High throughput and miniaturised systems for biodegradability assessments

Abstract

The society demands safer products with a better ecological profile. Regulatory criteria have been developed to prevent risks for human health and the environment, for example, within the framework of the European regulation REACH (Regulation (EC) No 1907, 2006). This has driven industry to consider the development of high throughput screening methodologies for assessing chemical biodegradability. These new screening methodologies must be scalable for miniaturisation, reproducible and as reliable as existing procedures for enhanced biodegradability assessment. Here, we evaluate two alternative systems that can be scaled for high throughput screening and conveniently miniaturised to limit costs in comparison with traditional testing. These systems are based on two dyes as follows: an invasive fluorescent dyes that serves as a cellular activity marker (a resazurin-like dye reagent) and a noninvasive fluorescent oxygen optosensor dye (an optical sensor). The advantages and limitations of these platforms for biodegradability assessment are presented. Our results confirm the feasibility of these systems for evaluating and screening chemicals for ready biodegradability. The optosensor is a miniaturised version of a component already used in traditional ready biodegradability testing, whereas the resazurin dye offers an interesting new screening mechanism for chemical concentrations greater than 10 mg/l that are not amenable to traditional closed bottle tests. The use of these approaches allows generalisation of high throughput screening methodologies to meet the need of developing new compounds with a favourable ecological profile and also assessment for regulatory purpose.

High Throughput Biodegradation-Screening Test To Prioritize and Evaluate Chemical Biodegradability

“…Other recent studies have also investigated high throughput miniaturized biodegradation tests based on measuring oxygen uptake as a proxy for ultimate biodegradation of two readily and one inherently biodegradable chemical . These tests report similar limits of detection and substrate concentration ranges as those reported here.…”

“…In RBTs, aerobic biodegradation is monitored using either nonspecific (oxygen demand, carbon dioxide evolution, or dissolved organic carbon, DOC) or more specific chemical analyses (detection of parent chemical concentrations using high performance liquid chromatography, HPLC, and/or mass spectrometry, MS), which measure so-called ultimate (i.e., complete mineralization) or primary (parent chemical disappearance) biodegradation, respectively. Innovations in sensor technologies are now allowing the high throughput measurement of ultimate biodegradation through oxygen uptake measurements . However, many of the analyses above are unsuited for development into a high throughput format, especially for primary biodegradation.…”

“…Innovations in sensor technologies are now allowing the high throughput measurement of ultimate biodegradation through oxygen uptake measurements. 17 However, many of the analyses above are unsuited for development into a high throughput format, especially for primary biodegradation.…”

Determining Biodegradation Kinetics of Hydrocarbons at Low Concentrations: Covering 5 and 9 Orders of Magnitude of Kow and Kaw

“…The application of passive dosing for setting initial hydrocarbon concentrations in combination with the very close alignment of test system and SPME-GC-MS analysis provided new possibilities for biodegradation testing. The chosen test volume of 15 mL was a compromise between the 100–1000 mL test systems often used in regulatory biodegradation studies , and high-throughput miniaturized systems. , This reduced test volume was very practical and appeared sufficient for the biodegradation testing with the activated sludge filtrate and seawater. However, for the specific lake water with limited biodegradation activity, we observed larger deviations between replicate test systems and a higher frequency of inconsistent data, which might indicate an insufficient test volume for such samples and asks for further studies.…”

From laboratory to environmental conditions: a new approach for chemical’s biodegradability assessment

“…The platform developed in our laboratory for biodegradation screening tests was used (Cregut et al 2013). The platform is based on non-invasive sensors for dissolved oxygen monitoring in 24-well plates (PreSens, Ge) filled with 2.5 ml of chemical stock solutions.…”