JPS5836383A - Prevention of biohazard by ozone - Google Patents

Abstract

PURPOSE:To prevent biohazard simply and efficiently, by introducing an ozone gas into a closed space to be used for the research of microbiological engineering, genetic engineering, etc., a sterilizing and decomposing biohazard factors. CONSTITUTION:Ozone-containing air is introduced from the ozonizer 1 through the line 7 to the safety cabinet 2, the biobox 3, the device 4 for treating waste water, etc., and biohazard factors are sterilized and decomposed. Ozone in an exhaust gas is removed with active carbon in the device 5 for eliminating ozone. Since guanine, thymine, etc. are subjected to cleavage of double bond and decomposed, DNA (deoxyribonucleic acid) will not be repaired by a repair enzyme, so this method has high biohazard preventing effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel method for preventing biohazards in safety cabinets and safety laboratories used in research in microbial engineering, genetic engineering, etc., or in wastewater from them. It is related to.

More specifically, the present invention relates to a simple and efficient method for preventing biohazards by using ozone to sterilize and decompose biohazardous agents.

In recent years, with the development of molecular biology and genetic engineering,
Research using gene recombination technology, for example, cutting the DNA (deoxyliponuclear, acid) that carries genetic information in cells, and cutting the DNA (plasmids, etc.) of biological cells of different species, By recombining DNA and introducing this recombinant DNA into host cells (such as Escherichia coli), research is actively being conducted to create organisms with genes that do not exist in nature.

Along with this, the risk of creating pathogenic microorganisms that did not exist before is increasing, and therefore, thorough biohazard protection measures are required depending on the content of these genetic experiments.

In addition, regarding research on pathogenic microorganisms that has been carried out in the past, for example, there is research that deals with extremely dangerous pathogens such as those that cause Lassa fever, or with unknown pathogens. It has become essential.

Therefore, recent countermeasures include the use of safety cabinets and the use of P3s equipped with safety equipment in the laboratory itself.
．． The use of a P. level laboratory (Recombinant DNA Experiment Guidelines, Prime Minister, August 27, 1978) is required.

By the way, the sterilization and disinfection methods currently used in biohazard protection facilities are the high-pressure steam method for laboratory equipment and waste, and the boiling (330°C) method for wastewater. For sterilization and disinfection, formalin (fumigation method) is specified (recombinant DNA
A experimental guideline).

However, although the high-pressure steam method can be applied to small-sized objects, it is difficult to apply to large-sized objects, and furthermore, it is unsuitable for sterilizing and disinfecting containers in which test specimens are contained. Also, regarding the boiling method for wastewater, it can only be used when the amount is φ.
It has the disadvantage that it is difficult to use in large quantities.

On the other hand, formalin (
The fumigation method is not easy as it requires bringing in a separate fumigation equipment, but the sterilizing and disinfecting power of formaldehyde is relatively strong (7000 ppp of formaldehyde is not required).
It requires high-concentration and long-time treatment, such as exposure to m for 60 minutes. Furthermore, formaldehyde after sterilization and disinfection is often released into the atmosphere, which poses a problem in terms of the toxicity of formaldehyde, and even if formaldehyde is removed by absorption into water, the waste water This process is necessary again, which is complicated.

For these reasons, this formalin fumigation method cannot necessarily be said to be a satisfactory method.

In addition, ultraviolet irradiation, which is used in conjunction with supplementary sterilization and disinfection, is not effective against the shadows of objects, and if the container containing the test object is glass, there is a risk of destroying the test object. It has some disadvantages such as.

The inventors of the present invention have conducted extensive research into developing a new biohazard protection method that is easy to operate and effective, and have found that ozone has excellent sterilization and decomposition power against biohazard factors. In addition, it can be easily manufactured from air and electricity, and its control is simple, and the sterilization and decomposition methods using it can be automated and are easy to operate in both atmospheric and water systems. , Residual ozone can be removed with activated carbon and does not pollute the atmosphere, and since ozone is a gas, unlike ultraviolet rays, it does not leave parts unsterilized or disinfected.
Furthermore, the present invention was completed by paying attention to the fact that there is no risk of damaging the test specimen, which is sealed inside the container.

That is, according to the method of the present invention, a safe cabin,
For closed spaces such as safety laboratories or drainage from them,
By introducing ozone to sterilize and decompose the biohazard factor, effective biohazard protection can be achieved.

The biohazard prevention method of the present invention is aimed at eliminating the dangers of recombinant organisms created by making full use of genetic recombination techniques such as molecular biology and genetic engineering, or the risks caused by pathogenic microorganisms, especially viruses. Therefore, it is a powerful sterilization and decomposition defense method that goes beyond traditional sterilization concepts. In other words, in conventional sterilization treatment, the treatment is considered to have ended when the number of bacteria reaches a certain standard value or less after a certain period of time.
In the biohazard protection method of the present invention, the cell membranes, envelopes, and capsids of biohazard factors are destroyed, and the DNA containing genetic information therein is destroyed, and the destroyed DNA cannot be reproduced.

The ozone used in the method of the present invention can be easily produced from air and electricity, and its control is simple. Moreover, it has superior sterilization, decomposition, and It has inactivating power. For example, in the case of the tobacco mosaic virus nucleic acid, the inactivating power of ozone is about that of formaldehyde] 0
Close to 00 times.

On the other hand, regarding the mechanism of gene inactivation by formaldehyde, it is known that amino groups such as guanine, cytosine, and adenine in nucleic acids are changed by formaldehyde into mono- or dimethylol derivatives; It is now known that to the extent that a base is converted to its analogue, it can be repaired by repair enzymes to restore its original activity.

The present inventors investigated the mechanism of DNA destruction caused by ozone and found that the destruction occurs at the center of all guanine bases, that is, guanine is further decomposed into several types of compounds from the cleavage of the double bond at the 4.5-position. However, we also found that thymine decomposes at a similar rate, eventually leading to molecular chain scission.

In this DNA destruction mechanism caused by ozone, DN
It is impossible to repair A. Therefore, the use of ozone as a biozard defense measure is extremely effective in terms of the speed and effectiveness of sterilization and inactivation.

In the method of the present invention, by passing ozone gas through a closed safety cabinet or safety laboratory, bio-zard factors floating in the air and biohazard factors that are sticky or fixed can be easily sterilized and decomposed. This method is more effective than conventional sterilization and disinfection methods such as high-pressure steaming, formalin vaporization, and ultraviolet irradiation.

Furthermore, in the method of the present invention, by passing ozone gas through the waste water from a safety cabinet or safety laboratory, biohazardous materials present therein can be effectively sterilized and decomposed.

The present invention will now be described in more detail with reference to the accompanying drawings.

The drawing is an example of a flow sheet of the method of the present invention, where ] is an ozone generator for generating ozone from air, 2 is a safety cabinet or safety laboratory, and 3 is a bath box (
4 is a wastewater treatment device for treating wastewater from a safety cabinet or a safety laboratory, and 5 is an activated backlight evacuation ozone removal device for removing ozone in exhaust gas.

Air is supplied from line 6 to ozone generator 1 to generate ozone, and the ozone-containing air obtained passes through line 7 to safety cabinet or safety laboratory 2, bath box 3 (
(In the case of a safety cabinet, there is no such thing) and wastewater treatment equipment 4, which sterilizes and decomposes biohazardous substances present indoors or in wastewater. safety cabinet or safety laboratory;
The exhaust ozone-containing air discharged from the bus box and the waste water treatment equipment is led to the exhaust ozone removal equipment 5 through lines 8, 9 and 10, respectively, and after the ozone is removed by activated carbon filled in this equipment, It becomes harmless air and is released into the atmosphere through line 1.

In the method of the present invention, when ozone is introduced into the atmosphere in a closed space at a concentration of ioo ppm, a treatment time of 60 minutes is sufficient, but the treatment time can be shortened by increasing the concentration.

The biono-zard protection method using ozone of the present invention effectively sterilizes and decomposes the biono-zard factors present in closed safety cabinets and safety laboratories, as well as the biono-zard factors present in the wastewater from them. It has the advantage that it is completely inert, and its defense system can be easily automated and is extremely simple to operate.

Next, the present invention will be explained in more detail with reference to Examples.

Example Safety cabinet-sized airtight chino, <-(IXIXl
Spray E. coli on the bottom of a petri dish (12 mm in diameter).
cm) After leaving several pieces still, ozone 0,3 W/l
, < 140ppm) or 1.0 rn9/ll
(470I) 1) m) at a flow rate of 1,5 m'
/min, and after a certain period of time, clean air was passed through the chamber for 10 minutes to completely drive out the ozone in the chamber, and the seaweed was taken out and cultured overnight at 37°C, and the number of survivors was measured. The following two sample petri dishes, A and B, were used for E. coli dispersion.

A: 100 μl of E. coli suspension was placed on the agar medium, spread on the surface with a glass rod, and then cultured at 37°C for 1 hour. B: After spreading E. coli on the agar medium in the same manner as in A. A thin layer of agar medium was placed on top of the agar medium (thickness: 02 m + n) to confine E. coli, and the bacteria was cultured at 37°C for 1 hour. The relationship is shown in Figure 2. As is clear from this figure, even under extreme conditions (CB) that make contact with ozone difficult, sterilization can be achieved at a lower concentration and in a shorter time than the conventional sterilization using formaldehyde.

Also, regarding sample A, the ozone concentration was 140 ppm.
(solid line) and 470 ppm (dashed line), the results of similar tests are shown in FIG. As is clear from the figures, the higher the ozone concentration, the shorter the processing time.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of the method of the present invention, and FIGS. 2 and 3 are graphs showing the relationship between ozone contact time and E. coli survival rate in Examples of the present invention. In the figure, symbol l indicates the ozone generator 22 is a safety cabinet or safety laboratory, 3 indicates a pass box, 4 indicates a wastewater treatment device,
5 is a removing device. Patent applicant Makoto Ishizaka, Director of the Agency of Industrial Science and Technology - Designated agent
Shun Sato, Director, Hokkaido Industrial Development Testing Institute, Agency of Industrial Science and Technology
Figure 1 Figure 2 10 Figure 3 0 5 10 15 Ozone contact time (minutes)

Claims (1)

[Claims] 1. A method for preventing biohazards in a closed system space, which comprises introducing ozone into the space to sterilize and decompose biohazard factors.