Molds, antimicrobial activity

The parabens are effective over a wide pH range and have a broad spectrum of antimicrobial activity, although they are most effective against yeasts and molds. Antimicrobial activity increases as the chain length of the alkyl moiety is increased, but aqueous solubility decreases therefore a mixture of parabens is frequently used to provide effective preservation. Preservative efficacy is also improved by the addition of propylene glycol (2-5%), or by using parabens in combination with other antimicrobial agents such as imidurea see Section 10. 

Parabens have some antimicrobial activity but are most effective against yeasts and molds. Although methyl paraben has the least antimicrobial activity, different combinations of methyl paraben with other long-chain parabens can lead to synergy. As the chain length of the paraben s alkyl moiety is increased, their antimicrobial activity increases. 

Arylisatogens show significant antimicrobial activity against bacteria,31 mycoplasma organisms, and the mold Candida albicans.19 No useful biological activity has been observed with indolones.49... 

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... 

Rifampin [RIF am pin], derived from the soil mold Streptomvces. has a broader antimicrobial activity than isoniazid and has found application in the treatment of other bacterial infections. Because resistant strains rapidly emerge during therapy, it is never given as a single agent in the treatment of active tuberculosis. 

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... 

Antimicrobial activity benzyl alcohol is bacteriostatic and is used as an antimicrobial preservative against Gram-positive bacteria, molds, fungi, and yeasts, although it possesses only modest bactericidal properties. Optimum activity occurs at pH below 5 little activity is shown above pH 8. Antimicrobial activity is reduced in the presence of nonionic surfactants, such as polysorbate 80. However, the reduction in activity is less than is the case with either hydroxybenzo-ate esters or quaternary ammonium compounds. The activity of benzyl alcohol may also be reduced by incompatibilities with some packaging materials, particularly polyethylene see Section 12. 

Antimicrobial activity activity is similar to that of the p-hydroxybenzoate esters (parabens). The greatest activity is against molds and Gram-positive bacteria, with less activity against Gram-negative bacteria. 

As a group, the parabens are effective over a wide pH range and have a broad spectrum of antimicrobial activity, although they are most effective against yeasts and molds see Section 10. 

Madagascan Saro essential oil was found to have an attractive odor with a fresh eucalyptus type aroma, being the oil dominated by 1,8-cineole. The oil was found to be safe for human use, with low irritation levels, no mutagenicity and cytotoxicity. This EO also showed antimicrobial activity against several mold and bacteria. Due to its favorable organoleptic and chemical profiles, its safety and effective microbial activity, this oil may have application in the cosmetic, perfumeiy and pharmaceutical industries. The identification of new uses and application of essential oils, can ultimately assist rural communities in Madagascar by generating interest and market access to their products only if these new applications find a sustainable market. 

Propionic acid (Figure 2.12) was first described in 1844. Propionic acid occurs in foods by natural processing. It has been found in Swiss cheese at concentrations of up to 1% and is produced by the bacterium Propionibacterium shermanii. Antimicrobial activity of propionic acid is reported to be primarily against molds and bacteria (Barbosa-Canovas et al., 2003). Commercial products containing propionic acid include... 

Extrusion is a cost effective manufacturing process. Extrusion is popularly used in large scale production of food, plastics and composite materials. Most widely used thermoplastics are processed by extrusion method. Many biopolymers and their composite materials with petroleum-based polymers can also be extruded. These include pectin/starch/poly(vinyl alcohol) (Fishman et al. 2004), poly(lactic acid)/sugar beet pulp (Liu et al. 2005c), and starch/poly(hydroxyl ester ether) (Otey et al. 1980), etc. In this study, composite films of pectin, soybean flour protein and an edible synthetic hydrocolloid, poly(ethylene oxide), were extruded using a twin-screw extruder, palletized and then processed into films by compression molding process or blown film extrusion. The films were analyzed for mechanical and structural properties, as well as antimicrobial activity. 

Antimicrobial activity of QACs extends across a broad spectrum of microbes, including bacteria, yeasts, molds, and viruses. This varies between organisms and efficacy for each organism also depends upon the chemical nature of each QAC. 

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