Department of Chemistry, Sapienza University of Rome, Rome, Italy.
Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, Rome, Italy.
PLoS One. 2024 Aug 19;19(8):e0307210. doi: 10.1371/journal.pone.0307210. eCollection 2024.
Peat is the main constituent of cultivation substrates and a precious non-renewable fossil material. Peatlands provide important ecosystem services and allow the absorption and storage of carbon. Protecting peatlands helps tackle climate change and contributes to biodiversity conservation. Due to its importance, it is necessary to implement strategies to reduce the use of peat, such as replacing it with biomass-based alternative growing media constituents, such as Sphagnum moss. In this study, we compared the metal release and binding properties at two different pH, antioxidant activity, and total phenolic content of peat and Sphagnum moss from the Tierra del Fuego (TdF) region of southern Patagonia. Levels of the elements were determined by inductively coupled plasma mass spectrometry (ICP-MS), while the types and amounts of functional groups were characterized and compared using Fourier transform infrared (FTIR) spectroscopy. The total phenol level and antioxidant capacity were assessed using the Folin-Ciocalteu method and 2,2-diphenyl-1-picrylhydrazyl test. There are generally higher concentrations of leachable elements in peat than in Sphagnum moss at pH = 2, except Cs, Rb, Ti, and Zr. In contrast, at pH = 5, levels of all leached elements are highest in Sphagnum moss. Sphagnum moss shows a higher metal adsorption capacity than peat, except for Be, Mn, Tl, and Zn. Finally, the results showed that both matrices contained similar total phenolic contents: 0.018 ± 0.011 mg gallic acid equivalent (GAE) per gram dry sample for peat and 0.020 ± 0.007 mg GAE g-1 for Sphagnum moss. Instead, Sphagnum moss extracts showed a significantly higher antioxidant activity [0.026 ± 0.028 mmol Trolox equivalents (TE) g-1] than that estimated in peat (0.009 ± 0.005 mmol TE g-1). Humic acids, carboxylic acids, and phenolic and lignin groups were identified as the functional groups that mainly determined the antioxidant activity of the Sphagnum moss compared to peat. The present study resulted in an advancement of knowledge of these materials for more thoughtful future use and possible replacements.
泥炭是栽培基质的主要组成部分，也是一种宝贵的不可再生化石材料。泥炭地提供了重要的生态系统服务，并允许吸收和储存碳。保护泥炭地有助于应对气候变化，有助于保护生物多样性。由于其重要性，有必要实施减少泥炭使用的战略，例如用生物质替代物替代泥炭作为生长介质的组成部分，如泥炭藓。在这项研究中，我们比较了来自巴塔哥尼亚南部火地岛（TdF）地区的泥炭和泥炭藓在两种不同 pH 值下的金属释放和结合特性、抗氧化活性和总酚含量。元素水平通过电感耦合等离子体质谱法（ICP-MS）测定，而官能团的类型和数量则通过傅里叶变换红外（FTIR）光谱进行表征和比较。总酚水平和抗氧化能力通过福林-考尔法和 2,2-二苯基-1-苦基肼试验进行评估。在 pH = 2 时，泥炭中的可浸出元素浓度通常高于泥炭藓，除了 Cs、Rb、Ti 和 Zr。相比之下，在 pH = 5 时，所有浸出元素的水平在泥炭藓中最高。泥炭藓的金属吸附能力高于泥炭，除了 Be、Mn、Tl 和 Zn。最后，结果表明，两种基质都含有相似的总酚含量：每克干样品中，泥炭的没食子酸当量（GAE）为 0.018 ± 0.011mg，泥炭藓为 0.020 ± 0.007mg。相反，泥炭藓提取物的抗氧化活性[0.026 ± 0.028mmol Trolox 当量（TE）g-1]明显高于泥炭中的估计值[0.009 ± 0.005mmol TE g-1]。与泥炭相比，鉴定出腐殖酸、羧酸、酚类和木质素基团是决定泥炭藓抗氧化活性的主要官能团。本研究增进了对这些材料的认识，以便在未来更周到地使用和可能的替代。
