Algal

Algal cellulose Algal cultures Algal gums Algiade... 

Problems associated with excessive levels of nutrients and unwanted nuisance species have already been mentioned. There are cases in which intentional fertilization is used by aquaculturists in order to produce desirable types of natural food for the species under culture. Examples of this approach include inorganic fertilizer appHcations in ponds to promote phytoplankton and zooplankton blooms that provide food for young fish such as channel catfish, the development of algal mats through fertilization of milkfish ponds, and the use of organic fertilizers (from Hvestock and human excrement) in Chinese carp ponds to encourage the growth of phytoplankton, macrophytes, and benthic invertebrates. In the latter instance, various species of carp with different food habits are stocked to ensure that all of the types of natural foods produced as a result of fertilization are consumed. 

Economic evaluations of algal production indicate that production costs vary from 0.15 to 4.00/kg of algal product, depending on type of bioreactor, culture technique, and operating conditions (51). For systems with controlled agitation and carbonation, including raceways and tubular reactors, production costs ate estimated to range from 2.00 to 4.00/kg. 

Crude protein = %nitrogen X 6.25. Does not accurately reflect true protein content. Algal cells may contain nonprotein nitrogen substances, eg, 4—6% nucleic acids, dry wt basis. 

T. Stadler, J. MolHon, M.-C. Verdus, Y. Karamanos, H. Morvan, and D. Christiaen, eds.. Algal biotechnology, Elsevier AppHed Science PubHshers, Ltd., London, 1988. 

M. A. Borowit2ka and L. J. Borowit2ka, Micro Algal biotechnology, Cambridge University Press, Cambridge, U.K., 1988. 

Dimethyl sulfoxide occurs widely at levels of <3 ppm. It has been isolated from spearmint oil, com, barley, malt, alfalfa, beets, cabbage, cucumbers, oats, onion, Swiss chard, tomatoes, raspberries, beer, coffee, milk, and tea (5). It is a common constituent of natural waters, and it occurs in seawater in the 2one of light penetration where it may represent a product of algal metaboHsm (6). Its occurrence in rainwater may result from oxidation of atmospheric dimethyl sulfide, which occurs as part of the natural transfer of sulfur of biological origin (7,8). 

Treatment of the algal cellulose (mixture of la—IP) from Valonia in ethylenediamine to give Cellulose IIIj simultaneously induced sub fibrillation in the initial microfihril (75). Thus crystallites 20 nm wide were spHt into subunits only 3—5 nm wide, even though the length was retained. Conversion of this IIIj back to I gave a material with an electron diffraction pattern and nmr spectmm similar to that of cotton Cellulose ip. 

On the macroscopic scale, two coal classifications have been used humic or banded coals and sapropeflc or nonbanded coals. Stratification in the banded coals, which result from plant parts, is quite obvious the nonbanded coals, which derive from algal materials and spores, are much more uniform. The physical and chemical properties of the different layers in a piece of coal or a seam can vary significantly. Therefore the relative amounts of the layers are important in determining the overall characteristics of the mined product. Coal petrography has been widely appHed in cokemaking and is important in coal hquefaction programs. 

Macerals. Coal parts derived from different plant parts, are referred to as macerals (13). The maceral names end in "-inite" as do the mineral forms of rocks. The most abundant (about 85%) maceral in U.S. coal is vitrinite, derived from the woody tissues of plants. Another maceral, called liptinite, is derived from the waxy parts of spores and poUen, or algal remains. The liptinite macerals fluoresce under blue light permitting a subdivision based on fluorescence. A third maceral, inertinite, is thought to be derived from oxidized material or fossilized charcoal remnants of early forest fires. 

Except as an index of respiration, carbon dioxide is seldom considered in fermentations but plays important roles. Its participation in carbonate equilibria affects pH removal of carbon dioxide by photosynthesis can force the pH above 10 in dense, well-illuminated algal cultures. Several biochemical reactions involve carbon dioxide, so their kinetics and equilibrium concentrations are dependent on gas concentrations, and metabolic rates of associated reactions may also change. Attempts to increase oxygen transfer rates by elevating pressure to get more driving force sometimes encounter poor process performance that might oe attributed to excessive dissolved carbon dioxide. 

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