prEN XXX

Soil improvers and growing media - Enumeration of Escherichia coli prEN XXX

Scope

This document specifies a method for the enumeration of Escherichia coli (E. coli) in soil improvers, soil improver blends, growing media and growing media blends. This document applies to material in solid form (including pre-shaped growing media) and liquid form.

This document specifies a colony-count technique at 44 °C ± 1 °C on a solid medium containing a chromogenic ingredient for the detection of the enzyme β-D-glucuronidase.

Strains of E. coli which do not grow at 44 °C ± 1 °C and, in particular, those that are β D glucuronidase-negative, such as E. coli O157, will not be detected

In case of any doubt on whether E. coli colonies are present on the primary agar medium, the indole test may be used as an additional confirmation test.

NOTE This method has been validated in an interlaboratory study with specific products that were present on the market during the study (Annex C). Products can change over time regarding their microbial composition and other characteristics, and the formulation of the products may also change in the future.

Related legislation

Legislation related to this standard