Yeasts and molds

Sorbates. The sodium and potassium salts of sorbic acid [110-44-1], ate used as mold and yeast inhibitors in dairy products, chemically... 

Other bacterial strains identified as biodegrading poly(vinyl alcohol) iaclude Flavobacterium (95) 2in.dFicinetobacter (96) and many others, as well as fungi, molds, and yeasts (97). Industrial evaluations at Du Pont (98) and Air Products (99) iadicate that over 90% of poly(vinyl alcohol) entering wastewater treatment plants is removed, and hence no environmental pollution is likely. 

Sodium benzoate is used as a broad-spectrum antimicrobial, inhibiting bacteria, molds, and yeasts. The high acid content of the soft drink is necessary for the preservative action. Sodium citrate buffers the acids, so the pH stays low (acidic). It also emulsifies any fats or fat-soluble compounds in the flavorings, keeping them in solution. 

This review deals with bacterial and related polysaccharides, such as those of molds and yeasts. The bacteriological nomenclature is that of Bergey10 non-systematic nomenclature is indicated by ( ). 

Although polysaccharide metabolic products of molds and yeasts are not strictly bacterial polysaccharides, they are considered briefly here because of similarities in chemical structure (see also page 191). 

It is a highly virulent soil-fungus that is thermally dimorphic, existing in both a mold and yeast form. It is normally found in soils in the southwest United States, northern Mexico, and certain areas in Central and South America. Does not cause clinical disease in cattle, sheep, and pigs. However, it may cause fatalities in dogs and sometimes in cats. This is a biosafety level 3 agent. Stable to drying. 

Consider using dimethylhydantoin to have protection against bacteria, and iodopropylbutyl-carbamate (IPBC) against molds and yeast. Use their mixture for lower usage and cost-effectiveness. 

Triclosan also has a broad-range bacteriostatic activity against gram-positive and gram-negative bacteria, fungi, molds, and yeasts. It is metabohzed to its glucuronide... 

Since drugs interact with optically active, asymmetric biological macromolecules such as proteins, polynucleotides, or glycolipids acting as receptors, many of them exhibit stereochemical specificity. This means that there is a difference in action between stereoisomers of the same compound, with one isomer showing pharmacological activity while the other is more or less inactive. In 1860, Louis Pasteur was the first to demonstrate that molds and yeasts can differentiate between (+)- and (-)-tartarates, utilizing only one of the two isomers. 

The parabens are most effective against molds and yeasts, but less active against bacteria, particularly gram-negative bacteria. The antimicrobial activity of the parabens is directly related to the molecular chain length (methyl is weakest butyl is strongest). However, the solubility... 

Foods dried to water activities in the range of 0.65 to 0.85 are often referred to as intermediate moisture roods. These partially dried foods tend to be soft and to rehydrale easily The remaining water acts as a plasticizer. Because molds and yeast may be able to grow in these partially dried products, they must be preserved by heaL vacuum, or modified atmosphere packaging, refrigeration, or chemical means. 

Other Bacterial, Mold, and Yeast Proteases Hiroshi Matsubara and Joseph Feder... 

Single-celled organisms without chlorophyll often filamentous and can cause fouling problems at lower cooling water pH levels or when process contamination occurs. Includes molds and yeasts. 

Arindam Bose (Pfizer Central Research) further discussed the ICH documents and presented a rationale for the recommended combination of test procedures and process clearance validations required to demonstrate that marketed biopharmaceuticals are free of adventitious agents. He showed that testing of Pre-Seed Stock (PSS), the Master Cell Bank (MCB), and the Working Cell Bank (WCB) is required to demonstrate that they are free from contamination by mycoplasma, bacteria, molds, and yeasts. In addition, viral clearance validation studies must be performed on scaled down versions of each chromatographic step and the viral inactivation/removal step employed in the product purification scheme. Finally, clearance studies must be conducted with a panel of relevant and model viruses (typically three to four) to establish that the purification scheme will indeed purge any viruses that may be inadvertently introduced during processing. 

Water activity has a profound effect on the rate of many chemical reactions in foods and on the rate of microbial growth (Labuza 1980). This information is summarized in Table 1-9. Enzyme activity is virtually nonexistent in the monolayer water (aw between 0 and 0.2). Not surprisingly, growth of microorganisms at this level of aw is also virtually zero. Molds and yeasts start to grow at aw between 0.7 and 0.8, the upper limit of capillary water. Bacterial growth takes place when aw reaches 0.8, the limit of loosely... 

The antimicrobial activity of parabens is proportional to the chain length of the alkyl group. Parabens are more active against molds and yeasts than against bacteria, and... 

Test for Yeasts and Molds The plate method is used for testing molds and yeast in semisolids. The procedure is similar to that of the total count test. Instead of SBCDA medium, Sabouraud dextrose agar (SDA) medium or potato dextrose agar (PDA) medium is used. Samples are incubated for five to seven days at 20-25 °C to identify the presence of yeasts and molds. 

Usually, total aerobic bacteria, molds, and yeasts are counted by using a standard plate count in order to test the microbial limits. The microbial limit test may be customized by performing a screening for the occurrence of Staphylococcus aureus, Pseudomonas aeruginosa, Pseudomonas cepacia, Escherichia coli, and Salmonella sp. [56],... 

Membrane ATPases have also been inhibited by carbodiimides. This reaction is associated with the membrane lipoprotein. Carbodiimide binding proteins have been isolated from bacterial membranes, chloroplasts, animal liver mitochondria, bovine heart mitochondria,molds and yeasts. The site of carbodiimide attack in the protein is probably in the hydrophobic region because only lipophilic carbodiimides are effective inhibitors. The addition of methyl glycinate protects erythrocyte membrane ATPase against carbodiimide inhibition. The inhibition reaction of carbodiimides may involve an O N acyl shift in the initially formed O-acylurea. 

The molecular phylogeny and systematics of the fungi will be discussed elsewhere in this book [13]. A simple division of fungi with respect to clinical aspects is that into molds and yeasts, the former characterized by the formation of septate and nonseptate hyphae, the latter by an unicellular life cycle with reproduction mainly by budding. The so-called dimorphic fungi, such as Histoplasma... 

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