RU2150503C1 - Strain of bacterium desulfovibrio vulgaris "egast-5" used for treatment of sewage from heavy metal ions - Google Patents

Abstract

FIELD: biotechnology. SUBSTANCE: invention relates to treatment of industrial sewage. Strain of bacterium Desulfovibrio vulgaris "EGAST-5" is isolated from flow containing heavy metal salts. Strain is active producer of hydrogen sulfide and can be used for precipitation of heavy metal ions from solutions, it grows in media with increased concentrations of heavy metal salts (up to 1.4 g/l of molybdate). Use of proposed strain of bacterium ensures to enhance the effectiveness of treatment of sewage of galvanic production from heavy metal ions, up to 99.9%. EFFECT: enhanced effectiveness of treatment. 1 tbl, 1 ex

Description

 The invention relates to industrial microbiology and relates to the production of a new strain of bacteria producing sulfide, which can be used in biotechnology for the treatment of industrial wastewater from engineering, instrument-making, and electrical enterprises.

 It is known about the use of sulfate reducing bacteria (SBB) for wastewater treatment from heavy metal ions. In the process of biochemical purification, heavy metal ions are bound by biogenic hydrogen sulfide to insoluble sulfides, as well as the reduction of certain metals and precipitation in the form of hydroxides. To increase the efficiency of biochemical purification methods using SVB, a high level of bacterial growth activity is required.

 To create the necessary concentration of microorganisms in the process of wastewater treatment from heavy metal ions, various methods are used or they add easily digestible organic food for SVB / 1 / or use specially selected microbial biocenoses / 2 /.

 However, the microorganisms used do not provide special activity for the growth of SFS in industrial wastewater, characterized by a different degree of pollution and a different composition of polluting components.

 The bacterial strain DesulfovibrioVulgaris VKM B-1970 D (UV-3) used for wastewater treatment from heavy metal ions was adopted as a prototype. This strain is a highly active strain of sulfate-reducing bacteria, providing a stable increase in biomass during wastewater treatment from heavy metal ions / 3 /.

 The strain SBB DesulfovibrioVulgaris VKM B-1970 D was obtained by isolating from the wastewater a galvanic shop with a high content of dissolved metals and subsequent selection by standard methods on elective media. The basic composition of the medium is shown in the example.

 The resulting bacterial strain was deposited in the All-Union Collection of Microorganisms (VKM) under the number VKM B-1970 D.

 The definition of culture is given by Bergey's determinant ("Bergey's Manual of Determinative Bacteriology", v. 1, 909, Baltimore William, Wilkins, 1984).

 Example.

 Cultural and morphological characteristics of the strain.

 The characteristic of vegetative cells - vibrios, cells 0.4-0.7 in size; 1.5-4 microns; gram negative; acid resistance - unstable, do not form spores. The type of reproduction and divergence of cells during division is direct uniform division, the type of flagellation is mobile, polar flagging; there are no inclusions. The type of colony — spherical and disk-shaped colonies in the thickness of agar, growth features on a nutrient medium — reduce sulfates to form sulfides.

 Physiological and biochemical characteristics of the strain.

The cultivation conditions are anaerobic, the optimum temperature is 30 ^o C (limits 10 ... 35 ^o C), the optimal pH is 7.2 ... 7.4 (limits 5.5 ... 8.5), the pH changes at growth - absent or weak alkalization. The smell is hydrogen sulfide.

 The relation to pH, temperature and oxygen is indicated under cultivation conditions; it is suppressed by streptomycin, ampicillin and other antibiotics that inhibit gram-negative microflora. Cells do not contain phages, are not lysogenic, withstand salt content up to 20 ... 30 g / l, gelatin does not thin, starch does not hydrolyze.

 This strain was used for wastewater treatment of galvanic production.

 The disadvantage of this strain is the insufficiently high efficiency of the degree of purification of wastewater from galvanic plants from heavy metal ions.

 The objective of the invention is to obtain a highly active strain of sulfate reducing bacteria used for wastewater treatment from heavy metal ions and thereby expanding the range of bacterial strains used for wastewater treatment from heavy metal ions.

 The invention is achieved by the use of the bacterial strain Desulfovibrio vulgaris EGAST-5 for wastewater treatment of galvanic production.

 The proposed strain of Desulfovibrio vulgaris EGAST-5 is not known in science and technology, therefore, the properties that it exhibits are new, and therefore, the claimed solutions have an inventive step.

 The proposed bacterial strain Desulfovibrio vulgaris EGAST-5 is isolated from a stock containing heavy metal salts and is an active producer of hydrogen sulfide for the precipitation of heavy metal ions from solutions. It develops in environments with an increased concentration of salts of heavy metals (up to 1.4 g / l of molybdate).

 The resulting strain of Desulfovibrio vulgaris EGAST-5 was deposited in the All-Union Collection of Microorganisms (VKM) of the Institute of Biology and Physiology of Microorganisms of the Russian Academy of Sciences under the number VKM B-2024 D.

 The proposed strain is identified by: Bergey's Manual of Systematic Bacteriology; Edit : Krieg N.R., Holt J.G. - Baltimore: Williams Wilkins, 1984.- V. 1.- 964 p.

 The proposed strain is characterized by the following cultural-morphological and physiological-biochemical properties.

Cultural and morphological characteristics of the patented strain are determined during its cultivation on standard media, the recipes of which are taken from the catalog of the All-Russian collection of microorganisms N 92 and 109 and are given below in the publication "All-Russian collection of microorganisms. Catalog". Pushchino - Moscow, VNITI, 1992, 362 p. Cultivation is carried out under anaerobic conditions at 30 ^o C for two days.

Cultivation conditions:
- cultivation is carried out under anaerobic conditions at 30 ^o C for 2 days;
- the optimum pH value is 7.2 ... 7.4;
- used environment: 63 DSM.

Morphological signs and cell cytology:
- under microscopy, cells are represented by single vibrios with a size of 0.7 ... 0.9 x 1.5 ... 2.0 microns;
- cells are motile, have one polar flagellum;
- Gram stain is negative;
- they do not form a dispute.

The physiology properties of the strain:
- strict anaerobic;
- Lactate, pyruvate, formate, ethanol are used as hydrogen donors and carbon sources.

Biochemical characteristics of the strain:
- cells contain cytochrome C and desulfoviridine.

Storage conditions:
- saved by reseeding on the cultivation medium;
- can be stored in the refrigerator at 4 ... 10 ^o C for 3 ... 6 months.

 Prescriptions of media from the catalog of the All-Russian collection of microorganisms: N 92. Medium with lactate for Desulfovibrio.

Solution 1:
K ₂ HPO ₄ - 0.5 g
NH ₄ Cl - 1.0 g
CaCl ₂ • 6H ₂ O - 0.1 g
MgSO ₄ • 7H ₂ O - 2.0 g
Na ₂ SO ₄ - 1.0 g
Na lactate - 5.0 g
yeast extract - 1.0 g
resazurin - 0.001 g
cysteine - 0.5 g
distilled water - 950.0 ml
Solution 2:
NaHCO ₃ - 4.0 g
distilled water - 40.0 ml
Solution 3:
Na ₂ S • 9H ₂ O - 0.3 g
distilled water - 6.0 ml
Solution 4
FeSO ₄ • 7H ₂ O - 0.4 g
distilled water - 10.0 ml
Preparation: bring solution 1 to a boil while blowing through a solution of an oxygen-free gas mixture consisting of 97% N ₂ and 3% H ₂ . Sterilize these gases in the atmosphere. Solution 3 to sterilize in an atmosphere of N ₂ . After sterilization, connect the solutions. After mixing, the pH of the medium is adjusted to 6.8.

N 109. Wednesday
Solution 1:
K ₂ HPO ₄ - 0.5 g
NH ₄ Cl - 1.0 g
Na ₂ SO ₄ - 1.0 g
CaCl ₂ • 6H ₂ O - 0.1 g
MgSO ₄ • 7H ₂ O - 2.0 g
Na lactate - 2.0 g
yeast extract - 1.0 g
resazurin - 1.0 g
distilled water - 980.0 ml
Solution 2:
FeSO ₄ • 7H ₂ O - 0.5 g
distilled water - 10.0 ml
Solution 3:
thioglycolate Na - 0.1 g
ascorbic acid - 0.1 g
distilled water - 10.0 ml
Solution 4 (trace element solution SL-10):
HCl (25%; 7.7 M) - 10.0 ml
FeCl ₂ • 4H ₂ O - 1.5 g
ZnCl ₂ - 70.0 mg
MnCl ₂ • 4H ₂ O - 100.0 mg
H ₃ BO ₃ - 6.0 mg
CoCl ₂ • 6H ₂ O - 190.0 mg
CuCl ₂ • 2H ₂ O - 2.0 mg
NiCl ₂ • 6H ₂ O - 24.0 mg
Na ₂ MoO ₄ • 2H ₂ O - 36.0 mg
distilled water - 900.0 ml
Preparation: all solutions are sterilized separately by autoclaving at 121 ^o C for 15 min in a nitrogen atmosphere. Solution 1 is boiled immediately before autoclaving, flushing with nitrogen. To prepare the medium, solutions 1, 2 and 3 are mixed, and 1 ml is added from solution 4. After mixing, the pH of the medium is set to 7.2 ... 7.4.

 An example of using the bacterial strain Desulfovibrio vulgaris EGAST-5 for wastewater treatment from heavy metal ions.

The process is carried out in bioten with loading from pumice with an upward flow of liquid. Seeds are microbial strains grown in a liquid medium in flasks. Biotenes are inoculated with strains of microorganisms Desulfovibrio vulgaris EGAST-5, which are fixed on pumice. The cultivation temperature in the biotank is maintained in the range 28 ... 30 ^o C. Through the biotenk wastewater of galvanic production is passed. As a result of the life of the SRB, hydrogen sulfide is released, which combines with heavy metal ions, forming metal sulfides, which precipitate.

 The effectiveness of the biotench is shown in the table.

 The table shows that the efficiency of wastewater treatment of galvanic production using the proposed strain is 99.9%.

 Thus, the wastewater of galvanic plants can be effectively cleaned of heavy metal ions using the strain - Desulfovibrio vulgaris EGAST-5.

LITERATURE
1. Copyright certificate N 857013, cl. C 02 F 3/28, 1979.

 2. Copyright certificate N 941319, cl. C 02 F 3/34, 1980.

 3. RF patent N 2055817, cl. C 02 F 3/34, C 12 N 1/20, 1996.

Claims (1)

 The bacterial strain Desulfovibrio vulgaris VKM B-2024 D used for wastewater treatment from heavy metal ions.

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