Abstract: There are here provided a method for biodegrading trichloroethylene which comprises the step of bringing an aqueous medium containing trichloroethylene into contact with microorganisms having a trichloroethylene degrading ability derived from intestines of termites to degrade trichloroethylene; a method for obtaining the microorganisms; a method for remediating a soil by the use of the microorganisms; and a method for biodegrading an chlorinated organic compound with the microorganisms.

Abstract: A composition and method for preserving Pseudomonads is described. The composition includes an alkali metal nitrate, and optionally monoammonium phosphate as a buffer in an aqueous solution to preserve the bacteria. The compositions are useful for bioremediation.

Abstract: A process for the treatment of sewage to provide effective removal of selenium (especially the 6-valent selenium) to meet required standards for the dissolved amount of selenium, and the like, at a low cost are developed. The process and apparatus reduces selenium from the 6-valent selenium using microbiological treatment to obtain 4-valent selenium and/or simple selenium, and then provide a solid-liquid separation.

Abstract: In a method of cleaning up heavy metal-laden waters and soils, conditions are established in the soils and waters to be treated so that the microorganism present there will form hydrogen sulfide, and optionally apathogenic facultative anaerobes that are tolerant of heavy metals are added to produce hydrogen sulfide, and the hydrogen sulfide formed by microbiological action is allowed to react with the heavy metals to form metal sulfides.

Abstract: Methods and compositions are disclosed for the microbial degradation of polychlorinated biphenyl compounds (PCBs) at a concentration of 100-200 mg/kg soil in contaminated environments, using natural, non-toxic, environmentally-acceptable compounds for application to such environments, such that PCB-contaminated environments are bioremediated by inducing a metabolic pathway in PCB-degrading microbes. Inoculated or indigenous PCB-degrading microbes, such as Arthrobacter strain B1B are induced to decontaminate the PCBs. Also disclosed are a plant and chemical screening assays for identifying plants that produce metabolites which promote PCB cometabolism. Further disclosed is a method for bioremediating PCB-contaminated environments in a commercially practical manner using l-carvone, a nontoxic and inexpensive chemical component of spearmint, for the in situ cleanup of PCB-contaminated soils, to induce Arthrobacter strain B1B to cometabolize and to substantially degrade PCBs.

Abstract: A process for treating an animal waste in a waste holding facility to reduce sulfides and enhance efficient degradation of large amounts of organic matter with reduced odor. The process includes a first inoculation with sulfide-utilizing bacteria and a second inoculation with organic digesting bacteria and lytic enzymes. The second organic digesting inoculation is performed at a time when the sulfide content of the animal waste in the facility is adequately reduced to support organic digesting bacterial growth and efficient degradation of organic matter.

Abstract: A method and a system for the treatment of organic hazardous wastes from plant waste and associated wastewater treatment processes, whereby the waste is either introduced directly, or continuously separated from wastewater, and routed to a bioreactor, and whereby no organic solids are generated for further offsite disposal. The system disclosed includes a bioreactor, containing selected bacteria, untreated sludges, and recirculated biomass, and a liquid/solid separator allowing water to be utilized elsewhere in the system and returning solids to the bioreactor. The biodegradation process, initiated continuously, converts hazardous organic constituents in waste stream and wastewater sludges from plant operations to inert materials, for extensive periods of operation, without the need for solids removal, external solids treatment or disposal.

Abstract: A process for treatment and disposal of wastewater having dissolved perchlorate salts is described and includes the steps of adding to the wastewater in a hydrogen gaslift recycle reactor a mixed bacterial culture containing the specific bacterium HAP1 for reducing the perchlorate ion to chloride in the wastewater; maintaining proper nutrient and environmental conditions for HAP1 to optimally reduce perchlorate in the wastewater; and discharging effluent wastewater from the gaslift reactor to an aerobic reactor and maintaining proper nutrient and environmental conditions for the optimal conversion of soluble organics to carbon dioxide and sludge.

Abstract: The present invention provides a process for the degradation of chlorite into chloride and oxygen with the aid of chlorite dismutase or chlorites dismutase-containing microorganisms. Virtually quantitative degradation of chlorite is obtained in the absence of reductors and under either aerobic or anaerobic conditions.

Abstract: A method for remedying an environment containing a pollutant using microorganisms comprising a step of injecting a liquid containing a microorganism which can decompose the pollutant into a predetermined site of the environment to be remedied, wherein a gas has been dissolved into or mixed with the liquid by applying a pressure higher than the pressure at the injection site and the liquid evolves the gas when injected into the predetermined site, and an apparatus which comprises a means for injecting a liquid containing a microorganism which can decompose a pollutant into a predetermined site of the environment, wherein the means injects the liquid in which a gas has been dissolved into or mixed with by applying a pressure higher than the pressure at the injection site, into the environment under a pressure so that the gas does not evolve from the liquid before injection.

Abstract: An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

Abstract: Butane-utilizing bacteria are used to degrade hydrocarbon pollutants such as trichloroethene (TCE). In-situ or ex-situ techniques may be used to reduce or eliminate hydrocarbon pollutants from liquid, gas and solid sources. In a preferred embodiment, TCE concentrations in various aqueous environments are reduced by contacting a contaminated water source with butane-utilizing bacteria in the presence of oxygen to degrade the TCE by cometabolism or direct metabolism. Suitable butane-utilizing bacteria include Pseudomonas, Variovorax, Nocardia, Chryseobacterium, Comamonas, Acidovorax, Rhodococcus, Aureobacterium, Micrococcus, Aeromonas, Stenotrophomonas, Sphingobacterium, Shewanella, Phyllobacterium, Clavibacter, Alcaligenes, Gordona, Corynebacterium and Cytophaga. The butane-utilizing bacteria have relatively low TCE toxicity in comparison with conventional methane-utilizing bacteria, and demonstrate an improved ability to degrade TCE.

Abstract: A system and process for delivering fluids into subsurface contaminated soil and ground water to enhance in situ microbial degradation of contaminants. The system consists of a high pressure/low volume slurry pump driven by an internal combustion engine. Pressure and volume are variable to suit site-specific subsurface soil conditions (e.g. texture, intrinsic permeabilities, etc.). The high pressure fluid liquifies the soil in front of the probe tip allowing the probe to be easily advanced by hand into the subsurface while the low volume prevents driving the contaminants. Microorganisms, soluble and insoluble nutrients, surfactants and chemical peroxygens and also gases can be delivered into the subsurface with this system. After delivery of the fluids, the probe is withdrawn by hand.

Abstract: In a method of biologically removing nitrogen and a system therefor according to the present invention, by utilizing the characteristics of AH bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the high concentration of ammonium nitrogen and the characteristics of AL bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the low concentration of the ammonium nitrogen, in the nitrifying process, operations capable of obtaining the maximum nitrifying speed in accordance with the concentration of the ammonium nitrogen can be performed, and the nitrifying reaction of nitrous acid type for producing nitrous acid as being an intermediate oxide material of the ammonium nitrogen can be performed.

Abstract: A first media provides an oxygen inducer such as catalase, bound and stabilized in pellet form so as to dissipate slowly into aqueous surroundings. A second media provides an oxygen supplier such as a peroxide, stabilized by combination with a proteinaceous compound such as urea and bound in a matrix that limits oxygen release. The two media are combined in aqueous environment to generate nascent oxygen at a modulated rate such that the oxygen is efficiently absorbed into the surrounding aqueous environment, promoting growth of aerobic species and reducing biological pollution. Specific adaptations demonstrate benefits of use in shrimp or fish ponds, raw milk, fruit juice, fresh food, silage and animal feed, fertilizer, plumbing systems, and grease traps. When used in ponds, further adaptations reduce algae and phytoplankton populations.

Abstract: A method for removing heavy metals and halogenated hydrocarbons from contaminated groundwaters is provided. The method provides utilizing a treatment solution comprising a soluble source of organic carbon, ferrous iron, and sulfate. Additionally, the treatment solution may comprise sulfate reducing bacteria as well as nutrients for bacterial metabolism. The treatment is designed to stimulate the growth of naturally occurring sulfate reducing bacteria such that the metals are coprecipitated in iron sulfide and the hydrocarbons are reduced to innocuous byproducts.

Abstract: The invention relates to a process for cleaning a waste water stream or the like, comprising:a desulphurization step, in the form of addition of a desulphurizing agent, and addition of a buffer; followed bya biodenitrification step carried out by micro-organisms which feed on the buffer remaining in the waste-water stream of the desulphurization step;wherein sulphur contamination and the like is removed in the desulphurization step and wherein nitrate contamination and the like as well an the buffer, are removed in the bio-denitrification step.

Abstract: Contamination by organic materials is treated by applying an aqueous composition comprising organisms which are useful in degradation of the contaminant, a nutrient for the organisms and a polymer which is soluble in or dispersible in the water and which increases the viscosity of the composition. The composition is useful in the treatment of contaminated liquids and solids and in the protection of solid surfaces against contamination.

Abstract: A process for remedying polluted soil which comprises the steps of injecting a liquid agent containing a microorganism into the polluted soil, and injecting a gas into a region wherein the water content of the soil became 0.6 or more times its saturation water content after the injection of the liquid agent. Using this method bioremediation of contaminated soil can be economically and efficiently carried out.

Abstract: A method and system for the treatment of the livestock wastewater which comprises (a) biodegrading the said wastewater with hydrolytic, acidogenic and acetogenic bacteria culture, (b) biodegrading the supernatant from the primary treatment in contact with a biofilm with immobilized photosynthetic bacteria and (c) biodegrading the liquid from the secondary treatment with the activated sludge mixed with photosynthetic and symbiotic bacteria culture.

Abstract: Methods of improving anaerobic digestion by enhancing the microorganism population through the creation of a nutrient environment more favorable for microbial growth and through the addition of microbes and, more particularly, by the addition of chelating agents, chelating agents and nutrients, and methanogens. Methods for the improved production of said methanogens by the provision of controlled amount of methanol and H.sub.2 and CO.sub.2. Methods for the improved preservation of said methanogen by ultra-freezing and freeze-drying.

Abstract: This invention provides a biological injector suitable for biologically treating a fluid flowing through or contained in a collection or treatment system. The biological injector comprises at least one porous section for containing bacterial cultures, at least one non-porous solid section and at least one removable piece which, combinedly, form an enclosed container. Each porous section is attached to at least one non-porous solid section. At least one non-porous solid section is used as a base to which some components of the biological injector can be attached. Each removable piece is attached to one non-porous solid section. The biological injector may include means for fastening the biological injector to a selected location within the collection or treatment system. The biological injector may include means for feeding liquid bacterial cultures and additives to the fluid.

Abstract: The present invention is for bioremediation method and compositions for promoting activity in indigenous micro-organisms, causing the micro-organisms to degrade organic contaminants.

Abstract: An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

Abstract: A process and apparatus for purifying lactose-containing wastewater. The process comprises first treating the wastewater with base. The treated wastewater is then introduced into a fermenter where the lactose present in the wastewater is fermented to form a fermentation broth and lactic acid. The broth is advantageously subjected to purification and the purified broth is subjected to bipolar electrodialysis to yield concentrated lactic acid and base solutions from the purified broth. A device is provided for carrying out the process.

Abstract: In a process of remediating chemical contamination of a pond contaminated with one or more toxic heavy metals or aromatic compounds, the steps include: preparing a silage of grass clippings, placing the silage on the surface of a pond, and inoculating the pond with an alga and Bacillus cereus in sufficient quantities to cause a mixed algal and bacterial bloom to form on the pond surface and become annealed to the silage, leaving the silage with the annealed bloom on the surface of the pond for a sufficient amount of time to allow the bloom to withdraw at least some of the toxic heavy metal content or to degrade at least some of the aromatic compound content of the pond, and removing the silage with the annealed bloom from the pond.

Abstract: Provided are methods and compositions for treating on-site animal waste pits in order to soften the fluidized hardened solid wastes therein. The methods and compositions involve the use of Lactobacillus bacteria in effective amounts. Also preferably, a nitrogen-fixing bacteria is included in order to fix nitrogen in removed wastes to increase their fertilizer value.

Abstract: A process and system for waste water treatment including a concentration means positioned at the front of the treatment system in order to concentrate the starches and sugars contained in a waste stream. In a mixing vessel, the concentrate stream is treated with a variety of additives in order to increase consumption of the biological components and to produce a stream having a predictable and predetermined level of soluble starches. The waste stream is solubilized by subjecting the stream to heat and enzyme treatment such that the starches and complex sugars are converted to simple sugars. In a fermentation vessel, a carefully selected yeast strain is introduced into the waste stream and permitted to feed on the sugars. The operating conditions in the vessel (e.g. pH, temperature, oxygen supply, and mineral supply) are carefully controlled to enhance consumption of the biological components in the waste stream.

Abstract: This invention provides a process for the biotreatment of effluent from waste gas scrubbing systems of hydrocarbon processing facilities and for the biotreatment of sulfide- and ammonia-containing wastewater streams from other sources. Sulfides are minimized by bacteria cultures, particularly Thiobacillus. COD, TKN and BOD are concurrently minimized by co-cultures of the bacteria with various heterotrophs. In a version of the process, the co-cultures of the bacteria with various heterotrophs are also capable of performing nitrification, without application of nitrifiers. Acclimation of the heterotrophs to the species to be removed is accomplished by biological acclimation and enrichment reactors which reduce mycell toxicity to the heterotrophs. To control pH of the heterotrophic reaction with sulfides, magnesium oxide (MgO) and caustic are used separately or in combination.

Abstract: Process for the inertization of liquid waste, mud and solid waste, containing sulphates and heavy metals, which comprises a neutralization step of the compounds to be treated and an anaerobic reduction step of the sulphate ion to allow the formation of sulphide ions necessary for the process. A consortium of sulphate-reducing bacteria and lactobacilli is used, with whey as a carbon and nitrogen source.

Abstract: A biological degradation process is disclosed. The biological gradation process utilizes a unique thermophilic aerobic bacterial mixture capable of converting, biologically or via oxidation, aqueous and other liquid streams containing substances that are ordinarily considered toxic to conventional biological systems. Substances ordinarily considered toxic to conventional biological systems, but which nevertheless are converted by the thermophilic aerobic bacterial mixture, include aniline; benzothiazole; 5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3-carboxamide; lindane (technically known as 1.alpha.,2.alpha.,3.beta.,4.alpha.,5.alpha.,6.beta.-hexachlorocyclohexane) ; 2-mercaptobenzothiazole; toluene; and combinations thereof. The unique thermophilic aerobic bacterial mixture comprises relative effective amounts of Pseudomonas stutzeri, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas mendocina and Alcaligenes denitrificans subsp. xylosoxydans.

Abstract: Provided are methods and compositions for treating on-site animal waste pits in order to soften the fluidized hardened solid wastes therein. The methods and compositions involve the use of Lactobacillus bacteria in effective amounts. Also preferably, a nitrogen-fixing bacteria is included in order to fix nitrogen in removed wastes to increase their fertilizer value.

Abstract: Novel methods for biodegrading nitroaromatic compounds present as contaminants in soil or water using microorganisms are disclosed. Water is treatable directly; dry soil is first converted into a fluid medium by addition of water. The preferred method comprises two stages, each employing microorganisms: a fermentative stage, followed by an anaerobic stage. The fermentative stage is rapid, wherein an inoculum of aerobic and/or facultative microorganisms ferments a carbohydrate added to the fluid medium, exhausting the oxygen in the fluid medium and thereby inhibiting oxidative polymerization of amino by-products of the nitroaromatics. In the subsequent anaerobic stage, an inoculum of a mixed population of anaerobic microorganisms completes the mineralization of the contaminant nitroaromatics, using the remaining carbohydrate as a carbon and energy source.

Abstract: Removal of a target metal having an insoluble phosphate (e.g. actinides), is effected by passing the solution through a bioreactor containing an immobilised phosphatase-producing microorganism which has been cultivated using a culture medium containing an assimilable organic source of phosphorus and which has been primed with an element, other than the metal to be removed, having an insoluble phosphate so as to deposit the phosphate of the priming element on cell surfaces of the microorganism. The priming element phosphate facilitates deposition of the target metal phosphate.

Abstract: A low concentration (0.1 to 0.5 mM) of aluminum ions is added to an organic wastewater to selectively raise specific bacteria which can grow without producing unpleasant odors. The bacteria is used for treating the organic wastewater of high density without producing odors thus contributing to the minimum size of a wastewater treatment system. Then, increase of the aluminum ions to a high concentration (more than 4 mM) accelerates flocculation and precipitation of the bacteria for disposal. When a proper mineral is added to the wastewater, a lower concentration (more than 1 mM) of the aluminum ions can encourage the flocculation and precipitation of the bacteria and also, a resultant sludge will be reduced in amount for ease of maintenance.

Abstract: The present invention relates to the aerobic reaction of compounds such as aromatic, nitro-aromatic, halo-aromatic, aliphatic and halo-aliphatic compounds with a microorganism, the microorganism being a member of the group consisting of microorganisms having ATCC Accession No. 55641, 55642, 55643, 55644, 55645, 55646, 55647, 55648 and 55649. More particularly, the present invention relates to the aerobic degradation of organic compounds in fluid or solid phase such that the compounds are bioremediated to products containing CO.sub.2 and H.sub.2 O.

Abstract: An apparatus for waste water treatment, wherein fluorine contained in waste water is treated into a fluoride through a chemical reaction and sludge containing the fluoride is thickened and dehydrated into a sludge cake, has first and second tanks each packed with calcium carbonate mineral. In the first tank, waster water containing fluorine is agitated by air discharged from an air diffuser and caused to react with the calcium carbonate mineral. Through this reaction of the waste water with the calcium carbonate mineral and action of microorganisms on the surface of the calcium carbonate mineral, a pH value and a fluorine concentration of the waste water is adjusted till the pH value and the fluorine concentration fall within their respective predetermined ranges.

Abstract: A waste water treatment apparatus is provided which can treat a high-concentration waste water containing persistent chemical substances including nitrogen and surfactant simultaneously with small amount of exhaust gases and is yet simple in construction. The apparatus has a first bioreactor having a lower portion including an inflow pipe for admission of waste water to be treated and aeration means, and an upper portion packed with vinylidene chloride fillers; a second bioreactor including a filler-packed portion packed with charcoal and calcium carbonate fillers; and an exhaust gas introduction diffuser for directing exhaust gases generated in an uppermost portion of the first bioreactor into the filler-packed portion. The water under treatment is anaerobically treated in the lower portion and is subjected to aerobic treatment and also to anaerobic treatment in the upper portion.

Abstract: The mixture of natural microorganisms causes a biodegradation of mineral oils and mineral oil products. It contains Pseudomonas putida and Geotrichum candidum in a ratio of the cell-numbers of 5:1 to 1:1. The mixture is induced by a cultivation in the presence of oil-acid. Afterwards, one works with it on hydrocarbons under the supply of oxygen as well as in the presence of stimulation-substances at a pH-value of 4.5 to 7.5 and at a temperature of 5.degree.+C. to 35.degree. C.

Abstract: A method of degrading hydrophobic organic compounds (HOCs) comprising heating the HOCs in the presence of a microorganism capable of metabolizing the HOCs to cause degradation thereof, an embodiment of such method including contacting at ambient temperature said HOCs with a microorganism capable of metabolizing the HOCs for a period of time sufficient to degrade some but not all of the HOCs, heating the HOCs not degraded, and thereafter contacting the HOCs not degraded with a microorganism capable of metabolizing said HOCs.

Abstract: The white rot fungus Scytinostroma galactinum strain F361 and mutants thereof are particularly effective in selectively grading the lignin component of lignin-containing materials, particularly processed wood pulps including chemical pulps, and also particularly effective in degrading lignin degradation products such as chlorinated degraded lignin by-products as found, for example, in E-1 effluents, and also in degrading chlorine-containing aromatic compounds generally as found in aqueous waste streams containing the same.

Abstract: Methods for the biological treatment of sewage in a sewage treatment plant, of wastestreams and of ponds are disclosed. The methods employ a composition comprising active amounts of an enzyme mixture, B. subtilis and P. fluorescens, and a nutrient source having a COD of 10,000 mg/kg or less, of which one source is used mushroom compost. The composition is first activated in fresh water, is then acclimated in a waste moiety, and the acclimated mixture is then used to treat the main body of the waste, such as sewage sludge, a wastestream or a pond.

Abstract: A method for reducing the viscosity of viscous petroleum liquids, such as heavy crude oil and bitumen, is disclosed. The method is appropriate for use with viscous petroleum liquids that contain sulfur-bearing heterocycles, the physicochemical properties of the heterocycles contributing significantly to the viscosity of the liquid. The method comprises contacting the viscous petroleum liquid with a biocatalyst that converts sulfur-bearing heterocycles into molecules that lack physicochemical properties condusive to viscosity. The biocatalyst works in a sulfur-specific manner, such that the sulfur-bearing heterocycle is altered at the sulfur heteroatom thereof. Through biocatalysis, carbon-sulfur bonds are cleaved and/or polar substituents such as hydroxyl groups are joined to the sulfur heteroatom, the hydrocarbon framework of the sulfur-bearing heterocycle, or both. Preferred biocatalysts for viscosity reduction include preparations of Rhodococcus rhodochrous ATCC No.

Abstract: This invention relates to remedial bacterial systems in a constructive mat including ensiliaged material, particularly constructed mixed microbial mats for specific bioremedial applications. Preferably, the constructed mixed microbial mat comprises ensiled grass clippings with a cyanobacteria and a chemotrophic bacteria.

Abstract: Metals have phosphates of low water solubility e.g. Cd, Pb, Cu, Mn, Sr, U, La, Pu, Am and Np, are removed from water by reaction with phosphate produced by enzymatically-cleaved polyphosphate which has been accumulated by one or more polyphosphate-accumulating microorganisms.

Abstract: The invention provides a method for removing sulphur compounds from water which contains low levels of organic matter, by anaerobic reduction of the sulphur compounds to sulphide, followed by partial oxidation of the sulphide to elementary sulphur.

Abstract: The invention includes remediating a medium contaminated with an organohalide using a microorganism that produces a bioemulsifier. The organohalide is dispersed within the medium by contacting the medium with the bioemulsifier directly produced from Pseudomonas cepacia ATCC 55487 or obtained from a growth medium supernatant of Pseudomonas cepacia ATCC 55487. Then, the medium and the organohalide is treated with Pseudomonas cepacia ATCC 55487 which causes the organohalide to degrade in the presence of the Pseudomonas cepacia ATCC 55487.

Abstract: The method and apparatus of the present invention feature the use of and electric current to induce movement of bacteria in situ to degrade contaminants in aquifers.

Abstract: A treatment zone 10 in the form of a basin 12 having an inlet port 14 and an outlet port 16. The inlet port 14 allows water to flow into the basin 12. The outlet port 16 allows water to flow out of the basin 12. The inlet port 14 and the outlet port 16 are located at opposite ends of the basin 12 so as to allow water from a body of water having a concentration of water soluble metal ions contained therein to flow substantially through the entirety of the basin 12. A porous matrix 22 is disposed within the treatment zone 10. The porous matrix 22 is inoculated with a population of aerobic metal oxidizing bacteria. The population of aerobic metal oxidizing bacteria is capable of metabolizing water soluble metal ions in the water from the body of water into water insoluble metal oxides. Thus, there is an overall decrease in the concentration of the metal ions in the water flowing out of the treatment zone 10 as compared to water flowing into the treatment zone 10.

Abstract: Method of decontamination of a hydrocarbon-polluted environment by the use of bacterial compositions. The method is a process of biological decomposition of the hydrocarbons using, as decontaminating active ingredients, bacterial compositions composed of one or more strains from among the following microorganisms: Azotobacter vinelandii 21, Pseudomonas sp.9, Pseudomonas sp.19, Pseudomonas sp.31 and Acinetobacter calcoaceticus 23. In the method, prior analysis of the chemical composition of the pollutants is essential in order to select, in accordance with this composition, the mixture of strains of the most active microorganisms from among the five mentioned above, taking into account the natural conditions of the polluted environment. The bacterial composition also contains inorganic salts supplying N and P, and additives needed for bacterial growth.