No abstract

Vitamin E as a dietary supplement or as part of an adjuvant vaccine formulation increases humoral and cell-mediated immunity and disease resistance in laboratory animals, farm animals, and humans. Adjuvant administration has far greater effect than dietary supplementation. Vitamin E as an antioxidant protects the cells of the immune response from peroxidative damage; possibly through a modulation of lipoxygenation of arachidonic acid, vitamin E alters cell membrane functions and cell-cell interactions. The most pronounced effect of vitamin E is on immune phagocytosis. Dietary supplementation is beneficial to animals, especially under stress, in decreasing susceptibility to infections. Vitamin E adjuvant vaccines have provided greater immunoprotection against enterotoxemia and epididymitis in sheep than conventional vaccines.

Phytase production was studied by three Mucor and eight Rhizopus strains by solid-state fermentation (SSF) on three commonly used natural feed ingredients (canola meal, coconut oil cake, wheat bran). Mucor racemosus NRRL 1994 (ATCC 46129) gave the highest yield (14.5 IU/g dry matter phytase activity) on coconut oil cake. Optimizing the supplementation of coconut oil cake with glucose, casein and (NH(4))(2)SO(4), phytase production in solid-state fermentation was increased to 26 IU/g dry matter (DM). Optimization was carried out by Plackett-Burman and central composite experimental designs. Using the optimized medium phytase, alpha-amylase and lipase production of Mucor racemosus NRRL 1994 was compared in solid-state fermentation and in shake flask (SF) fermentation. SSF yielded higher phytase activity than did SF based on mass of initial substrate. Because this particular isolate is a food-grade fungus that has been used for sufu fermentation in China, the whole SSF material (crude enzyme, in situ enzyme) may be used directly in animal feed rations with enhanced cost efficiency.

The production of phytase by three feed-grade filamentous fungi ( Aspergillus ficuum NRRL 3135, Mucor racemosus NRRL 1994 and Rhizopus oligosporus NRRL 5905) on four commonly used natural feed ingredients (canola meal, cracked corn, soybean meal, wheat bran) was studied in solid substrate fermentation (SSF). A. ficuum NRRL 3135 had the highest yield [15 IU phytase activity/g dry matter (DM)] on wheat bran. By optimizing the supplementation of wheat bran with starch and (NH(4))(2)SO(4), phytase production increased to 25 IU/g DM. Optimization was carried out by Plackett-Burman and central composite experimental designs. Using optimized medium, phytase, phosphatase, alpha-amylase and xylanase production by A. ficuum NRRL 3135 was studied in Erlenmeyer flask and tray SSF. By scaling up SSF from flasks to stationary trays, activities of 20 IU phytase activity/g DM were reproducibly obtained.

In this work the effects of environmental parameters on the performance of solid substrate fermentation (SSF) for protein production are studied. These parameters are (i) air flow rate, (ii) inlet air relative humidity, (iii) inlet air temperature, and (iv) the heat transfer coefficient between the outer wall of the fermentor and the air in the incubator. The air flow is supplied to effect cooling of the fermented mass by evaporation of water. A dynamic model is developed, which permits estimation of biomass content, total dry matter, moisture content, and temperature of the fermented matter. The model includes the effects of temperature and moisture content on both the maximum specific growth rate and the maximum attainable biomass content. The results of the simulation are compared with actual experimental data and show good agreement with them. The most important conclusions are that (i) the evaporative cooling of the biomass is very effective for temperature control and (ii) the air flow rate and the heat transfer coefficient have strong effects but they affect the biomass morphology and are not controllable easily. Also, a simple technique for the determination of the optimum temperature and moisture content profile for cell protein production is applied. The simulated biomass production increases considerably employing the optimum temperature and moisture content profiles. The ultimate goal is to implement the determined effects of the environmental parameters on the SSF biomass production and the temperature and moisture variation profiles to effectively control the SSF and optimize the biomass production.