Nanosilver application in sterilization of incubators
The purpose of this study is to use a suspension of nanosilver particles with a wide particle size spectrum, variable morphology, high stability and suitable physical and chemical properties to test the bactericidal and fungicidal properties of these against microorganisms found in poultry processing plants. At the same time, the particles have been tested to prevent the production of odor-causing pollutants during the incubation and thus to reduce harmful gas emissions from those vehicles. The results show that the use of nano inoculants for egg sterilization and incubators reduces microbiological contamination. The bactericidal and fungicidal effect of the applied preparation is equivalent to UV radiation and its effectiveness is increased during the incubation. Good results were obtained for the levels of organic gas contaminants, which were reduced by 86% after the application of nano inoculants.
(Copyright by NanoCMM Technology)
Poultry production and related chicken incubation processes, based on their technology of production on biological materials, are a source of microbiological contamination, including their microorganisms and their toxins. These factors are among the constituents of bioaerosols, especially organic dust. They are expelled through a ventilation system and maintained at as high as one kilometer from the source of the emissions. Many avian diseases, including respiratory infections, are transmitted through the air over long distances, even to locations 3 km away from formation.
The study was performed by Skorska et al. Poultry processing plants in the 1990s showed high levels of pollution in the hatchery. The average concentration of microorganisms in the air exceeded 37,000 cfu / m3 and increased to 310,000 cfu / m3 when the chicks were taken out. Today, even new technologies introduced for modernized plants at the request of the European Union do not completely eliminate biological air pollution. Research by Tymczyna et al. demonstrated that the average airborne bacterial concentration of a hatchery was up to 4,000 cfu / m3. In bioaerosol from the hatchery, a relatively high proportion (16%) of gram-negative bacteria was observed, and the following types of bacteria were identified: Acinetobacter, Citrobacter, Enterobacter, Escherichia, Flavobacterium, Klebsiella , Pseudomonas, Pseudomonas, Xanthomonas, Agrobacterium and Pantoea.
In chicken hatcheries, the gram-negative Acinetobacter calcoaceticus stick accounts for about 40% of all bacterial strains and is one of the most important sources of endotoxins in the air. Alcaligenes faecalis, Erwinia Herbicola, Enterobacter spp., And Pseudomonas spp. are other sources of endotoxins in the air. In certain cases, some species of Gram negative bacteria that are capable of causing infectious diseases, such as Klebsiella pneumoniae that causes pneumonia or Salmonella sticks that are the cause of salmonella infection, can enter. gas. Another microorganism observed in the chicken hatchery is Alcaligenes faecalis, which exhibit endotoxin and allergic properties.
Of particular note is the gram-negative bacterium of Erwinia Herbicola (synonyms: Pantoea agglomerans and Enterobacter agglomerans), which is a potent source of allergies and endotoxins. Bacteria of the genus Pantoea are the most abundant gram-negative microorganisms in bio-dust of plant origin. The gram-negative rods Alcaligenes faecalis and Erwinia Herbicola, due to their ability to activate both specific and nonspecific immune systems, can cause inflammation in the lungs and cause respiratory system diseases (toxicosis syndrome). organic dust) [1. In the study done by Stępien-Py ´ ´ sniaket al. , among the most frequently isolated bacteria in the family Enterobacteriaceae, Escherichia coli, Enterobacter spp., Klebsiella spp., And Citrobacter freundii were identified.
On the eggshell surface, the presence of Salmonella sticks, ie S. enteritidis and S. arizonae, was observed. Qualitative analysis of the egg’s microbiota also showed the presence of other gram-negative bacteria: Acinetobacter spp., Pseudomonas spp., Pseudomonas spp., Tatumella ptyseos, Providencia stuartii, Rahnella aquatilis, Proteus mirabilis and Achromobacter spp. . Furthermore, it was demonstrated that a high proportion of the eggshell under examination was contaminated with bacteria of the genus Staphylococcus spp. In addition to staphylococci, Enterococcus spp. and the rods of the genus Bacillus are usually isolated from the surface of the eggshell. Microbiological contamination of eggshell can cause contamination of egg products or egg products and, therefore, can lead to food poisoning or infection in humans. This is mainly the result of non-compliance with hygiene standards. Therefore, the microbiological purity of the eggshell is one of the main criteria for evaluating the value of this product in marketing and processing [10, 11].
In addition to microbiological contaminants in poultry production, a wide range of derived chemicals result from metabolic changes in embryonic development (inside the egg). The gaseous atmosphere of the embryo is an extremely important factor during the incubation process, especially during the first 96 hours. During the period of 38 to 48 hours of embryogenesis, growth of the ureter occurs, a vascular band develops on the umbilical sac and all organs begin to develop. If any organs fail to develop due to metabolic disturbances or the effects of toxic substances, a lethal disorder in the fetal circulation occurs, resulting in the formation of a blood clot in the membrane. Until day 8 of the incubation period, the umbilical sac and the urinary vessels act as respiratory organs. Pulmonary respiration occurs slowly, during umbilical sac retraction during the final stage of incubation. During this stage, the gaseous compounds can cross the eggshell barrier in both directions, causing embryonic development and decomposition disorders [1, 8]
In the hatchery air, in addition to ammonia, hydrogen sulfide, mercaptans, aldehydes and ketones, high concentrations of acrolein, acetaldehyde and mainly formaldehyde, mainly used for room sterilization, were detected. Other gases, such as p-tolualdehyd, benzaldehyd, isovaleric and butyl aldehyd, are present in relatively small amounts. It has been demonstrated that 1 m3 of air contains an average of 7.7 g of organic gas pollution.
The adverse effects of acetaldehyde are manifested in its addictive effects on the central nervous system, irritation of the skin and mucous membranes, lowering blood pressure and tachycardia. Likewise, acrolein is a mucosal and conjunctival irritant. It has a quick and direct effect on the respiratory tract. In the hatchery hall, the presence of benzaldehyd, a slime with a characteristic odor of bitter almonds, was also detected. In humans, benzaldehyde causes mucosal irritation and, when inhaled in large quantities through the respiratory tract, causes symptoms of allergy and central nervous system disturbances, and has also been associated with cytostatic and carcinogenic effects. letters. In previous research, it was demonstrated that the concentration of these selected compounds is lower than the TLV (threshold value) for air.
However, toxic gases are still potentially harmful, since these pollutants can affect the organism independently; they may neutralize their actions or increase mutual adverse effects [1-10]. The number of chemical products used for disinfection in food processing is limited due to the negative effects of these compounds on the human body and due to difficulty in solubility and applicability. direct. Furthermore, the eco-friendly lifestyles of many consumers force the food technology to use only naturally occurring chemical compounds. Among the favorite additives that spoil microbiota, organic acids.
The number of chemical products used for disinfection in food processing is limited due to the negative effects of these compounds on the human body and due to difficulty in dissolving and direct applicability. continued. Furthermore, the eco-friendly lifestyles of many consumers force the food technology to use only naturally occurring chemical compounds. Among the favored additives that spoil the microbiota, their organic acids and their salts, are generally considered safe.
Citric acid belongs to this group and is approved for use in the food industry. Studies involving microbial destruction have been carried out by a variety of methods, using a variety of chemical compounds including organic acids, hexadecylpyridinium chloride, sodium orthophosphate, hydrogen peroxide and sodium bicarbonate. Not all of these methods are effective, so there is a need to constantly look for effective methods of killing bacteria and fungi. Formaldehyde is often used in hatcheries because of its low cost and effective bactericidal effect, with little attention to its toxic and carcinogenic effects [1-10].
This compound is capable of damaging most microorganisms that exist on the outer shell. It is used either as a gas or as a 40% solution called formalin. Formaldehyde is an easy and effective disinfectant that is irritating to the eyes and mucous membranes of the respiratory system. It is a potent protoplasmic toxin, causing degenerative changes to the liver, kidney, and heart parenchymal cells. In the eye, degenerative changes not only affect the retina, but also the optic nerve and corneal epithelium. The silver nanoparticles, which, according to the literature, show good bactericidal properties, could be an alternative. Proposed inoculants could also be an effective means of neutralizing gas pollutants generated during incubation [12 shallow14]. Due to its bactericidal properties, nano-silver has become an important and valuable commercial product in the food industry (e.g., food packaging and containers), the clothing industry (e.g. for example, antibacterial clothing), the medical profession (eg, bandages), and others [15-17].
Nanosilver particles are effective damaging factor for a wide range of gram-negative and gram-positive bacteria, not excluding antibiotic-resistant strains . Gram-negative bacteria included genera Acinetobacter , Escherichia , Pseudomonas , Salmonella and Vibrio , while gram-positive bacteria included genera such as Bacillus , Clostridium  ], Enterococcus , Listeria , Staphylococcus  and Streptococcus . Antibiotic resistant bacteria are often resistant to metacycline and vancomycin, including some strains of Staphylococcus aureus and Enterococcus faecium. Recent research has shown that silver nanoparticles with a diameter of 22.5 nm increase the antibacterial activity of several antibiotics, such as penicillin G, amoxicillin, erythromycin, clindamycin and vancomycin . Many recent studies have revealed very promising properties of nanosilver against viruses, even HIV-1 viruses. Sun et al. It was observed that silver nanoparticles inhibited viral replication [30, 31]. Applying nanosilver to kill the fungus also gave satisfactory results. Studies have confirmed that silver nanoparticles are an effective and fast factor against many common fungi, including genera such as Aspergillus , Candida  and Saccharomyces . Furthermore, it was demonstrated that silver nanoparticles showed pronounced activity against yeast isolated from infected cow udders . Silver nanoparticles have been used in livestock production as a disinfectant used to sanitize transport chambers or the spaces used to store animals. Studies were performed to determine ammonia emissions from sheep manure after applying inoculants based on silver nanoparticles with the addition of mineral sorbents. It was concluded that the use of inoculants resulted in a reduction in ammonia emissions from the ground . The aim of this study is to develop methods of obtaining suspensions of nanosilver particles with a wide spectrum of particle size and morphology, with high stability and suitable physical and chemical properties, as well as testing of their bactericidal and fungicidal agent against microorganisms found in poultry processing plants. At the same time, the particles have been tested for their ability to prevent the generation of odor-causing pollutants during incubation, thereby leading to a reduction in toxic gas emissions from this facility type. Thus, it can prevent odor generation at its source.
2. MATERIALS AND METHODS
2.1. Features of silver nanoparticles.
The process of obtaining nanostructured silver using silver deionizing chemicals has been studied. Silver nitrate (V) (POCh, p.a. grade) is used as a source of silver ions. To reduce Ag + ions, L (+) ascorbic acid (POCh, pa grade) or glucose (POCh, pa grade) was used, while sodium pyrophosphate (POCh, pa grade), gelatine (POCh, pa grade) , or sodium tripolyphosphate (SIGMA ALDRICH, pa grade) is responsible for stabilizing the formation of metallic silver coagulants. A NaOH (0.1 M) solution was used for pH adjustment. The application of these matrices allows to reduce the use of toxic substances in the nanosilver synthesis, making the process environmentally friendly and consistent with green chemistry principles. A PARR 4525 pressure reactor was used in the process. An aqueous solution of stabilizer (50,0 cm3) was added to an aqueous solution of AgNO3 (100,0 cm3; 0.001 mol / dm3). The solution is heated in a reactor to 110-150∘C. After the set temperature is reached, an aqueous solution of the reducing agent (50,0 cm3) is added to the reactor by pump. Reducing reaction is carried out in 2-30 minutes. The process parameters for obtaining silver nanoparticles are summarized in Table 1.
Spectral analysis (UV-Vis) of the nanoparticle suspension was performed on the RAYLEIGH UV-1800 spectrophotometer in the range from 300 to 600 nm with 2 nm resolution. Size determination of the obtained nanoparticles was performed by dynamic light scattering technique (DLS) with Zetasizer Nano-ZS particle size analyzer. This device is also used to study the value of the electrodynamic potential (𝜁). The obtained silver nanoparticles were displayed using an atomic force microscope (AFM) on the NanoScope V device (Veeco Company, USA). The powder form of the product, obtained by centrifugation (90000 rpm) using a microultracentrifuge Thermo Science Sorvall MX 150 with the S140A rotor, is featured with the use of a scanning electron microscope, performed on a VP LEO 1430 device (Electron microscopy Ltd.). The UV-Vis absorption spectrum of the obtained nano-suspension is shown in Figure 1. The peak at 400-450nm corresponds to the characteristic surface plasmon resonance of silver nanoparticles. Surface plasmons are the combined vibrations of the valence electrons of the atoms present on the surface of the material.
The absorption of radiation by metal nanoparticles is mainly dependent on their size and shape. The asymmetric plasmon assembly means that the solutions contain synthetic particles. This has been confirmed by atomic force microscopy images in Figure 2. The resulting UV-Vis absorption bands are very wide, right deflection (with absorption tail at longer wavelengths), possibly leading to The size distribution of the nanoparticles is shown in Figure 3 The plasmon resonance intensity depends on the size of the synthetic particles and therefore the relationship between the particle number and the absorption intensity is nonlinear. Average particle size, kinetic potential and shape are summarized in Table 1.
Figure 1: Absorption spectrum for a corresponding nanosilver particle suspension (diluted to 50 mg/dm3)
2.2. Evaluation of the bactericidal and fungicidal properties of Nanosilver.
Evaluation of the antiseptic properties of nano-preparations, differing in particle size and morphology, was carried out in two stages. In the first phase, a test tube method was used, in which three preparations with the best bactericidal and fungicidal properties were selected. In the second phase, assessments are performed by dilution neutralization, according to PN-EN1040 and PN-EN1275. On the basis of the results obtained, the preparation of the best bactericidal and fungicidal properties was chosen. Five strains of microorganisms obtained from the American Type Culture Collection (ATCC) were used in this study: Escherichia coli 25922, Pseudomonas aeruginosa ATCC 27853, Salmonella enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923 and Candida albicans ATCC 10231.
2.2.1. Test tube suspension method.
A 0.5 test bacterial suspension on the McFarland scale was diluted in sterile distilled water to yield − 1, 𝑍 − 2, and 𝑍 − 3 dilutions. Then, 1 cm3 of bacterial suspension from vi-2 was added to each of the eight tubes containing 9.0 cm3 of nano inoculants (numbered 1 to 8).
A 𝑍-3 suspension was used as the control. Contact time between bacterial suspension and product up to 5 minutes and 30 minutes. Then, 0.1 cm3 samples were taken from each test tube and inoculated into a suitable agar matrix (MacConkey, TSA, SS or Sabouraud). After 24 h of incubation at 37∘C, colonies were counted. The reduction rates for each strain preparation and inspection were calculated relative to the control sample.
2.2.2. Dilution-neutral method.
Before the experiment, the microorganism strains tested were enriched on a suitable agar substrate for 24 hours at 37∘C. After incubation, a suspension of microorganisms from the obtained culture medium is prepared in sterile distilled water, to achieve a cell concentration of about 1.5 × 108 to 5 × 108 cfu / cm3 for microorganisms. bacteria and 1.5 × 106 cfu / cm3 for C.albicans. A series of decimal dilutions is prepared from the suspension obtained, and then 0.1 cm3 of a microbiological suspension from the last four dilutions is inoculated into two dishes with a suitable agar medium for determination. the exact number of cells in the initial suspension. At the same time, a neutralizing solution is prepared by adding 1.0 cm3 of sterile distilled water to 8.0 cm3 of the neutralizer. Suspended cells from 𝑍-1 with a volume of 1.0 cm3 were transferred to three tubes containing 9.0 cm3 of suspension supplemented with silver nanoparticles. After the specified exposure time has elapsed, the action of the preparation under study was neutralized by converting 1,0 cm3 of the bacterial suspension in the composition into 9.0 cm3 of a pre-prepared neutralization mixture. there and distilled water. After 5 min of neutralization, 0.1 cm3 of the suspension from the neutralizer is transferred to two Petri plates with a suitable agar medium. Experiments were carried out in 5, 15, 30 and 60 minutes of contact between microorganisms and nano products. Neutralization is done by creating four mixtures: 8.0 cm3 of neutralizer, 1.0 cm3 of sterile distilled water and 1.0 cm3 of a microorganism suspension tested from 10−5 dilution, while the remaining three mixtures contain 8.0 cm3 of the neutralizer, 1.0 cm3 of the inoculant studied and 1.0 cm3 of the microorganism suspension tested from dilution. dilute 10−5. Two plates with suitable agar medium are performed from each test tube (0.1 cm3). All plates were incubated at 37∘C for 24 hours. Then, all colonies that formed on the medium, in numbers between 15 and 300, were calculated to assess the viable bacterial count [cfu].
2.3. Evaluate the sterilization efficiency of the nanosilver incubator.
Eggs from a Polish breed called blue-footed hen were selected for the study. The test group (Group D) consisted of eggs that were sterilized with nanotubes before introducing them into the incubator (Incubator D). The control group (Group K) consisted of eggs that were sterilized by UV radiation for 30 minutes before introducing them into the incubator (K Incubator). In the test group, the incubator and the eggs were blurred with a nanoparticle. In both groups, the disinfection efficiency was assessed based on the microbiological analyzes of the egg surface and the incubator. Analyzes were performed before (series I) and 30 minutes after sterilization (series II). During the incubation period, experiments were performed three times, i.e. after day 1 (series III) and day 7, on day of incubation (series IV) and on day 17, before initiation of hatching ( series V). Microbiological analysis of the egg surface and incubator included the determination of the total number of bacteria, the total number of Staphylococcus and the total number of fungi. Eggs / embryos were collected in sterile containers and covered with 50,0 cm3 of sterile distilled water with Tween 80. After 15 minutes of shaking, the culture was carried out from the rins obtained using the above surface plating technique. suitable medium (Table 2) and incubated for 24 hours at 37∘C (bacteria) and for 5 days at 25∘C (fungi). After incubation, the number of surface microorganisms [cfu / eggs] were counted, based on the number of colonies. Magnetic stains of incubators The paintings were collected from an area of 10.0 cm2 using sterile samples and sterile cotton swabs (Copan, Italy). After collection, the smear was placed in transport tubes containing 20,0 cm3 of brine. The collected samples were shaken for 2 minutes. From the suspension obtained, the incubation was carried out on a suitable medium (Table 2) and incubated for 24 h at 37∘C (bacteria) and for 5 days at 25∘C (fungi). After incubation, the number of microorganisms on the incubator wall [cfu / 10 cm2] was calculated, based on the number of colonies.
2.4. The effect of silver nanoparticles on gas pollutant concentration is generated during the annealing process.
Gas composition assessments of sterilized incubators were performed in parallel with microbiological analyzes. Air samples were collected from the experimental device (Nano Incubator) and the control device (UV Incubator) before and 30 minutes after sterilization. During the incubation period, experiments were performed three times, i.e. after day 1 (series III) and day 7-on day of incubation (series IV) and on day 17, before initiation of hatching (series V). Concentrations of volatile organic compounds (VOCs) and inorganic compounds, especially sulfur compounds with strong odor-producing properties, were determined in the air samples collected. The organic air pollutants are determined by gas chromatography. Air samples were collected using an electric pump into a 2-3 liter Tedlar bag (Sensidyne Inc., Clearwater, USA). Organic compounds present in air samples are condensed and then desiccated with a desiccant device (TDV; Model 890, Dynatherm, Analytical Engine Inc., Oxford, USA) for the chromatic system. The gas sign (HP 5890 series II, Hewlett Packard, Santa Clara, USA) is equipped with a selective flame photometric probe (FPD) combined with an S filter with a wavelength of 393 nm. Determination of the inorganic compound content in the samples drawn into the effervescent washers was performed by ion chromatography using liquid chromatography (Waters) connected to the analytical column (IC-PAK Anion HR , Waters Corp, Milord, USA) Conductivity probe and UV indicator.
Bảng 3: Phần trăm giảm lượng vi sinh vật so với mẫu đối chứng cho các chế phẩm nano được thử nghiệm
Bảng 4: Số lượng tế bào vi khuẩn và nấm phát triển sau năm phút tiếp xúc với nano bạc so với nhóm đối chứng.
3. RESULTS AND DISCUSSION OF NANOSILVER RESEARCH
3.1. Bactericidal properties of nanosilver
On the basis of microbiological analysis (Table 3) conducted by a test tube method, the three most effective nano preparations, number 6, 7 and 8, were selected. The preparations in question experienced a high reduction after only 5 minutes of exposure (Table 4). Suspensions containing particles approximately 10 nm in size, stabilized with sodium pyrophosphate, have demonstrated the strongest bactericidal and fungicidal activity. The key property influencing the effectiveness of the preparations under study is the size of the nanosilver particles and the compounds used to stabilize the nanometer structure. Sodium phosphate dissociates in water, leading to the formation of phosphate anions adsorbed onto the surface of metal particles and preventing their agglomeration by surface charge of stable particles. The result is a negative high Zeta potential.
In other preparations a similar reduction was achieved only after extending the exposure time to 30 minutes (Table 5). Preparation No. 1, containing smaller nanoparticles (8nm), demonstrated weaker bactericidal activity against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus compared to preparations 6, 7 and 8. This may be the result of results of the electrophoresis potential. Effects on the cell membrane of the microorganisms under test, as well as a strong chemical stability is achieved due to the application of gelatine and, therefore, limited the ability of silver nanoparticles to act directly. Gelatine is a protein that, at high temperatures, breaks down its collagen bonds. A colloidal system is then formed, in which the stability of metal particles is facilitated. At that time, spherical stability occurred; that is, protein chains, due to their complex structure, are an efficient space factor that prevents the agglutination of metal particles by surface adsorption. It was found that the preparations containing nanosilver particles about 50 nm in size, stabilized with gelatine (preparations 2 and 3), showed the weakest antimicrobial effect. S. aureus was the most resistant of all the tested inoculants among the microorganisms tested, while the C.albicans yeast was the most sensitive.
The results of the evaluation of the bactericidal and fungicidal properties of nano preparations 6, 7 and 8, performed by dilute neutralization method (PN-EN 1040 and PN-EN 1275), are summarized in Table 6. -8. In accordance with the requirements contained in the aforementioned standards, a preparation meets the requirements of the basic bactericidal and fungicidal action when it reduces the viable bacteria 105 times and reduces 104 times or more in the case of fungi, under specific test conditions, for 60 minutes or less. Based on the results presented, it can be concluded that all of the preparations achieved the reduction required for the majority of studied strains after only 60 minutes of exposure. After 60 minutes of exposure, the preparations studied achieved 105-fold reductions for the majority of strains. This condition did not refer only to the gram-positive bacterium S. aureus, which in the case of in vitro evaluation was shown to be able to resist the strongest effects of silver nanoparticles. Suspension number 6 achieved the required reduction after only 15 minutes in the case of C. albicans enzymes (Table 6). A similar result for the same strain was obtained in case of preparation # 7 (Table 7), but the strongest bactericidal action was shown with suspension number 8 (Table 8). After 30 minutes of exposure, desirable reductions were observed for C. albicans, P. aeruginosa and S. enteritidis. The remaining two preparations (6 and 7) showed antiseptic action during this time against only S. enteritidis. On the basis of these results, preparation number 8 was chosen for application testing.
Table 6: Results of dilution-neutral assessment of suspension # 6.
Table 7: Results of dilution-neutral assessment of suspension # 7.
Table 8: Results of dilution-neutral assessment of suspension # 8.
3.2. Test the application.
In this part of the study, significant microbiological contamination of eggshell designed for incubation (Table 9) was observed. On the surface of the eggs, the average total bacteria amounted to 9.8 × 104 cfu / egg, while the average number of fungi was 2.1 × 102 cfu / egg. Therefore, maintaining microbiological purity is possible with proper sterilization of the eggs and incubators. In these trials, the efficacy of silver preparation was studied in the case of total bacteria at levels similar to that of UV sterilization (Table 9). After 30 minutes, the number of bacteria on the control egg and on the nanosilver particle sterilized eggs reached × 104, while on day 2 of the incubation it was even greater than on the eggs treated with Preparations. Visible changes in total bacteria were observed on day 7 of incubation, when the average number of bacteria per control egg was almost six times higher than that of the experimental egg. On day 17 of incubation, a significant increase in the average bacterial count on the surface of all eggs was observed, compared with the previous incubation periods. The cause of this condition is probably secondary contamination as a result of the 7 day burning. The mean difference between the bacterial count on the control and the tested eggs is different and half. quantity on test egg. In the case of total Staphylococcus counts, the contamination remained at the same level as the total number of bacteria (Table 9). No difference in mean staphylococci counts was observed between control and test eggs until day 17 of incubation, when the presence of cocci was not detected on experimental embryos.
The total fungal count remained stable in the control and experimental eggs (Table 9). On day 17 of incubation, in both groups, the presence of fungi was not observed. These results indicate that the antiseptic activity of nano-silver against all the microbial groups studied was observed from day 7 of incubation. An increase in total number of microorganisms on day 7 of incubation may be linked to secondary contamination of the egg surface as a result of incubation.
Table 9: Microbiological contamination of eggs before and after nanosilver treatment [cfu/egg].
Table 10: Microbiological contamination on the wall of the incubator before and after the nano-silver treatment [cfu / cm2].
Before sterilization, a difference was found in the level of contamination of the incubators. The experimental incubator (nanosilver) was more severely contaminated with bacteria than the control incubator (UV) (Table 10). After 30 minutes of disinfection and incubation, contamination of the incubator (UV) increased, inevitably due to secondary pollution, whereas contamination of the experimental incubator (Nano Silver) was significantly reduced. On day 2 of incubation, mean bacterial contamination was reduced in both the control and experimental incubators, but the mean bacterial count in the experimental incubator was significantly lower than that of the control. On day 17, the average total bacteria per cm2 of the control incubator decreased, as did the number of bacteria in the experimental incubator. The total number of Staphylococcus is low and fluctuating, possibly a result of secondary pollution from the air (Table 10).
The total fungal population exhibited a decreasing trend during the incubation period. The significant difference between the control and the experimental Incubator continued from the start of incubation to the 17th day. On the basis of the mean total bacteria count and the total number of fungi, it can be said that the nanocomposite is Research has demonstrated good bactericidal and fungicidal effects on the surface of the incubator. Variations in the staphylococci count can be explained by secondary contamination and may not be connected with the nanosilver activity.
Figure 4: VOC concentrations in the air inside the incubator during UV and nanosilver treatment during incubation [𝜇g / m3]
Very good results have been achieved in the case of organic gas pollutants VOCs. After applying nano inoculants, these levels decreased by 86% (Figure 4). During the 17-day incubation period, an increase in VOC levels was observed in both devices. At the end of the process, the level of contaminants in the air inside the UV Incubator is 40% higher than that of the NANO Incubator. Chromatographic studies did not demonstrate accumulation of inorganic compounds and sulfur compounds in the device (Figures 5 and 6). In the recent series of studies, the concentration of sulfur compounds in the air inside the UV and nanosilver Incubators was determined to be 11.0 𝜇g / m3 and 14.9 𝜇g / m3, respectively.
Figure 5: Concentrations of inorganic gas compounds in the air inside incubators under UV and nanosilver treatment during incubation [mg / m3]
Figure 6: Concentration of sulfur compounds in the air inside incubators under UV treatment and nanosilver during incubation [𝜇g / m3].
Among the identified VOCs, the highest concentrations in the UV Incubator were seen for 2-pentanamine (284.3 𝜇g / m3) and cyclobutanol (247.1 µg / m3), while There, in the NANO Incubator, the highest concentration was found for hexanal (255.4 µg / m3). In the nanosilver sterilized device, presence of 2-pentanamine, 2- methylpentane, 2-methyl-1-propanol, trichloroethylene, and toluene (Table 11) as well as sulfur compounds such as carbonyl sulphide (COS) and methyl mercaptan (Table 12) were not detected. The sterilization method applied had no effect on the levels of inorganic contaminants identified (Table 13).
Table 11: Concentrations as organic VOCs evaporated in the air inside the incubator on day 17 [𝜇g / m3].
Table 12 & Table 13: Sulfur and inorganic gas concentrations in the air inside the incubator on the 17th [𝜇g / m3].
According to current production standards, in most food industry plants, including the poultry industry, controls are required on the microbiological and chemical quality of the air and product surfaces. Export has already been put in place, which means cleanliness must be ensured. In chicks hatcheries, hatcheries constitute an important point because the temperature and humidity conditions as well as the presence of biological material within them pose a significant microbiological hazard. In such places, it is not without reason, that emphasis has been placed on maintaining microbial purity, which is achieved only by properly sterilizing eggs and eggs. Current research has demonstrated that nano inoculants applied to the sterilization of eggs and incubators reduce microbiological contamination. The preparation used showed bactericidal and fungicidal efficacy comparable to UV radiation and its efficiency increased during the incubation period. In the case of fungi, on day 7 of incubation, nanotube misting provides better protection of egg surface than UV irradiation.
Very good results have been obtained in the case of organic gas contaminants. After applying the nanosilver preparation, these levels were reduced by 86%. The level of contaminants in the air inside the incubator that was sterilized with ultraviolet light was 40% higher than in the nano-machine sterilized incubator. Proper incubation conditions during incubation are very important and lead to efficient hatching and healthy chicks. Aggressive metabolic processes and embryo respiration requires the air inside the incubator to contain a sufficient amount of oxygen. Exhaust gas during incubation must be removed from the device, because excessive amounts can lead to embryotoxicity and decomposition, so proper air exchange is important. Application of nanosilver can be used to optimize the annealing process. As this study shows, nanosilver cannot replace effective ventilation but can be a deterrent to air pollutants.
Reference: Nanosilver Biocidal Properties and Their Application in Disinfection of Hatchers in Poultry Processing Plants
Marcin Banach,1 Leszek Tymczyna,2
Anna Chmielowiec-Korzeniowska,2 and Jolanta Pulit-Prociak1
1Cracow University of Technology, Warszawska 24, 31-155 Krakow, Poland ´
2University of Life Sciences, Akademicka 13, 20-950 Lublin, Poland