Agricultural robots 1 Bio-hydrogen 1 Bio-hydrogen production 1 Bioeconomy 1 Biomass degradations 1 Clostridia 1 Clostridium 1 Clostridium beijerinckii 1 Clostridium tyrobutyricum 1 Composting 1 Dark fermentative hydrogen-producing bacteria (dHPB) 1 Environmental benefits 1 Fermentation 1 Gene expression 1 Greenhouse gases 1 Greenhouse gases (GHG) 1 Hydrogen economy 1 Hydrogen fuels 1 Hydrogen production 1 Modulation 1 Polymerase chain reaction 1 Refuse disposal 1 Reverse transcriptase quantitative PCR (RT-qPCR) Reverse transcriptases 1 Supply chains 1 [FeFe]-hydrogenase 1 [FeFe]-hydrogenase genes 1 alternative energy 1 autochthon 1 bacterium 1