Do the actual microbes emit CO2 or is some of that carbon used in replication? As awesome as it sounds that plastic will be biodegradable, I'm sure there's a lo

Do the actual microbes emit CO2 or is some of that carbon used in replication? As awesome as it sounds that plastic will be biodegradable, I'm sure there's a lot of plastics are used in critical places with the assumption they won't degrade in nature. If microbes/enzymes do release a lot of CO2 in this process, are we destroying the atmosphere for the sake of the landfill? Does anyone know how many tons of CO2 are trapped in plastics?