Chemistry: molecular biology and microbiology – Micro-organism – per se ; compositions thereof; proces of...
Reexamination Certificate
1997-06-26
2001-04-10
Lankford, Jr., Leon B. (Department: 1651)
Chemistry: molecular biology and microbiology
Micro-organism, per se ; compositions thereof; proces of...
C435S259000, C435S261000, C422S001000, C422S006000, C206S205000
Reexamination Certificate
active
06214601
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a method for inhibiting the growth of microorganisms in an aqueous medium.
BACKGROUND OF THE INVENTION
Microbial growth occurs in many systems in which aqueous media such as water, aqueous solutions and aqueous dispersions of material are employed.
For example, there is a significant biofouling problem in many areas of photoprocessing and other systems, in particular where low flowrate washes and water recycling is employed. Biofouling is a complex process which causes microorganisms e.g. bacteria to attach to surfaces and can occur over a wide range of bacterial levels. This may be due to a diffusion controlled process or the lack of food in solution encouraging the bacteria to attach to surfaces.
Biocides have been used for many years to control biogrowth but have several drawbacks. First, they are by nature fairly toxic chemicals and thus present handling and containment problems. Secondly, addition of biocides is not often controlled carefully and they can be added when not needed which is costly and potentially harmful to the environment. Thirdly, microorganisms can become resistant to a particular biocide which necessitates switching biocides at regular intervals. Fourthly, legislation on discharges to drains is becoming more stringent in many countries such that the levels of biocide disposal may become an issue preventing their conventional use. Finally, there is no universal treatment to kill or control all types of bacteria and fungi. Hence, the prior art is limited to these relatively toxic chemicals, chlorination, UV, ozonolysis and gamma radiation.
EP-A-0 536 087 describes a resevoir system for the prolonged and even release of soluble active materials into water or an aqueous medium which comprises a nonwoven fabric bag containing the active material e.g. an antifungal agent. The nonwoven material is made from continuous monofilaments or microfibres of a synthetic thermoplastic polymer which has been treated to give it the required degree of permeability.
PROBLEM TO BE SOLVED BY THE INVENTION
A method for inhibiting the growth of microorganisms in an aqueous medium is required which does not involve the use of toxic chemicals or radiation.
SUMMARY OF THE INVENTION
The invention provides a method for inhibiting the growth of microorganisms in an aqueous medium comprising contacting the aqueous medium with a permeable body comprising a material which interacts with the microorganisms characterised in that the material undergoes a change in its chemical structure resulting from the action of one or more of the microorganisms.
ADVANTAGEOUS EFFECT OF THE INVENTION
The invention provides a passive way of solving the problem of biofouling of surfaces. There is no dosing of toxic chemicals into the water.
As the microorganisms are attracted to the permeable body, biofouling of other components can be reduced.
The method is simple and, unlike methods employing filters or columns, does not depend on water flowrate or pressure. Also, there are none of the blockage problems associated with the use of filters and columns.
The permeable body used in the invention can be easily inserted and retrieved from the aqueous medium.
REFERENCES:
patent: 4034084 (1977-07-01), Siragusa
patent: 4396512 (1983-08-01), Beauman et al.
patent: 4587213 (1986-05-01), Malecki
patent: 4603006 (1986-07-01), Sikes et al.
patent: 4707263 (1987-11-01), Nishimori et al.
patent: 4781897 (1988-11-01), Geron et al.
patent: 5051189 (1991-09-01), Farrah
patent: 5222595 (1993-06-01), Gouge et al.
patent: 5283060 (1994-02-01), Shieh
patent: 4216571 (1993-11-01), None
patent: 0 496 905 (1992-08-01), None
patent: 0 536 087 A1 (1992-09-01), None
patent: 90058392B (1990-12-01), None
patent: 06279204A (1993-03-01), None
patent: 5345701A (1993-12-01), None
patent: 1032067 (1983-07-01), None
patent: 92/16461 (1992-10-01), None
Ackart, et al., Antimicrobial Polymers, 1975, vol., 9 pp. 55-68, J. Biomed. Mater. Res.
GJL Griffin, Chemistry and Technology of Biodegradable Polymers, 1994, Blackie Academic & Professional, London UX, paragraph 2.3.2.
Batts Gregory N.
Leeming Karen
Moore Christopher P.
Eastman Kodak Company
Lankford , Jr. Leon B.
LandOfFree
Method for inhibiting the growth of microorganisms in an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for inhibiting the growth of microorganisms in an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for inhibiting the growth of microorganisms in an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2526437