Solid state/substrate fermentation

One approach to extracting valuable compounds from shellfish processing waste is through the use of marine microorganisms in a procedure referred to as solid state (substrate) fermentation, or SSF. SSF may prove to be an economically advantageous tool for the production of certain compounds from marine waste. For example, the marine fungus Beauveria bassiana can be used to produce chitinase from chitinous prawn waste. Without the fungus, this conversion step normally accounts for 12% of the... 

Growth of Fungi in Solid State/Substrate and Submerged Fermentation. 190... 

A literature survey indicated that very little work has been done to produce an optimal cellulase system as described above. Here, we used solid-state fermentation (SSF) to achieve this objective. SSF processes, such as the "koji" process, have been used extensively for amylase production on wheat bran in Japan its application was extended to cellulase production on wheat bran and Ugnocellulosic materials by Toyama (13), Since then, wheat bran has become an important substrate for producing various products by SSF (14-20), In this study, we tested various lignocellulosic substrates for the production of cellulase and )3-glucosidase from T, reesei QMY-1 by SSF. 

Slugen, D., Stredansky, M., Stredanska, S., Certik, M., and Grego, J. 1994. Process for dietic treatment of cereal substrates using solid state fermentation of Mucoraceae filamentous fungi. Czech Patent 279043. 

Asagbra, A. E., Sanni, A. I., and Oyewole, O. B. (2005). Solid-state fermentation production of tetracycline by Streptomyces strains using some agricultural wastes as substrate. World ]. Microb. Biotechnol. 21,107-114. 

Tran, C. T. and Mitchell, D. A. (1995). Pineapple waste—A novel substrate for citric acid production by solid-state fermentation. Biotechnol. Lett. 17(10), 1107-1110. 

The operating conditions for solid-state fermentation for cellulase production are dependent on the strain to be used, the reactor type and the medium composition, but the basic operating procedure remains the same as shown in Fig. 2. The final product can be obtained as crude solid cellulase, liquid cellulase or powder cellulase according to the application. Figure 3 shows a process flowsheet for cellulase production [25]. In the process, wheat bran is used as substrate. Seeds are prepared in a stirred-tank fermentor and then sprayed into the medium by a spray distributor. The fermentation is performed in a shallow-tray fermentor. The temperature and humidity in the fermentor are automatically regulated. After fermentation, cellulase is recovered by water extraction and purified by salt precipitation and ion exchange. The final product is concentrat-... 

The operating conditions are very important for efficient cellulase production via solid-state fermentation. The effects of operating conditions, such as temperature, water content and water activity, pH, aeration and substrate composition, on the cellulase production by solid-state fermentation will be discussed in this section. 

In the solid-state fermentation process, the water activity is variable because of evaporation and metabolism. In order to keep the water activity constant, the humidity of the supplied air should be controlled or a humidifier should be installed in the fermentor. The relationship between the water activity within the solid substrate and the equilibrium relative humidity (ERH) of the surrounding air can be expressed as ... 

In the submerged fermentation process for cellulase production, crystal cellulose and paper pulp are commonly used substrates which are expensive. The solid-state fermentation for cellulase production should use a cheap medium. Because cellulase is an inducible enzyme, the inducer must be included in the medium. Cellulose is the best inducer [45,46] and its hydrolysate (glucose) is the carbon source for microbes to grow therefore, cellulosic material is the basic component in the medium. Complex nitrogen sources are used to supply nitrogen and to regulate the pH value. Other nutrient salts, such as Mn + and Zn etc., should also be involved in the medium. 

Gas-solid fluidized-bed bioreactors are actively used to perform solid-state fermentation [74,76]. The particular solid substrate is placed on a porous plate or metal net and sterilized air is blown in under the plate. When the air flow rate is high enough, solid substrate particles will be suspended in the gas phase. Advantages of the fluidized-bed bioreactor include ... 

Protease Production Profile in Different Substrates by Solid-State Fermentation Mediums containing 10 g of soybean extract (soybean milk), soybean flour, milk powder, rice, and... 

Protease Production Profile in Different Substrates by Solid-State Fermentation... 

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