Study On The Technology Of Preparing Algae Feed By Fermenting Algae Residue With Compound Bacteria

The main purpose of this paper is to dispose of seaweed residue,the by-products of seaweed industry,to change the material structure and nutrient composition.By using the method of pretreatment and fermentation by complex bacteria,to prepare qualified seaweed feed,and provide a new way for the high value utilization of seaweed residue.First of all,the pretreatment of seaweed residue was carried out successively by use of ammonia,hydrochloric acid and enzyme.The ammonia was used to partially dissolve the lignin by its alkalinity,so that the structure of the seaweed slag was loose and the cellulose was obvious,and the content of inorganic nitrogen was increased.Then,the seaweed residue is decomposed by hydrochloric acid,and the cellulose is decomposed by acid at high temperature,and the residual sodium carbonate in the production is neutralized to obtain the solution of the seaweed residue.At the end of this paper,cellulase was used to decompose the seaweed residue after acid hydrolysis,so as to further decompose the cellulose,and the macromolecular polysaccharide was hydrolyzed into small molecular oligosaccharides and monosaccharide.Cellulase was used for enzymatic hydrolysis of seaweed residue after acid hydrolysis.The content of neutral detergent fiber was for the detection of ammonification,and the content of monosaccharide was for the detection of acidification and enzymatic hydrolysis.In the end,the preprocessed seaweed residue has a loose structure and rich oligosaccharide and monosaccharide.It provided a favorable environment for the next fermentation treatment.On the basis of pretreatment,preprocessed seaweed residue was fermented with laboratory self-made compound bacteria.In order to optimize the fermentation process,extra5% wheat bran and soybean meal were added into the fermentation substrate.Using content of crude fiber as the index,according to the single factor test and orthogonal test,the optimum conditions were obtained: bacteria amount was 20%,and the water content was50%,at 37 ℃ constant temperature culture for 10 days.The analysis results indicated that after fermentation,the crude fiber content decreased from 18.11% to 33.5%,which was decreased by 45.94% compared to the original seaweed residue.At the same time,the crude protein content rose from 21.8% in the original seaweed residue 32.81% in the fermentation product with increase of 50.50%.These two indicators are close to the feed of cottonseed meal product standard(for grade five cottonseed meal crude fiber content is less than 16% and the crude protein content is higher than 38%).The content of monosaccharide was 56mg/kg,and the free amino acid was 7.03mg/g.The ash content decreased from 23.6%(before fermentation)to 21.15%(after fermentation).In addition,in view of the actual situation of seaweed processing commonly used formaldehyde in the soaking process,it’s necessary to test formaldehyde on fermented seaweed residue,the content of formaldehyde was decreased from 309mg/kg(before fermentation)to 40.28mg/kg(after fermentation),decreased by 86.96% which is proved that through the fermentation process can significantly reduce the residual formaldehyde.The contents of heavy metals were as follows: Hg 0.164mg/kg,Pb 1.751mg/kg,Cr 5.686mg/kg.The contents of Hg,Pb and Cr,were all in accordance with the requirements of feed hygiene standard GB13078-2001.