Food waste to new food: Risk assessment and microbial community analysis of anaerobic digestate as a nutrient source in hydroponic production of vegetables

In this study, the microbiological food safety of using anaerobic digestate as a fertilizer in hydroponic production vegetables was evaluated. The used liquid residue obtained from digestion waste biogas. Replacing customary inorganic with recycled (biofertilizer) could allow for sustainable urban close to retailers and consumers. However, striving circular production, it is vital that utilizing resources ensured. Especially application farming, where nutrient loop shorter than on arable land, risk assessment crucial when adopting new fertilizers. biofertilizer based therefore studied regard its microbial community (16S rRNA gene amplicon sequencing) during system. also challenge tested borne pathogens ( Salmonella enterica , Listeria monocytogenes Bacillus cereus ). Furthermore, activity isothermal calorimetry. results showed changed distinctly through necessary initial nitrification process, most abundant genus Mycobacterium . Deliberate contaminations 5 log 10 CFU mL ?1 either S. or L. nitrified were no longer detectable selective plating after 48 h incubation at 20 °C. Selective B. revealed contained low levels (?10 ) bacterium, an inoculation decreased these within 24 Analysis indicated does not seem support without addition external source contains accessible carbon trace elements. type investigated study thus regarded microbiologically safe use cultivation. constant presence viable however, emphasizes fundamental importance continuous case any modifications supplementations biofertilizer, since clearly can act reservoir bacterial endospores. • biofertilizer. Low naturally present digestate. Biofertilizer growth deemed microbially if added.