CN108611303A - A kind of preparation method except the prebiotic bacteria adsorbent of cadmium and its application in vegetable juice - Google Patents

Abstract

A kind of preparation method except the prebiotic bacteria adsorbent of cadmium and its application in vegetable juice, prebiotic bacteria adsorbent are mixed with the ratio of the compound freeze drying protectant of 1 3g per g lactobacillus bacterium mud by lactobacillus and compound freeze drying protectant, and viable count is 1.2 × 10¹¹CFU/g‑6.5×10¹¹CFU/g；Prebiotic bacteria adsorbent is added by the additive amount of 1 5g/L in vegetable juice, then standing adsorption removes 2~4h of cadmium at 37 DEG C, and cadmium removal rate is 95 100%, and then refrigerated centrifuge is to get no cadmium vegetable juice and the lactobacillus bacterium mud containing cadmium.The present invention had both solved the problems, such as that the heavy metal pollution of vegetable juice and safety were drunk, and implemented convenient, fast, efficiently.Lactobacillus, which is added to the lactic acid that proper fermentation generates in vegetable juice, can increase the flavor substance of vegetable juice, enhance mouthfeel.Pectin, chitosan and the zeolite added in compound freeze drying protectant also has cadmium the ability of absorption cadmium, collaboration probiotics stronger except cadmium ability.

Description

A preparation method of cadmium-removing probiotic adsorbent and its application in vegetable juice

technical field

The invention belongs to the field of food, and in particular relates to a preparation method of a cadmium-removing probiotic adsorbent and its application in vegetable juice.

Background technique

With the rapid development of industry and agriculture, mining wastewater, industrial wastewater from electroplating and batteries have not been treated or treated substandard sewage irrigation, fertilization containing cadmium elements, and industrial waste gas containing cadmium pollution enters the soil through rain and natural settlement. Cadmium in the soil enters the plants through uptake by the roots of the plants and accumulates in the vegetables. Cadmium is one of the three most toxic heavy metals (lead, cadmium, and mercury) announced by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). It can accumulate in the human body for 10 to 30 years. Chronic cadmium poisoning is most likely to cause lesions in the kidneys and liver, and can also cause bone pain, high blood pressure, diabetes, anemia, tumors, etc. Long-term intake of cadmium can cause cancer to a certain extent, and is especially harmful to children's health.

At present, the methods for removing cadmium mainly include: 1. Physical method. This method uses technologies such as low-frequency ultrasonic waves, cold and hot water exchange, and adsorption, and is assisted by polishing to remove the skin, cleaning and rinsing to remove cadmium. Due to different types of vegetables, the ability to bind cadmium ions is different, and the removal ability of physical methods is limited. ; Two, chemical method. This method uses reagents such as resin, tannin, sodium citrate and sodium oxalate to remove cadmium in food through methods such as organic capture, plasma exchange, complex formation, chelation and microprecipitation, but the use of some toxic chemical reagents may It will form residues in food and endanger human health; 3. Biological method. This method mainly removes cadmium in food through the adsorption or accumulation of microorganisms such as plants and their extracts, fungi, and bacteria. The biological method has the advantages of safety, no residue, and no pollution.

Studies have shown that lactic acid bacteria can scavenge cadmium in food such as water, grain, fruits, and vegetables. The possible mechanism of action is to rely on cell surface adsorption to bind unmetabolized free cadmium ions to the surface of the cell wall through positive and negative charges. The cell wall mainly Composed of peptidoglycan, teichoic acid and neutral polysaccharides, the network structure formed by teichoic acid and polysaccharides is conducive to adhesion and adsorption of cadmium. The proteins on the surface of lactic acid bacteria cells have a large number of negatively charged functional groups, which can effectively bind metal cations. The acidic environment formed by the lactic acid produced by the metabolism of lactic acid bacteria has a solubilizing effect on cadmium complexes. The surface of macromolecular substances such as polysaccharides, polypeptides and nucleic acids formed by the metabolism of lactic acid bacteria has groups such as COO ^- , HPO ^4- and OH ^- , which can Electrostatic adsorption occurs with cadmium ions, such as the S-Layer protein on the cell surface of Lactobacillus brevis has the ability to bind Cd ²⁺ . Lactic acid bacteria found to be able to remove cadmium mainly include Lactobacillus, Pediococcus, Enterococcus and Bifidobacterium. Bhakta et al. screened the strain L. reuteri Cd70-13 with good adhesion from the fish intestine, and the cadmium removal rate in the MRS medium was 25%. Zhai et al. used the strain Lactobacillus plantarum CCFM8610 to effectively remove 31.34% of cadmium in the initial concentration of 5mg/L Cd aqueous solution. Halttunen et al. found that the strain Bifidobacterium longum 46 could remove 54.7 mg/g of cadmium in water. Studies by Topcu et al. have shown that strains E.faecium EF031 and E.faecium M74 can effectively remove cadmium in water, and the removal ranges are 77.3%-98.1% and 53.5%-91.0%, respectively. Halttunen et al found that the strain L.rhamnosus GG removed 22.1%-49.1% of cadmium in phosphate buffered saline (PBS) through electrostatic adsorption on the cell surface. Fu et al. used L.plantarum and P.pentosaceus mixed at 2:1, then fermented at 40.8°C for 23.4h with 3% inoculum, which could effectively remove 85.73% of cadmium in rice. At present, there are not many studies on the removal of cadmium in fruit juice by using lactic acid bacteria, so it is necessary to screen probiotic adsorbents that can tolerate cadmium and remove heavy metal cadmium in fruit juice.

Contents of the invention

The object of the present invention is to provide a preparation method of a cadmium-removing probiotic adsorbent and its application in vegetable juice.

In order to achieve the above object, the preparation method of the cadmium-removing probiotic adsorbent of the present invention is as follows:

1) Preparation of compound lyoprotectant

Add 0.5-2g of pectin, 3-5g of chitosan, 0.3-0.8g of zeolite and 12.2-16.2g of distilled water per 20g and mix to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 2-3h, then suction filtered to obtain jujube juice, and then 2-5g/L casein and 1.5-2.0 g/L inulin, sterilized at 121°C for 20 minutes, cooled to 38-40°C, and then added membrane-filtered leucine and calf serum to make the final concentrations of leucine and calf serum respectively 10-16mg /L and 1-3g/L, and then add 1-5% activated lactobacilli according to the volume ratio, culture at a constant temperature of 37°C for 20-24h, and then freeze and centrifuge to collect the bacteria to obtain probiotic powder;

3) Add 1-3 times the weight of compound freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then use vacuum freeze-drying for 20-24 hours to obtain a viable count of 1.2×10 ¹¹ CFU/g-6.5 ×10 ¹¹ CFU/g of probiotic adsorbent.

The lactobacillus is one or both of Lactobacillus acidophilus and Lactobacillus rhamnosus.

Application of the probiotic adsorbent prepared by the preparation method of the present invention in removing cadmium in vegetable juice:

First wash, destem, and squeeze fresh water vegetables, add water according to the mass ratio of 1:2, then centrifuge to remove sediment, sterilize in a high-pressure steam sterilizer at 105°C for 10min, centrifuge to remove thermal coagulation, and add cadmium salt , so that the cadmium concentration is 2-5mg/L, then adjust the pH of the vegetable juice to 6-7, then add the probiotic adsorbent to the vegetable juice in an amount of 1-5g/L, and then let it stand at 37°C The cadmium is removed by adsorption for 2-4 hours, and the cadmium removal rate is 95-100%, and then refrigerated and centrifuged to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Described vegetable juice is celery juice, cucumber juice, tomato juice, pumpkin juice, spinach juice, carrot juice, cabbage juice.

The cadmium-containing lactobacillus sludge is recycled, suspended in physiological saline, then adjusted to a pH of 2.5-4.0, left to stand at room temperature for 0.5-1h, and then centrifuged to release the adsorbed cadmium into the supernatant, and the precipitation is a probiotic Bacteria adsorbent.

The recycled probiotic adsorbent of the present invention can be added to the vegetable juice for recycling to remove cadmium, and after 5 cycles, the probiotic slime can be used as a feed additive.

The effect of the invention

1) Lactobacillus, a microorganism generally recognized as safe (GRAS), is used as a cadmium removal agent, which not only solves the problem of heavy metal pollution and safe drinking of vegetable juice, but also is convenient, fast and efficient to implement.

2) Adding Lactobacillus to vegetable juice can increase the flavor of vegetable juice and enhance the taste of lactic acid produced by moderate fermentation.

3) The pectin, chitosan and zeolite added in the composite lyoprotectant also have the ability to adsorb cadmium, and the synergistic probiotics have a stronger ability to remove cadmium.

4) When the concentration of cadmium in the vegetable juice is 2-5mg/L, the removal rate of cadmium exceeds 95%.

Detailed ways

Below in conjunction with embodiment further illustrate the present invention:

Example 1:

1) Preparation of compound lyoprotectant

Add 2g of pectin per 20g, mix 5g of chitosan, 0.8g of zeolite and 12.2g of distilled water to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 2 hours, then suction filtered to obtain jujube juice, and then 2g/L casein peptone and 1.5g/L inulin were added to the jujube juice per liter of jujube juice Afterwards, sterilize at 121°C for 20 minutes, cool to 38°C, and then add membrane-filtered leucine and calf serum, so that the final concentrations of leucine and calf serum are 10mg/L and 1g/L respectively, and then press the volume Inject 2% of the activated Lactobacillus acidophilus strain, culture at a constant temperature of 37°C for 20 hours, and then freeze and centrifuge to collect the bacteria to obtain the probiotic powder;

3) Add 3 times the weight of composite freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then vacuum freeze-dry for 20 hours to obtain a probiotic adsorbent with a viable count of 1.2×10 ¹¹ CFU/g.

The application of probiotic adsorbent to remove cadmium in vegetable juice: firstly, fresh celery is washed, destemmed, squeezed, and then added water according to the mass ratio of 1:2, then centrifuged to remove the precipitate, and placed in a high-pressure steam sterilizer at 105°C Sterilize for 10 minutes, centrifuge to remove thermal coagulation, add cadmium salt to make the cadmium concentration 5mg/L, then adjust the pH of the vegetable juice to 6, then add the probiotic adsorbent to the juice, the addition amount is 1g/L, and then Stand at 37°C for 4 hours to remove cadmium by adsorption, the cadmium removal rate is 95%, and then refrigerate and centrifuge to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Suspend the obtained cadmium-containing Lactobacillus sludge into physiological saline, then adjust the pH to 2.5, let it stand at room temperature for 0.5h, and then centrifuge (8000rpm, 10min) to release the adsorbed cadmium into the supernatant, and precipitate as a probiotic adsorbent , add it to the vegetable juice again for recycling to remove cadmium, and after 5 cycles, use the probiotic bacteria slime as a feed additive.

Example 2:

1) Preparation of compound lyoprotectant

Add 0.5g of pectin per 20g, mix 3.5g of chitosan, 0.5g of zeolite and 15.5g of distilled water to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 2.5h, then suction filtered to obtain jujube juice, and then 3g/L of casein and 1.6g/L of chrysanthemum were added to the jujube juice per liter of jujube juice After sugaring, sterilize at 121°C for 20 minutes, cool to 40°C and add membrane-filtered leucine and calf serum so that the final concentrations of leucine and calf serum are 12mg/L and 1.5g/L, respectively. Add 2.5% activated Lactobacillus rhamnosus strains according to the volume ratio, culture at 37°C for 22 hours, and then refrigerate and centrifuge to collect the bacteria to obtain probiotic bacteria powder;

3) Add 1 times the weight of the compound freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then vacuum freeze-dry for 20 hours to obtain a probiotic adsorbent with a viable count of 1.6×10 ¹¹ CFU/g.

The application of probiotic adsorbent to remove cadmium in vegetable juice: first, fresh cucumbers are washed, destemmed, and juiced, then add water according to the mass ratio of 1:2, then centrifuge to remove sediment, and put them in a high-pressure steam sterilizer at 105°C Sterilize for 10 minutes, centrifuge to remove thermal coagulation, add cadmium salt to make the cadmium concentration 2mg/L, then adjust the pH of the vegetable juice to 6.5, and then add the probiotic adsorbent to the vegetable juice in an amount of 3g/L. Then stand at 37° C. to remove cadmium by adsorption for 3 hours, the cadmium removal rate is 100%, and then freeze and centrifuge to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Suspend the obtained cadmium-containing Lactobacillus sludge into physiological saline, then adjust the pH to 3.0, let it stand at room temperature for 0.75h, and then centrifuge (8000rpm, 10min) to release the adsorbed cadmium into the supernatant, and precipitate as a probiotic adsorbent , add it to the vegetable juice again for recycling to remove cadmium, and after 5 cycles, use the probiotic bacteria slime as a feed additive.

Example 3:

1) Preparation of compound lyoprotectant

Add 2g of pectin per 20g, mix 4.5g of chitosan, 0.8g of zeolite and 12.7g of distilled water to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 3 hours, then suction filtered to obtain jujube juice, and then 4g/L of casein and 2g/L of inulin were added to the jujube juice per liter of jujube juice Sterilize at 121°C for 20 minutes, cool to 39°C, add membrane-filtered leucine and calf serum, so that the final concentrations of leucine and calf serum are 16mg/L and 2g/L, respectively, and then press the volume ratio Insert 3% of the activated Lactobacillus acidophilus strains and Lactobacillus rhamnosus strains (the strain ratio is 2:1), culture at 37°C for 20 hours, then freeze and centrifuge to collect the bacteria to obtain probiotic powder ;

3) Add 2 times the weight of compound freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then vacuum freeze-dry for 20 hours to obtain a probiotic adsorbent with a viable count of 3.5×10 ¹¹ CFU/g.

The application of probiotic adsorbent to remove cadmium in vegetable juice: firstly, fresh tomatoes are washed, destemmed, and juiced, and water is added according to the mass ratio of 1:2, then centrifuged to remove sediment, and sterilized in a high-pressure steam sterilizer at 105°C. Bacteria for 10 minutes, centrifuged to remove thermal coagulation, add cadmium salt to make the cadmium concentration 4mg/L, then adjust the pH of the vegetable juice to 6, then add the probiotic adsorbent to the vegetable juice in an amount of 4g/L, and then Stand at 37°C for 3 hours to remove cadmium by adsorption, the cadmium removal rate is 99%, and then refrigerate and centrifuge to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Suspend the obtained cadmium-containing lactobacillus sludge into physiological saline, then adjust the pH to 2.8, leave it at room temperature for 0.6h, and then centrifuge (8000rpm, 10min) to release the adsorbed cadmium into the supernatant, and precipitate it into a probiotic adsorbent , add it to the vegetable juice again for recycling to remove cadmium, and after 5 cycles, use the probiotic bacteria slime as a feed additive.

Example 4:

1) Preparation of compound lyoprotectant

Add 1.5g of pectin per 20g, mix 3g of chitosan, 0.3g of zeolite and 15.2g of distilled water to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 3 hours, then suction filtered to obtain jujube juice, and then 5g/L casein peptone and 1.8g/L inulin were added to the jujube juice per liter of jujube juice Afterwards, sterilize at 121°C for 20 minutes, cool to 39°C and add membrane-filtered leucine and calf serum so that the final concentrations of leucine and calf serum are 14mg/L and 3g/L respectively. Inject 1% of the activated Lactobacillus acidophilus strain, culture at 37°C for 24 hours, then freeze and centrifuge to collect the bacteria to obtain probiotic powder;

3) Add 1.5 times the weight of composite freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then vacuum freeze-dry for 22 hours to obtain a probiotic adsorbent with a viable count of 5.2×10 ¹¹ CFU/g.

The application of probiotic adsorbent to remove cadmium in vegetable juice: firstly, fresh pumpkin is cleaned, destemmed and squeezed, then water is added according to the mass ratio of 1:2, and then the precipitate is removed by centrifugation. Sterilize for 10 minutes, centrifuge to remove thermal coagulation, add cadmium salt to make the cadmium concentration 3mg/L, then adjust the pH of the vegetable juice to 7, and then add the probiotic adsorbent to the vegetable juice in an amount of 5g/L. Then stand at 37° C. to remove cadmium by adsorption for 2 hours, the cadmium removal rate is 98%, and then refrigerate and centrifuge to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Suspend the obtained cadmium-containing lactobacillus sludge into physiological saline, then adjust the pH to 3.5, leave it at room temperature for 1 hour, and then centrifuge (8000rpm, 10min) to release the adsorbed cadmium into the supernatant, and precipitate it into a probiotic adsorbent. It is added to the vegetable juice for recycling to remove cadmium, and after 5 cycles, the probiotic bacteria slime is used as a feed additive.

Example 5:

1) Preparation of compound lyoprotectant

Add 0.5g of pectin per 20g, mix 3g of chitosan, 0.3g of zeolite and 16.2g of distilled water to obtain a composite lyoprotectant;

2) Preparation of probiotic bacteria powder

Wash the fresh jujubes and beat them, and add 0.08% of the jujube quality pectinase with an activity of 30000U/g, 0.15% of the cellulase with an activity of 8000U/g and 0.75% of the activity of the jujubes to the jujube pulp. Hemicellulase of 10000U/g was incubated at 60°C for 2 hours, then suction filtered to obtain jujube juice, and then 3.5g/L of casein and 1.9g/L of chrysanthemum were added to the jujube juice per liter of jujube juice After sugaring, sterilize at 121°C for 20 minutes, cool to 40°C and add membrane-filtered leucine and calf serum so that the final concentrations of leucine and calf serum are 15mg/L and 2.5g/L, respectively. Add 5% activated Lactobacillus rhamnosus strains according to the volume ratio, culture at 37°C for 21 hours, and then freeze and centrifuge to collect the bacteria to obtain probiotic bacteria powder;

3) Add 2.5 times the weight of compound freeze-drying protective agent to the probiotic powder, mix evenly with a vortex machine, and then vacuum freeze-dry for 24 hours to obtain a probiotic adsorbent with a viable count of 6.5×10 ¹¹ CFU/g.

The application of probiotic adsorbent to remove cadmium in vegetable juice: firstly, fresh spinach is washed, destemmed and squeezed, and then water is added according to the mass ratio of 1:2, then centrifuged to remove the precipitate, and placed in an autoclave at 105 °C Sterilize for 10 minutes, centrifuge to remove thermal coagulation, add cadmium salt to make the cadmium concentration 5mg/L, then adjust the pH of the vegetable juice to 7, and then add the probiotic adsorbent to the vegetable juice at an amount of 2g/L. Then stand at 37° C. to remove cadmium by adsorption for 3 hours, the cadmium removal rate is 96%, and then freeze and centrifuge to obtain cadmium-free vegetable juice and cadmium-containing lactobacillus sludge.

Suspend the obtained cadmium-containing lactobacillus sludge into physiological saline, then adjust the pH to 4, leave it at room temperature for 1 hour, and then centrifuge (8000rpm, 10min) to release the adsorbed cadmium into the supernatant, and precipitate as a probiotic adsorbent. It is added to the vegetable juice for recycling to remove cadmium, and after 5 cycles, the probiotic bacteria slime is used as a feed additive.

Claims (5)

1. a kind of preparation method except the prebiotic bacteria adsorbent of cadmium, it is characterised in that：

1) preparation of compound freeze drying protectant

The pectin of 0.5-2g is added by every 20g, the distilled water of the chitosan of 3-5g, the zeolite of 0.3-0.8g and 12.2-16.2g is mixed Conjunction obtains compound freeze drying protectant；

2) preparation of probiotics bacterium powder

The fruit that the activity that fresh honey raisin tree is beaten after cleaning, and honey raisin tree quality 0.08% is added in being starched to honey raisin tree is 30000U/g Glue enzyme, 0.15% active 8000U/g cellulase add with 0.75% activity be 10000U/g hemicellulase in 60 DEG C heat preservation 2-3h, then filters and obtains hovenia acerba juice, then into hovenia acerba juice by every liter of hovenia acerba juice be added 2~5g/L casein peptone, It sterilizes 20 minutes in 121 DEG C after the synanthrin of 1.5-2.0g/L, is cooled to after 38-40 DEG C and the leucine of membrane filtration and small ox blood is added Clearly, make the final concentration of leucine and calf serum be respectively 10~16mg/L and 1-3g/L, after accessed 1-5% by volume The lactobacillus of activation, in 37 DEG C of constant temperature incubation 20-24h, then refrigerated centrifuge collects thalline and obtains probiotics bacterium powder；

3) the compound freeze drying protectant of 1-3 times of weight is added into probiotics bacterium powder, is uniformly mixed with whirlpool instrument, then uses true Vacuum freecing-dry 20-24h, it is 1.2 × 10 to obtain viable count¹¹CFU/g-6.5×10¹¹The prebiotic bacteria adsorbent of CFU/g.

2. the preparation method of prebiotic bacteria adsorbent according to claim 1, it is characterised in that：The lactobacillus is acidophilus One or both of lactobacillus, Lactobacillus rhamnosus.

3. a kind of prebiotic bacteria adsorbent prepared such as claim 1 removes the application of cadmium in vegetables, it is characterised in that：It first will be new According to 1 after fresh vegetables cleaning, destemming, processing of squeezing the juice：2 mass ratioes add water, removal precipitation are then centrifuged for, in high-pressure steam sterilizing pan In sterilize at 105 DEG C 10min, be centrifuged off coarse sludge, add cadmium salt, it is 2-5mg/L to make cadmium concentration, then by vegetable juice pH tune To 6~7, then prebiotic bacteria adsorbent is added in vegetable juice, additive amount 1-5g/L, then standing adsorption is removed at 37 DEG C 2~4h of cadmium, cadmium removal rate are 95-100%, and then refrigerated centrifuge is to get no cadmium vegetable juice and the lactobacillus bacterium mud containing cadmium.

4. prebiotic bacteria adsorbent according to claim 3 removes the application of cadmium in vegetable juice, it is characterised in that：The vegetable Vegetable juice is Celery Juice, Fresh Cucumber Juice, Tomato juice, Pumpkin Juice, spinach juice, carrot juice, cabbage juice.

5. prebiotic bacteria adsorbent according to claim 3 removes the application of cadmium in vegetable juice, it is characterised in that：Described contains The lactobacillus bacterium mud of cadmium recycles, and is suspended into physiological saline, and it is 2.5-4.0 then to adjust pH, is stored at room temperature 0.5- Centrifugation discharges the cadmium of absorption into supernatant after 1h, is precipitated as prebiotic bacteria adsorbent.