Naturally occurring microorganisms can break down biowaste with enzymes under suitable conditions and make it usable for themselves to grow. This process is called microbial hydrolysis. Consortia of organisms are formed, mostly bacteria but also fungi, which secrete hydrolytic enzymes and produce digestate through the interactions of enzymatic decomposition, microbial growth and the accumulation of useful metabolic products that can be used, for example, as a compost-like fertiliser.
The foom technology consists of three main building blocks: (1) proprietary combined microorganisms, (2) plug flow-based reactor and (3) targeted process control.
The foom-proprietary blend of natural microorganisms enable the efficient conversion of a variety of different substrates. Food waste as well as compostable disposable tableware and cutlery (made of wood, cardboard, palm leaf, corn starch, among others) are degraded in record time. The added selected microbes adapt to the substrate and form a stable microbial community. The process is as follows: First, the mechanically comminuted substrate is broken down by hydrolytic exoenzymes into low-molecular building blocks (mono- and disaccharides, peptides or amino acids, etc.). In the second step, those are metabolised in a nitrogen- and phosphate-rich product, to be used as fertiliser.
For efficient hydrolysis, the reactor-side design plays a major role. To ensure the most intensive interaction between the microorganisms and the substrate matrix, the mixture must be stirred. Plug flow reactors are used for foom. In these, concentration gradients are formed along the reactor length, where each zone favours certain microbial, hydrolytically active communities, stabilising each step of the digestion.
The microbially driven decomposition process can be accelerated by process-analytical technologies. These include, among others, maintaining a certain pH value range, the exchange of gases and the prevention of excessive fluctuations in the microbial composition. The supply of oxygen is particularly important: if there is enough of it available to the microorganisms, it is called composting, otherwise it is called anaerobic fermentation. Due to the choice of process parameters, no methane is produced during the foom process and the overall gas production is neglectable. The process is monitored online with the relevant data being continuously collected via sensors. If necessary, rapid intervention is possible and the process can be optimised continuously.