Single cell protein

In essence a single cell protein is a protein extracted from cultured algae, yeasts, or bacteria and used as a substitute for protein-rich foods, especially in animal feeds. Many types of animal feeds contain single cell proteins.

Uses

A single cell protein has the capability to be used and transformed into one of the most immense sources of supplemental proteins in animal, mainly livestock feeds. In come locations the single cell protein could become the main protein source to feed domestic livestock, this however will depend on the population growth and the other protein sources available.

Origins

Single cell proteins develop when microbes ferment their waste materials. Examples are wood and straw. The problem with extracting single cell proteins from the wastes is the dilution and cost. They are found in very low concentrations, usually less than $5\%$. Luckily, scientists have developed a way to increase the concentrations. These include: centrifugation, precipitation, coagulation and filtration; these methods can be combined with semi-permeable membranes.

The next problem to be addressed is the cost. The methods to increase the concentrations to adequate levels, and de-watering process require equipment that is expensive and is not feasible for small-scale operations. For most instances the de-watering process that is required for storage and stabilization of single cell proteins is not economical. The single cell protein needs to be dehydrated to approximately $10\%$ moisture content. It can also be condensed and acidified to prevent spoilage. Perhaps the most economical method and the simplest is to feed the product shortly after it is produced.Single cell proteinsingle cell protein is a protein extracted from cultured algae, yeasts, or bacteria and used as a substitute for protein-rich foods, especially in animal feeds. Many types of animal feeds contain single cell proteins.A protein extracted from cultured algae, yeasts, or bacteria and used as a substitute for protein-rich foods, especially in animal feeds.Microorganisms which are allowed to grow on waste products from agro based industries produce a large amount of proteins and store them in their cell bodies. These organisms are called as single cell proteins. Description: Single cell protein has the potential to be developed into a very large source of supplemental protein that could be used in livestock feeding. In some regions single cell protein could become the principal protein source that is used for domestic livestock, depending upon the population growth and the availability of plant feed protein sources. This could develop because microbes can be used to ferment some of the vast amounts of waste materials, such as straws; wood and wood processing wastes; food, cannery and food processing wastes; and residues from alcohol production or from human and animal excreta. Producing and harvesting microbial proteins is not without costs, unfortunately. In nearly all instances where a high rate of production would be achieved, the single cell protein will be found in rather dilute solutions, usually less than 5 % solids. Methods available for concentrating include, filtration, precipitation, coagulation, centrifugation, and the use of semi-permeable membranes. These de-watering methods require equipment that is quite expensive and would not be suitable for most small-scale operations. Removal of the amount of water necessary to stabilize the material for storage, in most instances, is not currently economical. Single cell protein must be dried to about 10 % moisture, or condensed and acidified to prevent spoilage from occurring, or fed shortly after being produced.Caution: Microbial protein has a high nucleic acid content, so levels need to be limited in the diets of monogastric animals. Some organisms can also produce mycotoxins.Source: Single cell protein can be produced on a number of different substrates, often this is done to reduce the Biological Oxidation Demand of the effluent streams leaving various type of agricultural processing plants.

OriginsSingle cell proteins develop when microbes ferment their waste materials. Examples are wood and straw. The problem with extracting single cell proteins from the wastes is the dilution and cost. They are found in very low concentrations, usually less than 5%. Luckily, scientists have developed a way to increase the concentrations. These include: centrifugation, precipitation, coagulation and filtration; these methods can be combined with semi-permeable membranes.The next problem to be addressed is the cost. The methods to increase the concentrations to adequate levels, and de-watering process require equipment that is expensive and is not feasible for small-scale operations. For most instances the de-watering process that is required for storage and stabilization of single cell proteins is not economical. The single cell protein needs to be dehydrated to approximately 10% moisture content. It can also be condensed and acidified to prevent spoilage. Perhaps the most economical method and the simplest is to feed the product shortly after it is produced.Retrieved from "http://en.wikipedia.org/wiki/Single_cell_protein"

Nutrient Characteristics:

Yeast (Torulopsis utilis) CP = 49.9 % Single cell protein CP = 57.7 % (1)(AGRIS 82-806782)(Natividad, 1981)

Single cell protein CP = 29-30 %(AI)(CAB 930324260)(Shakir, 1992)

Single cell protein CP = 57.7 % (Q) (CAB N910498) (Mudgal, 1986)

Yeast (torulopsis utilis)(1)(AGRIS 82-806782)(Natividad, 1981)True CP Digestibility 89.15 %Biological Value 65.01Protein Efficiency Ratio 2.02Chemical Score 44%Limiting amino acids methionine and cystine

Single cell protein DM = 95 %, 44 % CP

Single cell protein (Geotrichum candidum) 35 . 40 % CP, in vitro digestion 73 . 88 % (A)(CAB N215145)(Vaccarino, 1989).

Single cell protein (Gaprin) (AG)(CAB N228220)(Ar`kov, 1988) CP = 77.9 %, lysine 4.4 %, methionine = 1.1 %, cystine = 0.4 %, tryp 1.2 %, EE = 0.8 %, Ca 0.18 %, P = 1.3 %, Na = 0.24 %, Metabolizable Energy = 1.26 MJ/100 grams

Single Cell Protein ProductionProduct Safety and QualitySCP has applications in animal feed, human food and as functional protein concentrates.Some bacterial SCP have amino acid profiles similar to animal/plant protein. Yeast, fungal and soya bean proteins tend to be deficient in methionine. Ingestion of RNA from non-conventional sources should be limited to 50g per day. Ingestion of purine compounds arising from RNA breakdown, leads to increased plasma levels of uric acid, which can cause gout and kidney stones.High content of nucleic acids causes no problems to animals since uric acid is converted to allantoin which is readily excreted in urine. Nucleic acid removal is not necessary from animal feeds but is from human foods. A temperature hold at 64C inactivates fungal proteases and allows RNA-ases to hydrolyse RNAwith release of nucleotides from cell to culture broth. A 30 min stand at 64C reduces intracellular RNA levels in Fusarium graminearum from 80mg/g to2mg/g.

UsesA single cell protein has the capability to be used and transformed into one of the most immense sources of supplemental proteins in animal, mainly livestock feeds. In come locations the single cell protein could become the main protein source to feed domestic livestock, this however will depend on the population growth and the other protein sources available.