explain how an organism that possesses the citrate lyase enzyme might not test positively on Simmons citrate agar. Is this a false negative result

The Simmons citrate test determines the action of the citrate permease enzyme

Explanation:

The Simmons citrate assay is used to determine the ability of an organism to utilize citrate as a carbon source by determining its ability for transporting citrate into the cell, which is due to the action of the citrate permease. Moreover, citrate lyase is an enzyme that converts citrate to oxaloacetate, which is independent of how citrate is transported into the cell. In consequence, an organism may not produce citrate permease but at the same time be citrate lyase-positive.

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bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.