All the isolates were screened for the production of
hydrogen cyanide (HCN) by adopting the methods of
Lorck [29] and Castric and Castric [30] with slight
modifications. Endophytic bacterial cultures were
grown in nutrient broth supplemented with 4.4 gm/l
glycine [31] and were streaked on nutrient agar
supplemented with 4.4 gm/l glycine. A disc of Whatman
filter paper No. 1 of diameter equal to the diameter of
Petri plate (impregnated with alkaline picric acid
solution (0.5 % w/v) was placed in upper lid of
inoculated Petri plates under aseptic condition. Plates
were sealed with parafilm and were incubated upside
at 28 + 10C for 24-72 hr. The control plates without
inoculation of endophytic bacteria were also
maintained. Change in color from yellow to light brown,
moderate brown or to strong reddish brown was taken
as indication of HCN production