Yeast, from molasses

Table 5 presents typical operating conditions and cell production values for commercial-scale yeast-based SCP processes including (63) Saccharomjces cerevisae ie, primary yeast from molasses Candida utilis ie, Torula yeast, from papermiU. wastes, glucose, or sucrose and Klujveromjces marxianus var fragilis ie, fragihs yeast, from cheese whey or cheese whey permeate. AH of these products have been cleared for food use in the United States by the Food and Dmg Administration (77). 

A plant for the fermentation of sulfite waste liquor in America was built at Mechanicsville, New York, by the West Virginia Pulp and Paper Company in 1914. The alcohol stills and some of the other equipment were imported from Germany and were considered the most modern at that time. In comparison to present American stills, these were very inefficient because they were wasteful of steam and did not recover all the alcohol. This plant reused the yeast from a previous fermentation for succeeding fermentations. The plant produced about 221,000 gallons of alcohol per year in 1919. In later years, because of the inefficiency of the alcohol stills with dilute alcohol solutions, molasses was added to the sulfite waste liquor to increase the alcohol content. The plant operated until 1939, when it was closed because of obsolescence. 

Ammonium sulfate occurs in trace concentrations in the upper atmosphere. It is widely used as a fertilizer for rice and other crops. It is a source of sulfur for the soil. It is also used as an additive to supply nutrient nitrogen in fermentation processes (e.g., yeast production from molasses). It also is used for fireproofing timber and plastics, and in treatment of hides, and leather production. 

Source (Food sources) Liver, kidney, yeast, crude molasses, milk, whole-grain cereals, rice. (Commercial sources) Produced synthetically from 2,4-dihydroxy-3,3-dimethylbutyric acid and (i-alanine. 

In 1929 Kinoshita [107] identified itaconic acid as the major metaboHc product of A. itaconicus. Later research showed that A. terreus is a better biocatalyst for itaconic acid accumulation. A number of yeast strains belonging to Candida and Rhodotorula [108] can also accumulate a limited amount of itaconic acid. Patents on the industrial production of itaconic acid using Aspergilli as the biocatalyst from molasses were issued in 1961. The currently preferred industrial process uses improved strains of A. terreus as the biocatalyst. The most often studied itaconic acid producers are A. terreus NRRL 265 and A. terreus NRRL 1960. 

Kopsahelis N., Agouridis N., Bekatorou A. and Kanellaki M. Comparative study of spent grains and delignified spent grains as yeast supports for alcohol production from molasses. Bioresource Technology 98 (7) (2007) 1440-1447. 

The vitamin is widely distributed indeed, the name is derived from the Greek pantothen, from everywhere , indicating its ubiquitous distribution. Rich sources are liver, egg yolk, groundnuts, peas, yeast and molasses. Cereal grains and potatoes are also good sources of the vitamin. The free acid is imstable. The synthetically prepared calcium pantothenate is the commonest product used commercially. 

Prepared in situ from molasses with baker s yeast)... 

In the acid hydrolysis process (79—81), wood is treated with concentrated or dilute acid solution to produce a lignin-rich residue and a Hquor containing sugars, organic acids, furfural, and other chemicals. The process is adaptable to all species and all forms of wood waste. The Hquor can be concentrated to a molasses for animal feed (82), used as a substrate for fermentation to ethanol or yeast (82), or dehydrated to furfural and levulinic acid (83—86). Attempts have been made to obtain marketable products from the lignin residue (87) rather than using it as a fuel, but currently only carbohydrate-derived products appear practical. 

Although the hydrolysis of wood to produce simple sugars has not proved to be economically feasible, by-product sugars from sulfite pulping are used to produce ethanol and to feed yeast (107). Furthermore, a hemiceUulose molasses, obtained as a by-product in hardboard manufacture, can be used in catde feeds instead of blackstrap molasses (108). Furfural can be produced from a variety of wood processing byproducts, such as spent sulfite Hquor, bquors from the prehydrolysis of wood for kraft pulping, hardboard plants, and hardwood wastes (109). 

Candida utilis is grown on sulfite waste Hquor in Western Europe and North America, on sugar cane molasses in Cuba and Taiwan and on ceUulose acid hydrolysates in Eastern Europe and the former Soviet Union. C. ///i/if utilizes hexoses, pentoses, and many organic acids. Sulfite Hquor from hardwoods contains 2—3% fermentable sugars of which 20% are hexoses and 80% pentoses in softwood Hquors the proportions are reversed. The SO2 must be stripped out to allow yeast growth, which is carried out in large, highly-aerated fermentors. Eor continuous fermentations, carried out at pH 4 and 30°C, the dilution rate is 0.27—0.30 (34). 

One of the more recent innovative approaches was to look for new micro-organisms and novel carbohydrate substrates. The early fermentations used sugar beet or cane molasses, various syrups, sweet potato starch or glucose itself and the micro-organism was always an Aspergillus spp. In the early 1930 s it was found that yeasts would produce dtric add from acetate. Since then a variety of yeasts, prindpally Candida spp., has been shown to convert glucose, w-alkanes or ethanol to dtric add with great effidency. 

The aim is to produce biomass or a mass of cells such as microbes, yeast and fungi. The commercial production of biomass has been seen in the production of baker s yeast, which is used in the baking industry. Production of single cell protein (SCP) is used as biomass enriched in protein.6 An algae called Spirulina has been used for animal food in some countries. SCP is used as a food source from renewable sources such as whey, cellulose, starch, molasses and a wide range of plant waste. 

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