KR930012101B1 - New microorganism for digestion of polyvinyl alcohol - Google Patents

Abstract

Two strains capable of assimilating polyvinyl alcohol were screened from soil and stream water near a wastewater treatment facility of polyvinyl alcohol, and designated as Pseudomonas sp. G5Y (KCTC-0020BP), Pseudomonas sp. PW (KCTC-0021BP). The preculture of two strains were added to a medium (pH 7.5) containing 0.5 % polyvinyl alcohol, and cultured with shaking for 3 days at 35 deg.C. The polyvinyl alcohol contained in the medium was hydrolyzed by over 90 %.

Description

Wastewater treatment of polyvinyl alcohol magnetized bacteria and microorganisms for polyvinyl alcohol wastewater treatment

1 is a graph showing the growth and PVA degradability of each of the PVA magnetizing bacteria G5Y (KCTC-0020 BP) and PW (KCTC-0021 BP) culture alone and mixed culture.

2 is a graph showing the effect of temperature on the PVA degradation of isolated mixed bacteria.

3 is a graph showing the effect of the pH change on the PVA degradation of isolated mixed bacteria.

4 is a PVA magnetizing strain Pseudomonas sp. Transmission electron micrograph of G5Y strain (magnification: 30,000 times).

5 is a PVA magnetizing strain Pseudomonas sp. Transmission electron micrograph of PW strain (magnification: 30,000 times).

6 shows Pseudomonas sp. G5Y and Pseudomonas sp. Graph showing PVA resolution by culture of mixed strain of PW (KCTC 0022 BP).

FIG. 7 is a graph showing PVA degradability of PVA magnetized strains separated by Suzuki et al.

8 is a cross-sectional view showing PVA decomposition force in wastewater by PVA magnetizing strains.

The present invention is to use the polyvinyl alcohol (PVA, hereinafter called PVA) as a carbon source to separate the microorganisms that strongly magnetize PVA in nature and to treat wastewater using the mutant strains causing mutations. To use.

In general, the treatment and degradation strains of various pollutants have been isolated and identified in nature. Pseudomonas sp is a large part of bacteria. In addition, microbial treatment systems have been developed and marketed to improve the efficiency of wastewater treatment. Most of these products are made using bacteria or mutants isolated from nature. These products are imported from Korea and marketed in Korea. . However, in the case of the imported microbial preparations, it is difficult to expect 100% effect if the treatment conditions are different from those of other countries as well as the characteristics of wastewater. In addition, since the microbial agent imported from abroad takes a long time, such as transportation, transport, storage, there is a fear that the activity of the microorganism is greatly reduced. Therefore, the present invention is to develop and apply microbial treatment agent and high activity strain for wastewater treatment suitable for our situation.

Wastewater from dyeing and processing plants contains a large amount of PVA, a biologically hardly degradable substance. These PVAs are widely used as raw materials for synthetic fiber vinylon, but they have been developed in a water-soluble state and are currently used for grass feeding in addition to textiles. It is widely used in adhesives, films, and paper processing agents.

Currently, the activated sludge method used in most dyeing wastewater treatment plants has a considerable difficulty because the residence time cannot be maintained for the time required for PVA decomposition. In addition, the ozone oxidation method has a lot of problems in the facility cost and operating costs, and in reality, the PVA wastewater treatment is difficult.

In order to solve this problem, it is possible only through improvement of the process or isolation of a new strain that can degrade PVA in a short time.

Therefore, the present invention is to isolate PVA in a short time, isolate the excellent microbial strain that can be magnetized by using these degradation products as a nutrient source, and then culture the mutant-induced mutations and put them into PVA wastewater to treat PVA wastewater at low cost economically. PVA magnetization was isolated for the purpose. Separation of PVA magnetized bacteria in the present invention was carried out as follows.

First, river water and soil samples around the wastewater treatment plant containing PVA were collected and used as the sample source. Suspension of the river water and soil in this sample with sterile distilled water, 0.1 ml each of the supernatant was plated on a solid plate medium with 1.5% agar added to the medium shown in Table 1 and incubated at 30 ° C. Strains with good PVA resolution were selected. At this time, the resolution investigation of PVA was performed according to the Finley method. Among the isolated strains, strains with excellent PVA resolution were selected and then Pseudomonas G5Y and PW two strains were selected by NTC treatment (Nitronitroso Guaine). Was removed. In addition, when the two strains were mixed, more than 90% of PVA was removed (FIG. 1). These two strains (G5Y, PW) was confirmed to remove the PVA by a symbiotic relationship. The isolated and mutated Pseudomonas strain G5Y was deposited as KCTC-0020BP, Pseudomonas PW as KCTC-0021BP. In addition, Pseudomonas G5Y and PW mixed strains were deposited with KCTC-0022BP. The results of investigation of the effect of temperature on the growth characteristics of the isolates on PVA degradation are shown in FIG. After culturing the culture temperature of bacteria in 25 ° C to 40 ℃ stepwise incubated for 6 days in the liquid medium of Table 1, the growth power and PVA removal of the bacteria at each temperature was examined and the growth power or PVA at 30 ℃ to 35 ℃ The removal rate was excellent and the optimum temperature was 35 ℃. In order to determine the optimal pH of the medium, the growth temperature and PVA degradation rate of the bacteria were examined by controlling the culture temperature at 35 ° C. in steps of 5.0 to 9.0.

As shown in FIG. 3, the growth rate and the PVA removal rate of bacteria were weak at pH 6.5 and below, but showed good results at pH 6.5 and above, and the optimum pH was 7.5.

In addition, various morphological, physiological and chemical data were examined for the identification of bacteria, and the data shown in Table 2, 4, and 5 were calculated.

Based on these data, the bacteria were identified as Pseudomonas cepacia and Pseudomonas pseudomallei, respectively, and these were identified as Pseudomonas sp. G5Y, Pseumonas sp. Named PW.

As shown in FIG. 6, 100 ml of medium containing 5 g of PVA per 1L was inoculated into a 250 ml Erlenmeyer flask, and 10% of this was inoculated with PVA magnetizing bacteria. As a result, the PVA resolution of these mixed strains was very good and could decompose more than 90% within 3 days.

This result can be said to be excellent results compared to the conventional strain Suzuki (SUZUKI, etc.) took more than 4 days to break down PVA more than 90% (Fig. 7).

In addition, in order to investigate the PVA resolution in the actual call wastewater (PVA-containing wastewater), the strain of the present invention was inoculated to the PVA-containing wastewater in D-D spinning, and the PVA resolution was examined as shown in FIG. After 3 days of incubation with PVA concentration of 5000mg / l and BOD: N: P = 100: 5: 1, it was found that about 75% of PVA was removed and PVA was removed quickly in real wastewater. . As described above, PVA magnetizing bacteria Pseudomonas sp G5Y and Pseudomonas sp. When PW strains were mixed in culture, PVA decomposed magnetization was excellent, and it is considered to be an excellent strain that can economically remove PVA even in actual wastewater treatment plant.

TABLE 1

TABLE 2

Claims (4)

Pseudomonas sp. G5Y (pseudomonas sp. G5Y, Accession No. KCTC-0020BP) with polyvinyl alcohol (PVA) magnetizing ability. Strain Pseudomonas S.P. P. with Polyvinyl Alcohol (PVA) Magnetization. W. (pseudomonas sp. PW, other number KCTC-0021BP). Use of the microorganism of claim 1 or 2 for wastewater treatment containing polyvinyl alcohol (PVA). A method for treating wastewater containing polyvinyl alcohol (PVA) using a mixed strain (KCTC-0022BP) of Pseudomonas S.P. G5Y and Pseudomonas S.P.W.