Inactivation of microorganisms

For inactivation of microorganisms disinfection. Typical disinfectants are chlorine, chlorine dioxide, chloramines, and ozone. 

Several novel porphyrin derivatives can then be obtained by following the mentioned cycloaddition methodologies many of the new products fulfil the requirements to be considered as potential new drugs mainly for the detection and treatment (PDT) of cancer situations and in the photo-inactivation of microorganisms. 

Several papers have been published on the photodynamic inactivation of microorganisms in waste water treatment (Acher and Juven, 1977 Gerba et al., 1977a,b, Kussovski et al., 2001 Martin and Perez-Cruet, 1987). Despite the fact that the effectiveness of photodynamic disinfection... 

TABLE 3.8 Photodynamic inactivation of microorganisms on the surface of paper treated with conjugates of Rose Bengal (RB) and Phloxine B (PhB) with poly (vinyl amine) (PVAm) (adapted from Brovko et ai, 2009)... 

The cytotoxic and photodynamic inactivation of microorganisms by Rose Bengal is an important line of research [337]. Rose Bengal causes ATP depletion [338] in killing Escherichia coli B/r [339]. Since E. coli is also killed... 

Jori G, Brown SB. Photosensitized inactivation of microorganisms. Photochem Photobiol Sci 2004 3 403-5. 

Fundamentals of heterogeneous photocatalysis have been described in Chapter 7. The photodynamic activity of Ti02 (based on its photocatalytic activity and high efficiency in ROS generation) can find applications in photodynamic therapy (PDT) and photodynamic inactivation of microorganisms (PDI), described in Chapters 17 and 18, respectively. Selected environmental aspects of heterogeneous photocatalysis are described below. 

Belhdovd, L., Kr sa, 1., Geryk, 1. and lirkovsky, 1. (1999) Inactivation of microorganisms in a flow-through photoreactor with an immobilized Ti02 layer. I. Chem. Technol. Biotechnol. 74, 149-154. 

In contrast to sterilization, the aim of disinfection techniques is to reduce the number of pathogenic bacteria, viruses, protozoa and spores by inactivation, so that the infectivity of the material is reduced drastically. During disinfection processes, the inactivation of microorganisms follows an exponential decay according to Eq. 9-1. 

Belhacova L, Krysa J, Geryk J, Jirkovsky J (1999) Inactivation of Microorganisms in a Flow-through Photoreactor with an immobilized Ti02 Layer, J. Chem. Technol. Bio-technol. 74 149-154. 

Veerkamp, C. H., Romijn, A. J. M., and Pol, J. C. 1974. Influence of varying residence time distribution on inactivation of microorganisms during pasteurization of egg products. Lehensm.-Wiss. u. -Technol. 7 306-310. 

Sterilization is a probability function. In the pharmaceutical industry, an item is deemed sterile if there is less than 1 chance in 1,000,000 that viable microorganisms are present in the sterilized article or dosage form. Therefore there is a 10 probability of non-sterility. In all sterilization processes, the inactivation of microorganisms develops as a first-order chemicalreaction, i.e., at a rate which is approximately logarithmic. ... 

Table 3 Ct values (mg min/L) for 99% inactivation of microorganisms with disinfectants at 5°C...

The effects of pressure on organic systems are known since the 19 century from qualitative experiments. The effects of high hydrostatic pressure treatment on the inactivation of microorganisms were reported 100 years ago by Hite. On 1899, Hite uses pressure for milk preservation. On 1914, Bridgman notices that egg white looks cooked after pressure treatment. Though it is not intuitive, proteins also unfold with pressure. 

Smiddy et al. (2005) confirmed higher baro-resistance of bacteria in oysters than in bnffer, which indicated that stndies of high-pressure-induced bacterial inactivation in bnffer systems may not predict inactivation of microorganisms in foods. Calci et al. (2005) indicated that 6-log redaction of Hepatitis A virus could be achieved via application of high pressure (350-400 MPa). Li et al. (2009) demonstrated that high-pressnre treatment (400 MPa, 5 min, 0°C) of oysters contaminated with murine norovirns-1 could reduce the levels of contaminant to undetectable levels. 

Black, E.P., Kelly, A.L., and Fitzgerald, G.F. 2005. The comhined effect of high pressnre and nisin on inactivation of microorganisms in milk. Innovative Food Science and Emerging Technologies. 6 286-292. 

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