This paper for the purpose of utilization, conducted a study of technological process of producing animal feed by fermenting seaweed waste. Anaerobic fermentation, which can improve the contents of protein and polysaccharide in seaweed waste, proved to be an available method to improve the nutritional value of animal feed by using seaweed waste. Also effects of different additives and fermentation time on the fermentation products was compared, combined CCRD with neural network to optimize these factors, the predict model among all factors was established, also obtained the optimal fermentation process.
The seaweed waste, the insoluble fiber residue of which glue, iodine and other substance has been extracted from seaweed waste, mostly used as waste discharged into the natural world directly, that not only caused waste of resources, also resulted in environmental pollution [
Microbial fermentation which is of advantage with short cycle and high efficiency, has been widely used in food, feed and other industries using the characteristics of the microorganism itself contains large amounts of protein, has a promising prospect. Algae residue contains major required nutrients of animal feed: protein, crude fiber and other trace elements, which the protein and crude fiber content is usually 8.86% - 8.92% and 43.16% - 43.65% respectively [
Fermentation results mainly influenced by the active of the bacteria agents, while the activity of the bacteria agents are influenced by the environment and dosage of auxiliaries, these factors impact on the fermentation results differently [
Seaweed industrial residues.
Mill, the production from the Beijing Kun Jie Yu Cheng Machinery Co., Ltd., Model KCS-10; heated oven, the production from Kim Nam Instrument Factory, model DHG-9053A; Biochemical incubator, the production from Hai Qixin Scientific Instruments Co., Ltd., model LRH-70.
Seaweed residue was crushed through the mill to a particle diameter of 3 mm - 5 mm, then added cellulase, potassium dihydrogen phosphate, ammonium chloride, the EM inoculants (the EM effective microbial agents is a novel compound microbial preparation, brown translucent liquid, PH value between 3.5 to 4.5, the composite culture of photosynthetic bacteria, lactic acid bacteria, yeasts, actinomycetes bacteria, Acetobacter and other five families, 10 are over 80 kinds of anaerobic or suspected of oxygen normal microbiala), Indian meal, lactose and water, later mixed into the airtight container well-proportionally and placed in a biochemical incubator (25˚C) for fermentation, until fermentation is completed and then removed from the container, placed in heated oven (50˚C) to dry.
In this study, all the protein and polysaccharide content of samples are determined by Kjeldahl method (GB5511- 85) (nitrogen protein conversion factor of 5.95) and the phenol sulfuric acid method.
The effect on fermentation products of cellulase, bacteria agents, ammonium chloride and number of days are investigated respectively. Combined with CCD and General Regression Neural Network (GRNN), protein content and polysaccharide content, two dependent variables, were analyzed to determine the extraction of the optimal process conditions.
The experimental data was analyzed by the desingexpert6.5, and Matlab2009b software.
Temperature is one of the most important factor to affect microbial growth and reproduction, same microorganisms has the different optimal temperature with variable physiological and biochemical processes, that means, the optimum growth temperature is not equal to the highest incubation temperature, neither does not mean fermentation speed is highest when incubation temperature nor the cumulative amount of metabolites when the incubation temperature, also does not mean the highest amount of incubation temperature either. For instance, Streptococcus thermophilus optimal growth temperature is of 37˚C, the optimal fermentation temperature is of 47˚C, the cumulative product of the optimum temperature is of 37˚C. From
Material-water ratios is an important influential factor in solid-state fermentation, extortionate water content will lead to aggregation of medium and cause lower porosity, affect the transfer of oxygen; while water content is too low, medium expansion will be retarded, which is not able to meet the needs of the microbial growth and metabolism, thereby inhibiting cell growth. The experiment has been carried out to study the effect of material-water ration on fermentation; results are shown in
clined sharply from 75% - 90%. Water-material ratio at the range of 50% - 65%, seaweed residue is of high hardness, bonded together in lumps, and turn to loose from 70% - 85% and semi-liquid at 90%, according to above analysis of data and phenomena, water-material ration at 65%, algae residues is of a fitting loose condition to maintain certain porosity and advantageous to interaction of water and air in solids, so that the dissolved oxygen can be delivered smoothly. Thus, the water-material ratio at 65%, the fermentation products is of the highest protein and polysaccharide content.
Basic raw materials: seaweed waste 1000 g, water 1500 g, potassium dihydrogen phosphate 10 g, Indian meal 15 g, lactose 15 g.
Under the condition of adding bacteria agents 10 g, ammonium chloride 15 g, fermentation of 10 days to study the effect of cellulase on fermentation. Cellulase can decompose raw materials in the natural cellulose into fermentable sugars, the other hand, cellulase can decompose the cell wall to release protein, starch and other nutrients in it, while the raw fiber can be degraded into the glucose which can be digested and absorbed by livestock.
prove the effect of fermentation; the other hand, enzyme fermentation environment of excessive make pH decreased, the agents normal metabolic activity, reduction of the fermentation product. Therefore, 10 g is an ideal addition amount of cellulase.
Under the condition of adding cellulase 10 g, ammonium chloride 15 g, fermentation of 10 days to study the effect of bacterial agents on fermentation.
Under the condition of adding cellulase 10 g, bacteria agent 8 g, fermentation of 10 days to study the effect of bacterial agents on fermentation. Adequate source of nitrogen are necessary for microbial propagation to synthesize such as amino acids, nucleic acids and other cellular material and to regulate metabolism, so necessary nitrogen should be added into fermentation, on the other hand, addition of inorganic nitrogen can promote microbial metabolism transformed it into protein, consequently improve the protein content in the algae residue directly.