Culture method of efficient nitrogen-fixing bacteria in water body

Abstract

The invention discloses a culture method of efficient nitrogen-fixing bacteria in a water body. The culture method comprises the steps that 1) huge bacillus is inoculated into a culture medium for preliminary culture; 2) the culture medium is subjected to gamma rays for secondary culture; 3) the culture medium is frozen, and then the temperature rises to 15-35 DEG C; 4) mixed florae in the culturemedium are selected, and the efficient nitrogen-fixing bacteria are screened out through a plate streak method; the culture medium contains ethyl nitrosourea and / or methyl nitrosourea. The culture method of the efficient nitrogen-fixing bacteria in the water body has the advantages that strains with an efficient nitrogen-fixing effect can be cultured, the operation is simple and convenient, and the cycle is short.

Description

technical field

[0001] The invention relates to nitrogen-fixing bacteria in water bodies, in particular to a method for cultivating high-efficiency nitrogen-fixing bacteria in water bodies. Background technique

[0002] As the scale, intensification and industrialization of my country's aquaculture industry continue to increase, the eutrophication of water bodies has intensified significantly, the ecological environment of water bodies in some areas has continued to deteriorate, and water body ecology has become unbalanced. Scholars at home and abroad have carried out a lot of research on the phenomenon of water body eutrophication, mainly focusing on the transformation and removal of inorganic nitrogen and phosphorus. Ammonifying bacteria and nitrogen-fixing bacteria are less studied. But with more and more eutrophic water bodies, algae blooms are more and more frequent. How can the organic nitrogen released after the death and decomposition of a large number of algae be q...

Examples

Embodiment 1

[0037] 1) Inoculate Bacillus megaterium with an inoculum size of 3%-5% in MS medium (containing nitrosoethylurea, the total content is 1.8% by weight) and carry out preliminary culture (cultivation temperature is 25°C, culture time for 8 days, the relative humidity is 50%);

[0038] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 25°C, the culture time is 20h, the relative humidity is 50%, and the energy of the gamma rays is 1 Mev);

[0039] 3) Place the culture medium for freezing treatment (the treatment temperature is -12°C, and the treatment time is 9h), and then the temperature is raised to 25°C;

[0040] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

Embodiment 2

[0042] 1) Inoculate Bacillus megaterium with 3% inoculum in MS medium (containing nitrosoethylurea and nitrosomethylurea, the total content is 1.2% by weight) and carry out preliminary culture (cultivation temperature is 15 ℃, the incubation time is 10 days, and the relative humidity is 60%);

[0043] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 15°C, the culture time is 24h, the relative humidity is 60%, and the energy of the gamma rays is 1.5 Mev);

[0044] 3) Place the culture medium for freezing treatment (the treatment temperature is -15°C, and the treatment time is 8h), and then the temperature is raised to 15°C;

[0045] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

Embodiment 3

[0047] 1) Inoculate Bacillus megaterium with 5% inoculum in 1 / 2MS medium (containing nitrosoethylurea and / or nitrosomethylurea, the total content is 2% by weight) for preliminary culture ( The culture temperature is 35°C, the culture time is 5 days, and the relative humidity is 40%);

[0048] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 35°C, the culture time is 15h, the relative humidity is 40%, and the energy of the gamma rays is 0.8 Mev);

[0049] 3) Place the culture medium for freezing treatment (the treatment temperature is -10°C, and the treatment time is 10h), and then the temperature is raised to 35°C;

[0050] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

technical field

[0001] The invention relates to nitrogen-fixing bacteria in water bodies, in particular to a method for cultivating high-efficiency nitrogen-fixing bacteria in water bodies. Background technique

[0002] As the scale, intensification and industrialization of my country's aquaculture industry continue to increase, the eutrophication of water bodies has intensified significantly, the ecological environment of water bodies in some areas has continued to deteriorate, and water body ecology has become unbalanced. Scholars at home and abroad have carried out a lot of research on the phenomenon of water body eutrophication, mainly focusing on the transformation and removal of inorganic nitrogen and phosphorus. Ammonifying bacteria and nitrogen-fixing bacteria are less studied. But with more and more eutrophic water bodies, algae blooms are more and more frequent. How can the organic nitrogen released after the death and decomposition of a large number of algae be q...

Examples

Embodiment 1

[0037] 1) Inoculate Bacillus megaterium with an inoculum size of 3%-5% in MS medium (containing nitrosoethylurea, the total content is 1.8% by weight) and carry out preliminary culture (cultivation temperature is 25°C, culture time for 8 days, the relative humidity is 50%);

[0038] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 25°C, the culture time is 20h, the relative humidity is 50%, and the energy of the gamma rays is 1 Mev);

[0039] 3) Place the culture medium for freezing treatment (the treatment temperature is -12°C, and the treatment time is 9h), and then the temperature is raised to 25°C;

[0040] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

Embodiment 2

[0042] 1) Inoculate Bacillus megaterium with 3% inoculum in MS medium (containing nitrosoethylurea and nitrosomethylurea, the total content is 1.2% by weight) and carry out preliminary culture (cultivation temperature is 15 ℃, the incubation time is 10 days, and the relative humidity is 60%);

[0043] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 15°C, the culture time is 24h, the relative humidity is 60%, and the energy of the gamma rays is 1.5 Mev);

[0044] 3) Place the culture medium for freezing treatment (the treatment temperature is -15°C, and the treatment time is 8h), and then the temperature is raised to 15°C;

[0045] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

Embodiment 3

[0047] 1) Inoculate Bacillus megaterium with 5% inoculum in 1 / 2MS medium (containing nitrosoethylurea and / or nitrosomethylurea, the total content is 2% by weight) for preliminary culture ( The culture temperature is 35°C, the culture time is 5 days, and the relative humidity is 40%);

[0048] 2) Place the culture medium under gamma rays for two-step culture (the culture temperature is 35°C, the culture time is 15h, the relative humidity is 40%, and the energy of the gamma rays is 0.8 Mev);

[0049] 3) Place the culture medium for freezing treatment (the treatment temperature is -10°C, and the treatment time is 10h), and then the temperature is raised to 35°C;

[0050] 4) Select the mixed flora in the culture medium and use the plate marking method (A, B, C and D four areas connected in sequence along the plate design, the area of ​​the four areas is D>C>B>A); select D area The bacteria are high-efficiency nitrogen-fixing bacteria in water.

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