This document gives general guidelines for the detection and identification of the specified microorganism Escherichia coli in technical and formulated biostimulant products, both in liquid and solid state, and also the horizontal method for the enumeration of \u00df-glucuronidase-positive Escherichia coli in plant biostimulants products (both in liquid and solid state). The qualitative method described in this document is based on the detection of Escherichia coli in a non-selective liquid medium (enrichment broth), followed by isolation on a selective agar medium. Other methods can be appropriate, depending on the level of detection required. NOTE For the detection of Escherichia coli, subcultures can be performed on non-selective culture media followed by suitable identification steps (e.g. using identification kits). The quantitative method described in this document uses a colony-count technique at 44 \u00b0C on a solid medium containing a chromogenic ingredient for detection of the enzyme \u00df-glucuronidase. WARNING \u2014 Strains of Escherichia coli which do not grow at 44 \u00b0C and, in particular, those that are \u00df glucuronidase negative, such as Escherichia coli O157, will not be detected.<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 4 Principle 4.1 Qualitative method 4.2 Quantitative method 5 Diluent and culture media 5.1 General 5.2 Broth and culture media in the qualitative method 5.2.1 Enrichment broth <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 5.2.2 Selective culture media: Tryptone-bile-glucuronic medium (TBX) for isolation of Escherichia coli 5.3 Diluent and culture media in the quantitative method 5.3.1 Diluent 5.3.2 Culture media: Tryptone-bile-glucuronic medium (TBX) 6 Apparatus and glassware 7 Handling of plant biostimulants products and sampling 8 Procedure 8.1 General 8.2 Qualitative method 8.2.1 General <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 8.2.2 Solid formulations: Wettable Powder (WP), Water dispersible granules (WDG), Pellets, granules, microgranules (slow release) formulation 8.2.3 Liquid formulations: water based formulations and oil based (emulsifiable concentrate – EC) formulations 8.2.4 Incubation of the inoculated enrichment broth 8.2.5 Detection and identification of Escherichia coli 8.2.5.1 Isolation 8.2.5.2 Identification of Escherichia coli <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 8.3 Quantitative method 8.3.1 Test portion and initial suspension 8.3.1.1 General 8.3.1.2 Liquid – water based – formulations 8.3.1.3 Liquid \u2013 oil based (emulsifiable concentrate – EC) formulations 8.3.1.4 Solid – Wettable Powder (WP) formulations 8.3.1.5 Solid – Water dispersible granules (WDG) formulations 8.3.1.6 Solid \u2013 Pellets, granules, microgranules (slow release) formulations 8.3.1.7 Solid – substrate 8.3.2 Serial dilutions <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 8.3.3 Inoculation (surface plate method) and incubation 8.3.4 Counting the colony-forming units 9 Expression of results 9.1 Expression of results in the qualitative test 9.2 Expression of results in the quantitative test <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 10 Test report <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | Annex A (informative)Enrichment broth in the qualitative method A.1 General A.2 Enrichment broth A.2.1 Eugon LT 100 broth A.2.1.1 General A.2.1.2 Composition A.2.1.3 Preparation <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | A.3 Other enrichment broth A.3.1 General A.3.2 Fluid lactose medium A.3.2.1 Composition A.3.2.2 Preparation <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | Annex B (informative)Selective agar medium in the qualitative and quantitative method B.1 General B.2 Selective agar medium for isolation B.2.1 Tryptone-bile-glucuronic medium (TBX) B.2.1.1 Composition B.2.1.2 Preparation <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | B.3 Other selective agar medium for isolation B.3.1 MacConkey agar medium B.3.1.1 Composition B.3.1.2 Preparation B.3.1.3 Morphological characteristics of Escherichia coli on MacConkey agar medium B.4 Selective agar medium for confirmation B.4.1 Levine eosin-methylene blue agar medium (EMB agar medium) B.4.1.1 Composition <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | B.4.1.2 Preparation B.4.1.3 Morphological characteristics of Escherichia coli on EMB agar medium <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | Annex C (informative)Diluent in the quantitative method C.1 General C.2 Phosphate Buffered Saline (PBS) C.2.1 Composition C.2.2 Preparation <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Annex D (informative)Neutralization of the antimicrobial properties of the product D.1 General D.2 Suitability of the detection method <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | D.3 Interpretation of suitability test results <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Plant biostimulants. Determination of Escherichia coli<\/b><\/p>\n |