Solid-state fermentation is widely used in traditional food production, but most of the complex processes involved were designed and are carried out without a scientific basis. Often, mathematical models can be established to describe mass and heat transfer with the assistance of chemical engineering tools. However, due to the complex nature of solid-state fermentation, mathematical models alone cannot explain the many dynamic changes that occur during these processes.
View Article and Find Full Text PDFWater is crucial for microbial growth, heat transfer and substrate hydrolysis, and dynamically changes with time in solid-state fermentation. However, water dynamics in the solid substrate is difficult to define and measure. Here, nuclear magnetic resonance was used to monitor water dynamics during the pure culture of Aspergillus oryzae YH6 on wheat in a model system to mimic solid starter (Qu or Koji) preparation.
View Article and Find Full Text PDFThe loss of carbon dioxide (CO ) to the environment during microalgae cultivation is undesirable for both environmental and economic reasons. In this study, a phototrophic biofilm growth model was developed and validated with the objective to maximize both CO utilization efficiency and production of microalgae in biofilms. The model was validated in growth experiments with CO as the limiting substrate.
View Article and Find Full Text PDFIn case of phototrophic cultures, photobioreactor costs contribute significantly to the total operating costs. Therefore one of the most important parameters to be determined is the maximum biomass production rate, if biomass or a biomass associated product is the desired product. This is traditionally determined in time consuming series of chemostat cultivations.
View Article and Find Full Text PDFA kinetic model is presented that describes functional biomass, starch and storage lipid (TAG) synthesis in the microalga Neochloris oleoabundans as a function of nitrogen and light supply rates to a nitrogen-limited turbidostat cultivation system. The model is based on the measured electron distribution in N. oleoabundans, which showed that starch is the primary storage component, whereas TAG was only produced after an excess of electrons was generated, when growth was limited by nitrogen supply.
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