Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy; Centro Interdipartimentale di Ricerca CERMANU, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.
Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.
Waste Manag. 2021 Feb 1;120:98-107. doi: 10.1016/j.wasman.2020.11.013. Epub 2020 Dec 5.
The acknowledgement of bioactive functions of compost teas promotes the research on characteristics and potential application of these heterogeneous water-soluble extracts from recycled biomasses. In this work, compost teas were isolated from on-farm composts made with agro-industrial residues of artichoke, pepper and coffee husks with the aim to evaluate the structural-activity relationship of dissolved bioactive molecules. The molecular features of compost teas were determined by C-CPMAS NMR spectroscopy, Infrared spectroscopy, and off-line pyrolysis-Gas Chromatography/Mass Spectrometry. Bioactivity of different compost teas was tested on Basil seeds germination, while the antioxidant capacity was measured by ABTS and DDPH spectrophotometric assays. The antimicrobial activity was measured against some pathogenic human bacterial strains. The seed germination experiment showed no phytotoxic effects and a significant increase of both root and epicotyls upon application of coffee husks and pepper CT samples. The same compost teas revealed the largest antioxidant activity and a clear antimicrobial effect determined by MIC (Minimal Inhibitory Concentration) against some gram-negative bacterial strains such as Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The bioactivity of CT-samples was related to their general hydrophobic features and to specific molecular composition. In particular, C-CPMAS NMR spectra and off-line thermochemolysis GC-MS highlighted a close correlation between radical scavenger activity and antibacterial bioactive functions with bio-available soluble aromatic compounds, such as lignin and phenols derivatives. The antioxidant and, antibacterial properties of compost teas from green composts encourages an innovative potential application of these eco-friendly products not only in agricultural applications but also in nutraceutical and pharmaceutical fields.
堆肥茶的生物活性功能的确认促进了对这些来自回收生物量的异质水溶性提取物的特性和潜在应用的研究。在这项工作中，从农场堆肥中分离出堆肥茶，这些堆肥是用朝鲜蓟、胡椒和咖啡壳等农业工业残渣制成的，目的是评估溶解生物活性分子的结构-活性关系。堆肥茶的分子特征通过 C-CPMAS NMR 光谱、红外光谱和离线热解-气相色谱/质谱法来确定。不同堆肥茶的生物活性在罗勒种子发芽试验中进行测试，而抗氧化能力则通过 ABTS 和 DDPH 分光光度法测定。抗菌活性通过对一些人类病原菌的测试来衡量。种子发芽实验表明，咖啡壳和胡椒 CT 样品的应用对植物没有毒性作用，而且根和上胚轴都显著增加。同样的堆肥茶显示出最大的抗氧化活性和明显的抗菌作用，通过 MIC（最小抑菌浓度）对一些革兰氏阴性菌，如铜绿假单胞菌、大肠杆菌和肺炎克雷伯菌，有明显的抑制作用。CT 样品的生物活性与其一般疏水性特征和特定的分子组成有关。特别是，C-CPMAS NMR 光谱和离线热解 GC-MS 突出表明，自由基清除活性和抗菌生物活性功能与生物可利用的可溶性芳香族化合物（如木质素和酚类衍生物）之间存在密切的相关性。堆肥茶的抗氧化和抗菌性能，鼓励这些环保产品在农业应用之外，在营养保健品和制药领域的创新应用。
