Bacterial hydrolysis

Modifications of the arylamino moiety profoundly influence the rate of hydrolysis. Thus, the hydrolysis of N- ace ty 1 -4-am i no be n zo i c acid was ca. 1000-fold slower than that of acetanilide [66]. Sorci and Macalady [67] investigated the influence of ring substitution on the hydrolysis of para-substituted acetanilides (4.104) in alkaline solution and in soil bacteria. No correlation was found between alkaline and biotic hydrolysis, which appeared to be controlled by different physicochemical properties. Bacterial hydrolysis was best correlated with the Van der Waals radius of the substituent, whereas chemical hydrolysis was correlated with the Hammett constant characterizing the electron-withdrawing capacity of the substituent. Other studies confirmed that a correspondence between bacterial and mammalian esterases... 

Akao, T., Kida, H., Kanaoka, M., Hattori, M., and Kobashi, K. (1998). Intestinal bacterial hydrolysis is required for the appearance of compound K in rat plasma after oral administration of ginsenoside Rbj from Panax ginseng.. Pharm. Pharmacol. 50,1155-1160. 

Cellobiose (XXV), the basic unit of cellulose, is a potentially inexpensive monomer obtained in 90-95% yield by bacterial hydrolysis of cellulose. It is another... 

Antibacterials may also prevent the intestinal bacterial hydrolysis of drug conjugates secreted into bile and thus reduce reabsorption of the active parent drug. In this way, antibacterials may reduce the... 

Keil, R. G., and D. L. Kirchman. 1992. Bacterial hydrolysis of protein and methylated protein and its implications for studies of protein degradation in aquatic systems. Applied Environmental Microbiology 58 1374-1375. 

Resolution of rac-Pantolactone by Bacterial Hydrolysis of L-Pantolactone The Development of a Novel Biocatalyst 505... 

Strains of obligately anaerobic bacteria in rat (and human) intestinal microflora have been shown to produce iodothyronine glucuronidase and sulfatase activities [22,23]. This explains why T4 and T3 appear in feces of rats as free iodothyronines [24] although they are excreted in bile mainly as glucuronide conjugates. Recent studies indicate that a large fraction of T3G introduced in the rat intestinal tract is resorbed as free T3 liberated by bacterial hydrolysis [25,26]. In rats, therefore, glu-curonidation does not seem an irreversible pathway for the elimination of T4 and T3 but an essential step in the enterohepatic cycle of these compounds. 

Thomas and Broadbridge 28 have developed a low-voltage electrophoresis method for the rapid separation of a penicillin from its penicilloic acid. Phenoxymethyl penicillin was one of 12 penicillins studied. The method was found to be particularly useful for rabbit sera and urine and the products of bacterial hydrolysis... 

The technique of soil bacterial hydrolysis has been applied to a number of saponins (see also p. 226). The secondary reactions which usually occur under the normal acidic hydrolysis conditions are avoided. Thus the saponin from the seed kernel of Madhuca longifolia afforded protobassic acid (130), suggesting that bassic acid (131) is an artefact of acid hydrolysis. Jegosaponin yielded four new acylated derivatives of barringtogenol C (132) 21-0-tigloyl-28-0-acetyl,... 

Fats and oils become rancid on standing, i.e., they develop disagreeable odors and tastes. Two reactions are involved in this process—hydrolysis and oxidation. Hydrolysis is important as a source of rancid odors only for certain triacylglycerols that contain C4 and C, carboxylic acids. Butter is an example—its triacylglycerols contain about 3 to 4 percent butanoic acid and about 1 to 2 percent hexanoic acid. Hydrolysis due to bacteria from the air releases these volatile and malodorous acids. Air oxidation of the double bonds of unsaturated fatty acids released by bacterial hydrolysis also contributes to rancidity. Oxidation cleaves the double bond, with each carbon of the double bond being converted to a COOH group. 

Unlike the normal proximal small intestine, there have been reports of appreciable quantities of unconjugated bile acids in the ileum (41). This is not a uniform finding (42) and may reflect differences in diet or other experimental variables. Insofar as there are appreciable quantities of unconjugated acids, which undoubtedly arise from bacterial hydrolysis, nonionic diffusion plays an important role. 

Animals that use cellulose as a food do so only with the help of bacteria that possess the necessary enzymes for breakdown. Herbivores such as cows, sheep, and horses are animals in this category. Each has a colony of such bacteria somewhere in the digestive system and uses the simple carbohydrates resulting from the bacterial hydrolysis of cellulose. Fortunately, the soil also contains organisms with appropriate enzymes. Otherwise, debris from dead plants would accumulate rather than disappear through biodegradation. 

The rate of bacterial hydrolysis of fish muscle is twice as great at 2.2°C as at — 1.1°C. Estimate the value of the activation energy for this reaction. Is there any relation to the problem of storing fish for food [Source J.A. Campbell, Eco-Chem. J. Ghent. Ed. 52, 390 (1975).]... 

Lactobacillus, Enterococcus, Enterobacter and Bifidobacterium types. The authors reported a partial hydrolysis of the masked form, thus outlining that DON conjugates could be cleaved to the parent form after bacterial hydrolysis in the human colon tract. ... 

The rate of bacterial hydrolysis of fish muscle is twice as great... 

The fact that substrates bearing a phenyl group behaved differently might be attributed to electronic effects. High selectivity of the bacterial hydrolysis of substrate 2.10... 

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