Predicting the persistence of chemicals - the significance of microbial diversity, catabolic prevalence and redundancy in naturally derived inocula

在被社会使用之后，用作农用化学品、药品和兽药的合成化学品被释放到环境中，在那里它们有可能对生态系统和人类健康造成不利影响。为了评估、管理和缓解这些风险，我们需要了解控制环境中化学命运和持久性的因素。在批准使用化学品之前，它们必须经过监管测试，以确定降解的速度和程度，以及它们在环境中持续存在的潜力。目前的监管研究，其中许多监管研究已经不再适用于目的，因为它们旨在识别经历快速降解的化学品，几乎没有能力筛选出高度持久性的化学品。此外，这些研究是在标准化的实验室条件下进行的，规模有限，无法复制现实世界环境的动态性质和复杂性。对于大多数化学品来说，微生物群落的生物降解是决定环境可持续性的关键过程。生物降解率由环境参数与微生物群落的丰度和功能特征之间的复杂相互作用决定。土壤、沉积物和水等环境隔间中的微生物群落高度多样化，并且在空间和时间上极其可变。测序方法的进展为表征微生物群落提供了新的途径，元基因组和元转录方法为揭示导致化学降解的微生物群落的性质和所涉及的具体降解途径提供了机会。最近的研究表明，在标准化的监管测试中，微生物群落降解化学品的潜力可能有很大的季节性变化。有证据表明，这与温度和光线等因素驱动的微生物群落组成的变化有关。这个项目将研究合成化合物的化学、环境隔间的物理化学特征和确定化学品生物降解的温度之间的相互作用。将特别注意利用基因组方法来揭开这些相互作用背后的微生物机制，以便开发可整合到化学库筛选中的预测工具和分析，促进新一代监管研究的开发，这些研究可以优先关注化学持久性，并了解负责生物降解的关键分解代谢基因的流行情况，以及通常用作这些生物降解分析的接种剂的微生物群落中存在的功能冗余/弹性。

Following their use by society, synthetic chemicals used as agrochemicals, pharmaceuticals and veterinary medicines are released into the environment, where there is the potential for them to exert adverse effects on ecosystems and human health. To assess, manage and mitigate these risks we need to understand the factors which control chemical fate and persistence in the environment. Before chemicals can be approved for use, they must undergo regulatory testing to determine the rate and extent of degradation, and their potential to persist in the environment. The current regulatory studies upon which many of these regulatory studies are no longer fit-for-purpose as they were designed to identify chemicals that undergo rapid degradation and offer little or no ability to screen out highly persistent chemicals. In addition, these studies are conducted under standardised laboratory conditions, are limited in scale, and fail to replicate the dynamic nature and complexity of real world environments. For most chemicals, biodegradation by microbial communities is the key process which determines environmental persistence. Biodegradation rates are determined by complex interplay between environmental parameters and the abundance and functional characteristics of microbial communities. Microbial communities in environmental compartments such as soil, sediment and water are highly diverse, and extremely variable in space and time. Advances in sequencing methodologies have provided new avenues to characterise microbial communities, with metagenomic and meta-transcriptomic approaches providing opportunities to unravel the nature of microbial communities contributing to chemical degradation, and the specific degradation pathways involved. Recent studies have suggested that there may be substantial seasonal variation in the potential of microbial communities to degrade chemicals within standardised regulatory tests. Evidence suggests this is linked to variation in microbial community composition driven by factors such as temperature and light. This project will investigate interactions between the chemistry of synthetic compounds, the physico-chemical characteristics of environmental compartments, and temperature for determining biodegradation of chemicals. Special attention will be made to unravelling the microbial mechanisms underlying these interactions using 'omic approaches to allow the development of predictive tools and assays that can be integrated into chemical library screening, foster the development of a new generation of regulatory studies that can prioritise on chemical persistence, and understand the prevalence of key catabolic genes responsible for biodegradation and the functional redundancy/ resilience that exists within microbial communities commonly used as inocula for these biodegradation assays.