Papale Maria, Romano Ida, Finore Ilaria, Lo Giudice Angelina, Piccolo Alessandro, Cangemi Silvana, Di Meo Vincenzo, Nicolaus Barbara, Poli Annarita
Institute of Polar Sciences, National Research Council of Italy, Spianata San Raineri 86, 98122 Messina, Sicilia, Italy.
Institute of Biomolecular Chemistry, National Research Council of Italy, Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy.
Microorganisms. 2021 Jan 21;9(2):218. doi: 10.3390/microorganisms9020218.
Waste biomass coming from a local coffee company, which supplied burnt ground coffee after an incorrect roasting process, was employed as a starting material in the composting plant of the Experimental Station of the University of Naples Federico II at Castel Volturno (CE). The direct molecular characterization of compost using C-NMR spectra, which was acquired through cross-polarization magic-angle spinning, showed a hydrophobicity index of 2.7% and an alkyl/hydroxyalkyl index of 0.7%. Compost samples that were collected during the early "active thermophilic phase" (when the composting temperature was 63 °C) were analyzed for the prokaryotic community composition and activities. Two complementary approaches, i.e., genomic and predictive metabolic analysis of the 16S rRNA V3-V4 amplicon and culture-dependent analysis, were combined to identify the main microbial factors that characterized the composting process. The whole microbial community was dominated by Firmicutes. The predictive analysis of the metabolic functionality of the community highlighted the potential degradation of peptidoglycan and the ability of metal chelation, with both functions being extremely useful for the revitalization and fertilization of agricultural soils. Finally, three biotechnologically relevant Firmicutes members, i.e., subsp. , , and (strains CAF1, CAF2, and CAF5, respectively) were isolated from the "active thermophilic phase" of the coffee composting. All strains were thermophiles growing at the optimal temperature of 60 °C. Our findings contribute to the current knowledge on thermophilic composting microbiology and valorize burnt ground coffee as waste material with biotechnological potentialities.
来自当地一家咖啡公司的废弃生物质被用作那不勒斯费德里科二世大学位于卡斯特尔沃尔图诺（CE）的实验站堆肥厂的原材料。该公司在错误的烘焙过程后提供了烧焦的咖啡渣。使用通过交叉极化魔角旋转获得的C-NMR光谱对堆肥进行直接分子表征，结果显示其疏水指数为2.7%，烷基/羟烷基指数为0.7%。对在“活跃嗜热阶段”早期（堆肥温度为63°C时）收集的堆肥样本进行了原核生物群落组成和活性分析。结合了两种互补方法，即对16S rRNA V3-V4扩增子的基因组和预测代谢分析以及基于培养的分析，以确定堆肥过程的主要微生物因素。整个微生物群落以厚壁菌门为主。对群落代谢功能的预测分析突出了肽聚糖的潜在降解和金属螯合能力，这两种功能对农业土壤的活化和施肥都极为有用。最后，从咖啡堆肥的“活跃嗜热阶段”分离出了三个与生物技术相关的厚壁菌门成员，即亚种、和（分别为菌株CAF1、CAF2和CAF5）。所有菌株都是嗜热菌，在60°C的最佳温度下生长。我们的研究结果有助于增进对嗜热堆肥微生物学的现有认识，并将烧焦的咖啡渣作为具有生物技术潜力的废料加以利用。
