Brevibacillus laterosporu with function in quickly decomposing nitrite nitrogen and bacteriostasis function and application thereof

[0017] Screening, isolation and identification of embodiment 1 bacterial strain

[0018] 1. Preparation of culture medium:

[0019] Nitrite nitrogen degrading bacteria enrichment screening liquid medium: NaNO 2 1g, Na 2 CO 3 1g, K 2 HPO 4 0.5g, MgSO 4 ·7H 2 O 0.03g, FeSO 4 ·7H 2 O 0.4g, aged sea water 1L, pH 7.2-7.5.

[0020] Solid medium for isolation and purification of nitrite nitrogen degrading bacteria: NaNO 2 0.5g, Na 2 CO 3 1g, K 2 HPO 4 0.5g, MgSO 4 ·7H 2 O 0.03g, FeSO 4 ·7H 2 O 0.4g, aged sea water 1L, agar powder 12g, pH 7.2~7.5.

[0021] 2216E liquid medium: peptone 5g, yeast extract 1g, FePO 4 0.1g, old sea water 1L, pH 7.2; solid medium is liquid medium by adding 15g l -1 agar powder.

[0022] Nutrient broth (NB) culture medium: peptone 10g, beef extract powder 3g, sodium chloride 30g, distilled water 1000ml, pH value 7.2; solid culture medium is liquid culture medium by adding 15g l -1 agar powder.

[0023] Before use, the above medium was ste

[0030] Morphological characteristics and physiological and biochemical characteristics of embodiment 2 YB-02

[0031] Morphological characteristics of YB-02: such as figure 1 As shown, the colony of YB-02 on the 2216E plate is round, earthy yellow, smooth, moist and shiny, slightly raised in the middle, opaque, with neat edges and no halos.

[0032] Table 1. Culture characteristics of strains on 2216E medium

[0033]

[0034] According to the physiological and biochemical detection method of "Bergery Bacteria Identification Manual" (eighth edition), the Brevibacillus spp. YB-02 was detected.

[0035] The isolated and purified YB-02 has wide salinity, can grow in the salinity range of 20-40‰, and the optimum growth salinity is in the range of 28-32‰; it can grow normally in the temperature range of 10-40℃, and the most suitable The growth temperature is 20-30°C; it can grow in the range of pH 7-9, the optimum growth pH is 7.2-8.5, and it has poor tolerance to acidic environment

[0040] Growth characteristics and culture conditions of embodiment 3 Brevibacillus lateralsporosa YB-02

[0041] Brevibacillus laterosporu (Brevibacillus laterosporu) CGMCC-No.9757 has eurysalinity because it is isolated from the marine aquaculture environment, and the optimum growth salinity is 28-32‰; the optimum growth temperature is 26-28°C, The growth pH is 7.2-8.5. After 14-16 hours of fermentation, the logarithmic phase is reached, and the number of bacteria reaches 5×10 10 cfu / mL.

[0042] The medium used for cultivation is as follows:

[0043] Seed medium (Nutrient Broth (NB) medium): beef extract powder 5g, peptone 10g, sodium chloride 30g, water 1L, pH 7.2-7.5.

[0044] 2216E liquid medium: peptone 5g, yeast extract 1g, FePO4 0.1g, aged sea water 1L, pH 7.2~7.5.

[0045] Fermentation medium: 150g of corn flour, 250g of bean cake powder, 3.5g of medium-temperature amylase, 2.5g of neutral protease, 40g of corn steep liquor, 25g of glucose, 10g of magnesium sulfate