacillus species are encountered. Forty Bacillus spp. (20 Bacillus subtilis, 11 Bacillus licheniformis, 7 Bacillus sonorensis, 2 Bacillus cereus) isolated from acid fermented primary starters to produce Gergoush, a Sudanese fermented snack, were screened for their ability to grow and to hydrolyze linamarin, the major cyanogen found in cassava at pH levels below 5.0; also the cyanogen amygdalin was assessed. The B. subtilis isolates grew in both HCl and lactic acid environments from pH. 4.5-6.0 while being able to break down the cyanogenic glycosides. The B. licheniformis and B. sonorensis isolates grew and degraded cyanogens at pH. 5.0 in a HCl environment, while two B. cereus isolates used in the study showed no breakdown reaction under all conditions tested. One B. subtilis isolate was observed to have substrate specificity between the breakdown of linamarin and amygdalin. We conclude that some Bacillus spp. isolates are important in the microbiological breakdown of cyanogens in cassava fermentations even at pH. 4.5-5.0 though further investigations are required.
U2 - 10.1016/j.ijfoodmicro.2012.11.019
DO - 10.1016/j.ijfoodmicro.2012.11.019
M3 - Journal article
C2 - 23261810
SN - 0168-1605
VL - 161
SP - 31
EP - 35
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
IS - 1
ER -