Using a new video rating tool to crowd-source analysis of behavioural reaction to stimuli.

Quantifying the intensity of animals' reaction to stimuli is notoriously difficult as classic unidimensional measures of responses such as latency or duration of looking can fail to capture the overall strength of behavioural responses. More holistic rating can be useful but have the inherent risks of subjective bias and lack of repeatability. Here, we explored whether crowdsourcing could be used to efficiently and reliably overcome these potential flaws. A total of 396 participants watched online videos of dogs reacting to auditory stimuli and provided 23,248 ratings of the strength of the dogs' responses from zero (default) to 100 using an online survey form. We found that raters achieved very high inter-rater reliability across multiple datasets (although their responses were affected by their sex, age, and attitude towards animals) and that as few as 10 raters could be used to achieve a reliable result. A linear mixed model applied to PCA components of behaviours discovered that the dogs' facial expressions and head orientation influenced the strength of behaviour ratings the most. Further linear mixed models showed that that strength of behaviour ratings was moderately correlated to the duration of dogs' reactions but not to dogs' reaction latency (from the stimulus onset). This suggests that observers' ratings captured consistent dimensions of animals' responses that are not fully represented by more classic unidimensional metrics. Finally, we report that overall participants strongly enjoyed the experience. Thus, we suggest that using crowdsourcing can offer a useful, repeatable tool to assess behavioural intensity in experimental or observational studies where unidimensional coding may miss nuance, or where coding multiple dimensions may be too time-consuming.

The smoker's paradox during the COVID-19 pandemic? The influence of smoking and vaping on the incidence and course of SARS-CoV-2 virus infection as well as possibility of using nicotine in the treatment of COVID-19 - Review of the literature.

AIM OF THE STUDY: The study aims to present the current state of knowledge on the impact of traditional cigarettes and the nicotine contained in them on the incidence and course of SARS-CoV-2 infection. Moreover, we decided to exhibit the possibility of using this substance to treat COVID-19 infections. MATERIAL AND METHODS: The latest available scientific publications were reviewed until November 14, 2020, from the PubMed platform. RESULTS: Nicotine is a cholinergic agonist and pro-inflammatory cytokines inhibitor. Some authors present that smoking and nicotine reduce the amount of the ACE2 receptors which are used by the novel coronavirus to enter cells, while others claim that ACE2 receptors are upregulated in smokers. Moreover, the interaction of SARS-CoV-2 with nAChR is suspected of dysregulation of the nicotinic cholinergic system, which is associated with the pathophysiology of COVID-19. Due to the harmfulness of cigarettes, a high frequency of smokers is suspected among people suffering from COVID-19. However, some studies report that the number of current smokers hospitalized for SARS-CoV-2 infection is lower than expected, considering the prevalence of smoking in individual countries. Nicotine could restore the impaired function of the nicotine cholinergic system and possibly mitigate the cytokine storm. CONCLUSIONS: There is no clear attitude regarding the impact of smoking on the new coronavirus infection now. Researchers do not recommend smoking as a tool to combat the pandemic and show the importance of fighting addiction to reduce the adverse health effects of smoking. Both the relationship between cigarettes and the morbidity and severity of COVID-19, as well as the possibility of using nicotine in the treatment of the disease, require further analysis.

Preparation and of PVA-based compositions with embedded silver, copper and zinc oxide nanoparticles and assessment of their antibacterial properties.

A series of poly(vinyl alcohol) (PVA) based liquid compositions with addition of zinc oxide, silver and copper nanoparticles has been prepared. The compositions also contained other consistency-forming organic components. The physico-chemical properties of the products have been determined. Their pH and density have been assessed. Also, the size of nanoparticles has been defined with using a dynamic light scattering technique. The compositions were subjected to XRD, FT-IR and microscopic analysis as well. Thanks to the incorporation of both metal oxide and metallic nanoparticles, it was possible to enrich the products with antibacterial properties. Their inhibiting properties in the growth of microorganisms have been confirmed against both Gram-negative and Gram-positive strains such as E. coli, S. aureus and P. aeruginosa. Thanks to the ability for solidification, the compositions may be applied on a bacterially contaminated surface, and after destroying the microorganisms and its solidification, it may be peeled off along with the dead bacterial film.

The influence of vaccination against tuberculosis with the Bacillus-Calmette-Guérin(BCG) vaccine on COVID-19 incidence and mortality - review of the literature.

THE AIM OF THE STUDY: Is to present the state of knowledge from April and May 2020 about the influence of Bacillus-Calmette-Guérin vaccination against tuberculosis on incidence and mortality due to COVID-19. MATERIAL AND METHODS: A review of the latest literature till 9 May 2020 has been made. PubMed and ResearchGate databases and WHO reports were used. RESULTS: Immunomodulatory properties of the tuberculosis vaccine which protects against severe cases of tuberculosis and partly against other infections are indicated, including viral and respiratory infections. The BCG vaccine induces heterologous immunity and trained innate immunity. It was noted that in countries which maintain obligatory BCG vaccination COVID-19 incidence and mortality are lower than in countries that have stopped or never introduced BCG as mandatory vaccination. Most analysis confirmed this relationship, but they indicated the possible impact of other factors, such as genetics in the population, the type of strain from BCG vaccine, the level of health care and the wealth of a nation, the structure of migration, co-morbidities and a policy of introducing social distance. CONCLUSIONS: At the moment, we do not have enough evidence to support or deny the hypothesis of COVID-19 reduction in incidence and mortality in countries maintaining obligatory BCG vaccination. Other factors that might affect the results should be considered in further analysis. The results of clinical trials will provide more reliable proofs than analysis of epidemiological data. WHO does not recommend BCG vaccination to prevent COVID-19 and recommends it to newborns from areas with a higher incidence of tuberculosis.

Impact of level of vitamin D in the body on the severity of COVID-19 - review of the literature.

INTRODUCTION: The aim of the study is to present the current state of knowledge on the influence of vitamin D levels on the severity of the course of COVID-19. MATERIAL AND METHODS: The latest available literature was reviewed until October 30, 2020 from the PubMed database. RESULTS: The literature reports that vitamin D has immunomodulatory and anti-inflammatory effects. It reduces the expression of cytokines such as IL-6, TNF-α and INF-γ, regulates the activity of T helper lymphocytes, and other elements of the immune system at the molecular level. The deficiency of this vitamin promotes the activation of the renin-angiotensin-aldosterone system, contributing to the development of acute respiratory distress syndrome. The severity of the course of SARS-CoV-2 infection depends on comorbidities, the development and course of which may also be affected by vitamin D levels (coagulopathies, pulmonary, cardiological, metabolic diseases). Most of the analyzed research studies from different countries indicated a relationship between insufficient vitamin D levels and a more severe course of COVID-19 and an increase in mortality due to it, especially among the elderly. Researchers agree that further analyzes are necessary concerning both the influence of the vitamin D blood serum levels on the morbidity and mortality due to COVID-19 as well as the use of its supplementation in the struggle against SARS-CoV-2 virus. There are reports of possible beneficial interactions of vitamin D with other substances, such as quercetin, estradiol, some microelements, and other vitamins. CONCLUSIONS: Maintaining an adequate level of vitamin D has a positive effect on the functioning of the immune system. At the moment, there is insufficient evidence to establish a clear relationship between vitamin D levels and the severity of COVID-19. It is necessary to conduct further research on a larger study group. The literature does not mention the use of vitamin D as a medication for COVID-19. People at risk of vitamin D deficiency should consider vitamin D supplementation at the current time of the pandemic.

Staphylococcus aureus carriage state in healthy adult population and phenotypic and genotypic properties of isolated strains.

INTRODUCTION: At present, infections induced by staphylococci, especially methicillin-resistant Staphylococcus aureus (MRSA) are one of key therapeutic and epidemiological problems. AIM: The assessment of Staphylococcus aureus carrier state occurrence among a healthy adult population as well as determination of phenotypic and genotypic properties of the isolated strains. MATERIAL AND METHODS: The study included 100 healthy individuals. Material for bacteriological evaluation was collected from the posterior pharyngeal wall and tonsils, nasal vestibule and the skin of anterior nares using a sterile swab. The isolates identified as Staphylococcus aureus were analysed further, towards slime-forming capacity and the presence of genes mecA and nuc. RESULTS: The analysis included 300 samples obtained from the posterior vault of the pharynx and tonsils, nasal vestibule and the skin of nares. Pharyngeal and vestibular S. aureus carriage was determined in 20% of the examined adults, whereas in 11 people with recognized positive throat colonization, the concurrent presence of golden staph was detected in the vestibule of the nose and on the skin, in the nose region. Identification process indicated the occurrence of strains defective in clumping factor synthesis (5% of isolates) and lack of the coa gene (11% of examined isolates). The PCR technique used to screen for the presence of the mec gene, did not confirm it in any of the strains under study. All the isolates had the gene encoding the thermostable nuclease nuc. CONCLUSIONS: S. aureus is a pervasive pathogen in community settings with constantly changing trends.

Dogs perceive and spontaneously normalize formant-related speaker and vowel differences in human speech sounds.

Domesticated animals have been shown to recognize basic phonemic information from human speech sounds and to recognize familiar speakers from their voices. However, whether animals can spontaneously identify words across unfamiliar speakers (speaker normalization) or spontaneously discriminate between unfamiliar speakers across words remains to be investigated. Here, we assessed these abilities in domestic dogs using the habituation-dishabituation paradigm. We found that while dogs habituated to the presentation of a series of different short words from the same unfamiliar speaker, they significantly dishabituated to the presentation of a novel word from a new speaker of the same gender. This suggests that dogs spontaneously categorized the initial speaker across different words. Conversely, dogs who habituated to the same short word produced by different speakers of the same gender significantly dishabituated to a novel word, suggesting that they had spontaneously categorized the word across different speakers. Our results indicate that the ability to spontaneously recognize both the same phonemes across different speakers, and cues to identity across speech utterances from unfamiliar speakers, is present in domestic dogs and thus not a uniquely human trait.

Evaluating bioaerosol exposure among bus drivers in the public transport sector.

Occupational hazards and consequent health problems suffered by drivers in the public transport sector require preventive measures. The aim of this study was to assess the exposure of drivers to microbiological air contamination (airborne bacteria and fungi) in buses. The air in public transport vehicles was examined in autumn, winter and spring. To evaluate the exposure of drivers to bioaerosols, air samples were collected and examined for the total number of bacteria and fungi in the air, the number of mesophilic aerobic bacteria specified by the number of colony forming units (CFU) per 1 m3 of air. The results of the research show that public transport as a workplace can be considered to be a significant risk to health.

Effect of VP, MAP and combined packaging systems on the physicochemical properties and microbiological status of veal from unweaned calves.

The packaging system is one of the factors influencing the preservation of the nutritional value, microbiological safety, and sensory attributes of meat. The study investigated changes in physicochemical and microbiological properties taking place during 15-day refrigerated storage of two calf muscles, the longissimus lumborum (LL) and semitendinosus (ST), packaged in three systems, respectively, vacuum packing (VP), modified atmosphere packaging (MAP, 80% O2 + 20% CO2), and a combined system (VP + MAP, 8 d in VP followed by 7 d in MAP). LL and ST stored in VP had significantly lower levels of lipid oxidation, higher α-tocopherol content, and higher instrumentally measured tenderness in comparison with the samples stored in MAP. On the other hand, the MAP samples had lower purge loss at 5 and 15 days, a higher proportion of oxymyoglobin up to 10 days of storage, and a better microbiological status. Calf muscle samples stored in the VP + MAP system had intermediate values for TBARS and α-tocopherol content and at the same time were the most tender and had the lowest counts of Pseudomonas and Enterobacteriaceae bacteria at 15 days. All packaging systems ensured relatively good quality of veal characteristics up to the last day of storage. However, for MAP at 15 days of storage, unfavourable changes in colour (a high level of metmyoglobin and a decrease in oxymyoglobin, redness and R630/580 ratio) and in the lipid fraction (a high TBARS value and a significant decrease in α-tocopherol content) were observed.

Centring individual animals to improve research and citation practices.

Modern behavioural scientists have come to acknowledge that individual animals may respond differently to the same stimuli and that the quality of welfare and lived experience can affect behavioural responses. However, much of the foundational research in behavioural science lacked awareness of the effect of both welfare and individuality on data, bringing their results into question. This oversight is rarely addressed when citing seminal works as their findings are considered crucial to our understanding of animal behaviour. Furthermore, more recent research may reflect this lack of awareness by replication of earlier methods - exacerbating the problem. The purpose of this review is threefold. First, we critique seminal papers in animal behaviour as a model for re-examining past experiments, attending to gaps in knowledge or concern about how welfare may have affected results. Second, we propose a means to cite past and future research in a way that is transparent and conscious of the abovementioned problems. Third, we propose a method of transparent reporting for future behaviour research that (i) improves replicability, (ii) accounts for individuality of non-human participants, and (iii) considers the impact of the animals' welfare on the validity of the science. With this combined approach, we aim both to advance the conversation surrounding behaviour scholarship while also serving to drive open engagement in future science.

Effect of pitch range on dogs' response to conspecific vs. heterospecific distress cries.

Distress cries are emitted by many mammal species to elicit caregiving attention. Across taxa, these calls tend to share similar acoustic structures, but not necessarily frequency range, raising the question of their interspecific communicative potential. As domestic dogs are highly responsive to human emotional cues and experience stress when hearing human cries, we explore whether their responses to distress cries from human infants and puppies depend upon sharing conspecific frequency range or species-specific call characteristics. We recorded adult dogs' responses to distress cries from puppies and human babies, emitted from a loudspeaker in a basket. The frequency of the cries was presented in both their natural range and also shifted to match the other species. Crucially, regardless of species origin, calls falling into the dog call-frequency range elicited more attention. Thus, domestic dogs' responses depended strongly on the frequency range. Females responded both faster and more strongly than males, potentially reflecting asymmetries in parental care investment. Our results suggest that, despite domestication leading to an increased overall responsiveness to human cues, dogs still respond considerably less to calls in the natural human infant range than puppy range. Dogs appear to use a fast but inaccurate decision-making process to determine their response to distress-like vocalisations.

Anti-inflammatory and antibacterial effects of human cathelicidin active fragment KR-12 in the mouse models of colitis: a novel potential therapy of inflammatory bowel diseases.

INTRODUCTION: Inflammatory bowel diseases (IBD) are a group of chronic gastrointestinal tract disorders with complex etiology, with intestinal dysbiosis as the most prominent factor. In this study, we assessed the anti-inflammatory and antibacterial actions of the human cathelicidin LL-37 and its shortest active fragment, KR-12 in the mouse models of colitis. MATERIALS AND METHODS: Mouse models of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) and dextran sulfate sodium (DSS) were used in the study. The extent of inflammation was evaluated based on the macro- and microscopic scores, quantification of myeloperoxidase (MPO) activity and microbiological analysis of stool samples. RESULTS: A preliminary study with LL-37 and KR-12 (1 mg/kg, ip, twice daily) showed a decrease in macroscopic and ulcer scores in the acute TNBS-induced model of colitis. We observed that KR-12 (5 mg/kg, ip, twice daily) reduced microscopic and ulcer scores in the semi-chronic and chronic TNBS-induced models of colitis compared with inflamed mice. Furthermore, qualitative and quantitative changes in colonic microbiota were observed: KR-12 (5 mg/kg, ip, twice daily) decreased the overall number of bacteria, Escherichia coli and coli group bacteria. In the semi-chronic DSS-induced model, KR-12 attenuated intestinal inflammation as demonstrated by a reduction in macroscopic score and colon damage score and MPO activity. CONCLUSIONS: We demonstrated that KR-12 alleviates inflammation in four different mouse models of colitis what suggests KR-12 and cathelicidins as a whole are worth being considered as a potential therapeutic option in the treatment of IBD.

Effect of Fermented Rapeseed Meal on the Gastrointestinal Microbiota and Immune Status of Rabbit (Oryctolagus cuniculus).

The present study was conducted to determine the effect of the use of varying amounts of fermented rapeseed meal in diets for rabbits on the immune status and microbiota of segments of the GIT. Forty 35 day old rabbits used in the experiment were assigned to four groups: the control group (group C) were fed a standard diet and the experimental received 4%, 8% or 12% fermented rapeseed meal (included in place of standard soybean meal). Class A, G and M immunoglobulins were determined in the blood plasma. In the food content collected after slaughter, microbiological parameters were determined for individual sections of the digestive tract. Rabbits from the groups receiving a diet with an increased proportion of fermented rapeseed meal (8% or 12%) had lower concentrations of anaerobic bacteria and Escherichia coli in the intestinal contents. Research has shown that the increase in intake of fermented rapeseed meal was correlated with an increase in the correlations between the immunoglobulin level and the size of the microbial population in the GIT. In light of the presented results fermented rapeseed meal, by supplying valuable bioactive substances, appears to be a good component in the diet of rabbits, enhancing immune system development and helping to prevent disturbances of the gut microbiota.

Fermented Rapeseed Meal as a Component of the Mink Diet (Neovison vison) Modulating the Gastrointestinal Tract Microbiota.

Fermented rapeseed meal (FRSM) was used in the diet of American mink (Neovison vison). An advantage of this product is its prebiotic and functional properties, which can modify the bacterial microbiota of the GIT. A control group and three experimental groups were formed, with 60 animals in each group. The control group received a basal diet and the experimental groups received a diet with a 2%, 4% or 6% of FRSM as a replacement of extruded wheat. Bacillus subtilis strain 87Y was used to ferment the rapeseed meal (RSM). The study was conducted on mink from the age of 16-17 weeks until slaughter. Changes in the microbiota were analysed in samples of the animals' faeces and intestinal contents. The analyses included determination of the total number of bacteria and fungi, the number of coliforms and Escherichia coli, the total number of anaerobic Clostridium perfringens, and the presence of Salmonella spp. In animals receiving 4% and 6% FRSM (groups II and III), the content of microscopic fungi and the number of C. perfringens bacteria was significantly (p ≤ 0.05) lower than in the animals from the control group (group 0). A decrease in E. coli was observed in all experimental groups (I, II and III), although these differences were not statistically significant. The inclusion of FRSM in the feed ration did not affect the number of lactic acid intestinal bacteria. Analysis of the results obtained from the stool samples showed that the inclusion of FRSM in the ration did not significantly affect the number of microorganisms in each group. However, as in the case of the intestinal contents, in these samples there was a decrease in the total number of C. perfringens in the experimental groups (I, II and III), with a simultaneous increase in the number of mesophilic bacteria in relation to the control. There was no detection of Salmonella bacteria in any of the analysed material.

Assessment of the Level of Organic Dust and Mould Spores in the Work Environment of Baker.

AIM: This study was conducted to determine the level of fungal contamination of the air in bakeries to assess health hazards for workers. MATERIALS AND METHODS: Six bakeries producing traditionally baked goods were selected for the study. After a background survey, samples of exhaled air were collected to test for fungal aerosols. The inhalable and respirable fraction in the bakery air environment was measured by the gravimetric method. STATISTICAL ANALYSIS USED: All data analyses were performed using Statistica software (v 8.0). RESULTS: The mean concentration of fungi and particles in the bakeries did not exceed the recommended levels. The air in the bakeries had a low level of microbial contamination. The identified fungi included biological agents from hazard group 2. CONCLUSIONS: Proper employee training and the introduction of preventive measures (including both individual and group protection) can significantly reduce employees' exposure and thus their occupational risk.

Occupational exposure level of pig facility workers to chemical and biological pollutants.

OBJECTIVE: The aim of the study was to assess the impact of a fattening season on the level of airborne chemical and microbial pollutants in the pig fattening house. MATERIAL AND METHODS: Evaluation of the air composition as well as the microbiological air quality were made during 2 series, i.e. in the summer and winter period of fattening. Airborne gaseous pollutants were analyzed by gas (organic compounds) and liquid (inorganic compounds) chromatography methods. Air microbial contamination was determined in compliance with the Polish Standard PN-EN 13098:2007. RESULTS: The air/gas composition in the pig unit showed that irrespective of the fattening season, the level of determined pollutants - especially ammonia, volatile organic compounds (VOCs), including methanethiol and total dust - could have an adverse effect on the health of swine facility workers. The investigated pig building was found to be a source of chemical pollutants as well as biological agents. The total bacterial count in 1 m3 of air was 3.6×106 and 4.6×106 cfu, during the winter and summer periods of fattening, respectively. Gram-positive cocci predominated in both seasons. In the winter, fungi of the Trichoderma genus were represented equally often. In the summer period, up to 90% of the isolated fungus was Aspergillus spp. CONCLUSIONS: Workers engaged in swine rearing and production are occupationally exposed not only to a high concentration of microbial contamination, but also to irritating and odorogenous volatile compounds. Thus, activities directed at the promotion of health prevention strategies, as well as effective guidelines for safe and hygienic animal housing, should be implemented.

Opioid Antagonists and the A118G Polymorphism in the µ-Opioid Receptor Gene: Effects of GSK1521498 and Naltrexone in Healthy Drinkers Stratified by OPRM1 Genotype.

This corrects the article DOI: 10.1038/npp.2016.60.

Health effects of exposure to organic dust in workers of a modern hatchery.

The aim of the presented study was to determine the health status of workers occupationally exposed to moderate amounts of organic dust, employed in a modern hatchery with an efficient ventilation system. A group of 32 hatchery workers was examined. As a reference group, 50 urban dwellers not exposed to any kind of organic dust were examined. All people were interviewed for the presence of work-related symptoms and subjected to physical and spirometric examinations. Blood sera were examined for the presence of precipitins against 13 antigens associated with organic dust, and for the presence of total and chicken-specific No significant differences were found between the spirometric values in the group of hatchery workers and the reference group. Positive precipitin reactions were noted mostly with the antigens of Gram-negative bacteria associated with organic dust. The frequencies of positive reactions to antigens of Escherichia coli and Acinetobacter baumannii in hatchery workers were significantly greater compared to the reference group (p<0.05). Precipitin reactions to Gram-positive non-branching bacteria, actinomycetes, fungi and birdactions to antigens of Escherichia coli and Acinetobacter baumannii in hatchery workers were significantly greater compared to the reference group (p<0.05). Precipitin reactions to Gram-positive non-branching bacteria, actinomycetes, fungi and bird protein, were rare or absent. The mean concentration of total IgE in sera of hatchery workers was nearly 3 times greater compared to the reference group, and the difference proved to be statistically significant (p<0.05). No specific IgE antibodies against chicken feathers were detected in the blood of hatchery workers and referents. In conclusion, the examined hatchery workers showed a moderate frequency of work-related symptoms, no decline in lung function and low reactivity to most microbial and bird protein allergens. These results suggest that the effects of exposure to organic dust in workers of modern hatcheries with an efficient ventilation system are less compared to the workers of poultry farms, such as broiler or egg laying houses.

Efficacy of a novel biofilter in hatchery sanitation: I. Removal of airborne bacteria, dust and endotoxin.

A novel biofilter containing organic, bentonite and halloysite media was applied for elimination of microbial pollutants from the air of an industrial hatchery. The concentrations of total mesophilic bacteria, Gram-negative bacteria, thermophilic actinomycetes, dust and bacterial endotoxin were determined in the air of hatchery during 2 months before installation of the biofilter, and during 6 months after installation of the biofilter, at the inlet and outlet ducts from each medium. Before installation of the biofilter, the concentrations of total mesophilic bacteria, Gram-negative bacteria, thermophilic actinomycetes, dust and endotoxin in the air were within the ranges of 0.97-131.2x10(3) cfu/m3, 0.0-34.4x10(3) cfu/m3, 0.0-0.02x10(3) cfu/m3, 0.37-4.53 mg/m3, and 50.9-520,450.4 ng/m3, respectively. Enterococcus faecalis and Gram-negative bacteria (Acinetobacter spp., Escherichia coli, Enterobacter cloacae, and other species) prevailed among bacterial species recovered from the air of the hatchery. A total of 56 species or genera of bacteria were identified in the air samples taken in the examined hatchery; of these, 11, 11 and 6 species or genera respectively were reported as having allergenic, immunotoxic and/or infectious properties The concentrations of total mesophilic bacteria, Gram-negative bacteria, Enterococcus faecalis and endotoxin found at the inlet duct of the biofilter after its installation were significantly smaller compared to those recorded before its installation (p<0.05). The concentrations of Gram-negative bacteria, Enterococcus faecalis and dust found at the outlet ducts of biofilter after its installation were significantly smaller compared to those recorded at the inlet duct of the biofilter (p<0.01). The concentrations of total meso-philic bacteria were also smaller at the outlet ducts of the biofilter compared to that at the inlet duct; however, the difference was not significant because of the massive growth of Streptomyces species in the biofilter's media which contaminated the outcoming air. In conclusion, the applied biofilter proved to be effective in the elimination of potentially pathogenic bacteria, dust and endotoxin from the air of the hatchery. The efficacy of the biofilter could be improved by the inhibition of the Streptomyces growth in the media of the biofilter.

Efficacy of a novel biofilter in hatchery sanitation: II. Removal of odorogenous pollutants.

The present research assessed the treatment efficiency of odorogenous pollutants in air from a hatchery hall vented on organic and organic-mineral beds of an enclosed-container biofilter. In this study, the following media were used: organic medium containing compost and peat (OM); organic-mineral medium containing bentonite, compost and peat (BM); organic-mineral medium containing halloysite, compost and peat (HM). The concentration of odorogenous gaseous pollutants (sulfur compounds and amines) in the hatching room air and in the air after biotreatment were determined by gas chromatography. In the hatchery hall among the typical odorogenous pollutants, there were determined 2 amines: 2-butanamine and 2-pentanamine, hydrogen sulfide, sulfur dioxide, carbon disulfide, sulfides and mercaptans. Ethyl mercaptan showed the highest levels as its mean concentration in the hatchery hall air exceeded 60 microg/m3 and in single samples even 800 microg/m3. A mean concentration of 2-butanamine and sulfur dioxide in the examined air also appeared to be relatively high--21.405 microg/m3 and 15.279 microg/m3, respectively. In each filter material, the air treatment process ran in a different mode. As the comparison reveals, the mean reduction of odorogenous contaminants recorded in the hall and subjected to biotreatment was satisfying as it surpassed 60% for most established pollutants. These high removal values were confirmed statistically only for single compounds. However, a low removal level was reported for hydrogen sulfide and sulfur dioxide. No reduction was recorded in the bentonite supplemented medium (BM) for sulfur dioxide and methyl mercaptan. In the organic medium (OM) no concentration fall was noted for dipropyl sulfide either. In all the media investigated, the highest removal rate (100%), not confirmed statistically, was observed for carbon disulfide. Very good results were obtained in the medium with a bentonite additive (BM) for both identified amines, whose mean elimination rate exceeded 60% (p