Nutritional Requirements in Anaerobic Digesters: A PRISMA-Based Review on Mineral and Vitamin Supplementation

Anaerobic digestion is an essential process for converting organic waste into renewable fuels such as biogas, offering an efficient alternative for the energy transition while also promoting the sustainable management of materials such as animal manure, industrial effluents, and agricultural waste. Optimal performance of anaerobic digestion requires strict control of operational parameters, including pH, temperature, and the availability of minerals and vitamins. Understanding the nutritional requirements of the involved microorganisms, as well as the micro- and macronutrient profiles of the substrates used, is fundamental to ensuring process efficiency. In this context, the present study conducted a literature review aimed at identifying the mineral and vitamin supplementation needs in biodigesters, based on the substrates applied. The PRISMA methodology (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) was used to identify the most relevant experimental studies that reported either efficiency gains or inhibitory effects. The results showed that nutritional requirements vary not only according to the type of substrate but also with the operational time of the reactor, the composition of the microbial consortium, and other operational factors. Therefore, it is not possible to establish a generalized recommendation for mineral and vitamin supplementation in commercial biodigesters based solely on the substrate type.