| Technique | HYDROGEN SULFIDE
PRODUCTION ,(/,)/,( |
| Principle | Hydrogen sulfide is produced from
the amino acid cysteine by the presence of the enzyme
cysteine desulfurase. It is also produced from the
reduction of inorganic sulfur compounds such as sulfates.
The hydrogen sulfide will react ith heavy metal salts
such as lead acetate or ferrous sulfate to form black
metal sulfides Hydrogen sulfide production by bacteria is
such a common feature that of itself it has little
differential value. With a delicate indicator almost all
the enteric bacteria can be shown to have the ability to
produce hydrogen sulfide. with a poor medium or a less
sensitive indicator, only strong producers are detected. Important in identification of Salmonella |
| Cautions | Lead acetate papers are 10 times
more sensitive than lead acetate in the medium and they
eliminate the toxicity of the lead for the growing
bacteria. In the Brucella group the time of hydrogen sulfide production may be significant; this is found by changing the lead acetate papers each day. |
| Method | Triple sugar iron or ferrous chloride gelatin are recommended. |
| Results | |
| Positive control | |
| Negative control | |
| Reagents | |
| Reference |