Flavobacterium columnare NY-1 and application thereof in prevention and treatment of microcystis water bloom
By targeting the structure of Microcystis colonies with Flavobacterium columnare NY-1, driving their sedimentation and extinction, the problem of low efficiency and long cycle in the treatment of Microcystis blooms in natural water bodies has been solved, achieving efficient and safe removal of Microcystis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN AGRICULTURE COLLEGE
- Filing Date
- 2026-02-12
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies are unable to efficiently and specifically target and drive the sedimentation and extinction of Microcystis colonies in natural water bodies, resulting in poor treatment effects and long treatment cycles for Microcystis blooms.
The NY-1 strain of Flavobacterium columnare was used. By applying it to the microcystis bloom area, it targeted the microcystis community structure, driving its sedimentation and death. The culture method included activation and shaking culture on R2A medium, with the bacterial concentration reaching 106 CFU/L.
It effectively eliminated Microcystis blooms within 72 hours, with an algae suppression rate of up to 99%, and has good ecological safety, making it suitable for natural water bodies such as crustacean breeding ponds.
Smart Images
Figure CN122012327A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microbial technology, specifically to a strain of Flavobacterium columnare NY-1 and its application in the prevention and control of Microcystis blooms. Background Technology
[0002] Microcystis blooms are one of the most common and serious ecological hazards in eutrophic freshwater bodies. In natural water bodies, Microcystis mainly exists in the form of multicellular aggregates. This community structure not only provides a physical barrier against zooplankton feeding and some environmental stresses, but more importantly, it significantly enhances the buoyancy of algal cells in the water. This is a key ecological strategy for Microcystis to maintain itself on the water surface for a long time, forming and sustaining blooms. For example, the literature "Environmental Factors Mediate Cell Surface Properties to Analyze the Community Formation Mechanism of Microcystis aeruginosa" details that the community can enhance the adaptability of Microcystis cells to adverse environments; the literature "Microcystis aeruginosa ( Microcystis aeruginosa The study, "Bacterial Community Changes During Microcystis Community Formation," also investigated the changes in the bacterial community during the formation of Microcystis communities. The natural decline of Microcystis blooms often begins with the loss of stability of the community in the water, eventually leading to sedimentation and death.
[0003] However, in the field of microbial algae control, existing research mostly focuses on free, single-celled Microcystis aeruginosa. For example, the algae strains tested in the literature "Isolation, Identification and Comparison of Alginolytic Effects of Alginolytic Bacteria from Different Sources", "Screening and Isolation of Alginolytic Bacteria in South Taihu Lake and Identification of Their Active Components", and "Isolation and Identification of Alginolytic Bacteria in Litopenaeus vannamei Aquaculture Water" are all single-celled Microcystis aeruginosa cultured in the laboratory. The reported alginolytic bacteria mainly achieve the lysis or killing of single-celled Microcystis aeruginosa through secretion of extracellular enzymes or direct contact. However, these research results based on single-cell models face significant application bottlenecks when dealing with actual Microcystis aeruginosa blooms. One important reason is that the Microcystis aeruginosa that form blooms in natural water bodies do not exist in single-celled form, but rather aggregate and float in a colony form. The literature "The Aggregation-Promoting Effect and Growth Influence of Pseudomonas aeruginosa A2" also mentions that Microcystis aeruginosa under laboratory culture conditions does not easily exhibit aggregation-driven behavior. Researchers transferred laboratory-amplified single-celled algae to naturally eutrophic water bodies for in-situ reculture, but found that their intercellular aggregation behavior remained significantly restricted, making it difficult to restore them to their original colony state. This demonstrates a significant difference between single-celled Microcystis algae cultured in the laboratory and those in natural water bodies. The strong physical barrier formed by the colony structure provides a significant advantage for Microcystis algae in resisting external environmental stresses. Therefore, managing Microcystis algae populations that have formed algal blooms presents a technical challenge and complexity that differs from treating dispersed single-celled algae.
[0004] In the paper "Study on the Physiological and Ecological Effects and Mechanisms of Algicidal Bacteria on Algae," the authors conducted an algicidal experiment by introducing a compound bacterial solution containing Bacillus cereus DC22, Flavobacterium tumefaciens DC-P, and budding yeast into the enclosed waters of Dianchi Lake. The results showed that water transparency significantly increased approximately 40 days after inoculation. Although this algicidal experiment targeted Microcystis blooms in natural water bodies, the algicidal cycle was as long as one month or even more than three months, and the algicidal effect was not sustained. Furthermore, it is noteworthy that while previous studies in this paper demonstrated that strains DC22 and DC-P had a certain inhibitory effect on single-celled Microcystis under laboratory culture conditions, the actual algicidal treatment process did not use a single strain but instead employed a compound bacterial agent and introduced budding yeast as an auxiliary strain. This may be due to the dependence of strains DC22 and DC-P on natural conditions such as temperature, light, and pH, and the complexity of the actual algicidal treatment process compared to single-celled Microcystis.
[0005] Currently, finding a specialized functional strain that can efficiently and specifically target the structure of Microcystis colonies and drive their sedimentation and extinction in natural aquatic environments is of great significance for the prevention and control of Microcystis blooms. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a strain of Flavobacterium columnare NY-1 and its application in controlling Microcystis blooms.
[0007] The technical solution of this invention is as follows: A strain of Flavobacterium columnare NY-1, the Flavobacterium columnare ( Flavobacterium columnare NY-1 was deposited on February 11, 2026, at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC 67866.
[0008] The 16S rRNA sequence of the columnar flavobacterium NY-1 is shown in SEQ ID NO.1.
[0009] The method for culturing Flavobacterium columnare NY-1 includes the following steps: (1) Flavobacterium columnare NY-1 was inoculated onto R2A solid medium and activated at 28±2℃ to obtain the activated strain; (2) Inoculate the activated strain from step (1) into R2A liquid culture medium and culture it with shaking at 180~200 rpm and 28±2℃ to obtain activated bacterial solution; (3) Inoculate the activated bacterial solution from step (2) into R2A liquid culture medium at an inoculation amount of 5-10% by volume, and culture with shaking at 180-200 rpm and 28±2℃ to obtain columnar Flavobacterium NY-1 bacterial solution.
[0010] The application of the columnar flavonoid NY-1 in the prevention and control of Microcystis blooms.
[0011] Preferably, the dominant algal species in the microcystic bloom are *Microcystis aeruginosa* and *Microcystis thunbergii*.
[0012] Preferably, the application method is to apply Flavobacterium columnare NY-1 to the microcystis algal bloom area in a natural water body.
[0013] The natural water body mentioned above is a crustacean breeding pond.
[0014] A further preferred dosage is one that achieves a bacterial concentration of 10 in the water. 6 CFU / L.
[0015] A microbial algaecide comprising the aforementioned Flavobacterium columnare NY-1.
[0016] The beneficial effects of this invention are: (1) This invention provides a columnar flavonoid NY-1 strain, which can efficiently and specifically target the structure of Microcystis community and drive it to complete the "sedimentation-death" process. After applying it to natural water bodies where Microcystis blooms occur for 72 hours, the algae inhibition rate is as high as 99%, which almost completely eliminates Microcystis in the water body, thereby effectively controlling Microcystis blooms.
[0017] (2) The strain NY-1 was isolated from a naturally dying Microcystis population. Its function is consistent with the mechanism of algal bloom decline in the natural ecological process. It has a good ecological safety background and provides key core strain resources for developing a new biological algae control technology that truly simulates the natural decline process, is highly targeted and has low environmental risk. Attached Figure Description
[0018] Figure 1 A phylogenetic tree constructed based on the 16S rRNA gene sequence of strain NY-1; Figure 2 This describes the process of microcystis population extinction under the action of strain NY-1; Figure 3 The study investigated the inhibitory effect of strain NY-1 on Microcystis blooms in shrimp farming ponds. Detailed Implementation
[0019] The following description is based on specific embodiments: Example 1: Isolation and identification of Flavobacterium columnare NY-1 In July 2024, a dead Microcystis colony was collected from a Microcystis blooming pond in Jinghai District, Tianjin, China. Epiphytic bacteria were isolated from the bottom water using EDTA-Na2 solution combined with glass bead shaking method. The bacterial suspension was then spread on Shieh solid medium and cultured at 28°C for 48 hours. After the culture was completed, single colonies were picked and purified multiple times. Finally, a pure culture was isolated. The colony morphology was irregular edge, yellow, and mucous. It was named "NY-1".
[0020] Genomic DNA was extracted from strain NY-1, and its 16S rRNA gene sequence was amplified by PCR and sequenced. The sequencing results are shown in SEQ ID NO.1. A phylogenetic tree was constructed based on the 16S rRNA sequence, and the results are shown in [Figure 1]. Figure 1 As shown. By Figure 1 It can be seen that the strain NY-1 obtained from the above screening is similar to... Flavobacterium columnare The similarity to LV339-01 (AY842900.1) was 100%. Based on the physiological characteristics of the strain, it was identified as Flavobacterium columnare (…). Flavobacterium columnare ).
[0021] Flavobacterium columnare ( Flavobacterium columnare NY-1 was deposited on February 11, 2026, at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC67866.
[0022] Example 2: Culture of Flavobacterium columnare NY-1 bacterial suspension Follow these steps: (1) Flavobacterium columnare NY-1 was inoculated onto R2A solid medium and activated at 28°C to obtain the activated strain; (2) The activated strain was inoculated into R2A liquid medium and cultured in a constant temperature shaker at 180 rpm and 28℃ for 12 h to obtain the activated bacterial solution; (3) Inoculate the activated bacterial solution into R2A liquid culture medium at an inoculation rate of 5% (v / v) and continue to culture at 180 rpm and 28℃ for 24 h to obtain columnar Flavobacterium NY-1 bacterial solution.
[0023] Example 3: The extinction process of Microcystis colonies under the action of strain NY-1 Microcystis thuringiensis collected from natural water bodies (with Microcystis thuringiensis as the main species) Microcystis flos-aquae and Microcystis aeruginosa Microcystis aeruginosa The dominant algal species was repeatedly rinsed with sterile water and then suspended in BG-11 medium to obtain an algal suspension. The suspension was collected during the logarithmic growth phase (OD). 600A 5% (v / v) inoculum of *Flavobacterium columnare* NY-1 (approximately 1.8 g) was added to the algal community suspension. A control group containing an equal volume of sterile R2A liquid culture medium was used. The cultures were co-cultured at 25°C under natural light for 12 hours, with the sedimentation and mortality of the *Microcystis* community monitored every 6 hours.
[0024] The results are as follows Figure 2 As shown, Figures A and B are photographs taken at 0h, 6h, and 12h for the control group and the NY-1 bacterial solution treatment group, respectively. Visual observation revealed that in the control group, the Microcystis colony remained floating on the water surface. However, after treatment with the NY-1 bacterial solution, the number of suspended Microcystis colonies gradually decreased with increasing treatment time, and light green to yellow flocculent matter settled to the bottom and disappeared.
[0025] The density of Microcystis aeruginosa in suspension was monitored by microscopy, and the results are shown in Table 1.
[0026] Table 1. The process of microcystis colony extinction under the action of strain NY-1
[0027] Table 1 shows that compared with the initial time point (0h), after 6 hours of treatment with NY-1 bacterial solution, the density of suspended Microcystis began to decrease significantly (P<0.05), with the population density decreasing by 27.5% and the cell density decreasing by 40.8%. After 12 hours of treatment with NY-1 bacterial solution, the population density of suspended Microcystis decreased by 57.3% and the cell density decreased by 91.8%. These results demonstrate that strain NY-1 can effectively drive the sedimentation and death of Microcystis populations, achieving a kill rate of up to 91.8% after 12 hours of treatment with strain NY-1.
[0028] Example 4: Inhibitory effect of strain NY-1 on Microcystis blooms in shrimp farming ponds Follow these steps: Flavobacterium columnare NY-1 was inoculated into R2A liquid medium and cultured at 28°C with shaking at 180 rpm until the late logarithmic growth phase (OD5). 600 (≈2.0), to obtain NY-1 fermentation broth.
[0029] An experiment was conducted in a Litopenaeus vannamei shrimp farming pond (10 mu in area, average water depth 1.5 meters) in Baodi District, Tianjin, where a Microcystis bloom had occurred. Focusing on the downstream area where the microcystis bloom was concentrated, the aforementioned NY-1 fermentation liquid was sprayed into the microcystis bloom area, resulting in a bacterial concentration of approximately 10 in the water. 6 CFU / L.
[0030] Regularly monitor the dynamic changes in Microcystis cell density in the water body, and the results are as follows: Figure 3 As shown. By Figure 3It was found that after applying NY-1 fermentation broth, the density of Microcystis cells in the water showed a rapid and continuous downward trend. Specifically: after 12 hours of application, the density of Microcystis cells decreased significantly, with an algae inhibition rate of 42.1%; after 48 hours of application, the algae inhibition rate reached 84.3%; and after 72 hours of application, the algae inhibition rate was as high as 99%, almost achieving complete elimination of Microcystis in the water.
[0031] Throughout the entire experiment and the subsequent week-long observation period, no abnormalities were observed in the feeding and swimming behaviors of the Litopenaeus vannamei shrimp in the pond, and no poisoning or abnormal mortality was reported. These results indicate that strain NY-1, while achieving efficient algae control, exhibits good biocompatibility and ecological safety for cultured organisms.
Claims
1. A strain of Flavobacterium columnare NY-1, wherein the Flavobacterium columnare ( Flavobacterium columnare NY-1 was deposited on February 11, 2026, at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC 67866.
2. The method for culturing *Flavobacterium columnare* NY-1 according to claim 1, characterized in that, Includes the following steps: (1) Flavobacterium columnare NY-1 was inoculated onto R2A solid medium and activated at 28±2℃ to obtain the activated strain; (2) Inoculate the activated strain from step (1) into R2A liquid culture medium and culture it with shaking at 180~200 rpm and 28±2℃ to obtain activated bacterial solution; (3) Inoculate the activated bacterial solution from step (2) into R2A liquid culture medium at an inoculation amount of 5-10% by volume, and culture with shaking at 180-200 rpm and 28±2℃ to obtain columnar Flavobacterium NY-1 bacterial solution.
3. The application of the columnar flavonoid NY-1 described in claim 1 in the prevention and control of Microcystis blooms.
4. The application as described in claim 3, characterized in that, The dominant algal species in the microcystic blooms are *Microcystis aeruginosa* and *Microcystis thunbergii*.
5. The application as described in claim 3, characterized in that, The application method is as follows: Flavobacterium columnare NY-1 is applied to the microcystis bloom area in natural water bodies.
6. The application as described in claim 5, characterized in that, The natural water body is a pond for raising crustaceans.
7. The application as described in claim 5, characterized in that, The dosage applied is such that the bacterial concentration in the water reaches 10. 6 CFU / L.
8. A microbial algae inhibitor, characterized in that, Includes Flavobacterium columnare NY-1 as described in claim 1.