Acid-forming organisms

This response is interpreted by engineers to mean that acid-forming organisms can tolerate adversity better than gas formers and that an accumulation of Phase I waste products (the acids) can be tolerated by acid formers to a rather marked degree. 

However, acetic acid fermentation has its limits also. When the concentration of acetic acid in fermenting liquor has reached eight per cent the activity of the acetic acid forming organisms becomes slower and slower and ceases almost altogether when 12 to 14 per cent acid content is reached. 

Adametz, an Austrian, published the results of his work on cheese in 1889. He was one of the first to work on cheese after the innovation of the plate method of obtaining pure cultures. This fact made his work very important at this time as he outlined the flora of cheese quite definitely. He found 90% of the organisms of cheese to be lactic acid forming organisms. 

Yeast (Saccharomyces cerevisae, Saccharomyces minor and others), which are mainly responsible for dough leavening, and a complex bacterial flora in which lactic acid-forming organisms dominate Lactobacillus plantarum, Lactobac, San Francisco and Lactobacillus brevis) are present in sour dough. 

A lactic-acid forming organism, which occurs as rods sometimes united in short chains found in intestinal contents of young infants. 

The tendency to form organized monolayers improves with chain length. This is illustrated in a study of adsorption kinetics in alkanoic acid monolayers on alumina by Chen and Frank [36]. They find that the Langmuir kinetic equation, discussed in Section XVII-3, (see Problem XI-6)... 

Metallic sodium. This metal is employed for the drying of ethers and of saturated and aromatic hydrocarbons. The bulk of the water should first be removed from the liquid or solution by a preliminary drying with anhydrous calcium chloride or magnesium sulphate. Sodium is most effective in the form of fine wire, which is forced directly into the liquid by means of a sodium press (see under Ether, Section II,47,i) a large surface is thus presented to the liquid. It cannot be used for any compound with which it reacts or which is affected by alkalis or is easily subject to reduction (due to the hydrogen evolved during the dehydration), viz., alcohols, acids, esters, organic halides, ketones, aldehydes, and some amines. 

Chloroacetic acid forms a2eotropes with a number of organic compounds. It can be recrystaUized from chlorinated hydrocarbons such as trichloroethylene, perchloroethylene, and carbon tetrachloride. The freezing poiat of aqueous chloroacetic acid is shown ia Figure 1. 

Sulfonation. Sulfonation of naphthalene with sulfuric acid produces mono-, di-, tri-, and tetranaphthalenesulfonic acids (see Naphthalene derivatives), ah of the naphthalenesulfonic acids form salts with most bases. Naphthalenesulfonic acids are important starting materials in the manufacture of organic dyes (15) (see Azo dyes). They also are intermediates used in reactions, eg, caustic fusion to yield naphthols, nitration to yield nitronaphthalenesulfonic acids, etc. 

Nitric acid can be used for the dissolution of nickel from many inorganic substances. In some cases perchloric acid is used in combination with nitric acid. Simple organic forms of nickel also can be dissolved in nitric acid. In the case of compHcated stmctural organic forms of nickel, oxidation calorimetry must be used to decompose the substances. 

Another method for producing petoxycatboxyhc acids is by autoxidation of aldehydes (168). The reaction is a free-radical chain process, initiated by organic peroxides, uv irradiation, o2one, and various metal salts. It is terrninated by free-radical inhibitors (181,183). In certain cases, the petoxycatboxyhc acid forms an adduct with the aldehyde from which the petoxycatboxyhc acid can be hberated by heating or by acid hydrolysis. If the petoxycatboxyhc acid remains in contact with excess aldehyde, a redox disproportionation reaction occurs that forms a catboxyhc acid ... 

There are numerous misconceptions about the sources of various chemical elements in waste, particularly those that are potential acid formers when the waste is incinerated or mechanically converted and used as a refuse-derived fuel. For example, it is often mistakenly stated that the source of chlorine in waste, hence a potential source of HCl emissions, is poly(vinyl chloride). The relative contents of selected, potentially acid-forming elements in the organic portion of a sample of waste collected from various households in one U.S. East Coast city is given in Table 2 (17). In this city, a chief source of chlorine in the waste is NaCl, probably from food waste. 

The microbial assay is based on the growth of l ctobacillus casei in the natural (72) or modified form. The lactic acid formed is titrated or, preferably, the turbidity measured photometrically. In a more sensitive assay, l euconostoc mesenteroides is employed as the assay organism (73). It is 50 times more sensitive than T. casei for assaying riboflavin and its analogues (0.1 ng/mL vs 20 ng/mL for T. casei). A very useful method for measuring total riboflavin in body fluids and tissues is based on the riboflavin requirement of the proto2oan cHate Tetrahjmenapyriformis which is sensitive and specific for riboflavin. 

Organic acids, including carbon dioxide, lower the wort pH during fermentation. The principal acids formed are lactic, pymvic citric, malic, and acetic acids, at concentrations ranging from 100—200 ppm. The main sulfur compounds formed during fermentation and thek perception thresholds are as follows H2S (5—10 ppb) ethanethiol (5—10 ppb) dimethyl sulfoxide (35—60 ppb) and diethyl sulfide (3—30 ppb). At low levels, these may have a deskable flavor effect at higher levels they are extremely undeskable. Sulfur dioxide also forms during fermentation, at concentrations of 5—50 ppm its presence can be tasted at levels above 50 ppm. 

Nitric acid oxidizes antimony forming a gelantinous precipitate of a hydrated antimony pentoxide (8). With sulfuric acid an indefinite compound of low solubihty, probably an oxysulfate, is formed. Hydrofluoric acid forms fluorides or fluocomplexes with many insoluble antimony compounds. Hydrochloric acid in the absence of air does not readily react with antimony. Antimony also forms complex ions with organic acids. 

Copper—Liquor Scrubbing. Cuprous ammonium salts of organic acids form complexes with carbon monoxide. 

Properties are furthermore determined by the nature of the organic acid, the type of metal and its concentration, the presence of solvent and additives, and the method of manufacture. Higher melting points are characteristics of soaps made of high molecular-weight, straight-chain, saturated fatty acids. Branched-chain unsaturated fatty acids form soaps with lower melting points. Table 1 Hsts the properties of some soHd metal soaps. 

Nitroanthraquinone is prepared from anthraquinone by nitration in sulfuric acid (11), or in organic solvent (12). Nitration in nitric acid is dangerous. The mixture of anthraquinone and nitric acid forms a Sprengel mixture (13,14) which may detonate. However, detonation can be prevented by a dding an inert third component such as sulfuric acid. Experimental results of the steel-tube detonation tests for the anthraquinone—HNO2—H2SO4 system have been pubUshed (13). 

Deposits contained organic acids formed by oxidation of rolling oils. Up to 40% by weight of the lumps shown in Fig. 4.27A and B was iron oxides, hydroxides, and organic-acid iron salts. Acidic species concentrated in the deposits. 

Common impurities found in aldehydes are the corresponding alcohols, aldols and water from selfcondensation, and the corresponding acids formed by autoxidation. Acids can be removed by shaking with aqueous 10% sodium bicarbonate solution. The organic liquid is then washed with water. It is dried with anhydrous sodium sulfate or magnesium sulfate and then fractionally distilled. Water soluble aldehydes must be dissolved in a suitable solvent such as diethyl ether before being washed in this way. Further purification can be effected via the bisulfite derivative (see pp. 57 and 59) or the Schiff base formed with aniline or benzidine. Solid aldehydes can be dissolved in diethyl ether and purified as above. Alternatively, they can be steam distilled, then sublimed and crystallised from toluene or petroleum ether. 

There are many reactions in which the products formed often act as catalysts for the reaction. The reaction rate accelerates as the reaction continues, and this process is referred to as autocatalysis. The reaction rate is proportional to a product concentration raised to a positive exponent for an autocatalytic reaction. Examples of this type of reaction are the hydrolysis of several esters. This is because the acids formed by the reaction give rise to hydrogen ions that act as catalysts for subsequent reactions. The fermentation reaction that involves the action of a micro-organism on an organic feedstock is a significant autocatalytic reaction. 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

A large variety of salts of triflic acid formed both from metals and nonmetals are known Many of these salts are versatile reagents for organic synthesis because of such properties of the tnflate anion as very low nucleophilicity and low coordinating ability However, despite low nucleophilicity, the triflate anion can combine with carbocationic intermediates under appropriate conditions to form triflate esters [116, 117, II8. ... 

Organisms differ with respect to formation, processing, and utilization of polyunsaturated fatty acids. E. coli, for example, does not have any polyunsaturated fatty acids. Eukaryotes do synthesize a variety of polyunsaturated fatty acids, certain organisms more than others. For example, plants manufacture double bonds between the A and the methyl end of the chain, but mammals cannot. Plants readily desaturate oleic acid at the 12-position (to give linoleic acid) or at both the 12- and 15-positions (producing linolenic acid). Mammals require polyunsaturated fatty acids, but must acquire them in their diet. As such, they are referred to as essential fatty acids. On the other hand, mammals can introduce double bonds between the double bond at the 8- or 9-posi-tion and the carboxyl group. Enzyme complexes in the endoplasmic reticulum desaturate the 5-position, provided a double bond exists at the 8-position, and form a double bond at the 6-position if one already exists at the 9-position. Thus, oleate can be unsaturated at the 6,7-position to give an 18 2 d5-A ,A fatty acid. 

The first natural products shown to be cyclic hydroxamic acids belong to the group of aspergillic acids, formed by cultures of Aspergillus flavus and related organisms. 

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