[Chemical and biochemical characteristics of the microbial biomass]

The nutritional potential of microbial biomass products is determined by their chemical and biochemical characteristics. The same vary according to the microbial species, the source of nutrients employed for their growth, the operational mode of bioreactor and, finally, due to processing effects during growth or in the unit operations employed for its recovery. In this review, a detailed chemical description is given for those microbial biomass products from algae, bacteria, yeast and fungi, which have been either commercially produced or produced for demonstration purposes in pilot installations. Lastly, the effect of some operational parameters over the biomass chemical composition are illustrated in order to show general tendencies that have been experimentally observed, without a claim to be an exhaustive literature review of all aspects involved.