MXPA98002436A - Methods and compositions to control biocontamination using ami - Google Patents

Abstract

The present invention relates to a method for inhibiting the bacteria from adhering to a submergible surface. The method contacts the submergible surface with an effective amount of at least one amide to inhibit bacterial adhesion to the submergible surface. The present invention also relates to a method for controlling biocontamination of an aqueous system. This method adds an effective amount of at least one amide to inhibit the bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biocontamination without substantially killing the bacteria. The amide used in the method of the invention has the formula (I). The present invention also relates to compositions containing amides and usable in the above methods. The compositions comprise at least one amide in an amount sufficient to inhibit bacteria from adhering to submergible or submerged surfaces.

Description

METHODS AND COMPOSITIONS FOR CONTROLLING BIOCONTA INATION USING AMIDAS DESCRIPTION OF THE INVENTION The invention uses amides to inhibit bacterial adhesion to submergible or submerged surfaces, particularly those surfaces within an aqueous system. The invention also relates to methods and compositions for controlling biological contamination. Microorganisms adhere to a wide variety of surfaces, particularly surfaces in contact with aqueous fluids which provide an adequate environment for microbial growth. For example, microorganisms are known to adhere to ship hulls, marine structures, teeth, medical implants, cooling towers, and heat exchangers. Adhering to such submerged or submerged surfaces, microorganisms can contaminate the surface or cause its deterioration. In mammals (for example, humans, pets, pets), microorganisms attached to a surface can lead to health problems. The plaque, for example, results from microorganisms that adhere to the surfaces of the teeth. Medical implants with unwanted microorganisms attached to their surfaces often become embedded and must be replaced. Scientific studies have shown that the first stage of biocontamination in aqueous systems is generally the formation of a thin biofilm on submerged or submerged surfaces, that is, surfaces exposed to the aqueous system. By attaching to, and colonizing on a submerged surface, microorganisms such as bacteria, are thought to generally form the biofilm and modify the surface in favor of the development of the more complex community of organisms that form the advanced biocontamination of the aqueous system and its submerged surfaces. . A general summary of the mechanisms of biofilm importance as well as the initial stage in biocontamination is given in CA Kent in "Biological Fouling: Basic Science and Models" (in Meló, LF, Bott, R., Bernardo, CA ( eds.), Fouling Science and Technology, NATO ASI Series, E Series, Applied Sciences: No. 145, Kluwer Acad. Publishers, Dordrecht, The Netherlands, 1988). Other literature references include. Fletcher and G. I. Loeb, Appl. Environ, Microbiol 37 (1979) 67-72; M. Humphries et. al., FEMS Microbiology Ecology 38 (1986) 299-308; and M. Humphries et. al., FEMS Microbiology Letters 42 (1987) 9-101. Biocontamination, or biological contamination, is a persistent concern or problem in a wide variety of aqueous systems. Biocontamination, both microbiological and macrobiological pollution is caused by the accumulation of microorganisms, macroorganisms, extracellular substances, and dirt and debris that become trapped in the biomass. The organisms involved include microorganisms such as bacteria, fungi, yeasts, algae, diatoms, protozoa, and macroorganisms such as macroalgae, limpets and small molluscs such as Asian clams or zebra mussels. Another phenomenon of objectionable biocontamination that occurs in aqueous systems, particularly in fluids of aqueous industrial processes, is the formation of silt. Mud formation can occur in brackish, fresh or saltwater systems. Mud or silt consists of caked deposits of microorganisms, fibers and debris. This can be fibrous, pasty, sticky, tapioca-like or hard and has a characteristic, undesirable odor that is different from that of the aqueous system in which it is formed. The microorganisms involved in slime formation are fundamentally different species of spore-forming and non-spore-forming bacteria, particularly encapsulated forms of bacteria, which secrete gelatinous substances that envelop or conceal the cells. Mud or sludge microorganisms also include filamentous bacteria, filamentous fungi of mold type, yeast, and yeast-like organisms. Biocontamination, which often degrades an aqueous system, can manifest itself as a variety of problems, such as loss of viscosity, gas formation, odors, decreased pH, color change, and gelling. Additionally, the degradation of an aqueous system can cause contamination of the system that carries water, which can include, for example, cooling towers, pumps, heat exchangers and pipe lines, heating systems, scrubber systems, and other systems Similar. Biocontamination can have an adverse economic impact, direct when it occurs in industrial process waters, for example in cooling waters, metalworking fluid, or other recirculating water systems, such as those used in the manufacture of textiles or manufacturing of paper. If left unchecked, biological contamination of water from industrial processes can interfere with process operations, decreased process efficiency, wasted energy, obstruct the water management system, and even degrade the quality of the product. For example, cooling water systems used in power plants, refineries, chemical plants, air conditioning systems, and other industrial operations frequently encounter biocontamination problems. Airborne organisms introduced from cooling towers, as well as organisms transported in water from the system's water supply, commonly contaminate these aqueous systems. Water in such systems generally provides an excellent growth medium for these organisms. Aerobic and heliotropic organisms flourish in the towers. Other organisms grow and colonize such areas as tower wells, pipe lines, heat exchangers, etc. If left unchecked, the resulting biocontamination can clog towers, block pipe lines, and coat heat transfer surfaces with silt layers and other biological materials. This prevents proper operation, reduces cooling efficiency, and perhaps more importantly, increases the total process costs. Industrial processes subject to biocontamination also include papermaking, the manufacture of pulp, paper, cardboard, etc., and the manufacture of textiles, particularly non-spun textiles found in water. These industrial processes generally recirculate large amounts of water under conditions which favor the growth of biocontaminating organisms. Paper machines, for example, handle very large volumes of water in recirculation systems, called "white water systems". To say a paper machine typically contains only about 0.5% solids for making fibrous and non-fibrous paper, which means that for each ton of paper, almost 200 tons of water pass through the main line. Most of this water is recirculated in the white water system. White water systems provide excellent growth media for biocontaminating microorganisms. This growth can result in the formation of silt and other deposits in the main boxes, water lines and papermaking equipment. Such biocontamination can not only interfere with the water and supply flows, but when they expand, they can cause stains, holes and odors in the paper as well as band breaks-expensive alterations in the operations of paper machines. Biocontamination of recreational waters such as splashes or bridges or decorative waters such as ponds or springs can severely detract from the people's enjoyment of them. Biological contamination often results in objectionable odors. More important particularly in recreational waters, biocontamination can degrade water quality to such an extent that it becomes inadequate for use and may even pose a health risk. Sanitation waters, such as industrial process waters and recreational waters, are also vulnerable to biocontamination and its associated problems. The sanitization waters include water for bathing, cistern water, septic water and sewage or wastewater treatment water.

Due to the nature of the waste contained in the sanitization waters, these water systems are particularly susceptible to biocontamination. To control biocontamination, the technique has traditionally treated a system of water affected with chemicals (biocides) in concentrations sufficient to kill or greatly inhibit the growth of biocontaminating organisms. See, for example, U.S. Patent Nos. 4,293,559 and 4,295,932. For example, chlorine gas and hypochlorite solutions made with gas have been added in large quantities in water systems to kill or inhibit the growth of bacteria, fungi, algae, and other problematic organisms. However, chlorine compounds can not only damage the materials used for the construction of aqueous systems, they can also react with organic compounds to form undesirable substances in effluent streams, such as chloromethanes and carcinogenic chlorinated dioxides. Certain organic compounds, such as methylenebiothiocyanate, dithiocarbamates, haloorganics, and quaternary ammonium surfactants, have also been used. While many of these are quite efficient in destroying microorganisms or inhibiting their growth, they can also be toxic or dangerous to humans, animals, or other non-target organisms. One possible way to control the biocontamination of aqueous systems, which include associated submerged surfaces, may be to prevent or inhibit bacterial adhesion to submerged surfaces within the aqueous system.

This can be done, of course, using microbicides, which, however, generally suffer from some of the disadvantages mentioned above. As an alternative, the present invention provides methods and compositions useful for substantially inhibiting bacterial adhesion to a submerged or submergible surface and for controlling biocontamination of aqueous systems. The invention makes obvious the disadvantages of previous methods. Other advantages of this invention will become apparent after reading the specifications and appended claims. The present invention relates to a method for inhibiting bacteria from adhering to the submersible surface. The method contacts the submersible surface with an effective amount of at least one amide to inhibit bacteria from adhering to a submergible surface. The amide used in the method has the following formula: the substituents R.sup.1 and R.sup.2 can each independently be hydrogen, a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.x hydroxyalkyl group, or together with the nitrogen atom that bears them form a heterocyclic ring of the formula: The group X can be 0, NH, or CH. The substituent R4 can be methyl, hydroxymethyl, or hydroxyethyl. The integer n is in the range of 0 to 3. The substituent R3 is a saturated C5-C2o alkyl group. The present invention also relates to a method for controlling biocontamination of an aqueous system. This method adds to an aqueous system an effective amount of at least one amide described above to inhibit bacteria from adhering to submerged surfaces within the aqueous system. This method effectively controls biocontamination without substantially killing the bacteria. The present invention also relates to a composition for controlling biocontamination of an aqueous system. The composition comprises at least one amide in an amount effective to inhibit bacteria from adhering to a submergible surface or a submerged surface within the aqueous system.

In one embodiment this invention relates to a method for inhibiting bacteria from adhering to a submergible surface. A submersible surface is one which can at least be covered, overfilled or moistened with a liquid such as water or another fluid or aqueous liquid. The surface may be in intermittent or continuous contact with the liquid. As discussed above, Examples of submersible surfaces, include, but are not limited to, ship hulls or boats, marine structures, teeth, medical implants, surfaces within an aqueous system, such as the inner part of a pump, pipe, cooling tower or heat exchanger. A submersible surface may be composed of hydrophobic, hydrophilic, or metallic materials. Advantageously, by using an amide according to the invention, it can be effectively inhibited that the bacteria adhere to submergible or submerged hydrophobic, hydrophilic or metallic surfaces. To inhibit the adhesion of a bacterium to a submergible surface, the method contacts the submergible surface with an amide. The surface is contacted with an effective amount of an amide, or a mixture of amides to inhibit bacterial adhesion to the surface. The amide can be applied to the submersible surface using means known in the art. For example, as discussed below, the amide may be applied, spreading, coating or wetting the surface with a liquid formulation containing the amide. Alternatively, the amide can be formulated as a paste which is then dispersed or brushed on the submergible surface. Advantageously, the amide can be a compound of a composition or formulation commonly used with a particular submergible surface. "Inhibiting bacteria from adhering" to a submersible surface means allowing a small or insignificant amount of bacterial adhesion for a desired period of time. Preferably, that bacterial adhesion does not occur essentially and more preferably is avoided. The amount of amide employed should allow only poor or insignificant bacterial adhesion and can be determined by routine tests. Preferably, the amount of amide used is sufficient to apply at least one monomolecular amide film to the submergible surface. Such a film preferably covers the surface completely submergible. Contacting a submersible surface with an amide according to this method, allows the surface to be pre-treated against bacterial adhesion. Accordingly, the surface can be contacted with an amide then submerged in an aqueous system. The present invention also relates to a method for controlling biocontamination of an aqueous system. An aqueous system comprises not only the aqueous fluid or water or liquid flowing through the system but also the submerged surfaces associated with the system. Like the submergible surfaces discussed above, the submerged surfaces are those surfaces in contact with the fluid or aqueous liquid. Submerged surfaces include, but are not limited to, the internal surfaces of pipes or pumps, the walls of a cooling tower or a main case, heat exchangers, screens, etc. In brief, the surfaces in contact with the fluid or aqueous liquid are submerged surfaces and are considered part of the aqueous system. The method of the invention adds at least one amide to the aqueous system in an amount which effectively inhibits bacteria from adhering to the submerged surface within the aqueous system. At the concentration used, this method effectively controls the biocontamination of the aqueous system without substantially killing the bacteria. "Controlling biocontamination" of the aqueous system means controlling the amount or degree of biocontamination at or below a desired level and for a desired period of time for the particular system. This can eliminate biocontamination of the aqueous system, reduce biocontamination to a desired level or completely avoid biocontamination or a desired level. According to the present invention, "inhibiting bacteria from adhering" to a submerged surface within the aqueous system means allowing a small or insignificant amount of bacterial adhesion for a desired period of time for the particular system. Preferably, essentially bacterial adhesion does not occur and more preferably bacterial adhesion is avoided. Using an amide according to the invention can, in many cases, interrupt or reduce other existing fixed microorganisms to undetectable limits and maintain that level for a significant period of time. While some amides may exhibit biocidal activity at concentrations above certain threshold levels, the amides effectively inhibit bacterial adhesion at concentrations generally well below such threshold levels. According to the invention, the amide inhibits bacterial adhesion without substantially killing the bacteria. In this way, the effective amount of an amide used according to the invention is well below its toxic threshold, if the amide also has biocidal properties. For example, the concentration of the amide used may be ten or more times below its toxicity threshold. Preferably, the amide must also not be harmful to non-target organisms, which may be present in the aqueous system. An amide, or a mixture of amides, can be used to control biocontamination in a wide variety of aqueous systems, such as those discussed above. Those aqueous systems include, but are not limited to, industrial aqueous systems, aqueous sanitation systems, and recreational aqueous systems. As discussed above, examples of industrial aqueous systems are metalworking fluids, cooling waters (e.g., quench cooling water, recirculating cooling water and effluent water), and other recirculating water systems such as those used in papermaking or textile manufacturing. Aqueous sanitation systems include wastewater systems (eg, industrial, private, and municipal wastewater systems), bathrooms, and water treatment systems (eg, sewage treatment systems). Pools, fountains, decorative or ornamental wells, ponds or streams, etc., provide examples of recreational water systems. The effective amount of an amide used to inhibit bacteria from adhering to a submerged surface in a particular system will vary somewhat depending on the aqueous system to be protected, the conditions for microbial growth, the degree of any existing biocontamination and the degree of control of desired biocontamination. For a particular application, the amount of choice can be determined by routine test 5 of several quantities before the treatment of the total affected system. In general, an effective amount used in an aqueous system may be in the range of about 1 to about 500 parts per million and more preferably from about 20 to about 100 parts per million of the aqueous system. The amides employed in the present invention have the following general formula: the substituents R1 and R2 can each independently be hydrogen, an alkyl group of C? -C, or a hydroxyalkyl group of C? -C4. The C? -C4 alkyl group, or the hydroxyalkyl group of C? -C4 may be branched or unbranched. Preferably, R1 and R2 are methyl, ethyl, propyl, hydroxyethyl, and more preferably, both R1 and R2 are methyl. Alternatively, R1 and R2 together with the nitrogen atom that carries them form a heterocyclic ring of the formula: n (R4) 1 (> The group X can be 0, NH or CH2. The substituent R4 can be methyl, nidroxypieiyl, or hydroxyethyl. The integer n may be in the range of 0 to 3 and preferably is 0 or 1. Preferably, the heterocyclic ring is a 5- or 6-membered ring. Specific preferred rings include morpholino, piperidinyl, methylpiperidinyl, or dimethylpiperidinyl. The substituent R3 is an alkyl group of C5-C20 alkyl group. The alkyl group R1 may be linked through a terminal carbon or a carbon in the alkyl chain. The alkyl group in R3 may be branched or unbranched. Preferably, R3 is a satur Cn-Ciß alkyl and more preferably, a satur C15-C17 alkyl group. Preferred specific amides of the above formula include N, N-dimethylacylamide, compound a; N, N-dimethylnonilamide, compound b; N, N-dipropyldodecylamide, compound c; N, N-diethylhexylamide, compound d; N, N-dimethylododecanolamide, compound e; N, N-dimethylstearamide, compound f; dodecanoylmorpholine; compound g; N-stearamido-3-methylpiperidine, compound h; N-stearamidomorpholine, compound i; N-stearamido-3,5-dimethylpiperidine, compound j; and 1- hexadecoylhexahydro [1 H] azepine, compound k; and hexadecoyl-3-methylpiperidine. The amides discussed above can be prepared by reacting an appropriorganic acid and an amine using techniques known in the art. Many are also available from chemical supply houses. The N, N-dimethylstearamide, compound f, can be prepared by, for example, reacting stearic acid with dimethylamine at high temperatures and pressures. The w produced by the reaction can be separ by distillation or incorpor into the product formulation. Separating the w by-product helps force the reaction to completion. The methods according to the invention can be part of a total w treatment regime. The amide can be used with other chemicals for w treatment, particularly with biocides (for example, algicides, fungicides, bactericides, molluscicides, oxidants, etc.), ink removers, clarifiers, flocculants, coagulants, or other chemicals commonly used in the w treatment. For example, submergible surfaces can be contacted with an amide as a pretreatment to inhibit bacterial adhesion and placed in an aqueous system using a microbicide to control the growth of microorganisms. Or, an aqueous system that experiences heavy biological contamination can be tre first with an appropribiocide to solve the existing contamination. An amide can then be used to maintain the aqueous system. Alternatively, an amide in combination with a biocide can be used to inhibit bacteria from adhering to submerged surfaces within the aqueous system while the biocide acts to control the growth of microorganisms in the aqueous system. Such a combination generally allows less microbicide to be used. "Control of the growth of microorganisms" in an aqueous system, means controlling to, at, or below a desired level and a desired period of time for the particular system. This can be by eliminating microorganisms or preventing their growth in aqueous systems. The amide can be used in the methods of the invention as a solid or liquid formulation. Accordingly, the present invention also relates to a composition containing an amide. The composition comprises at least one amide in an amount effective to inhibit bacteria from adhering to a submergible surface or a submerged surface within an aqueous system. When used in combination with another chemical for water treatment, such as a biocide, the composition may also contain that chemical. If they are formulated together, the amide and the chemical for water treatment, they should not suffer adverse interactions that could reduce or eliminate their effectiveness. Separate formulations are preferred where adverse interactions may occur.

Depending on the use of a composition according to the present invention it can be prepared in various ways known in the art. For example, the composition can be prepared in a liquid form as a solution, dispersion, emulsion, suspension or paste; a dispersion, suspension, or paste in a non-solvent; or as a solution by dissolving the amide in a solvent or in a combination of solvents. Suitable solvents include, but are not limited to, acetone, glycols, alcohols, ethers, or other water dispersible solvents. Aqueous formulations are preferred. The composition can be prepared as a liquid concentrate for dilution before its proposed use. Common additives such as surfactants, emulsifiers, dispersants and the like, can be used as is known in the art to increase the solubility or compatibility of the amide or other components in a liquid composition or system, such as a composition or aqueous system. In many cases, the composition of the invention can be solubilized by simple agitation. Dyes or fragrances can also be added for appropriate applications such as bathing waters. A composition of the present invention can also be prepared in solid form. For example, the amide can be formulated as a powder or tablet using means known in the art. The tablets may contain a variety of excipients known in the art of tabletting, such as dyes or other coloring agents, and perfumes and fragrances. Other components known in the art may also be included, such as fillers, binders, glidants, lubricants, or antiadhesives. These latter components can be included to improve the properties of the tablet and / or the tablet formation process. The following illustrative examples are given to describe the nature of the invention more clearly. It is understood, however, that the invention is not limited to the specific conditions or details indicated in those examples. EXAMPLES: Test Method: The following method effectively defines the ability of a compound to inhibit bacterial adhesion or attack the formation of existing bound bacteria on various types of surfaces. As a summary, bioreactors are constructed in which approximately 2.54 cm x 7.62 cm (1 inch x 3 inches) strips (glass or polystyrene) are attached to the edge of the bioreactor. The lower ends (approximately 5.08 cm) (2 inches) of the strips are moistened with the bacterial growth medium (pH 7) within the bioreactor which contains a known concentration of the test chemical. After inoculation with known bacterial species, the test solutions are stirred continuously for 3 days. Unless otherwise stated in the subsequent results, the medium within the bioreactor is cloudy by the end of the three days. This turbidity indicates that the bacteria proliferate in the medium despite the presence of the tested chemical. This also shows that the chemical, in the test concentration, does not show substantially biocidal (bactericidal) activity. A dyeing process is then used on the strips in order to determine the amount of bacteria bound to the surfaces of the strips. Construction of Bioreactors: The bioreactors comprise a 400 ml glass beaker on which a lid is placed (cover of a standard 9 cm diameter glass petri dish). When the lid is removed, the strips of the material of choice are covered at one end with adhesive tape and suspended within the bioreactor from the top edge of the vessel. This allows the strips to be submerged within the test medium. Typically, four strips are placed (replicas) uniformly around the bioreactor. The report presented below is an average of the four replicas. A magnetic stirring bar is placed on the bottom of the unit, the lid is placed, and the bioreactor is autoclaved. The glass strips are used as a hydrophilic surface. Bacterial Growth Medium: The liquid medium used in bioreactors is previously described by Delaquis, et al., "Detachment Of Pseudomonas fluorescens From Biofilms On Glass Surfaces In Response To Nutrient Stress ", Microbial Ecology 18: 199-210, 1989. The composition of the medium is: Glucose 1.0 g K2KP04 5.2 g KH2P04 2.7 g NaCl 2.0 g NH4C1 1.0 g MgSO4. 7H20 0.12 g Trace Elements 1.0 ml Deionised Water 1.0 1 Trace Element Solution: CaCl2 1.5 g FeS04. 7H20 1.0 g MnS0. 2H20 0.35 g NaMo04 0.5 g Deionized Water 1.0 1 The medium is autoclaved and then allowed to cool. If sediment is formed in the autoclaved medium, the medium is re-suspended by agitation before use. Preparation of Bacterial Inocula: The bacteria of the genus Bacillus, Flavobacterium, and Pseudomonas are isolated from a sludge deposit of paper mill and maintained in continuous culture. The test organisms are placed in separate strips on plaque-counted agar and incubated at 30 ° C for 24 hours. With a sterile cotton swab, portions of the colonies are removed and suspended in sterile water. The suspensions are mixed very well and adjusted to an optical density of 0.858. { Bacillus), 0.625 (Flavobacterium), and 0.775 (Pseudomonas) at 686 nm. Biofilm Production / Chemical Test: 200 ml of sterile medium prepared above is added to four separate bioreactors. The compounds to be evaluated are first placed as a stock solution (40 mg / 2 ml) using either water or a mixture of acetone-methanol 9: 1 (ac / MeOH) as a solvent. An aliquot of 1.0 ml of stock solution is added to the bioreactor using moderate, continuous magnetic stirring. This provides an initial concentration of 100 ppm for the test compound. Other concentrations tested for a particular compound are indicated in the following Table. A bioreactor does not contain a test compound (Control). Aliquots (0.5 ml) of each of the three bacterial suspensions are then introduced. The bioreactors are then provided with continuous agitation for three days to allow an increase in the bacterial population and deposition of cells on the surfaces of the strips. Evaluation of results: The a-n compounds are evaluated using the above procedure. After the test is completed, the bioreactor strips are removed and placed vertically to allow air drying. The degree of bacterial adhesion to the test surface is then estimated using a staining procedure. The strips are briefly flared in order to fix the cells to the surface, and then transferred for two minutes to a container with Gram Crystal Violet (DIFCO Laboratories, Detroit, MI). The strips are gently rinsed under continuous running water and then carefully dried. The degree of bacterial adhesion is then determined by visual examination and subjective classification of each strip. The intensity of the staining is directly proportional to the amount of bacterial adhesion. The following classifications are given: 0 = essentially none 3 = moderate 1 = scarce 4 = coarse 2 = light Chemical treatments are evaluated in relation to the control which typically receives an average rating for the strips of the four bioreactors in the range of 3 -4. The compounds which receive an average rating in the range 0-2, are considered effective to prevent bacterial adhesion to the submerged strips. The results are shown in the following Table: Solvent and Concentration MIC STRIPS CLASSIFICATION 1 minimum inhibitory concentration (MIC) for each compound against E. Aerogenes bacteria using a Basal Salts 18 hour test both at pH 6 and pH 8. 2 MIC against E bacteria. Aerogenes determined in water. 3 combinatorial experiment. While particular embodiments of the invention have been described, it will be understood, of course, that the invention is not limited to those embodiments. Other modifications can be made. The appended claims are proposed to cover any such modifications that fall within the true spirit and scope of the invention.

Claims (14)

1. -(1 CLAIMS 1. A method for inhibiting bacteria from adhering to a submersible surface characterized in that it comprises the step of contacting the submergible surface with an amide in an effective amount to inhibit bacteria from adhering to the submergible surface, wherein the amide it is a compound of the formula: wherein R1 and R2 can each independently be hydrogen, an alkyl group of C? -C4, a hydroxyalkyl group of C? -C4, or together with the nitrogen atom that carries them form a heterocyclic ring of the formula: X can be O, NH, or CH2. R 4 can be methyl, hydroxymethyl, or hydroxyethyl. n is in the range of 0 to 3, and R3 is a saturated C5-C20 alkyl group.
2. 2. The method according to claim 1, characterized in that R1 and R2 are methyl, ethyl, propyl, hydroxyethyl, or together with the nitrogen atom that carries them form a heterocyclic ring of 5 or 6 members, n is 0 or 1 , and R3 is a saturated Cn-C? 8 alkyl group.
3. The method according to claim 1, characterized in that the amide is N, -dimethyldecylamide, N, N-dimethylnonilamide, N, -dipropyldodecylamide, N, N-diethylhexylamide, N, N-dimethyloctadecanyl amide, N, N-dimethylstearamide, dodecanoylmorpholine; N-stearamide-3-methylpiperidine, N-stearamidomorpholine, N-stearamide-3,5-dimethylpiperidine, and 1-hexadecoylhexahydro [1 H] azepine, and hexadecoyl-3-methylpiperidine or mixtures thereof and wherein the submerged surface is a boat hull, a boat hull, a marine structure, a dental surface, a medical implant surface, or a surface of an aqueous system.
4. 4. A method for inhibiting biocontamination of an aqueous system characterized in that it comprises the step of adding to the aqueous system an amide in an amount effective to inhibit bacteria from adhering to the submerged surface within the aqueous system, wherein the amide is a compound of the formula: wherein R1 and R2 can each independently be hydrogen, an axxyl group of Cx-C4, a hydroxyalkyl group of Ci-C, or together with the nitrogen atom carrying them form a heterocyclic ring of the formula: wherein X can be O, NH, or CH2. R 4 can be methyl, hydroxymethyl, or hydroxyethyl. n is in the range of 0 to 3, and R3 is a saturated C5-C0 alkyl group.
5. 5. The method according to claim 4, characterized in that the amide is N, N-dimethyldecylamide, N, N-dimethylnonilamide, N, N-dipropyldodecylamide, N, N-diethylhexylamide, N, N-dimethyloctadecanyl amide, N, N- dimethylstearamide, dodecanoylmorpholine; N-stearamido-3-methylpiperidine, N-stearamidomorpholine, N-stearamido-3, 5-dimethylpiperidine, and 1-hexadecoylhexahydro [1H] azepine, and hexadecoyl-3-methylpiperidine or mixtures thereof and wherein the effective amount of the Amide is in the range of 1 ppm to 500 ppm.
6. 6. The method according to claim 4, characterized in that the addition step comprises adding sufficient amide to the aqueous system to substantially reduce any existing biocontamination in the aqueous system.
7. The method according to claim 4, characterized in that the aqueous system is an industrial water system selected from a cooling water system, a fluid system for metal working, a water system for paper mills, and a Water system for textile manufacturing.
8. 8. The method according to claim 6, characterized in that the aqueous system is a recreational water system selected from a pool, a fountain, an ornamental lake, an ornamental pool, and an ornamental stream.
9. 9. The method according to claim 4, characterized in that the aqueous system is a sanitization water system selected from a bathing water system, a water treatment system, and a sewage treatment system.
10. 10. The method according to claim 4, characterized in that it further comprises the step of adding an effective amount of a biocide to the aqueous system to control the growth of a micro-organism in the aqueous system.
11. 11. The method according to claim 10, characterized in that the aqueous system is selected from an industrial water system, a recreational water system, and a sanitation system.
12. 12. A method for controlling bio-contamination of an aqueous system characterized in that it comprises at least one amine in an amount effective to inhibit bacteria from adhering to a submergible surface or a submerged surface within the aqueous system, the amide having the formula: wherein R1 and R2 can each independently be hydrogen, a C1-C1 alkyl group, a hydroxyalkyl group of C? -C, or together with the nitrogen atom that carries them form a heterocyclic ring of the formula: wherein X can be O, NH, or CH2. R 4 can be methyl, hydroxymethyl, or hydroxyethyl. n is in the range of 0 to 3, and R3 is a saturated C5-C20 alkyl group. The composition according to claim 12, characterized in that the amide is N, N-dimethylacylamide, N, N-dimethylnonilamide, N, N-dipropyldodecylamide, N, -diethylhexylamide, N, N-dimethyloatedecanylamide, N, -dimethylstearamide, dodecanoylmorpholine; N-stearamide-3-methylpiperidine, N-stearamidomorpholine, N-stearamide-3,5-dimethylpiperidine, and 1-hexadecoylhexahydro [1 H] azepine, and hexadecoyl-3-methylpiperidine or mixtures thereof. The composition according to claim 12, characterized in that it comprises a biocide in an amount sufficient to control the growth of a microorganism in the aqueous system.