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Biomass preparation for optimised bioreaction kinetics

An Italian SME with a focus on biotransformations and energy saving has recently patented an innovative method for fresh biomass production. The properties of the biomass produced, greatly accelerate the solid state biotransformations and consequently, the use of bioreactors is drastically reduced. Solid-state bioreactions involve growing micro-organisms on solid organic materials and is one of the most promising areas of development of modern biotechnological sciences.
Biomass preparation for optimised bioreaction kinetics
During solid state bioreactions, microbial growth and product formation occur on the surface of a solid substrate. These reactions, also known as solid substrate fermentations, involve a variety of agricultural products that can be used as substrates, fermented though in the solid state. Such products are rice, wheat, barley, corn and soybeans. For future industrial purposes non-traditional substrates like food processing waste or forest waste could also be used.

Solid state culture of micro-organisms has a number of positive aspects: Energy consumption is minimal; the process of growing the micro-organisms is done under environmental conditions that closely resemble natural processes; the possibility of bacteria contamination is very small and finally the biomass produced is economical to collect. Until now the techniques used for solid state oxidative biotransformations of specific substrates were more or less based on composting and are quite unsatisfactory due to a number of serious limitations. The composting method, a solid state thermophilic oxidative biotransformation, uses polygenic substrates in order to obtain biomass, and whilst lacking uniformity, has to remain in the bioreactors for a long time. Apart from the need for a large capacity bioreactor with high attendance costs, the most serious limitation of the composting method is its unsuitability for growth for mycelial micro-organisms.

To overcome the above limitations and enable the potential of this biotechnology to be exploited economically on industrial scales, the Italian SME has developed and patented a method for the preparation of biomasses for subjection to mesophilic or thermophilic oxidative biotransformations. The technology improves the kinetics of the solid state bioreactors and permits optimal development of mycelial micro-organisms.

The patented biomass preparation method consists of grinding the solid substrate finely thus increasing surface area and porosity. Next the solid substrate is mixed thoroughly with inoculums until saturation is achieved and finally the biomass is agglomerated into small pieces. The oxygen present in the resulted biomass initiates the bio-oxidation process even at preparation stage. This method of preparation also reduces or totally eliminates the lag phase associated with these transformations therefore the biomass remains for shorter period of time in the bioreactors.

In conclusion, the patented method of fresh biomass preparation accelerates the biotransformations, reduces costs of bioreactor use and produces homogeneous products. It offers the suitable process and the necessary equipment for industrial large scale production and immediate economic exploitation.

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Record Number: 80349 / Last updated on: 2005-09-18
Domain: Energy