Name: Aerobic Biodegradation Testing of Materials Using a Natural Marine Seawater Inoculum and Closed Loop Respirometer (Video) | JoVE Journal
Uploaded: 2025-10-24T13:40:00.000+00:00
Duration: 8 min 43 s
Description: Learn aerobic biodegradation testing of materials using natural marine seawater inoculum and closed loop respirometry. This standardized protocol enables reliable quantification of biodegradation rates for environmental science research.

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5 minutes

The authors thank Columbus Instruments and the Biodegradability Laboratory at the School for Marine Science and Technology at the University of Massachusetts Dartmouth for technical support and facility access. Funding for the Columbus Instruments Micro-Oxymax Respirometry System and laboratory start-up was provided by PrimaLoft and the Massachusetts Technology Collaborative.

<ol><li>Avio, C. G., Gorbi, S., Regoli, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Plastics+and+microplastics+in+the+oceans%3A+From+emerging+pollutants+to+emerged+threat%5BTitle%5D)+AND+%22Marine+Environ+Res%22%5BJournal%5D)">Plastics and microplastics in the oceans: From emerging pollutants to emerged threat.</a> Marine Environ Res. 128, 2-11 (2017).</li>
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<li>Andrady, A. L. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aAndrady%2C+AL+%22Plastics+and+Environmental+Sustainability%22">Plastics and Environmental Sustainability</a>. , John Wiley and Sons. (2015).</li>
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<li>Gilbert, J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+taxonomic+and+functional+diversity+of+microbes+at+a+temperate+coastal+site%3A+a+%27multi-omic%27+study+of+seasonal+and+diel+temporal+variation%5BTitle%5D)+AND+%22PLoS+ONE%22%5BJournal%5D)">The taxonomic and functional diversity of microbes at a temperate coastal site: a 'multi-omic' study of seasonal and diel temporal variation.</a> PLoS ONE. 5 (11), e15545(2010).</li>
<li>Chafee, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Recurrent+patterns+of+microdiversity+in+a+temperate+coastal+marine+environment%5BTitle%5D)+AND+%22ISME+J%22%5BJournal%5D)">Recurrent patterns of microdiversity in a temperate coastal marine environment.</a> ISME J. 12 (1), 237-252 (2018).</li>
<li>Jannasch, H. W., Eimhjellen, K., Wirsen, C. O., Farmanfarmaian, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microbial+degradation+of+organic+matter+in+the+deep+sea%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Microbial degradation of organic matter in the deep sea.</a> Science. 171 (3972), 672-675 (1971).</li>
<li>Zumstein, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Biodegradation+of+synthetic+polymers+in+soils%3A+Tracking+carbon+into+CO2+and+microbial+biomass%5BTitle%5D)+AND+%22Sci+Adv%22%5BJournal%5D)">Biodegradation of synthetic polymers in soils: Tracking carbon into CO2 and microbial biomass.</a> Sci Adv. 4, eaas9024(2018).</li>
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The authors declare no competing financial interests.

Positive-control performance determines test validity. A minimum of 70% biodegradation of a readily marine biodegradable positive control substrate (e.g., analytical grade cellulose, Kraft paper, etc.), based on its theoretical maximum gas yield, is required. This benchmark verifies favorable conditions and sufficient microbial activity in the natural seawater during the incubation. Failure to meet this threshold indicates a potential issue with replicate preparation, seawater inoculum handling (i.e., microbial community...

Plastic waste poses a threat to marine ecosystems and human health1. The growing concern over plastic pollution, along with marine debris from any materials in the ocean, underscores the need for sustainable solutions, such as improved end-of-life waste management and biodegradable materials that readily biodegrade in the marine environment. Unlike traditional synthetic plastics, which persist for decades to centuries and generate microplastics that accumulate in food webs2,3,4, biodegradable materials, organic components of carbon, may be metabolized to CO2 and methane (CH4), or assimilated into microbial biomass5. Understanding biodegradation of materials in seawater is therefore key for quantifying and mitigating the environmental impacts of marine debris.
Biodegradation in the marine environment is controlled by the interaction of spatiotemporal variables, including light and nutrient availability, pressure, temperature, microbial species composition, and physicochemical nature and structure of the polymer, which all determine the rate, degree, and mechanism of degradation6. These variables present a significant challenge for laboratory-based biodegradation studies simulating marine environments. This standard operating procedure (SOP) uses natural seawater as the inoculum, capturing the in situ microbial community present, and records relevant variables including seawater dissolved nutrients, particulate carbon and nitrogen, chlorophyll, salinity, pH, and temperature. This controlled laboratory-based approach optimizes conditions for promoting mineralization and allows for direct biodegradation measurements that are not feasible in situ. The ASTM International D6691-24a, Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in the Marine Environment by a Defined Microbial Consortium or Natural Sea Water Inoculum (hereafter ASTM D6691), and this SOP were developed as a rapid, reliable screening tool for assessing the biodegradability of materials7,8,9,10.
Aligned with ASTM D6691, a screening test for inherent polymer biodegradability, this protocol evaluates biodegradation of materials under optimal conditions, 30 &#176;C, maximum surface area from milled sample, and excess inorganic nutrients (nitrogen, 130 mg/L; phosphorus, 23 mg/L)9, to promote mineralization and prevent nutrient limitations. While screening tests offer valuable initial insights, further testing, such as coastal and deep-sea moorings, which measure weight loss as a function of time, might be necessary for a comprehensive evaluation under natural marine conditions. Since these coastal and deep-sea mooring tests estimate biodegradation based on weight loss as a function of time10,11, researchers should first perform this screening test, which directly measures microbial metabolism, before going to an in situ coastal and deep-sea mooring experiment, which is also more expensive.
The ASTM D6691 standard test method outlines procedures for evaluating the aerobic biodegradation of non-floating plastic materials in marine environments. This standard, along with specification standards, such as ASTM D7081 (Standard Specification for Non-Floating Biodegradable Plastics in the Marine Environment; focusing on biodegradability in an aqueous medium, currently withdrawn from ASTM and being reballoted), provides a framework for certifying experimental polymers as marine biodegradable9,12. In general, a specification is a consensus standard from ASTM International that sets requirements that a material, product, or system must meet. It ensures that materials designed to biodegrade in marine environments do so within acceptable timeframes and do not release potentially toxic additives, such as dyes or plasticizers.
Building on ASTM D6691, this protocol quantifies the rate and degree of aerobic biodegradation of materials (experimental substrate) in natural seawater and expands on positive material controls (i.e., cellulose, Kraft paper, chitin/chitosan), historically shown to be biodegradable in the marine environment7,9,10. The goal of this method is to screen materials under optimized conditions to see if the materials biodegrade in the marine environment. The inoculum leverages the natural microbial community present in the seawater, collected following specific guidelines outlined in ASTM. These guidelines emphasize using seawater with a salinity of approximately 32, collected from a location free from pollutants like sewage, chemical dumping, or oil spills. The test uses an automated closed-loop respirometer with 250 mL reactor vessels maintained at 30 &#176;C, each containing 75 mL of seawater and ~20 mg of the experimental or control substrate8. Mineralization (biodegradation) is expressed as the percentage of net carbon biogas (CO2-C) produced relative to the initial carbon mass added. This method does not account for carbon assimilation into microbial biomass.

<table><tbody><tr><td>0.2 &amp;micro;m, 47 mm cellulose acetate filter</td><td>Geotech Geofilter</td><td>83100056</td><td>Filter seawater</td></tr><tr><td>100 mL Volumetric pipet</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>13-650-2U</td><td>Class A; acid leached and rinsed with deionized water</td></tr><tr><td>100-600 mL Glass beakers</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>50-194-5690</td><td>Class A; acid leached and rinsed with deionized water</td></tr><tr><td>20 mm milling balls</td><td>Retsch</td><td>53680062</td><td>Stainless steel. Used with milling jar for cryogenic milling of polymer</td></tr><tr><td>50 mL milling jars</td><td>Retsch</td><td>14620216</td><td>Stainless steel. Used with Mixer Mill 400 and 20 mm milling balls for cryogenic milling of polymer</td></tr><tr><td>75 mL Volumetric pipet</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>13-650-2T</td><td>Class A; acid leached and rinsed with deionized water</td></tr><tr><td>Air pump and bubbler system</td><td>Tetra</td><td>77846</td><td>Aerate seawater during pre-incubation equilibration</td></tr><tr><td>Aluminum foil</td><td>Fisherbrand</td><td>01-213-100</td><td>Cover for autoclaving and clean storage</td></tr><tr><td>Ammonium chloride (NH&lt;sub&gt;4&lt;/sub&gt;Cl)</td><td>Thermo Fisher Scientific, Fisher Chemical</td><td>A661-500</td><td>Seawater nutrient spike</td></tr><tr><td>Analytical balance</td><td>Mettler</td><td>AT201</td><td>To weigh out experimental and control substrates</td></tr><tr><td>Autoclave</td><td>Tuttnauer</td><td>MFI-TTN-3870EA</td><td>To sterilize vessels and lid assemblies</td></tr><tr><td>Base Micro-Oxymax 120VAC Single Channel</td><td>Columbus Instruments</td><td>0135-8000</td><td>Used to store positive controls and polymer</td></tr><tr><td>Calibration gas</td><td>Airgas</td><td>X03NI92P3000001</td><td>Primary Standard Gas Mixtures; 2.7% Carbon dioxide, 4.5% Methane, balance Nitrogen</td></tr><tr><td>Computer Monitor</td><td>Dell</td><td>210-BMKK</td><td>Dell Pro 24 Plus USB-C Hub Monitor. Used with computer to run Micro-Oxymax software</td></tr><tr><td>Cryogenic Gloves</td><td>Thermo Fisher Scientific, Tempshield, Cryo Gloves</td><td>11-394-306</td><td>Used to handle liquid nitrogen</td></tr><tr><td>Dial Thermometer</td><td>Thermo Fisher Scientific, H-B Instrument Durac</td><td>13-201-433</td><td>Calibrated thermometer for seawater temperature at time of collection</td></tr><tr><td>Disposable pipettes</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>13-711-7M</td><td>Rinse sides of vessel to free up material</td></tr><tr><td>ENC52 Temperature and Light Controlled Enclosure</td><td>Columbus Instruments</td><td>4740-4054</td><td>Maintain temperature and light conditions</td></tr><tr><td>Flask Tongs</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>S07387</td><td>Used to handle milling jars in liquid nitrogen</td></tr><tr><td>Flasks, 250 mL</td><td>DWK Life Sciences</td><td>14395-250</td><td>Sample reactor vessels</td></tr><tr><td>Glass Shell Vials with Plug Style Closures</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>03-339-26D</td><td>Sample storage</td></tr><tr><td>H22PX Handheld Depthfinder</td><td>West Marine, Norcross Marine</td><td>6849368</td><td>Determine seawater collection site depth</td></tr><tr><td>Handheld GPS 73</td><td>Garmin</td><td>10-01504-00</td><td>Used to determine seawater collection site location</td></tr><tr><td>HDPE Pan</td><td>Thermo Scientific, Nalgene</td><td>13-359-26</td><td>Used to acid leach glassware&amp;nbsp; in 10% HCl solution</td></tr><tr><td>Hydrochloric Acid (acidic water solution)</td><td>Thermo Fisher Scientific, Fisher Chemical</td><td>A144-212</td><td>Certified ACS Plus, 36.5 to 38.0%. CO&lt;sub&gt;2&lt;/sub&gt; sensor check and acid leaching glassware</td></tr><tr><td>Laminar flow hood</td><td>Air Science</td><td>FLOW-48-A</td><td>Minimize airborne contaminants during sample preperation</td></tr><tr><td>Large Niskin; Beta Plus Bottle Only - 8.2L Horizontal, PVC</td><td>Science First</td><td>3-1980-H65</td><td>For seawater collection from pier or boat</td></tr><tr><td>Liquid Nitrogen Pan</td><td>Thermo Fisher Scientific, Bel Art Magic Touch 2</td><td>11-999-063</td><td>Hold Liquid Nitrogen&amp;nbsp;</td></tr><tr><td>Liquid Nitrogen Transfer Vessel, 10 L</td><td>Thermo Scientific</td><td>TY509X2</td><td>Store and dispense liquid nitrogen for cryomilling</td></tr><tr><td>Liquid Nitrogen, Industrial Grade, 22 PSI</td><td>Airgas</td><td>NI 180LT22</td><td>Used to embrittle and mill polymers</td></tr><tr><td>Mechanical Sieve Shaker</td><td>Humbolt, Grainger</td><td>5DPL6</td><td>Sieve analysis for particle size distribution</td></tr><tr><td>Micro-Oxymax&amp;nbsp;</td><td>Columbus Instrumentts</td><td>7395-113-D64</td><td>Silicon sealed o-ring, metal port w/ 3 fittings, and GL45 screw cap&amp;nbsp;</td></tr><tr><td>Micro-Oxymax 10 Channel Expansion Interface</td><td>Columbus Instruments</td><td>0135-8101</td><td>Respirometry System Component</td></tr><tr><td>Micro-Oxymax Respirometer (3% CO&lt;sub&gt;2&lt;/sub&gt; sensor)</td><td>Columbus Instruments</td><td>0135-8403</td><td>Non-dispersive infrared</td></tr><tr><td>Mixer Mill 400</td><td>Retsch</td><td>207450001</td><td>Mixer Mill 400. Used for cryogenic milling of polymer</td></tr><tr><td>Motorized pipette controller</td><td>Eppendorf</td><td>4430000018</td><td>Transfer seawater to sample reactor vessels</td></tr><tr><td>Narrow-Mouth Amber HDPE Lab Quality Bottle, 1 L</td><td>Thermo Scientific, Nalgene</td><td>02-923-5</td><td>Discrete wholewater seawater sample</td></tr><tr><td>Nylon Mesh 20 Micron</td><td>ELKO Filtering Co.</td><td>41718</td><td>Used to sieve raw seawater to remove larger heterogeneous particulates</td></tr><tr><td>Open Air Orbital Shaker</td><td>Thermo Fisher Scientific</td><td>SK4000</td><td>Maintain orbital motion of reactor vessels during incubation</td></tr><tr><td>OptiPlex 5090 Small Form Factor Computer</td><td>Dell</td><td>C0SL03</td><td>Desktom computer used to run Micro-Oxymax software&amp;nbsp;</td></tr><tr><td>pH/Cond Meter</td><td>Mettler Toledo, SevenExcellence S470-Basic</td><td>30046252</td><td>Benchtop pH/conductivity meter to measure initial and final seawater inoculum</td></tr><tr><td>Polyethylene bottle, 60 mL</td><td>Qorpak</td><td>PLC-03564</td><td>Discrete filtered seawater sample</td></tr><tr><td>Potassium phosphate monobasic (KH&lt;sub&gt;2&lt;/sub&gt;(PO&lt;sub&gt;4&lt;/sub&gt;))</td><td>Thermo Fisher Scientific, Fisher BioReagents</td><td>BP362-500</td><td>Seawater nutrient spike</td></tr><tr><td>Precision balance</td><td>Sartorius</td><td>Practum2102-1S</td><td>To weigh out tare and whole weight of vessels</td></tr><tr><td>Round Carboy, 20 L</td><td>Thermo Fisher Scientific</td><td>02961A</td><td>Acid-leached for seawater storage</td></tr><tr><td>Safety Goggles</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>19-181-513</td><td></td></tr><tr><td>Scoopula</td><td>Thermo Fisher Scientific, Fisherbrand, Scoopula</td><td>01-257-567</td><td>Stainless steel lab scoopula</td></tr><tr><td>Sieves</td><td>Advantech, Grainger</td><td>40PR18-40PR55</td><td>Stainless steel sieves. Number of sieves and sizes will depend on the material being tested.</td></tr><tr><td>Sigmacell Cellulose, Type 101</td><td>Sigma-Aldrich</td><td>435236-250G</td><td>Powder, positive control substrate</td></tr><tr><td>Sodium Bicarbonate</td><td>Thermo Fisher Scientific, Fisher Chemical</td><td>S233-500</td><td>CO&lt;sub&gt;2&lt;/sub&gt; sensor check</td></tr><tr><td>Sodium sulfite, anhydrous, 98%</td><td>Thermo Fisher Scientific, Thermo Scientific Chemicals</td><td>AAA1793336</td><td>CO&lt;sub&gt;2&lt;/sub&gt; sensor check</td></tr><tr><td>Thermometer/thermistor probe</td><td>Fisherbrand</td><td>15-079-700</td><td>Verify incubator temperature</td></tr><tr><td>Traceable Precision Dial Barometer</td><td>Fisherbrand</td><td>14-648-51</td><td>Record atmospheric pressure at start of experiment</td></tr><tr><td>Victor Medium Duty Hydrogen, Methane Two Stage Regulator, CGA - 350</td><td>AirGas</td><td>VIC0781-3559</td><td>Calibration gas regulator&amp;nbsp;</td></tr><tr><td>Volumetric flasks, 2 L</td><td>Thermo Fisher Scientific, Fisherbrand</td><td>FB4002000</td><td>Class A; acid leached and rinsed with deionized water. Used to prepare nutrient spiked seawater.</td></tr><tr><td>Weigh pans</td><td>Thermo Fisher Scientific</td><td>02-202-101</td><td>Polyethylene</td></tr></tbody></table>

aerobic biodegradation testing of materials using a natural marine seawater inoculum and closed loop respirometer

Aerobic Biodegradation Testing of Materials Using a Natural Marine Seawater Inoculum and Closed Loop Respirometer

Proper assessment of biodegradable materials depends on the wide adoption of standard test methods. Although such methods exist, testing capacity remains limited, constrained by cost and the start-up time to establish new laboratories. This modified screening protocol is based on the ASTM International D6691-24a, Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in the Marine Environment by a Defined Microbial Consortium or Natural Sea Water Inoculum. It assesses the biodegradation of materials in a marine environment, comparing results to positive and negative controls, and uses a natural seawater inoculum supplemented with ammonium and phosphate to prevent nutrient limitation. Materials are exposed to this nutrient-enriched seawater and incubated at 30 &#176;C. A Micro-Oxymax respirometer measures the production of biogas (carbon dioxide, CO2) over time. The degree of mineralization (biodegradation) is determined by calculating the proportion of material-derived carbon converted to biogas-carbon. The percent CO2 production, expressed as a fraction of the measured or theoretical carbon content, is reported as a function of time. The closed-loop respirometry system accommodates a range of reactor vessels, prepared in triplicate for each material, a negative control (seawater inoculum only), and a positive control (thin-layer chromatography cellulose). This method is important for evaluating materials in the marine environment and addresses global pollution prevention.

The results from marine biodegradation tests are presented. Biodegradation was assessed for each sample by measuring the proportion of carbon converted to carbon dioxide. Cumulative, rate, and percent biodegradation plots typically exhibit a lag phase, followed by a growth phase, and eventually a plateau. The timing and magnitude of these phases depend on the sample material, experimental conditions, and the composition of the seawater inoculum.
Seawater collected year-round from a temperate e...

The protocol describes standard operating procedure for testing potentially biodegradable materials both synthetic and natural under aerobic conditions using a natural seawater inoculum and automated closed loop respirometry system.

Proper assessment of biodegradable materials depends on the wide adoption of standard test methods. Although such methods exist, testing capacity remains ...

Our research quantifies the aerobic biodegradation rate and degree of natural materials in the marine environment using natural seawater inoculum for data comparison. Our current experimental challenges include limited testing capacity and a lack of infrastructure to meet growing demand for biodegradation testing, while ensuring uniform and transparent methods across laboratories. To begin, collect 10 to 20 liters of sea water into a 20-liter acid-leached carboy using a large Niskin bottle.Transport the filled carboy back to the laboratory. Transfer one liter of whole sea water from the carboy into an acid-leached, one-liter amber HDPE bottle for particulate carbon and nitrogen analysis. Filter it through a 0.2-micrometer, low-nitrogen, cellulose acetate membrane.Now, fill a one, two, or four-liter volumetric flask halfway with seawater. If the seawater has high-particulate organic matter, sieve it through a 20-micrometer mesh to remove large heterogeneous particles. Then collect 60 milliliters of filtrate into an acid-leached polyethylene bottle for dissolved inorganic and organic nitrogen and phosphorus analysis.Loosely cover the opening of the carboy to allow aerobic conditions. Store in the dark at 30 degrees Celsius for up to seven days. Next, place 10 to 15 grams of the experimental substrate in a 50-milliliter, stainless-steel milling jar.With a 20-millimeter steel ball. Submerge the milling jar in liquid nitrogen for 15 minutes to embrittle it. Secure the milling jar in the ball mill attachment.Then set the instrument to 30 hertz and two minutes, 30 seconds, and press start. Perform milling four times with 30 seconds of cooling in liquid nitrogen between each cycle. Mill the substrate to a uniform particle size between 0.10 and 0.25 millimeters prior to the start of the test.Using a precision balance with 0.001-gram sensitivity, weigh out 0.5 grams per liter of ammonium chloride and 0.1 grams per liter of monobasic potassium phosphate. Add the inorganic nutrients to the flask. Bring the volume to mark using seawater.Then drop in a stir bar and stir on a stir plate until all salts dissolve. On an analytical balance, weigh out 20 milligrams of the experimental or control substrate. Record the full readout weight and set the vial aside.To set up the reactor vessels, use an acid-leached, 75-milliliter volumetric pipette with a motorized pipette controller and aspirate the sea water to dispense 75 milliliters of the nutrient-supplemented sea water into each reactor vessel. Remove approximately three milliliters of sea water from each vessel. Then place it on a clean surface next to the vessel to rinse the milled substrate from the teared vial.Now transfer the milled substrate into the corresponding reactor vessel from the teared vial. Place an O-ring on the reactor vessel rim. Then place a two-port lid over the O-ring and secure with a screw cap.Connect each reactor vessel to its matching gas or condensation lines. Firmly insert the gas lines into the appropriate inlet and outlet ports on the lid. Turn on the shaker platform to 0.05G in continuous mode.Visually check that all vessels are secure, then close the incubator door. On the instrument software, navigate to Experiment and click Setup. Enter the start and end channel numbers from the dropdown menus corresponding to occupied channels.Set the refresh threshold to 0.50. Refresh interval to NA and refresh window to Auto. Then check the box for purge sensors under Miscellaneous Setup.Ensure that the Auto Volume Measurement, Oxygen Consumption Positive and Enable Open Flow Mode are not selected. Set the sample interval to 8.00. Then set the gas and time units as required.If using a primary temperature probe for incubation temperature correction, ensure Manually Enter Chamber Temps is not selected. Check the box for Venting Mode and ensure Drain Mode is not selected. Now, select Chamber Setup and enter the descriptive channel labels.If a leak is indicated, then ensure the O-ring is clean, seated and free of particles or fibers. Tighten the screw cap. Inspect the tubing connections at inlet and outlet.Trim worn or deformed tubing ends with a sharp blade to produce clean cuts. From the menu, select Tools, then click on Service Menu, and confirm that the primary temperature probe measures 30 degrees Celsius with two degree variations and is stable. Click Run to begin the experiment.Save the experiment file under a descriptive name, including the date, and record the file name on the data sheet. Cumulative carbon dioxide production over 84 days confirmed expected performance. Over 84 days, cellulose showed rapid carbon dioxide production after a short lag, and reached about 700 micromoles.PHA showed a slower initial rate over three days. And the sea water control remained low at 150 micromoles. Individual negative control replicates showed low variability, with all curves remaining close together.Cellulose positive control replicates showed consistently low variability, confirming stable performance across all four replicates. In the negative result dataset, replicate five exhibited an anomalous spike in carbon dioxide production rate, likely due to labile organic matter, but its cumulative production began to plateau at 100 micromoles. Replicates one in six had lower cumulative carbon dioxide production compared to others, suggesting potential technical issues.The standard error of average cumulative carbon dioxide production in the negative control was 2.5%indicating low variability among replicates. The standard error for the cellulose positive control was 0.83%further confirming high reproducibility of the biodegradation assay. PHA has high mineralization close to the positive control with standard error comparable to the control.This protocol addresses the gap in standardized accessible methods for screening the biodegradability of materials in the marine environment for industry, academia and regulatory bodies. The protocol provides a faster standardized way to directly measure this biodegradation, with shorter test duration in simultaneous sample evaluation. The protocol enables high throughput standardized testing for material and laboratory comparability for machine learning and predictive modeling of material performance.

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Research

JoVE Journal

Environment

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Aerobic Biodegradation Testing of Materials Using a Natural Marine Seawater Inoculum and Closed Loop Respirometer

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