RU2270806C2 - Strain pseudomonas aeruginos xp-25 carrying out biodegradation of aromatic compounds - Google Patents

Abstract

FIELD: biotechnology, industrial microbiology, ecology.

SUBSTANCE: invention relates to a new strain that can be used for treatment of sewage from chemical plants containing aromatic compounds. The strain Pseudomonas aeruginosa XP-25 is isolated from phenol-polluted soils of Sterlitamak petrochemical plant by culturing a soil sample in mineralized medium and the following selection of the most active forms. The strain is deposited in All-Russian Collection of Industrial Microorganisms at number № B-8613. The strain carries out the effective biological degradation of aromatic compounds.

EFFECT: enhanced effectiveness of strain.

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Description

The invention relates to biotechnology and relates to a new strain of bacteria that can be used for wastewater treatment of chemical plants containing aromatic compounds.

The closest in essence is the strain Pseudomonas aeruginosa No. 28, decomposing phenol [USSR AS No. 499227 by application No. 203990 from 01.07.74]. However, the known strain decomposes phenol only at a concentration of 200-300 mg / L with a duration of 24 hours to 99.6%, a mixture of volatile and non-volatile phenols at a total concentration of 200 mg / L for 48 hours.

The objective of the invention is to obtain a new strain, with high efficiency decomposes aromatic compounds, in particular phenol and other aromatic compounds, in wastewater of petrochemical plants.

The task is realized by the identification and use of the strain Pseudomonas aeruginosa for biodegradation of aromatic compounds. The strain Pseudomonas aeruginosa XP-25 was isolated from phenol-contaminated soils of the Sterlitamak Petrochemical Plant by cultivating the soil sample in a mineralized medium and then selecting the most active forms. The strain is deposited in the All-Russian collection of industrial microorganisms under the number B-8613, carries out effective biological degradation of aromatic compounds and differs from the known morphological, physiological and cultural characteristics.

Morphological signs. Sticks with 1 polar flagellum. Gram-negative. They do not form a dispute. In strokes are located singly, in pairs, in short chains.

Cultural signs. Growth on meat-peptone agar in grayish-white colonies with uneven edges. A bluish-green staining of the medium and a characteristic smell of flowering linden were noted. After 18 hours, a uniform turbidity of the medium, the appearance of a thick film on the surface and sediment at the bottom were observed on the meat-peptone broth. The formation of mucus is characteristic.

Physiological signs. Aerob, optimal growth temperature 25-33 ° C, maximum 42 ° C, no growth at 4 ° C.

Biochemical signs. Hydrolyzes gelatin, starch does not hydrolyze. It grows in a purely mineral environment, is not transmitted in growth factors. It utilizes citrate on Simmens' medium; oxidase is positive. It breaks down glucose in a Hugh-Leifson medium under aerobic conditions; under anaerobic conditions, it does not break down lactose and does not form indole.

When fermented on rocking flasks, the strain destroys phenol at a concentration of 1000 mg / l in 4 hours by 99.98%. In a flowing laboratory setup in an immobilized state on activated carbon, the strain oxidizes phenol with a concentration of at least 2500 mg / l in 1 hour.

Cultivation in the laboratory. The phenol-destructive activity of the strain Pseudomonas aeruginosa XP-25 is maintained on a liquid mineralized medium into which phenol is added, for example, of the following composition, g / l:

Phenol - 0.1 KN ₂ PO ₄ - 0.16 Na ₂ HPO ₄ - 0.55 (NH ₄ ) ₂ SO ₄ - 0.50 MgSO ₄ · 7H ₂ O - 0.20 FeSO ₄ · 7H ₂ O - 0.01 CaCl ₂ · 2H ₂ O - 0.01

pH 7.2.

A suspension of bacteria is introduced into the liquid medium by rinsing from the jamb with a small amount of sterile tap water at a rate of 1-3 vol.%.

The strain is stored on solid agar media at a temperature of + 4 ° C.

Here are examples of the use of the strain Pseudomonas aeruginosa XP-25 for biodegradation of aromatic compounds.

Example 1

Phenol at a concentration of 500 mg / l is introduced into the mineralized medium of the above composition with an incubated strain. After an hour-long incubation in flasks on a shaker (200 rpm, T = 34 ° C), the residual phenol concentration is 150 mg / l; after 2 hours phenol is not detected.

Example 2

Phenol is added to the medium at a concentration of 1000 mg / L. After 3 hours of incubation, 87.3% of utilization, after 4 hours, complete absence.

Example 3. In a laboratory setup, consisting of a column filled with coal with immobilized biomass, with a ratio of the diameter and height of the column 1:10, operating in a flow of model wastewater, wastewater of the following composition is supplied, g / l:

Phenol - 0.5 KN ₂ PO ₄ - 0.16 Na ₂ HPO ₄ - 0.55

After an hour's stay in the installation, there is a complete absence of phenol at the outlet.

Examples of biodegradable activity of the strain Pseudomonas aeruginosa XP-25 for other aromatic compounds are shown in table 1.

Table 1
Examples of biodegradable activity of the strain Pseudomonas aeruginosa XP-25 in a model flow-through installation Example No. Substance Initial concentration, mg / l Cleaning time, h Residual concentration, mg / l The degree of purification,% four Phenol 2800 one 2,8 99.9 5 Toluene 3000 one out one hundred 6 Catechol 3200 one out one hundred 7 Resorcinol 2950 one 1,0 99.9 8 Naphthalene 300 8 out one hundred 9 Anthracene 200 12 out one hundred

In all examples, the determination of the content of organic compounds is carried out spectrophotometrically in the UV region (240-400 nm) on a Specord UV-VIS instrument, and a calibration graph is constructed for each substance.

Thus, the strain Pseudomonas aeruginosa XP-25 with high efficiency provides biodegradation of aromatic compounds, in particular phenol. Sewage treated with a strain can be used for further treatment with domestic wastewater.

Claims (1)

The bacterial strain Pseudomonas aeruginosa XP-25 VKPM B-8613, carrying out biodegradation of aromatic compounds.