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UV radiation Effects on Pathogenic Microorganisms

#2520


Study of Modification Effects in Pathogenic Microorganisms Exposed to Near Vacuum Ultraviolet Radiation (170-200 nm)

Tech Area / Field

  • BIO-SFS/Biosafety and BioSecurity/Biotechnology
  • BIO-MIB/Microbiology/Biotechnology

Status
3 Approved without Funding

Registration date
24.05.2002

Leading Institute
VNIIEF, Russia, N. Novgorod reg., Sarov

Supporting institutes

  • Russian Scientific Center of Applied Chemistry, Russia, St Petersburg\nInstitute of Highly Pure Biopreparations, Russia, St Petersburg

Collaborators

  • Kyoto University, Japan, Kyoto\nCornell University, USA, NY, Ithaca\nPolyclinique Maymard/Service de Cancerologie Medicale et de Radiotherapie, France, Bastia\nUniversity of Illinois / College of Medicine, USA, IL, Chicago

Project summary

The main goal of the project is to study and develop an alternative technology for destruction of some pathogenic microorganisms in the indoor air and in water. The project is orientated towards control of highly dangerous and resistant microorganisms, specifically viruses of poliomyelitis and hepatitis, bacilli spores, helminth cysts. It is these species of microorganisms, which are used as indicators of sanitary conditions of the indoor air and water, according to the recent standards of the World Health Organization.

Bacilli of anthrax and tuberculosis mycobacterium fall under this category.

Currently, there are two methods most extensively used for indoor disinfection and for sanitary treatment of water. The first one is chemical method using chlorine and chlorine-containing compounds. The other is physical method using treating with irradiation at wavelength of 254 nm by means of bactericide lamps. Advantages and shortcomings of these methods are described in detail [31].

As far as the goal of the project is to develop a new alternative technology for destruction of pathogenic microorganisms, that is disinfection technology, let us note shortcomings of the above-mentioned method for disinfection by means of treating with irradiation at wavelength of 254 nm, which is widely used.

They are as follows:

– low quantum yield of lethal damage of microorganisms (10-5 - 10-4);


– high percentage of self- reparation of irradiated microorganisms [2];

Differences in mechanisms of damage after irradiation between the spectral regions of (more than) >200 nm and < 200 nm were established already in the early works in photobiology [2, 3]. It is significant that together with the decreasing of wavelength the quantum yield of lethal damage of microorganisms grows, while the efficiency of self-reparation decreases. Over the recent years radiation sources highly efficient in the spectral range of near vacuum ultraviolet (VUV) were developed [26]. This permits to develop new highly efficient irradiation technologies for disinfection. Radiation in the VUV range results in photo-destruction of the air oxygen. Incidentally ozone is formed. There is a well-known effect of mutual intensification ("synergism") for UV-radiation (254 nm) and ozone, which affect microorganisms simultaneously [30]. Problems of the combined effects of ozone and UV-radiation on microorganisms will be studied in the proposed project.

Furthermore, because VUV, unlike UVC radiation, is similar to gamma irradiation, we can expect that many types of DNA damage might occur, and the investigation of such modifications of microorganisms would be useful and interesting.

Specialists involved in the project are as follows:

– physicists of RFNC-VNIIEF (Russian Federal Nuclear Center – All Russia Scientific Research Institute of Experimental Physics);


– biologists of SSC (State Scientific Center) - Research Institute of High Purity Bio-preparations;
– photo-chemists of RSC (Russian Scientific Center) for Applied Chemistry.

We expect the following results:

– To develop and produce a mobile facility for study of the VUV-radiation (170-200 nm) effects on pathogenic microorganisms.


– To study the mechanisms of lethal effects of the VUV-radiation (170-200 nm) on pathogenic microorganisms.
– To study the combined effect of VUV-radiation and ozone, generated photo-chemically.
– To obtain data on the safety of methods under investigation.
– To provide recommendations for the application of technology developments.


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