SIST EN 17714:2025
(Main)Plant biostimulants - Determination of microorganisms' concentration
Plant biostimulants - Determination of microorganisms' concentration
This document specifies the general rules to determine the concentration of microorganisms present in plant biostimulants expressed as the number of active units per volume or weight, or in any other manner that is relevant to the microorganism, e.g. colony forming units per gram (cfu/g).
This document is applicable to the blends of fertilizing products where a blend is a mix of at least two of the following component EU fertilising products categories: Fertilizers, Liming Materials, Soil Improvers, Growing Media, Plant Biostimulants, and where the following category Plant Biostimulants is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If Plant Biostimulants is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a blend of fertilizing products is composed of components in equal quantity or in case the component EU fertilising products used for the blend have identical formulations , the user decides which standard to apply.
Pflanzen-Biostimulanzien - Bestimmung der Konzentration von Mikroorganismen
Dieses Dokument legt allgemeine Regeln für die Bestimmung der Konzentration von Mikroorganismen in Pflanzen-Biostimulanzien fest, ausgedrückt als Anzahl der aktiven Einheiten je Volumen oder Masse oder in einer anderen für den Mikroorganismus zutreffenden Weise, z. B. als koloniebildende Einheiten je Gramm (KBE/g).
Dieses Dokument ist für die Mischungen von Düngeprodukten anwendbar, in denen eine Mischung aus mindestens zwei der folgenden Kategorien von Komponenten-EU Düngeprodukten besteht: Düngemittel, Kalkdünger, Bodenverbesserungsmittel, Kultursubstrate, Pflanzen-Biostimulanzien und wenn die folgende Kategorie Pflanzen-Biostimulanzien prozentual den höchsten Massen- oder Volumenanteil in der Mischung bzw., bei flüssiger Form, den höchsten Trockenmasseanteil aufweist. Wenn Pflanzen-Biostimulanzien nicht den höchsten prozentualen Anteil in der Mischung ausmachen, ist die für den höchsten prozentualen Anteil geltende Europäische Norm anwendbar. Falls eine Düngemittelmischung aus Komponenten gleicher Menge besteht oder falls die für die Mischung verwendeten Komponenten-EU Düngeprodukte identische Formulierungen haben, entscheidet der Anwender, welche Norm angewendet wird.
Biostimulants des végétaux - Détermination de la concentration en microorganismes
Le présent document spécifie les règles générales pour déterminer la concentration en microorganismes présents dans les biostimulants des végétaux, exprimée en nombre d’unités actives par volume ou par masse, ou de toute autre manière pertinente pour le microorganisme, par exemple en unités formant colonies par gramme (UFC/g).
Le présent document est également applicable aux mélanges de fertilisants constitués d’au moins deux composants appartenant aux catégories de fertilisants UE suivantes : engrais, amendements minéraux basiques, amendements du sol, supports de culture, biostimulants des végétaux et, dans lesquels la catégorie Biostimulants des végétaux représente le % le plus élevé du mélange en masse ou en volume, ou dans le cas d’un liquide, en masse sèche. Si les biostimulants des végétaux ne représentent pas le % le plus élevé du mélange, la Norme européenne relative au composant représentant le % le plus élevé du mélange s’applique. Dans le cas où un mélange de fertilisants contient des composants en quantité égale ou dans le cas où les composants des fertilisants UE utilisés pour le mélange ont des formulations identiques, l’utilisateur décide quelle norme appliquer.
Rastlinski biostimulanti - Določanje koncentracije mikroorganizmov
Ta dokument določa splošna pravila za določanje koncentracije mikroorganizmov, prisotnih v rastlinskih biostimulantih, ki je izražena kot število aktivnih enot na prostornino ali maso oziroma na kateri koli drug način, ki ustreza mikroorganizmu (npr. enote, ki tvorijo kolonije na gram (cfu/g)).
Ta dokument se uporablja za mešanice sredstev za gnojenje, ki vsebujejo najmanj dve od naslednjih kategorij sredstev za gnojenje EU: gnojila, sredstva za apnenje, izboljševalci tal, rastni substrati in rastlinski biostimulanti, pri čemer rastlinski biostimulanti predstavljajo največji masni ali prostorninski odstotek mešanice ali, v primeru tekoče oblike, odstotek suhe mase. Če rastlinski biostimulanti ne predstavljajo največjega odstotka v mešanici, se uporablja evropski standard za največji odstotek mešanice. Če vsebuje mešanica sredstev za gnojenje sestavine v enakih količinah ali če imajo posamezna sredstva za gnojenje EU, uporabljena za mešanico, enake formulacije1, standard za uporabo izbere uporabnik.
General Information
Relations
Overview
EN 17714:2024 - "Plant biostimulants - Determination of microorganisms' concentration" (CEN) defines general rules for measuring and reporting the concentration of microorganisms in plant biostimulant products. The standard specifies how to express microbial load (for example as active units per volume or weight, such as colony forming units per gram (cfu/g)) and covers applicable product blends where the plant biostimulant component is the dominant fraction. EN 17714:2024 supports conformity with the EU Fertilising Products Regulation (Regulation (EU) 2019/1009) and was prepared by CEN/TC 455.
Key Topics
- Scope and applicability
- Applies to plant biostimulants and blends where the plant biostimulant is the highest mass/volume (%), or chosen by agreement when components are equal.
- Expression of results
- Concentrations reported as number of active units per volume/weight or other relevant units (e.g., cfu/g, UPM for mycorrhiza).
- Enumeration methods
- Enumeration using solid media (plate counts, pour-plate and surface inoculation techniques) and liquid media methods (e.g., Most Probable Number - MPN) when counts are low.
- Sample handling and preparation
- Sample preparation requirements reference EN 17708:2024; sampling recommendations reference EN 17702-1:2024.
- Laboratory procedures
- Guidance on dilutions, number of Petri dishes per dilution (minimum provisions to ensure reliability), incubation and calculation of results.
- Quality assurance and test reporting
- Requirements for documenting test results, laboratory practices, and traceability; Annex ZA links the standard to EU regulatory requirements.
Applications
- Quality control in manufacturing and R&D of plant biostimulants to verify microbial content, stability and label claims.
- Regulatory compliance for producers and conformity assessment bodies assessing products under the EU Fertilising Products Regulation.
- Product development and formulation decisions for companies blending fertilizers, soil improvers, growing media and biostimulants.
- Laboratory testing services that perform microbial enumeration for agritech, certification bodies, and third‑party testing labs.
Who should use this standard
- Plant biostimulant manufacturers and formulators
- Microbiology and analytical laboratories
- Regulatory authorities and conformity assessment bodies
- Certification schemes and quality managers in the fertilizer/biostimulant sector
Related Standards
- EN 17708:2024 - Preparation of sample for microbial analysis (referenced for sample prep)
- EN 17702-1:2024 - Sampling guidance (referenced for sampling procedures)
- EN 17724:2024 and other CEN/TC 455 deliverables supporting biostimulant standardization
EN 17714:2024 provides a harmonized, practical framework for reliable microbial enumeration in plant biostimulants, enabling consistent microbial analysis, product safety assessment and regulatory compliance across Europe.
Frequently Asked Questions
SIST EN 17714:2025 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Plant biostimulants - Determination of microorganisms' concentration". This standard covers: This document specifies the general rules to determine the concentration of microorganisms present in plant biostimulants expressed as the number of active units per volume or weight, or in any other manner that is relevant to the microorganism, e.g. colony forming units per gram (cfu/g). This document is applicable to the blends of fertilizing products where a blend is a mix of at least two of the following component EU fertilising products categories: Fertilizers, Liming Materials, Soil Improvers, Growing Media, Plant Biostimulants, and where the following category Plant Biostimulants is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If Plant Biostimulants is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a blend of fertilizing products is composed of components in equal quantity or in case the component EU fertilising products used for the blend have identical formulations , the user decides which standard to apply.
This document specifies the general rules to determine the concentration of microorganisms present in plant biostimulants expressed as the number of active units per volume or weight, or in any other manner that is relevant to the microorganism, e.g. colony forming units per gram (cfu/g). This document is applicable to the blends of fertilizing products where a blend is a mix of at least two of the following component EU fertilising products categories: Fertilizers, Liming Materials, Soil Improvers, Growing Media, Plant Biostimulants, and where the following category Plant Biostimulants is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If Plant Biostimulants is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a blend of fertilizing products is composed of components in equal quantity or in case the component EU fertilising products used for the blend have identical formulations , the user decides which standard to apply.
SIST EN 17714:2025 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 17714:2025 has the following relationships with other standards: It is inter standard links to SIST-TS CEN/TS 17714:2023. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 17714:2025 is associated with the following European legislation: EU Directives/Regulations: 2019/1009; Standardization Mandates: M/564, M/564 AMD 1. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
You can purchase SIST EN 17714:2025 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of SIST standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2025
Nadomešča:
SIST-TS CEN/TS 17714:2023
Rastlinski biostimulanti - Določanje koncentracije mikroorganizmov
Plant biostimulants - Determination of microorganisms' concentration
Pflanzen-Biostimulanzien - Bestimmung der Konzentration von Mikroorganismen
Biostimulants des végétaux - Détermination de la concentration en microorganismes
Ta slovenski standard je istoveten z: EN 17714:2024
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 17714
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2024
EUROPÄISCHE NORM
ICS 65.080 Supersedes CEN/TS 17714:2022
English Version
Plant biostimulants - Determination of microorganisms'
concentration
Biostimulants des végétaux - Détermination de la Pflanzen-Biostimulanzien - Bestimmung der
concentration en microorganismes Konzentration von Mikroorganismen
This European Standard was approved by CEN on 26 August 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17714:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle of the method . 6
5 Sampling . 7
6 Preparation of sample for microbial analysis . 7
7 Method for the enumeration of microorganisms . 7
7.1 General. 7
7.2 Enumeration using solid media . 7
7.2.1 General. 7
7.2.2 Number of Petri dishes per dilution . 7
7.2.3 Pour plate techniques . 8
7.2.4 Surface inoculation . 8
7.2.5 Incubation. 9
7.2.6 Calculation and expression of results obtained with solid media . 9
7.3 Enumeration and quantification using a liquid medium . 15
7.3.1 Principle . 15
7.3.2 Inoculation . 16
7.3.3 Choice of inoculation system . 16
8 Expression of results . 17
9 Test report . 18
10 Quality assurance . 18
Annex ZA (informative) Relationship of this European Standard and the essential
requirements of Regulation (EU) 2019/1009 making available on the market of EU
fertilising products aimed to be covered . 19
Bibliography . 20
European foreword
This document (EN 17714:2024) has been prepared by Technical Committee CEN/TC 455 “Plant
biostimulants”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2025, and conflicting national standards shall be
withdrawn at the latest by May 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TS 17714:2022.
— the European foreword and the Introduction have been updated;
— normative references have been updated;
— Annex ZA has been added.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this
document.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
The European Committee for Standardization (CEN) was requested by the European Commission (EC) to
draft European Standards or European Standardization deliverables to support the implementation of
Regulation (EU) 2019/1009 of 5 June 2019 [1] laying down rules on the making available on the market
of EU fertilising products (“FPR” or “Fertilising Products Regulation”).
This standardization request, presented as SR M/564 and relevant amendments, also contributes to the
Communication on “Innovating for Sustainable Growth: A Bio economy for Europe”. The interest in plant
biostimulants has increased significantly in Europe as a valuable tool to use in agriculture.
Standardization was identified as having an important role in order to promote the use of biostimulants.
The work of CEN/TC 455 seeks to improve the reliability of the supply chain, thereby improving the
confidence of farmers, industry, and consumers in biostimulants, and will promote and support
commercialisation of the European biostimulant industry.
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices and to ensure compliance
with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably trained staff.
1 Scope
This document specifies the general rules to determine the concentration of microorganisms present in
plant biostimulants expressed as the number of active units per volume or weight, or in any other manner
that is relevant to the microorganism, e.g. colony forming units per gram (cfu/g).
This document is applicable to the blends of fertilizing products where a blend is a mix of at least two of
the following component EU fertilising products categories: Fertilizers, Liming Materials, Soil Improvers,
Growing Media, Plant Biostimulants, and where the following category Plant Biostimulants is the highest
% in the blend by mass or volume, or in the case of liquid form by dry mass. If Plant Biostimulants is not
the highest % in the blend, the European Standard for the highest % of the blend applies. In case a blend
of fertilizing products is composed of components in equal quantity or in case the component EU
fertilising products used for the blend have identical formulations , the user decides which standard to
apply.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 17708:2024, Plant biostimulants — Preparation of sample for microbial analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp;
— IEC Electropedia: available at https://www.electropedia.org/
3.1
plant biostimulant
product stimulating plant nutrition processes independently of the product’s nutrient content with the
sole aim of improving the nutrient use efficiency, the tolerance to abiotic stress, the quality traits of the
plant or the plant rhizosphere or the availability of confined nutrient in soil or rhizosphere
[SOURCE: EN 17724:2024, 3.1.1.8 [3], modified – editorial changes]
3.2
microorganism
any microbiological entity, including lower fungi, bacteria and viruses, cellular or non-cellular, capable of
replication or of transferring genetic material, including dead or empty cells, microorganisms and non-
harmful elements of the media on which they were produced
[SOURCE: EN 17724:2024, 3.2.2 [3], modified – “including dead or empty cells, microorganisms and non-
harmful elements of the media on which they were produced” added]
An example of such a blend is a product with 2 claimed functions consisting of a non-microbial plant biostimulant
and an organic fertilizer composed of 1kg/kg of plant biostimulant from seaweed.
3.3
colony
localized visible accumulation of microbial mass (such as prokaryotes, bacteria, micromycetes, yeasts and
fungi) or organisms (such as Dreissena species) developed on or in a solid nutrient medium from a viable
particle or organism
Note 1 to entry: Frequently, microcolonies from nearby viable particles, before becoming visible, fuse into one
macrocolony. The number of visible colonies is, therefore, usually an underestimate of the number of viable
particles.
[SOURCE: ISO 6107:2021, 3.119 [4]]
3.4
product
portion of an identified plant biostimulant received in the laboratory for testing
3.5
laboratory sample
final sample intended for laboratory testing and in relation to microbiological testing, each separate
segment sample intended for laboratory testing
3.6
initial suspension
suspension (or solution) of the laboratory sample (3.5) in a defined volume of an appropriate diluent
3.7
Unit Potential Mycorrhizal
UPM
unit of counting for mycorrhiza
where
U is unit, spore or propagule of any type able to initiate mycorrhiza formation in a host plant’s root;
P is potential, since the development of the symbiosis depend on different factors (soil, plant,
agriculture practises, competition with other soil borne microorganisms, etc.);
M is mycorrhizal, since the inoculum is able to synthesize new mycorrhizae in association with plant
roots depending on factors previously cited
EXAMPLE UPM per gram (% spores, % propagules) (in vivo, in vitro).
4 Principle of the method
The method for determining the concentration of microorganisms has been developed to provide a
general method for the enumeration of the microorganisms present in the plant biostimulant. The results
are expressed as the number of active units by volume or mass, or in any other way relevant to the
microorganism, for example colony forming units per gram or the UPM for Mycorrhizae.
5 Sampling
Sampling is not part of the method specified in this document (see EN 17702-1:2024 [2]). If there is no
specific International or European Standard, it is recommended that the parties concerned come to an
agreement on this subject.
It is important that the laboratory receives a sample which is representative and has not been damaged
or changed during transport or storage.
6 Preparation of sample for microbial analysis
The test sample shall be prepared from the laboratory sample in accordance with EN 17708:2024. If there
is no specific International or European Standard, it is recommended that the parties concerned come to
an agreement on this subject.
7 Method for the enumeration of microorganisms
7.1 General
When assessing the microbiological quality of plant biostimulants, it is often not enough to know only
which microorganisms are present. In most cases, the quantitative aspect is equally important, which
brings about the need to enumerate microorganisms [5]. This may be achieved in various ways: through
direct examination (microscopy), by inoculating solid or liquid media. However, this document only
covers enumeration using solid and liquid media.
Enumeration on solid media is based on the capacity of many microorganisms to produce colonies in or
on agar media that can be recognized as such with the naked eye or with the aid of a simple magnifying
glass.
If the level of bacteria is expected to be very low (less than 10 colonies in or on a plate at the lowest
dilution), enumeration using liquid media is recommended (e.g. Most Probal Number (MPN)) to improve
the statistical reliability of the results.
7.2 Enumeration using solid media
7.2.1 General
The different methods for enumeration using solid media (number of Petri dishes/dilutions, pour plate
techniques, surface inoculation, incubation) are described in the different chapters below and/or in
specific standards for microorganism detection/determination.
Petri dishes should be labelled with the sample number, dilution, date and any other desired information.
Dilutions should be selected to ensure that plates containing the appropriate number of colonies are
obtained (see 7.2.6.1) and to overcome any possible inhibitory properties.
Use a separate sterile pipette for transfers from each dilution, except if working from the highest dilution
to the lowest dilution.
7.2.2 Number of Petri dishes per dilution
For enumeration techniques in plant biostimulant(s), one plate per dilution shall be used with at least
two successive dilutions. Two plates per dilution may also be used to improve reliability.
If only one dilution is used, then two plates of this dilution shall be used to improve reliability of the
results.
For laboratories that do not operate under quality assurance principles, two plates per dilution shall be
used to improve reliability of the results.
7.2.3 Pour plate techniques
Withdraw the defined volumes of the dilution to be examined, touching the tip of the pipette against the
side of the tube to remove excess liquid adhering to the outside. Lift the sterile Petri dish lid just high
enough to insert the pipette, then dispense the contents.
After removing the tempered agar medium from the water bath, blot the bottle dry with a clean towel to
prevent water from contaminating the plates. Avoid spilling the medium on the outside of the container
or on the inside of the plate lid when pouring. To avoid contamination of the medium, hold the bottle in
a near horizontal position.
Also avoid setting down the bottle between pouring steps. Pour the agar medium at (44 ± 1) °C to
(47 ± 1) °C into each Petri dish (generally 18 ml to 20 ml of agar in 90 mm Petri dishes and 45 ml to 50 ml
in 140 mm Petri dishes, to obtain at least 3 mm of thickness) within 15 min of inoculation (to avoid
aggregation of colonies). Avoid pouring the molten medium directly on the inoculum. Immediately mix
the molten medium and the inoculum carefully so as to obtain a homogeneous distribution of the
microorganisms within the medium, e.g. by gently moving the dish backwards and forwards, from side
to side and in a circular direction. Allow to cool and solidify by placing the Petri dish on a cool horizontal
surface (the solidification time of the agar shall not exceed 10 min).
7.2.4 Surface inoculation
7.2.4.1 General
Methods of plating designed to produce only surface colonies on agar plates have certain advantages. The
morphology of surface colonies is easily observed, improving the analyst’s ability to distinguish between
different types of colonies.
Use pre-poured plates, of at least 3 mm of thickness of the agar medium, that are level and free from air
bubbles and surface moisture.
To facilitate uniform spreading, the surface of solidified agar should be dried in accordance with
EN ISO 11133:2014 [5] or as specified in the relevant International Standard so that the inoculum is
absorbed within 15 min.
7.2.4.2 Spreading-spatula method
Using a sterile pipette, transfer the inoculum (usually 0,1 ml or 0,5 ml) of the liquid test sample, or of the
initial suspension in the case of other samples, to the agar plate (90 mm or 140 mm in diameter,
respectively). Repeat this step for the next decimal dilution (the colonies to be counted will then be
−1 −2
present in a dilution step of 10 in the case of liquid sample materials and 10 in the case of other sample
materials) and, if necessary, repeat for further decimal dilutions.
The limit of enumeration can be lowered by a factor of 10 by inoculating 1,0 ml of the test sample if liquid,
or 1,0 ml of the initial suspension for other products, either on the surface of one large agar plate
(140 mm) or on the surface of three small agar plates (90 mm). In both cases, if only one dilution is used,
prepare duplicates by using two large plates or six small ones.
Using a spreading spatula made of glass, plastic or steel (for example made from a glass rod and shaped
like a hockey stick of about 3,5 mm in diameter and 20 cm long, bent at right angles at about 3 cm from
one end and flattened at the ends by heating), spread the inoculum as quickly as possible evenly over the
agar surface without touching the side walls of the Petri dish. Allow the inoculum to absorb with the lids
in place for about 15 min at room temperature.
In certain cases (as stated in the relevant International Standard), the inoculum may be deposited on a
membrane then spread as described previously.
As impacted by EN ISO 11133:2014/A1:2018 and EN ISO 11133:2014/A2:2020
7.2.5 Incubation
Unless otherwise stated in specific standards, invert dishes once they have been inoculated, and place
them quickly in the incubator set at the appropriate temperature. If excessive dehydration occurs (e.g. at
(55 ± 1) °C or in the event of strong air circulation), wrap the dishes loosely in plastic bags prior to
incubation or use any similar system of equivalent efficiency.
During the incubation period, minor variations in the incubation temperature may be unavoidable and
acceptable, for example during the usual operations of loading or unloading the incubator, but it is
important that these periods are kept to a minimum. The duration of these variations should be
monitored to ensure that they do not have a significant effect on the result.
It may sometimes be useful to laboratory operations to refrigerate inoculated dishes before incubation
for no more than 24 h. If this is done, the laboratory shall ensure that this practice does not affect the
resulting counts.
Generally, Petri dishes should be stacked no more than six heights for aerobic incubation and the stacks
should be separated from each other and from the incubator walls by at least 25 mm. However, higher
stacks with less spacing may be acceptable in incubators fitted with air circulation systems; in this case,
the temperature distribution should be verified. After incubation, the dishes should normally be
examined immediately. They may, however, be stored, unless otherwise specified in specific standards,
for up to 48 h in a refrigerator. Refrigerated storage is only acceptable if it has been shown to have no
effect on the numbers, appearance or the subsequent confirmation of the colonies. With certain media
containing indicator dyes, refrigerated plates should be allowed to equilibrate at room temperature
before examining, to ensure that the correct colour is regained.
7.2.6 Calculation and expression of results obtained with solid media
7.2.6.1 Counting of colonies
Following the period of incubation stated in the specific standard, count the colonies (total colonies,
typical colonies or presumed suspect colonies) for each dish containing up to and including 300 colonies
(or any other number stated in the specific standard).
In this subclause, the cases dealt with correspond to the following general cases:
— inoculation of one 90 mm-diameter Petri dish per dilution, and at least two successive dilutions are
performed;
— maximum countable number for the total colonies present: 300 per dish;
— maximum total number of colonies (typical and atypical) present on a dish when counting typical or
presumptive colonies: preferably 300 per dish;
— maximum countable number for typical or presumptive colonies: 150 per dish;
— number of presumptive colonies inoculated for identification or confirmation in each dish retained:
in general 5.
These figures shall be defined in the specific standards.
The methods of calculation defined in the following are for the cases which occur most frequently when
tests are carried out in accordance with good laboratory practice. Special cases can occasionally occur
(e.g. the number of colonies in two dishes with the same dilution may show significant discrepancy or the
ratio of the dilution factors used for two successive dilutions may be very different) and it is therefore
necessary for the counting results obtained to be examined and interpreted by a qualified microbiologist
and, if necessary, rejected.
...
SIST EN 17714:2025は、植物バイオスティミュラントにおける微生物の濃度を測定するための標準文書であり、その範囲は多岐にわたります。この標準は、植物バイオスティミュラントに存在する微生物の濃度を、体積または重量あたりの活性単位数として、またはコロニー形成単位（cfu/g）など、微生物に関連する他の方法で表現するための一般的なルールを明示しています。 この文書の強みは、肥料製品の混合物に適用される点にあります。具体的には、少なくとも2つのEU肥料製品カテゴリー（肥料、石灰材料、土壌改良剤、成長媒体、植物バイオスティミュラントなど）から成る混合物が対象であり、植物バイオスティミュラントがその混合物において質量または体積で最も高い割合を占める場合、標準が適用されるという明確なルールがあります。これにより、利用者はどの標準を適用するかを容易に判断でき、結果として標準の実用性が向上します。 また、文書は液体状の製品の場合、乾燥質量に基づいてという条件を設けている点も見逃せません。このような柔軟性は、さまざまな植物バイオスティミュラントの特性に応じた適切な評価を促進し、業界における標準化の重要性を再確認させます。 全体として、SIST EN 17714:2025は、植物バイオスティミュラントの微生物濃度の測定に関する非常に関連性の高い標準であり、農業分野における製品の品質向上に寄与することが期待されます。
SIST EN 17714:2025 표준은 식물 생물자극제에서 미생물의 농도를 결정하기 위한 일반 규칙을 명확하게 제시합니다. 이 문서는 미생물의 농도를 부피 또는 질량 단위의 활성 단위 수로 표현하며, 예를 들어, 그램당 배양 집합체 수(cfu/g)와 같은 관련 방식으로도 설명합니다. 이 표준의 강점 중 하나는 다양한 비료 제품 조합에 적용될 수 있다는 점입니다. 특히, 비료 제품 조합은 비료, 석회 재료, 토양 개선제, 성장 매체, 식물 생물자극제와 같은 최소 두 가지 EU 비료 제품 카테고리의 혼합물로 정의됩니다. 여기서 식물 생물자극제의 비율이 혼합물의 질량이나 부피에서 가장 높은 경우에만 이 표준이 적용된다는 점은 사용자가 실제 상황에 따라 신중히 적용할 수 있도록 돕습니다. 또한, 혼합물의 성분이 같은 비율로 구성되거나 동일한 공식을 가진 EU 비료 제품이 사용되는 경우, 사용자가 적용할 표준을 선택할 수 있다는 유연성은 이 표준의 또 다른 장점입니다. 이는 사용자가 다양한 혼합 조건에서 혼란을 줄이고 표준화된 절차를 통해 신뢰할 수 있는 결과를 도출하는 데 기여합니다. SIST EN 17714:2025 표준의 중요성과 관련성은 오늘날 농업 및 원예 산업에서 더욱 강조되고 있으며, 미생물의 정량적 결정이 이러한 비료의 효과성을 평가하는 데 필수적임을 입증합니다. 이 표준은 식물 생물자극제의 품질 관리 및 생산 과정에서 발생할 수 있는 다양한 문제를 해결하는 데 중요한 역할을 합니다.
Le document SIST EN 17714:2025 établit des règles générales pour la détermination de la concentration des microorganismes dans les biostimulants végétaux, exprimée en unités actives par volume ou poids, ou de toute autre manière pertinente, comme les unités formant des colonies par gramme (cfu/g). Cette norme est d'une grande importance dans le domaine des biostimulants, car elle garantissant des méthodes de mesure précises et fiables, essentielles pour les producteurs et les utilisateurs. L'un des principaux atouts de cette norme réside dans son application aux mélanges de produits fertilisants, incluant les biostimulants végétaux en tant que catégorie principale. Cela permet une harmonisation des pratiques de mesure dans le secteur des fertilisants, en facilitant la comparaison entre différents produits et en assurant une transparence pour les consommateurs. De plus, en tenant compte des mélanges où la catégorie des biostimulants est prépondérante, la norme renforce la crédibilité des biostimulants sur le marché, favorisant ainsi une adoption plus large de ces produits. La pertinence de la norme SIST EN 17714:2025 est par ailleurs renforcée par sa flexibilité dans l'application. En cas d'égalité dans la quantité des composants d'un mélange ou d'identité des formulations, l'utilisateur a la liberté de choisir quelle norme appliquer, ce qui encourage une personnalisation des méthodes en fonction des spécificités des produits. Cela ouvre la voie à une innovation continue dans le secteur des biostimulants, avec des implications positives pour la durabilité et l'efficacité des pratiques agricoles. Enfin, cette norme contribue de manière significative à la sécurité alimentaire et à la préservation de l'environnement en s'assurant que les biostimulants vegetaux utilisés respectent des standards de qualité élevés. Ainsi, le SIST EN 17714:2025 joue un rôle clé dans la promotion de l'utilisation responsable et efficace des biostimulants sur le marché européen.
Die Norm SIST EN 17714:2025 behandelt die Bestimmung der Mikrobenkonzentration in Pflanzenbiostimulanzien. Ihr Anwendungsbereich umfasst die allgemeinen Regeln zur Ermittlung der Konzentration von Mikroorganismen, die in diesen Produkten vorkommen, und zwar in Form von aktiven Einheiten pro Volumen oder Gewicht, oder in einer anderen relevanten Darstellung, wie etwa koloniebildenden Einheiten pro Gramm (cfu/g). Ein wesentlicher Stärke dieser Norm liegt in ihrer Klarheit und Genauigkeit. Die Festlegung, dass Mischungen von Düngemittelprodukten - bestehend aus mindestens zwei der folgenden Kategorien: Düngemittel, Bodenverbesserungsmittel, Wachstumsmedien und Pflanzenbiostimulanzien - unter spezielle Regularien fallen, fördert einheitliche Prüfmethoden, die für die gesamte Branche von Bedeutung sind. Durch die Definition von Mischungen, bei denen Pflanzenbiostimulanzien den höchsten Anteil haben, wird die Relevanz der Norm für die Praxis deutlich, da sie eine präzise Identifikation und Quantifizierung von Mikroorganismen ermöglicht. Ein weiterer Vorteil der Norm ist die Flexibilität, die sie dem Anwender bietet. Wenn Pflanzenbiostimulanzien nicht den höchsten Prozentanteil in einer Mischung ausmachen, ist es klar, welche europäische Norm dann zur Anwendung kommt. Dies stellt sicher, dass die Norm für verschiedene Mischungsverhältnisse anwendbar bleibt und gleichzeitig die Konsistenz in der Produktbewertung gewährleistet ist. Die Regelung für den Fall, dass die Bestandteile in gleicher Menge vorhanden sind oder identische Formulierungen aufweisen, gibt den Benutzern die Möglichkeit, die anzuwendende Norm selbst zu wählen, was den praktischen Nutzen erhöht. Die SIST EN 17714:2025 hat somit eine zentrale Bedeutung für die Qualitätskontrolle und -sicherung in der Herstellung und Verwendung von Pflanzenbiostimulanzien. Ihre präzise Ausrichtung auf die Bestimmung der Mikrobenkonzentration trägt nicht nur zur Sicherstellung der Produktqualität bei, sondern auch zur Förderung eines umweltbewussten Umgangs mit Düngemitteln und Pflanzenbiostimulanzien.
The SIST EN 17714:2025 standard provides a comprehensive framework for determining the concentration of microorganisms in plant biostimulants. The primary focus of this standard is to establish the rules necessary for accurately quantifying microorganisms, which is vital for ensuring the efficacy and safety of plant biostimulants in agricultural applications. One of the significant strengths of this standard is its clear definition of active units per volume or weight, including alternative expressions like colony forming units per gram (cfu/g). This level of specificity ensures that users can consistently assess the concentration of microorganisms, which is crucial for regulatory compliance and product labeling. The document also accommodates various forms of fertilizers, including blends that involve Plant Biostimulants, emphasizing its applicability across multiple fertilizing product categories. This inclusivity enhances the standard's relevance in the market, as it meets the needs of diverse agricultural practices. Moreover, the standard's provision regarding the highest percentage component in a blend enhances clarity for manufacturers and users alike. It guides users through the selection process of applying the appropriate standard based on the composition of their products. This feature not only simplifies compliance but also promotes transparency in formulation practices, leading to better consumer trust. In essence, SIST EN 17714:2025 plays a pivotal role in the realm of plant biostimulants by providing standardized methods to determine microorganism concentrations, thereby underpinning the quality and reliability of these products in the agriculture sector. Its strengths lie in its clear definitions, inclusive scope, and practical guidance for blends, which collectively align with industry needs and regulatory frameworks.
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