False positive fecal coliform in biosolid samples assayed using A-1 medium.
Two most probable number (MPN) methods-lauryl tryptose broth with Escherichia coli broth confirmation and direct A-1 broth incubation (A-1)--were compared for the enumeration of fecal coliform in lime-treated biosolid. Fecal coliform numbers were significantly higher using the A-1 method. Analysis of positive A-1 tubes, however, indicated that a high percentage of these were false positives. Therefore, the use of A-1 broth for 40 CFR Part 503 Pathogen Reduction (CFR, 1993) compliance testing is not recommended.
Baker
Katherine H
KH
Environmental Engineering Program, Penn State Capital College, Middletown, PA 17057, USA. khb4@psu.edu
Redmond
Brady
B
Herson
Diane S
DS
D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry*; D004755:Enterobacteriaceae / Q000254:growth & development / Q000302:isolation & purification*; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification; D005189:False Positive Reactions; D005243:Feces / Q000382:microbiology*; D014871:Water Microbiology
D003470:Culture Media