{"id":6474,"date":"2024-06-27T12:44:29","date_gmt":"2024-06-27T12:44:29","guid":{"rendered":"https:\/\/www.ncimb.com\/?page_id=6474"},"modified":"2026-01-22T20:27:23","modified_gmt":"2026-01-22T20:27:23","slug":"mara-ecotoxicity-test","status":"publish","type":"page","link":"https:\/\/www.ncimb.com\/ecotoxicity-testing\/mara-ecotoxicity-test\/","title":{"rendered":"MARA ecotoxicity test"},"content":{"rendered":"
<\/div><\/div>
<\/div><\/div><\/div>

MARA ecotoxicity test<\/h1>\n<\/div><\/div><\/div><\/div><\/div><\/div><\/div>

MARA is an ecotoxicity test that includes 11 different species of microorganisms. It assesses toxicity by measuring their growth in the presence of the sample.\u00a0 MARA offers a more genetically diverse alternative to ecotoxicity testing using a single species of bacteria, and includes marine, freshwater and terrestrial species of bacteria as well as one yeast species.\u00a0<\/span><\/p><\/div>

Ecotoxicology testing<\/span><\/h2>
Ecotoxicology testing gives an insight into the impact that chemicals or industrial effluents could have on the environment. It can also be a useful tool for assessing sites or environmental samples for the presence of toxic compounds. Testing involves exposing living organisms to samples and assessing the effect. Living organisms commonly used for testing can include bacteria, algae, crustacea and fish.<\/div>

Benefits of bacteria for ecotoxicology testing<\/span><\/h2>

Bacteria have a number of benefits for ecotoxicity testing compared to higher order organisms:<\/p>\n\n

    \n \t
  1. Convenient format:<\/strong> bacteria are small and easy to handle in large numbers, so for example, testing can be carried out in a test tube or microtiter plate.<\/li>\n \t
  2. Fast:<\/strong> bacteria grow and respond quickly to the presence of toxins, so test results can be obtained quickly.<\/li>\n \t
  3. No ethical issues:<\/strong> testing with microorganisms has none of the ethical issues associated with testing with higher order organisms such as fish.<\/li>\n<\/ol><\/div>

    MARA includes ten species of bacteria and one species of yeast.<\/span><\/h2>
    The use of bacterial bioassays to assess toxicity is well established, with single species bacterial tests described in ISO 11348-3:2007. However, microorganisms are a highly diverse group of living things and this diversity is crucial for maintaining a healthy ecosystem. Testing with multiple strains of microorganisms is easy with the MARA ecotoxicity test and gives much more information on the toxicity of a substance than testing with a single marine strain.<\/div>

    Marine, freshwater and terrestrial species of bacteria in one test\n<\/span><\/h2>
    Ecotoxicity testing with bacteria is often based on a single strain of the marine species Aliivibrio<\/em> fischeri<\/em> (previously Vibrio<\/em> fischeri<\/em>). However MARA includes not only strains of marine bacteria, but also freshwater and terrestrial strains. Ecotoxicity with MARA therefore gives results more representative of a range of different environments and groups of organisms.<\/div>

    Test with bacteria and yeast\n<\/span><\/h2>
    MARA includes a yeast species in addition to ten different species of bacteria. Like bacteria, yeasts can be grown quickly in a microtiter plate, but as eukaryotes, they share many biological properties with higher order organisms.\u00a0 This combination makes yeasts an excellent model organisms for the study of eukaryotes.\u00a0<\/span><\/div>

    Application in the oil and gas industry\n<\/span><\/h2>
    The Oslo and Paris Commission (OSPAR) Recommendation 2012\/5 requires contracting parties, of which the UK is one, to implement a risk-based approach for the management of produced water from offshore oil and gas installations. NCIMB\u2019s MARA and LumiMARA bioassays are recommended by the UK\u2019s Department of Business, Energy and Industrial Strategy (BEIS), as part of their preferred approach to achieving this.\u00a0<\/span><\/div>