Fermentation of starch

Starches. In the United States, all potable alcohol, most fermentation industrial alcohol, and most fuel alcohol is currendy made principally from grains com is the principal feedstock for fuel alcohol. Fermentation of starch from grain is somewhat more complex than fermentation of sugars because starch must first be converted to sugar and then to ethanol. This process was known to the ancient Egyptians and Mesopotamians who brewed beer almost 5000 years ago (202). The simplified equations for the conversion of starch to ethanol are... 

Glutamates can be produced by fermentation of starches or sugars, but also by breaking the bonds between amino acids in proteins, leaving free amino acids. This process is done by heat or by enzymes it is called hydrolyzing, because the bonds are broken by adding water. 

Different routes for converting biomass into chemicals are possible. Fermentation of starches or sugars yields ethanol, which can be converted into ethylene. Other chemicals that can be produced from ethanol are acetaldehyde and butadiene. Other fermentation routes yield acetone/butanol (e.g., in South Africa). Submerged aerobic fermentation leads to citric acid, gluconic acid and special polysaccharides, giving access to new biopolymers such as polyester from poly-lactic acid, or polyester with a bio-based polyol and fossil acid, e.g., biopolymers . 

As a matter of fact, most of the processes currently developed to generate biochemicals out of biomass involve fermentation of starch originating from corn, wheat, or rice, for example. The various chemicals obtainable from theses processes and their end applications are listed in Table 10.3. A lot of these fermented biochemicals, however, are not yet economically competitive compared with their petrochemical equivalent, essentially due to the large capital investment in equipment and land needed to implement the fermentation process on an industrial scale. An additional disadvantage of this route is that it competes with feedstock needed by the food industry. More research to reduce the costs of fermentation technology is needed. 

Jin, B., Huang, L. R, Lant, R. (2003). Rhizopus arrhizus - a producer for simultaneous saccharification and fermentation of starch waste materials to L(+)-lactic acid. Biotechnol. Lett., 25, 1983-1987. 

Amoiytic fermemation—the fermentation of starch, but specifically it is an incomplete fermentation of starch in which simple sugars are not produced. 

Maltose. Also known as malt sugar, maltose is a product of the fermentation of starches by enzymes or yeast. Barley malt, which is used as an adjunct in brewing, enhances die flavor and color of beer because of its maltose content Maltose also is formed by yeast during breadmaking. Maltose is the most common reducing dlsaccharide, H2O,... 

PLA is finding a wide range of uses, both as a moulded product for the packaging sector, as a film for wrapping and lamination applications, as a fibre fill (pillows/duvets etc.), as a foam, and as a spun textile fibre. Lactic acid produced from microbial fermentation of starch also has many other industrial opportunities, as it is a useful base chemical feedstock for a range of applications. Lactic acid can be chemically converted to propylene glycol, the base for a range of... 

Ethanol is made by both ethylene hydration and fermentation of starches and sugars. In this section the synthetic route will be discussed. The fermentation route is covered in Chapters 32 and 33. 

Pullulanase Aerobacter aemgenes, Increase fermentability of starch worts or... 

Ethanol is manufactured by the controlled enzymatic fermentation of starch, sugar, or other carbohydrates. A fermented liquid is produced containing about 15% ethanol ethanol 95% v/v is then obtained by fractional distillation. Ethanol may also be prepared by a number of synthetic methods. 

The lactic acid (p. 121) that is extracted from muscle tissue rotates light to the right, and hence is known as dextrorotatory lactic acid, or ( i )-Iactic acid. The 2-methyl-1-butanol thai is obtained from fusel oil (a by-product of the fermentation of starch to ethyl alcohol) rotates light to the left, and is known as levorotatory 2-melhyl-l-butanol, or ( — )-2-mcthyl-l-butanol. 

Maltose can be obtained, among other products, by partial hydrolysis of starch in aqueous acid, (-f )-Maltose is also formed in one stage of the fermentation of starch to ethyl alcohol here hydrolysis is catalyzed by the enzyme diastase, which is present in malt (sprouted barley). ... 

Particle size distribution analysis was considered, in one of the latest Pittsburgh Conferences, as one of the most outstanding trends in analytical science. This is not an overstatement, as most of the real samples of analytical interest occur either in dispersed form or in dispersed matrices. Just for argument s sake, in industrial applications the characterization of the size of sample particles is routine and is an essential part of the overall quality control procedures. In the medical field, for particles used to carrier drugs, the size is a critical performance factor (e.g., liposomes). In the food industry, the alcoholic yield from fermentation of starch, and even the taste of chocolate, depends on the size of particles of which these samples are composed. 

Y. Nakamura, F. Kobayashi, M. Ohnaga and T. Sawada. 1997. Alcohol Fermentation of Starch by a Genetic Recombinant Yeast Having Glucoamylase Activity. Biotechnology and Bioengineering, 53, 21-25. 

Figure 3 Fermentation of starch by V. fluvialis T-522 (A) and H2 production by R. marinum A-501 from the fermentate (B). Synthetic medium containing 4.05 g/1 soluble starch was inoculated with V. fluvialis T-522 and incubated at 30°C. The fermentate produced by V. fluvialis T-522 was inoculated with R. marinum A-501 and incubated under illumination of 330 W/m2 at 30°C. The evolved H2 ( ), starch concentration ( ), acetic acid concentration (O), and ethanol concentration (A) were analyzed.

Derivation Fermentation of starches and sugars by certain molds. 

Yeast fermentation of starch to form a biodegradable plastic called pullulan (a trigluco polysaccharide) has been reported to be commercially feasible. See Pullulan. ... 

Altaf, M., Naveena, B.J., Venkateshwar, M., Kumar, E.V., and Reddy, G. 2006. Single step fermentation of starch to 1(+) lactic acid by Lactobacillus amylophi-lus GV6 in SSF using inexpensive nitrogen sources to replace peptone and yeast extract—Optimization by RSM. Proceedings in Biochemistry 41 465-472. 

The process was developed by Monsanto to use the hydrogen cyanide byproduct of acrylonitrile from the Sohio process [64], However, synthetic lactic acid is not as competitive as that from the fermentation of starch or sugar [65]. 

Lactic acid can be produced by fermentation of starch wastes or cheese whey.29 It has also been prepared from ethylene, carbon dioxide, and water using a Pt/Sn/Si02 catalyst.30 It can be converted to an analogue of maleic anhydride by a two-step oxidation (12.10).31... 

From the slope of the curve for addition of sodium carbonate to the rumen fermentation of starch, one can estimate tht the net rate of acid formation is equivalent to 36 millimoles of acetic acid per liter per hour. If a level of no more than 0.2% acid must be maintained in the rumen fermentor, then the exchange rate across the membrane must be at least one liter per hour or half of the total reactor volume each hour. This is well below the observed exchange rate of 20 liters per hour. 

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