Study on the bactericidal effect of slightly acidic water electrolysis on feathers
April 14, 2017
1833
At present, the disinfection and sterilization procedures for domestic chicken farms are not yet perfect. Due to the safe and effective bactericidal effect of water electrolysis, this study aimed to investigate the bactericidal effect of water electrolysis treatment with different effective chlorine concentrations (ACC) on feathers under laboratory conditions. The experimental results indicate that slightly acidic water electrolysis has a good bactericidal effect on bacteria and fungi on the surface of feathers. The most significant bactericidal effect was observed in the acidic water electrolysis treatment with a pH value of around 6.8, an ORP of around 840mV, and an ACC of 20 mg/l.
Water electrolysis is a new type of functional water, mainly obtained by electrolyzing aqueous solutions containing electrolytes. The research on the function of water electrolysis began in Japan in the early 1980s and has been widely studied and applied in fields such as medicine, food processing, aquaculture, and horticulture. Research and application in agriculture mainly focus on sterilization and disinfection, disease prevention and control, and the impact on plant breeding and growth [7]. The research results on water electrolysis indicate that strong acidic water electrolysis has a broad-spectrum, rapid bactericidal effect, no pollution, no residual toxicity, is safe and economical, and is conducive to environmental protection.
Disinfection plays a crucial role in the chicken industry. At present, large-scale chicken farms in China mainly adopt a full in and full out epidemic prevention system, and thoroughly disinfect the chicken coop environment after a batch of chickens is raised. Some breeders also use the chicken body spray disinfection method to carry out spray disinfection on chickens of different ages. This method has a killing effect on a variety of viruses, bacteria, and even spores, and has no adverse effect on the egg production rate and hatching rate of chicks, adult chickens, and egg laying breeders. Small scale chicken farmers do not disinfect their chickens and directly sell them to the market. Scientific disinfection methods require high standards, especially for the selection of disinfectants, which require broad-spectrum, high efficiency, strong bactericidal effect, low toxicity and irritation, and will not remain in meat or eggs.
Given the application of water electrolysis in the field of sterilization and disinfection, as well as its safe and rapid killing effect, this study explores the sterilization effect of water electrolysis on chicken feathers under laboratory conditions by soaking them in water electrolysis with different physical and chemical indicators, and proposes a safe and effective sterilization method, which has important practical significance.
1. Materials and Methods
1.1 Experimental Materials
The chicken feathers used in this experiment were purchased from a regular agricultural market and stored at a constant temperature of 4 ℃ in a refrigerator. No sterilization treatment was performed before the experiment, and the bacteria in the feathers were kept as they were.
1.2 Test Method
This experiment was conducted in June 2011 at the Key Open Laboratory of Facility Agriculture Engineering, Ministry of Agriculture, China Agricultural University.
1.2.1 Preparation of water electrolysis
Electrolyze a 0.9% HCl solution to obtain three groups of water electrolysis, numbered A, B, and C. Measure their pH value, effective chlorine concentration (ACC), and redox potential (ORP), and set deionized water as the control group CK, as shown in Table 1.
Table 1 Water and electricity splitting indicators for different treatments
Water electrolysis is a new type of functional water, mainly obtained by electrolyzing aqueous solutions containing electrolytes. The research on the function of water electrolysis began in Japan in the early 1980s and has been widely studied and applied in fields such as medicine, food processing, aquaculture, and horticulture. Research and application in agriculture mainly focus on sterilization and disinfection, disease prevention and control, and the impact on plant breeding and growth [7]. The research results on water electrolysis indicate that strong acidic water electrolysis has a broad-spectrum, rapid bactericidal effect, no pollution, no residual toxicity, is safe and economical, and is conducive to environmental protection.
Disinfection plays a crucial role in the chicken industry. At present, large-scale chicken farms in China mainly adopt a full in and full out epidemic prevention system, and thoroughly disinfect the chicken coop environment after a batch of chickens is raised. Some breeders also use the chicken body spray disinfection method to carry out spray disinfection on chickens of different ages. This method has a killing effect on a variety of viruses, bacteria, and even spores, and has no adverse effect on the egg production rate and hatching rate of chicks, adult chickens, and egg laying breeders. Small scale chicken farmers do not disinfect their chickens and directly sell them to the market. Scientific disinfection methods require high standards, especially for the selection of disinfectants, which require broad-spectrum, high efficiency, strong bactericidal effect, low toxicity and irritation, and will not remain in meat or eggs.
Given the application of water electrolysis in the field of sterilization and disinfection, as well as its safe and rapid killing effect, this study explores the sterilization effect of water electrolysis on chicken feathers under laboratory conditions by soaking them in water electrolysis with different physical and chemical indicators, and proposes a safe and effective sterilization method, which has important practical significance.
1. Materials and Methods
1.1 Experimental Materials
The chicken feathers used in this experiment were purchased from a regular agricultural market and stored at a constant temperature of 4 ℃ in a refrigerator. No sterilization treatment was performed before the experiment, and the bacteria in the feathers were kept as they were.
1.2 Test Method
This experiment was conducted in June 2011 at the Key Open Laboratory of Facility Agriculture Engineering, Ministry of Agriculture, China Agricultural University.
1.2.1 Preparation of water electrolysis
Electrolyze a 0.9% HCl solution to obtain three groups of water electrolysis, numbered A, B, and C. Measure their pH value, effective chlorine concentration (ACC), and redox potential (ORP), and set deionized water as the control group CK, as shown in Table 1.
Table 1 Water and electricity splitting indicators for different treatments
| Group number | PH value |
ACC(mg/l)
|
ORP(mV)
|
|
A
|
6.98
|
12
|
825
|
|
B
|
6.90
|
15
|
830
|
|
C
|
6.82
|
20
|
838
|
|
CK
|
7.52
|
0
|
281
|
1.2.2 Sample Preparation
According to the "GB/T 10288-2003 Testing Method for Down Feathers", the bacterial content in feather samples is tested. Take two feather samples, each weighing 12g, and weigh them to the nearest 0.1g. Add 1200mL of peptone physiological saline to each sample and stir mechanically for 3 hours. Filter the solution through disinfectant gauze and mix the two original filtrates under sterile conditions. Take 200mL of the original filtrate and use it for bacterial colony counting.
1.2.3 Determination of colony count
Suck the original filtrate with a 1mL sterile pipette and slowly inject it into a test tube containing 9mL of diluent. Following this sequence of operations, perform a 10 fold incremental dilution and dilute to 7 gradients.
All colony counts in this experiment were performed using the coated plate method. Take 0.1 mL of gradient diluted bacterial solution, place it on the surface of a solidified sterile agar plate, and then evenly spread the bacterial solution on the entire plate with a glass rod. Incubate in a constant temperature incubator at (30 ± 1) ℃ for 72 hours for counting. Repeat twice for each dilution.
1.2.4 Colony count
Select a plate with a colony count between 30 and 300 as the counting standard, and calculate the average of two plates at the same dilution. The total number of bacteria per gram of sample is obtained by multiplying the bacterial count by the dilution factor.
1.2.5 Preparation of bacterial suspension
Select 4 feathers of similar size, shape, and color, each weighing 5g. Treat each feather with 100mL of A, B, C, and CK liquids at room temperature for 10 minutes, then immerse the feathers in 10mL of termination solution for 1 minute and shake with an electric mixer.
1.2.6 Bacterial Sterilization Experiment
The bacterial sterilization test of feathers by water electrolysis was conducted according to the test method in the "Disinfection Technical Specification" issued by the Ministry of Health in 2009.
Take 0.5mL of various bacterial suspensions and add 4.5mL of phosphate buffer solution (0 Mix 1% sodium thiosulfate+0.07% lecithin, which has been proven to be an effective neutralizing agent for water electrolysis, with an electric mixer for 20 seconds and dilute continuously 7 times. Take 0.1mL of each dilution of bacterial suspension and evenly spread it onto the bacterial culture medium. Place the bacterial culture medium in a 37 ℃ constant temperature incubator and incubate for 24 hours before counting [12].
1.2.7 Fungal sterilization experiment
The bacterial sterilization test of leafy vegetables by water electrolysis was conducted according to the test method in the "Disinfection Technical Specification" issued by the Ministry of Health in 2009. Take 1mL of each dilution of bacterial suspension and pour it into a culture dish. Then pour 15mL of fungal culture medium into the culture dish and mix well. After cooling, place the fungal culture medium in a constant temperature incubator at 28 ℃ for 48 hours and count.
1.2.8 Odor determination
Odor is often one of the distinguishing features of feathers from other sterilization objects. Primitive chicken feathers generally have a putrid odor. The odor measurement in this experiment was carried out using a fixed temperature dry olfaction method [11].
Mix the untreated and sterilized samples evenly, divide each group into two parts, and loosely place them in an odor free sealed container for one day to use. Clean the 1000 mL wide mouthed bottle with distilled water, dry and cool it for later use. Weigh 10 g each from two loose samples of feather fluff that have been stored for a day, place them in two processed wide mouthed bottles, and cap them. Place the sample bottle in a constant temperature chamber, dry at 50'C for 1 hour, and then remove and cool to room temperature. Open the bottle cap in a odorless environment, smell the odor, and describe the intensity of the odor level in words.
2. Results and Analysis
2.1 Sterilization effect
After soaking chicken feathers in water electrolysis with different physical and chemical indicators for 10 minutes of sterilization treatment, the water electrolysis with different physical and chemical indicators has a certain bactericidal effect on the fungi on the surface of the feathers.
The bactericidal effect of slightly acidic water electrolysis is related to the oxidation-reduction potential and effective chlorine concentration. The C group with higher oxidation-reduction potential has the best bactericidal effect in water electrolysis, supporting the oxidation-reduction potential theory, electron motion theory, and electrical conductivity theory proposed by Beck in 1960 [13]. At the same time, Group C has a higher effective chlorine content in water electrolysis, which strongly supports the chemical theory that the most important factor for water electrolysis sterilization is its complex chemical factors, including hypochlorous acid, hydrogen peroxide, and OH - [14].
Experimental results have shown that alkaline water electrolysis with high pH, low oxidation-reduction potential, and low effective chlorine also exhibits significant bactericidal effects. Analyzing the reasons, it may be due to the physiological metabolism of the chicken body. The surface of most feathers is in a slightly acidic environment, and soaking in alkaline water electrolysis changes the surface acidity and alkalinity environment, thereby inhibiting the growth of some fungi. This also confirms that individual physical or chemical theories cannot effectively explain the sterilization mechanism of water electrolysis, and the sterilization effect of water electrolysis is likely to be the result of multiple factors working together [15].
However, overall, acidic water electrolysis with lower pH value, higher effective chlorine concentration, and higher oxidation-reduction potential has better sterilization effect. Group C water electrolysis has 1.63% and 1.70% higher killing rates for bacteria and fungi than Group B water electrolysis, and 8.56% and 11.40% higher than Group A water electrolysis, respectively. Whether it is bacteria or fungi, the C group has the best water electrolysis sterilization effect.
2.2 Odor detection
After soaking chicken feathers in water with different physical and chemical indicators for 10 minutes of sterilization treatment, the deodorization effect is shown in Table 2.
Table 2 Deodorization effect of water electrolysis on feathers
According to the "GB/T 10288-2003 Testing Method for Down Feathers", the bacterial content in feather samples is tested. Take two feather samples, each weighing 12g, and weigh them to the nearest 0.1g. Add 1200mL of peptone physiological saline to each sample and stir mechanically for 3 hours. Filter the solution through disinfectant gauze and mix the two original filtrates under sterile conditions. Take 200mL of the original filtrate and use it for bacterial colony counting.
1.2.3 Determination of colony count
Suck the original filtrate with a 1mL sterile pipette and slowly inject it into a test tube containing 9mL of diluent. Following this sequence of operations, perform a 10 fold incremental dilution and dilute to 7 gradients.
All colony counts in this experiment were performed using the coated plate method. Take 0.1 mL of gradient diluted bacterial solution, place it on the surface of a solidified sterile agar plate, and then evenly spread the bacterial solution on the entire plate with a glass rod. Incubate in a constant temperature incubator at (30 ± 1) ℃ for 72 hours for counting. Repeat twice for each dilution.
1.2.4 Colony count
Select a plate with a colony count between 30 and 300 as the counting standard, and calculate the average of two plates at the same dilution. The total number of bacteria per gram of sample is obtained by multiplying the bacterial count by the dilution factor.
1.2.5 Preparation of bacterial suspension
Select 4 feathers of similar size, shape, and color, each weighing 5g. Treat each feather with 100mL of A, B, C, and CK liquids at room temperature for 10 minutes, then immerse the feathers in 10mL of termination solution for 1 minute and shake with an electric mixer.
1.2.6 Bacterial Sterilization Experiment
The bacterial sterilization test of feathers by water electrolysis was conducted according to the test method in the "Disinfection Technical Specification" issued by the Ministry of Health in 2009.
Take 0.5mL of various bacterial suspensions and add 4.5mL of phosphate buffer solution (0 Mix 1% sodium thiosulfate+0.07% lecithin, which has been proven to be an effective neutralizing agent for water electrolysis, with an electric mixer for 20 seconds and dilute continuously 7 times. Take 0.1mL of each dilution of bacterial suspension and evenly spread it onto the bacterial culture medium. Place the bacterial culture medium in a 37 ℃ constant temperature incubator and incubate for 24 hours before counting [12].
1.2.7 Fungal sterilization experiment
The bacterial sterilization test of leafy vegetables by water electrolysis was conducted according to the test method in the "Disinfection Technical Specification" issued by the Ministry of Health in 2009. Take 1mL of each dilution of bacterial suspension and pour it into a culture dish. Then pour 15mL of fungal culture medium into the culture dish and mix well. After cooling, place the fungal culture medium in a constant temperature incubator at 28 ℃ for 48 hours and count.
1.2.8 Odor determination
Odor is often one of the distinguishing features of feathers from other sterilization objects. Primitive chicken feathers generally have a putrid odor. The odor measurement in this experiment was carried out using a fixed temperature dry olfaction method [11].
Mix the untreated and sterilized samples evenly, divide each group into two parts, and loosely place them in an odor free sealed container for one day to use. Clean the 1000 mL wide mouthed bottle with distilled water, dry and cool it for later use. Weigh 10 g each from two loose samples of feather fluff that have been stored for a day, place them in two processed wide mouthed bottles, and cap them. Place the sample bottle in a constant temperature chamber, dry at 50'C for 1 hour, and then remove and cool to room temperature. Open the bottle cap in a odorless environment, smell the odor, and describe the intensity of the odor level in words.
2. Results and Analysis
2.1 Sterilization effect
After soaking chicken feathers in water electrolysis with different physical and chemical indicators for 10 minutes of sterilization treatment, the water electrolysis with different physical and chemical indicators has a certain bactericidal effect on the fungi on the surface of the feathers.
The bactericidal effect of slightly acidic water electrolysis is related to the oxidation-reduction potential and effective chlorine concentration. The C group with higher oxidation-reduction potential has the best bactericidal effect in water electrolysis, supporting the oxidation-reduction potential theory, electron motion theory, and electrical conductivity theory proposed by Beck in 1960 [13]. At the same time, Group C has a higher effective chlorine content in water electrolysis, which strongly supports the chemical theory that the most important factor for water electrolysis sterilization is its complex chemical factors, including hypochlorous acid, hydrogen peroxide, and OH - [14].
Experimental results have shown that alkaline water electrolysis with high pH, low oxidation-reduction potential, and low effective chlorine also exhibits significant bactericidal effects. Analyzing the reasons, it may be due to the physiological metabolism of the chicken body. The surface of most feathers is in a slightly acidic environment, and soaking in alkaline water electrolysis changes the surface acidity and alkalinity environment, thereby inhibiting the growth of some fungi. This also confirms that individual physical or chemical theories cannot effectively explain the sterilization mechanism of water electrolysis, and the sterilization effect of water electrolysis is likely to be the result of multiple factors working together [15].
However, overall, acidic water electrolysis with lower pH value, higher effective chlorine concentration, and higher oxidation-reduction potential has better sterilization effect. Group C water electrolysis has 1.63% and 1.70% higher killing rates for bacteria and fungi than Group B water electrolysis, and 8.56% and 11.40% higher than Group A water electrolysis, respectively. Whether it is bacteria or fungi, the C group has the best water electrolysis sterilization effect.
2.2 Odor detection
After soaking chicken feathers in water with different physical and chemical indicators for 10 minutes of sterilization treatment, the deodorization effect is shown in Table 2.
Table 2 Deodorization effect of water electrolysis on feathers
| Group number | Strength grade | Degree | Describe |
|
A
|
1
|
Extremely weak | Not easily noticeable |
|
B
|
0
|
Odorless | No odor at all |
|
C
|
0
|
Odorless | No odor at all |
|
CK
|
3
|
Obvious | Highly noticeable |
3. Conclusion
In the experiment, the most significant bactericidal effect was observed in acidic water electrolysis with pH values of around 6.8, ORP of around 840mV, and ACC of around 20 mg/l in each group.
The bactericidal effect of water electrolysis on feather bacteria and fungi is basically the same, and there is no difference in effect due to different sterilization targets.
Micro acidic water electrolysis has a good bactericidal effect on bacteria and fungi on the surface of feathers. After soaking feathers in slightly acidic water for 10 minutes, the number of surviving bacteria on their surface can be reduced by more than 80%. And after soaking the feathers in water electrolysis, there will be no significant damage to their surface, no significant change in appearance color, and a significant reduction in odor.
In the experiment, the most significant bactericidal effect was observed in acidic water electrolysis with pH values of around 6.8, ORP of around 840mV, and ACC of around 20 mg/l in each group.
The bactericidal effect of water electrolysis on feather bacteria and fungi is basically the same, and there is no difference in effect due to different sterilization targets.
Micro acidic water electrolysis has a good bactericidal effect on bacteria and fungi on the surface of feathers. After soaking feathers in slightly acidic water for 10 minutes, the number of surviving bacteria on their surface can be reduced by more than 80%. And after soaking the feathers in water electrolysis, there will be no significant damage to their surface, no significant change in appearance color, and a significant reduction in odor.
