Photoluminescent bacteria detection method is widely used in biological toxicity detection because of its sensitivity and simplicity. Experimental principle: It will happen when the bacterial metaboli

Photoluminescent bacteria detection method is widely used in biological toxicity detection because of its sensitivity and simplicity. Experimental principle: It will happen when the bacterial metabolism is normal. The metabolic mode of (1) photobacterium is heterotrophic, and the purified strain can be obtained by inoculating it on solid medium with inoculation ring. Then, the liquid culture medium is used for expanding culture.

(2) According to the experimental design, the test tube 1 in the table 1 should be the control group and play a control role.

(3) According to the principle of comparative equivalence, seawater samples should not be added to the test tube 1, and the liquid in the test tube should be kept equal, so 4.99ml 3% NaCl solution and 0.0 1mL of luminescent bacteria suspension should be added.

(4) The measurement index of this experiment can be expressed by luminous rate, so the luminous intensity of each test tube can be measured by biological toxicity tester.

(5) According to the results in Table 2, it can be seen that the pH value of photobacteria is between 6.0 and 9.0, and the EC50 value increases with the increase of pη value, so the toxicity of sodium pentachlorophenol to photobacteria decreases.

(6) According to the data analysis, the possible reason is that PCP easily enters bacteria through the cell membrane and is toxic to bacteria. When the pH value of photobacteria is between 6.0 and 9.0, with the increase of pH, the proportion of molecular PCPs decreases, and the number of PCPs entering bacterial cells decreases, so the toxicity decreases.

So the answer is: (1) heterotrophic inoculation ring solid streaking liquid.

(2) control

(3)

Luminescence intensity of TubeNo 13%NaCl solution (mL) 4.99 seawater sample (mL) 0 photobacterium suspension (mL) 0.0 1 seawater concentration (%) 0(4) mixed solution.

(5) When the pH value of photobacteria is between 6.0 and 9.0, the EC50 value increases with the increase of pη value, and the toxicity of sodium pentachlorophenol to photobacteria decreases.

(6) PCP can easily enter bacteria through cell membrane, which is toxic to bacteria. When the pH value of photobacteria is between 6.0 and 9.0, with the increase of pH, the proportion of molecular PCPs decreases, and the number of PCPs entering bacterial cells decreases, so the toxicity decreases.