Uncovering new indicators to predict stability, maturity and biodiversity of compost on an industrial scale.

•Heterogeneity of composting process hinds the establishment of bioindicators.•Biodiversity and respirometric index affect phytostimulant power of compost.•Phenolic content and nitrification index could impact compost biodiversity.•Compost biodiversity is greater the lower the activity of xylanase.•Different raw materials evolve similar products by different bioestrategies.