CN-121991823-A - Mixed strain for bioremediation of benzene and petroleum hydrocarbon co-polluted site and application thereof

Abstract

The invention discloses a mixed strain for bioremediation of benzene and petroleum hydrocarbon co-polluted sites and application thereof. The mixed strain is formed by mixing aerobic rhodococcus bifidus (Rhodococcus biphenylivorans, collection number CGMCC No. 1.12975) and cornfield sphingosine bacteria (Sphingomonas yanoikuyae, collection number CGMCC No. 29277). The rhodococcus bifidus is mainly used for degrading benzene series, the procyanidin bacteria is mainly used for degrading petroleum hydrocarbon, and the synergistic effect is exerted through mixed culture, so that the degradation efficiency is improved. The mixed strain is applied to repairing a benzene and petroleum hydrocarbon co-polluted site, and after the mixed strain is added to the polluted site, the benzene removal rate is up to 99% and the petroleum hydrocarbon removal rate is up to 89% within 16 days. The invention is environment-friendly, economical and efficient, and is suitable for restoring the combined pollution of the underground water and the soil.

Inventors

• YANG JIAWEN
• XU ZEHAO
• JIA YUQIAN
• ZHENG QINGYA
• FAN YIKE
• LU YUNPENG
• XU WANZHEN
• JI XIAONAN
• SHEN YIFAN
• WANG HAIMING
• LI XIANG
• WU HAIYANG
• Mi Baohan

Assignees

• 无际(嘉善)科技有限公司

Dates

Publication Date

20260508

Application Date

20260210

Claims (8)

1. 1. The mixed bacterial strain for bioremediation of benzene and petroleum hydrocarbon co-polluted sites is characterized by being formed by mixing aerobic rhodococcus bifidus (Rhodococcusbiphenylivorans) and procyanidins bacteria (Sphingomonasyanoikuyae), wherein the preservation number of the aerobic rhodococcus bifidus is CGMCC No.1.12975, and the preservation number of the procyanidins bacteria is CGMCC No.29277 and is preserved in the China general microbiological culture Collection center of the China general microbiological culture Collection center.
2. 2. The method for preparing the mixed strain according to claim 1, which comprises the following specific steps: Resuscitates the aerobic rhodococcus bifidus and the procyanidin bacteria from the freezing tube, and the mixed strains are inoculated in LB culture medium by mixing according to the volume ratio of 1:1 to 1:5, are subjected to shaking culture for 24 to 48 hours at 30 ℃ and 150rpm until the OD 600 value is about 1 to 1.5 in logarithmic growth phase, and are prepared, trace element solution is added in the culture process, and the pH value is maintained within the range of 6.8 to 7.2.
3. 3. The method according to claim 2, wherein the trace element solution comprises FeSO 4 ·7H 2 O 0.5mg/L、MnCl 2 ·4H 2 O 0.1mg/L、ZnSO 4 ·7H 2 O 0.2mg/L、CuSO 4 ·5H 2 O 0.05mg/L.
4. 4. A liquid microbial agent for bioremediation of benzene and petroleum hydrocarbon co-contaminated sites, characterized by being obtained by fermentation of the mixed strain of claim 1.
5. 5. The preparation method of the liquid microbial inoculum according to claim 4 is characterized by comprising the specific steps of carrying out gradual amplification fermentation on 0.5L of the mixed strain in an LB culture medium, sequentially carrying out respective culture on 48 h, 72 h and 96 h in fermentation tanks of 5L, 50L and 500L, wherein the fermentation temperature is 30 ℃ and the stirring speed is 180-200 rpm, and adding a trace element solution into the culture medium.
6. 6. The liquid microbial inoculant according to claim 4, wherein the effective viable count of the liquid microbial inoculant is 10 9 -10 10 CFU/mL, the viable count is 85-95%, the mixed bacterial count is less than 1%, and the pH is 6.8-7.2.
7. 7. Use of the mixed strain of claim 1 or the liquid microbial inoculum of claim 6 in bioremediation of benzene and petroleum hydrocarbon co-contaminated sites.
8. 8. The use according to claim 7, characterized in that it is in particular: The mixed strain or the liquid microbial inoculum is added to a polluted site in an injection mode, the final concentration is 1 multiplied by 10 5 CFU/mL, and according to the volume of the polluted site, 450g/m 3 long-acting carbon source soybean oil, 36g/m 3 dispersing agent Tween 80, 120g/m 3 quick-acting carbon source sodium acetate, 22.5g/m 3 nitrogen source yeast extract powder and 50g/m 3 colonizing auxiliary materials of 200-500 meshes of activated carbon are added, so that benzene and petroleum hydrocarbon are removed.

Description

Mixed strain for bioremediation of benzene and petroleum hydrocarbon co-polluted site and application thereof Technical Field The invention belongs to the field of environmental engineering, and in particular relates to a mixed strain for bioremediation of a benzene and petroleum hydrocarbon co-polluted site and application thereof. Background Benzene series and petroleum hydrocarbon are common environmental pollutants and widely exist in the production and use processes of industries such as petroleum, chemical industry, automobiles, plastics and the like. These contaminants pose a serious threat to the environment and human health, especially benzene-based compounds, which have high volatility and toxicity, and long-term exposure can cause acute and chronic poisoning, even carcinogenesis. Petroleum hydrocarbons accumulate in water and soil, affecting the growth of organisms and even destroying the ecosystem. However, the traditional physicochemical repair methods such as chemical oxidation, adsorption, combustion and the like have high cost and risk of secondary pollution to the environment, and cannot effectively pollute the benzene series and petroleum hydrocarbon with high concentration. With the continuous development of biological repair technology, the degradation of organic pollutants by microorganisms gradually becomes an environment-friendly, economical and feasible repair means. Many microorganisms, particularly specific anaerobic or aerobic strains, have been shown to degrade benzene-based and petroleum hydrocarbon-based contaminants. The bioremediation not only can effectively convert pollutants into harmless products, but also has lower cost and good environmental compatibility. However, single strains have limited degradability, especially in a co-contaminated environment, and often cannot simultaneously and effectively degrade benzene-based compounds and petroleum hydrocarbons. In recent years, the use of mixed strains has become a research hotspot in the field of bioremediation. By combining strains with different degradation characteristics, the synergistic effect between the strains can be exerted, so that the restoration efficiency of the composite pollution is remarkably improved. For example, some strains are able to break down benzene-based compounds and produce intermediates, just providing the other strain with the desired nutrient source, thus enhancing the degradability of the latter. In addition, existing bioremediation techniques still face some difficulties in large-scale applications. Most research remains limited to laboratory bench-tests, lacking verification and experience for large-scale field applications. Aiming at restoration of benzene series and petroleum hydrocarbon co-polluted sites, how to improve adaptability and degradation capability of mixed strains in complex polluted environments is still needed to be solved. Disclosure of Invention The invention aims to provide a mixed strain for repairing benzene and petroleum hydrocarbon co-polluted sites and application thereof, wherein the mixed strain is formed by mixing aerobic rhodococcus bifidus (Rhodococcus biphenylivorans) and cornfield sphingosine bacteria (Sphingomonas yanoikuyae), the aerobic rhodococcus bifidus is a strain for degrading benzene series independently, and the cornfield sphingosine bacteria is a strain for degrading petroleum hydrocarbon independently. The mixed fermentation of the two is added to a polluted site, so that the growth concentration, benzene degradation efficiency and petroleum hydrocarbon degradation efficiency of the strain can be obviously improved, and efficient bioremediation is realized. In order to achieve the above object, the technical scheme of the present invention is as follows: In a first aspect, the invention provides a mixed strain for repairing benzene and petroleum hydrocarbon co-contaminated sites, which is formed by mixing rhodococcus aerobics (Rhodococcus biphenylivorans) representing a strain degrading benzene series and rhodococcus cornfield (Sphingomonas yanoikuyae) representing a strain degrading petroleum hydrocarbon. Wherein the collection number of the aerobic rhodococcus bifidus is CGMCC No.1.12975, the collection number of the cornfield sphingosine bacteria is CGMCC No. 29277, and the cornfield sphingosine bacteria are all collected in China general microbiological culture Collection center (CGMCC) with collection address of North Star Xiyang No.1 and Xiyu No. 3 of the Beijing Kogyo area. The aerobic rhodococcus bifidus and the procyanidin bacteria are complemented by metabolism in a combined pollution environment, so that substrate competition is avoided, the cross nutrition effect promotes the growth of flora, and the signal molecule communication enhances the enzyme system expression, thereby improving the degradation performance as a whole. The method comprises the steps of preparing a biological surfactant, preparing a membrane-related dioxygenase s