Meilander Jeff, Herman Chloe, Manley Andrew, Augustine Georgia, Birdsell Dawn, Bolyen Evan, Celona Kimberly R, Coffey Hayden, Cocking Jill, Donoghue Teddy, Draves Alexis, Erickson Daryn, Foley Marissa, Gehret Liz, Hagen Johannah, Hepp Crystal, Ingram Parker, John David, Kadar Katarina, Keim Paul, Lloyd Victoria, Osterink Christina, Monsaint-Queeney Victoria, Ramirez Diego, Romero Antonio, Ruby Megan C, Sahl Jason W, Soloway Sydni, Stone Nathan E, Trottier Shannon, Van Orden Kaleb, Painter Alexis, Wallace Sam, Wilcox Larissa, Wood Colin V, Yancey Jaiden, Caporaso J Gregory
Center for Applied Microbiome Science, Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States.
Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, United States.
ISME Commun. 2025 May 29;5(1):ycaf089. doi: 10.1093/ismeco/ycaf089. eCollection 2025 Jan.
Human excrement composting (HEC) is a sustainable strategy for human excrement (HE) management that recycles nutrients and mitigates health risks while reducing reliance on freshwater, fossil fuels, and fertilizers. A mixture of HE and bulking material was collected from 15 composting toilets and composted as 15 biological replicates in modified 19-liter buckets under mesophilic conditions with weekly sampling for one year. We hypothesized that (i) the microbiome of 1 year old compost would resemble that of a soil and/or food and landscape waste compost microbiome more closely than the original HE; and (ii) the human fecal indicators, and , would be undetectable after 52 weeks using qPCR and culturing. This investigation identified unique successional trajectories within buckets (i.e. biological replicates) and significant shifts in microbial communities around 25 weeks across buckets, with reductions in fecal-associated taxa and increases in environmental taxa indicating effective composting. We present a comprehensive microbial time series analysis of HEC and show that the initial gut-like microbiome of HEC systems transitions to a microbiome similar to soil and traditional compost but that pathogen risk assessment is important if thermophilic temperatures are not achieved. This study also produced the highest resolution composting microbiome data to date, establishing a baseline for HEC optimization and thermophilic composting studies while serving as a resource for bioprospecting for enzymes and organisms relevant to upcycling waste.
人类粪便堆肥（HEC）是一种可持续的人类粪便（HE）管理策略，它能循环利用养分、降低健康风险，同时减少对淡水、化石燃料和肥料的依赖。从15个堆肥厕所收集了人类粪便与填充材料的混合物，并在改良的19升桶中作为15个生物学重复样本在中温条件下进行堆肥，为期一年，每周采样。我们假设：（i）一年期堆肥的微生物组与土壤和/或食品及景观废物堆肥的微生物组的相似程度将高于原始人类粪便；（ii）使用定量聚合酶链反应（qPCR）和培养法，在52周后将无法检测到人类粪便指示菌和。这项调查确定了桶内（即生物学重复样本）独特的演替轨迹，以及25周左右各桶间微生物群落的显著变化，粪便相关分类群减少，环境分类群增加，表明堆肥有效。我们对人类粪便堆肥进行了全面的微生物时间序列分析，结果表明，人类粪便堆肥系统最初类似肠道的微生物组转变为类似于土壤和传统堆肥的微生物组，但如果未达到嗜热温度，病原体风险评估就很重要。这项研究还产生了迄今为止分辨率最高的堆肥微生物组数据，为优化人类粪便堆肥和嗜热堆肥研究建立了基线，同时为与废物升级回收相关的酶和生物的生物勘探提供了资源。
