For enhancing anaerobic sludge digestion and biogas recovery, an increase in organic load rate (OLR) from 1.0 to 3.0kgVS/(m3·day) was imposed upon a new anaerobic digestion process combined with a sludge recirculation. The new setup requires a traditional mesophilic anaerobic digester coupled with a centrifuge for maintaining relatively high solid content within the digester. The hypothesis of this study was that increasing continuously OLR from 1.0 to 3.0kgVS/(m3·day) in a pilot-scale anaerobic digester with recycled sludge would not badly influence the digester stability, based on which biogas production would be enhanced. To test this hypothesis, a continuous 73-day study with laboratory experiment was conducted. Due to scarcity of original feeding sludge and its deteriorating quality, OLR had to be increased relied on introduction of extra sludge followed by measurement of total solid (TS) and volatile solid (VS) contents in both feeding sludge and digester sludge, for calculating OLR and examining its variations. To assess the relationship between biogas production and OLR, a measurement of gas yield and methane content was a necessity, performed by applying a biogas flow meter and MSA AUER EX-METER II (P). Moreover, temperature, pH value, volatile fatty acid (VFA) and alkalinity must be tested frequently, for the purpose of preventing system failure. The results demonstrate that the digester succeeded in withstanding an OLR up to 3.15kgVS/(m3·day). Furthermore, an enhancement in biogas yield and methane content were observed after increasing the OLR by introducing extra sludge. Biogas production measurement performed during this study indicated that biogas yield was enhanced by 73%, with a maximum production of 14.5m3/day, when OLR was increased from 2.05 to 3.15kgVS/(m3·day). However, methane content was merely promoted by 10.5%, to the highest value of 63%, with the same increase in OLR. Specific gas production (SGP), as another means of evaluating the relationship between biogas production and OLR, was observed to be 0.65Nm3/kg VSin averagely.

Bacterial resistance to antibiotics has become a worldwide health problem, resulting in untreatable infections and escalating healthcare costs. Wastewater treatment plants are a critical point of control between anthropogenic sources of pathogens, antibiotic resistant bacteria (ARBs), antibiotic resistance genes (ARGs), and the environment through discharge of treated effluent and land application of biosolids. Recent studies observing an apparent resuscitation of pathogens and pathogen indicators and the widening realization of the importance of addressing environmental reservoirs of ARGs all lead toward the need for improved understanding of ARG fate and pathogen inactivation kinetics and mechanisms in sludge stabilization technologies. This research has investigated the fate of two pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli, and various ARGs under pasteurization, anaerobic digestion, biosolids storage, and land application conditions. Pathogen die-off occurs at a rate specific to each pathogen and matrix in ambient and mesophilic temperature environments. Viable but nonculturable (VBNC) states are initiated by thermal treatments, such as thermophilic digestion and possibly pasteurization, and allow the persistence of pathogen cells and any ARGs contained therein through treatment and into the receiving environment where resuscitation or transformation could occur. Raw sludge ARG content does affect digester effluent quality, although the predominant mechanisms of ARG persistence may be different in mesophilic versus thermophilic digestion. In both thermophilic and mesophilic digestion, a correlation was observed between raw sludge and digester ARGs associated with Class 1 integrons, possibly as a result of horizontal gene transfer. ARB survival was shown to contribute to ARG content in mesophilic digestion, but not thermophilic digestion. Thermophilic digestion may achieve a higher ARG reduction because of reduced microbial diversity compared to mesophilic digestion. However, it is evident that horizontal gene transfer still does occur, particularly with highly mobile integrons, so that complete reduction of all ARGs would not be possible with thermophilic digestion alone. Surprisingly, the experiments that introduced various concentrations of antibiotic sulfamethoxazole and antimicrobial nanosilver did not induce enhanced rates of horizontal gene transfer. Finally, ARG concentrations in biosolids increased during cold temperature storage suggesting that there is a stress induction of horizontal gene transfer of integron-associated ARGs. / Ph. D.

Avloppsslam innehåller näringsämnen, som bör återföras till naturen för att skapa ett så kallat näringskretslopp. Genom att optimera hygieniseringen av avloppsslam med effektivare behandlingsmetod kan avloppsslam bli mer lämpligt att avsättas ur ett bättre ekonomiskt- och miljömässigt perspektiv. Syftet med arbetet var att undersöka och bedöma om effektiviseringav befintlig slambehandling är möjlig för att uppnå tillräcklig hygienisering. Utifrån den effektiviserade slambehandlingsmetoden utreda möjliga avsättningsalternativ som lämpar sig bäst för avloppsslammet i Avesta kommun. En litteraturöversikt utfördes för att öka kunskapen och förståelsen av avloppsslam, desshantering och avsättning. Fallstudien är utformad med kvalitativ metod och informationen har inhämtats från vetenskapliga artiklar, myndigheter, rapporter, examensarbeten och personligkontakt som komplement för att erhålla en god förståelse. Uppgradering av mesofil rötning av avloppsslam vid 37 °C till termofil rötning, 55 °C – 65 °C innebär förhöjd temperatur; det kräver mer energi och ökade energikostnader. Komponenter av den mesofila rötningsprocessen kommer att behöva uppgraderas eller bytas ut och därför tillkommer extra kostnader som också behöver ses över. Fördelarna med termofil rötning inkluderar kortvariga uppehållstider, mindre rötkammare och slammet blir tillräckligt hygieniserat. Ett framtidsscenario är framtaget utifrån effektiviserad slambehandling där två avsättningsalternativ är mest lämpliga för avloppsslammet i Avesta kommun. Gödsel till produktiv mark är ett av de föreslagna alternativ som tillåter fosforn återvinnas och återanvändas. Om inte termofil rötning som effektivisering hade erhållit tillräcklig hygienisering borde andra komplementerande processer ha införts, exempelvis komposteringstrumma eller pastörisering. En fullständig kostnadsjämförelse mellan befintlig slambehandlingsmetod och mer effektiviserad slambehandlingsmetod är dock nästan omöjlig att utföra då alla kostnader beror på val av komponenter och faktorer. Denna fallstudie bidrar med ett underlag som kan ge större möjligheter för Avesta Vatten och Avfall AB att välja den mest lämpliga avsättningen för avloppsslammet i Avesta kommun i framtiden. / Sewage sludge contains nutrients, which should be returned to nature to create a so-called nutrient circulation. By optimizing sanitisation of sewage sludge with effective treatment methods, sewage sludge can be more appropriately disposed from a better economic- and environmental perspective. The aim of this work was to investigate and judge the efficiency of existing sludge treatment is possible to achieve a sufficent sanitation. Based on the streamlined sludge treatment method investigate the disposal options that is best suited for sewage sludge in Avesta town. A literature review was conducted to increase the knowledge and understanding of sewage sludge, its treatment and disposal. The case study is formed with qualitative method and information which has been collected from the scientific articles, authorities, reports, theses and personal contact as a complement to obtain a good understanding. Upgrading of mesophilic digestion of sludge at 37 ° C to thermophilic digestion at 55 ° C - 65 ° C means increased temperature; this requires more energy and hence increases energy costs. Components of the mesophilic digestion process need to be upgraded or replaced and therefore additional costs should also be considered. The advantages of the thermophilic digestion include short residence time, smaller digester and sludge becomes sufficiently disinfected. A future scenario is developed based on more efficient sludge treatment where two disposal options are most appropriate for the sewage sludge in Avesta town. Returning digestate to productive land is one of those suggested alternatives that allows phosphorus to be recovered and recycled. If not thermophilic digestion as streamlining is not effective enough for sufficient sludge sanitation, other complementary processes have to be introduced, for instance, composting drum or pasteurization. A full cost comparison between the existing sludge treatment and more efficient sludge treatment method is, however, almost impossible to be performed when all costs depend on the choice of components, factors and so on. This case study contributes with first-hand information that can provide greater opportunities for Avesta Vatten och Avfall AB to select the most appropriate options for sewage sludge disposal in Avesta town in the future.

Gram-positive bacteria are part of the normal flora of fish from different aquatic environments. They are mesophilic bacteria and demonstrate optimum growth at ambient temperature. In the sub-tropics, marine fish are caught from seas at temperatures of 16 to 34C, they are usually not iced and are handled at ambient temperature. It was hypothesized that under these conditions Gram-positive bacteria will be abundant in sub-tropical marine fish and will have roles in the spoilage of fish. A review of literature showed that there is a gap in understanding the Gram-positive bacterial populations in sub-tropical marine fish. This is partly due to the fact that the selective media used for isolating Gram-positive bacteria have limitations. Ecological and speciation studies have revealed that the ecology and speciation of many Gram-positive bacteria have not been clearly elucidated. The effect of ambient storage on the individual genera and species of Gram-positive bacteria in fish has been rarely studied. The spoilage potential of Gram-positive bacteria of marine fish origin has not been clearly determined. Therefore, the main aims of this study were to isolate Gram-positive bacteria from fresh and ambient-temperature-stored sub-tropical marine fish, speciate the isolates and study the spoilage potential of the isolates. The practical components of this study were conducted in four parts. The first part dealt with validation of tryptone soya agar with 0.25% phenylethyl alcohol (PEA-TSA) to enumerate Gram-positive bacteria. The second part enumerated Gram-positive bacteria from the muscles, gills and gut of Pseudocaranx dentex (Silver Trevally), Pagrus auratus (Snapper) and Mugil cephalus (Sea Mullet) stored at 25C for 15 hours using PEA-TSA. The third part dealt with the speciation of the isolates using appropriate methods such as polymerase chain reaction, 16S rRNA gene sequence, the VITEK JR system and conventional biochemical methods. In the fourth part, the isolates were assayed qualitatively for their ability to produce volatile sulphur compounds (VSC), reduce trimethylamine oxide and decarboxylate histidine, lysine and ornithine at mesophilic temperature, 32C. Initial studies indicated that PEA-TSA significantly (P< 0.05) reduced the total aerobic bacterial count of fish whereas control Gram-positive bacteria were not affected (P> 0.05). Gram-positive aerobic bacterial counts (GABC) significantly (P< 0.05) increased in the muscles and gills during ambient storage for 15 hours. Within each species, no significant (P> 0.05) differences were found in GABC between muscles and gills. Moreover, there were no significant differences (P> 0.05) in GABC between fish species during storage. In total, 390 bacteria were isolated from the fresh and stored fish; 339 isolates (87%) were found to be Gram-positive. Two hundred and sixty-six isolates (78%) of Gram-positive bacteria were identified to fall into 13 genera, namely Staphylococcus, Micrococcus, Bacillus, Virgibacillus, Brevibacillus, Corynebacterium, Streptococcus, Enterococcus, Aerococcus, Exiguobacterium, Carnobacterium, Vagococcus and Sporosarcina and 30 species. In fresh fish, Staphylococcus epidermidis and Micrococcus luteus were the most frequent isolates. The effect of storage at 25C for 15 hours resulted in a change of Gram-positive bacterial populations; while S. epidermidis, S. xylosus and Bacillus megaterium were no longer present, S. warneri, B. sphaericus, Brevibacillus borstelensis, Enterococcus faecium and Streptococcus uberis increased. Three species, E. faecium, Str. uberis and B. sphaericus, were the most prevalent at the end of storage. Micrococcus luteus and S. warneri were the most prevalent isolates from Pseudocaranx dentex, but E. faecium and Str. uberis were the most frequently isolated from Pagrus auratus and Mugil cephalus. With respect to different parts of the fish body, E. faecium, Str. uberis and B. sphaericus were the most frequent isolates from the muscles, E. faecium, Str. uberis from the gills and M. luteus from the gut. Among the 228 isolates examined, Br. borstelensis 73, Br. borstelensis 291, Str. uberis 339, Vagococcus fluvialis 31 and Vag. fluvialis 132 produced VSC from sodium thiosulphate, cysteine and methionine. However, strains varied in sulphur source utilization. Exiguobacterium acetylicum 5, Exiguobacterium spp. 191, Carnobacterium spp. 338, Br. borstelensis 73, Br. borstelensis 291, Str. uberis 30, Str. uberis 339, Vag. fluvialis 31 and Vag. fluvialis 132 reduced TMAO. No histidine decarboxylase activity was found in the Gram-positive bacterial species tested. Lysine and ornithine were decarboxylated mainly by different strains of S. warneri, S. epidermidis and M. luteus. During ambient storage of fish, the frequency of lysine-decarboxylating bacteria increased and became more diverse after 5 hours of storage. Among fish species examined, the frequencies of lysine- and ornithine-decarboxylating bacteria were higher and more diverse in Pseudocaranx dentex than in Pagrus auratus and Mugil cephalus. This study found that Gram-positive bacteria were abundant and diverse in sub-tropical marine fish; however, their frequencies were affected by fish habitat and fish body part. Ambient temperature storage determined which Gram-positive bacterial species were dominant. With the exception of one isolate of S. aureus, Gram-positive bacteria isolated from sub-tropical marine fish caught from unpolluted water were not potential pathogens. The study also showed that Gram-positive bacteria had greater ability to decarboxylate lysine and ornithine than to produce VSC or reduce TMAO, and the spoilage potential of a bacterial species was a strain-dependent behaviour. This is a significant study as it is the first study on this aspect sub-tropical marine fish. It validated a selective medium that can be used to enumerate most Gram-positive bacteria from a marine environment. Most of the Gram-positive bacterial species from sub-tropical marine fish identified in this study were documented for the first time. The effects of ambient storage and the spoilage potential of Gram-positive bacteria from sub-tropical marine were clearly elucidated.

Anaerobic digestion, which is the process by which bacteria breakdown organic matter to produce biogas (renewable energy source) and digestate (biofertiliser) in the absence of oxygen, proves to be the ideal concept not only for sustainable energy provision but also for effective organic waste management. However, the production amount of biogas to keep up with the global demand is limited by the underperformance in the system implementing the AD process. This underperformance is due to the difficulty in obtaining and maintaining the optimal operating parameters/states for anaerobic bacteria to thrive with regards to attaining a specific critical population number, which results in maximising the biogas production. This problem continues to exist as a result of insufficient knowledge of the interactions between the operating parameters and bacterial community. In addition, the lack of sufficient knowledge of the composition of bacterial groups that varies with changes in the operating parameters such as temperature, substrate and retention time. Without sufficient knowledge of the overall impact of the physico-environmental operating parameters on anaerobic bacterial growth and composition, significant improvement of biogas production may be difficult to attain. In order to mitigate this problem, this study has presented a nonlinear multi-parameter system modelling of mesophilic AD. It utilised raw data sets generated from laboratory experimentation of the influence of four operating parameters, temperature, pH, mixing speed and pressure on biogas and methane production, signifying that this is a multiple input single output (MISO) system. Due to the nonlinear characteristics of the data, the nonlinear black-box modelling technique is applied. The modelling is performed in MATLAB through System Identification approach. Two nonlinear model structures, autoregressive with exogenous input (NARX) and Hammerstein-Wiener (NLHW) with different nonlinearity estimators and model orders are chosen by trial and error and utilised to estimate the models. The performance of the models is determined by comparing the simulated outputs of the estimated models and the output in the validation data. The approach is used to validate the estimated models by checking how well the simulated output of the models fits the measured output. The best models for biogas and methane production are chosen by comparing the outputs of the best NARX and NLHW models (each for biogas and methane production), and the validation data, as well as utilising the Akaike information criterion to measure the quality of each model relative to each of the other models. The NLHW models mhw2 and mhws2 are chosen for biogas and methane production, respectively. The identified NLHW models mhw2 and mhws2 represent the behaviour of the production of biogas and methane, respectively, from mesophilic AD. Among all the candidate models studied, the nonlinear models provide a superior reproduction of the experimental data over the whole analysed period. Furthermore, the models constructed in this study cannot be used for scale-up purpose because they are not able to satisfy the rules and criteria for applying dimensional analysis to scale-up.

A água empregada na produção de doses inseminantes (DIs) de suínos pode ser um dos veículos de introdução de bactérias contaminantes, podendo levar à perda de qualidade das mesmas. O objetivo do presente estudo foi avaliar o número de mesófilos aeróbios totais (MAT) na água utilizada em centrais de inseminação de suínos e sua influência nas contagens bacterianas das DIs produzidas. Foram conduzidos três ciclos de amostragem em seis centrais de inseminação (A-F), intencionalmente incluídas no estudo de acordo com os critérios: estar localizada no sul do Brasil; produzir >1.000 DIs mensais; e concordar em participar do estudo. A cada ciclo, eram colhidas amostras de água antes da purificação, água após a passagem pelo sistema de purificação, água após armazenamento, diluente, sêmen in natura de três machos distintos de fertilidade comprovada; e das respectivas doses inseminantes preparadas com sêmen e diluente amostrados. A água colhida antes do sistema de purificação foi avaliada quanto ao número mais provável (NMP) de coliformes totais e Escherichia coli, em 100 mL. pela técnica dos tubos múltiplos. Todas as amostras colhidas foram avaliadas quanto ao número de mesófilos aeróbios totais (MAT), por meio da semeadura em profundidade em Ágar para Contagem (PCA). Todas as 18 amostras de água colhidas antes da purificação apresentaram <1,1 NMP.100 mL-1 de Escherichia coli. A média de MAT nas amostras de água variou entre 0,1 log UFC.mL-1 na água após-purificação da central E e 3,5 log.UFC.mL-1 na água antes da purificação da central F. Não houve diferença significativa (P>0,05) entre as contagens médias de MAT obtidas em diferentes tipos de amostra de água e entre as centrais de inseminação. A média de MAT nas amostras de diluente variou de 0,16 log UFC. mL-1 à 2,78 log UFC.mL-1. As centrais D e F apresentaram diluentes significativamente (P<0,05) mais contaminados. No sêmen, a média de MAT variou de 1,75 log. UFC.mL-1 à 3,79 log UFC.mL-1 e nas DIs entre 0,73 log.UFC.mL-1 e 2,88 log UFC.mL-1. A central de inseminação F apresentou média de MAT significativamente (P<0,05) maior que as demais centrais. Considerando os padrões existentes, conclui-se que a água captada, purificada e armazenada apresentou boa qualidade microbiológica em todas as centrais de inseminação e não influenciou a média de mesófilos aeróbios totais das DIs preparadas. O incremento de bactérias, quando observado, foi provavelmente resultante da contaminação de origem ambiental durante o preparo do diluente e das doses inseminantes. / The water employed in the production of insemination doses (IDs) of swine may be one of the vehicles for introduction of contaminant bacteria, and can lead to their quality loss. The objective of this study was to assess the number of total aerobic mesophilic (TAM) in water used in swine artificial insemination centers (SAIC) and its influence in the total bacterial counting of the IDs produced. Three cycles of sampling were conducted in six SAIC (A-F) intentionally included in the study according to the following criteria: to be located in the south of Brazil, to produce > 1.000 (IDs) monthly, and to agree in participating of the study. At each cycle, samples were collected from water before the purification, water after passage through the purification system, water after storage, extenders, fresh semen collected from three different boars and the respective (ID) prepared with the semen and extender sampled. The water collected before the purification system was evaluated for total coliforms and Escherichia coli most probable number (NMP) in 100 mL using the multiple tubes technic. All samples collected were evaluated for the number of total aerobic mesophilic (TAM) by the pour plate technic. All the 18 samples of water collected before the purification presented < 1.1 NMP. 100 mL-1 of Escherichia coli. The average of TAM in the water samples varied between 0.1 log.CFU. ml-1 in the water after purification of the central E and 3.5 log. CFU.mL-1 in the water before purification of the central F. There was no significant difference (P>0.05) among the average counting of TAM obtained in different water samples types and among SAICs. The average TAM in samples of diluents varied from 0.16 log.CFU.mL-1 to 2.78 log.CFU.mL-1; the SAICs D and F presented diluents significantly (P< 0.05) more contaminated. Among the semen samples, the TAM average varied from 1.75 log.CFU.mL-1 to 3.79 log CFU.mL-1 and in the DIs between 0.73 log.CFU.mL-1 and 2.88 log.CFU.mL-1. The SAIC F presented average of TAM significantly (P<0.05) higher than the others SAICs. Considering the available standards, it was concluded that water collected, purified and stored presented a good microbiological quality in all insemination centers and did not influence the number of TAM in the prepared IDs. The increase on bacterial population may have resulted from contamination of environmental origin during the preparation of the extender and insemination doses.

A água empregada na produção de doses inseminantes (DIs) de suínos pode ser um dos veículos de introdução de bactérias contaminantes, podendo levar à perda de qualidade das mesmas. O objetivo do presente estudo foi avaliar o número de mesófilos aeróbios totais (MAT) na água utilizada em centrais de inseminação de suínos e sua influência nas contagens bacterianas das DIs produzidas. Foram conduzidos três ciclos de amostragem em seis centrais de inseminação (A-F), intencionalmente incluídas no estudo de acordo com os critérios: estar localizada no sul do Brasil; produzir >1.000 DIs mensais; e concordar em participar do estudo. A cada ciclo, eram colhidas amostras de água antes da purificação, água após a passagem pelo sistema de purificação, água após armazenamento, diluente, sêmen in natura de três machos distintos de fertilidade comprovada; e das respectivas doses inseminantes preparadas com sêmen e diluente amostrados. A água colhida antes do sistema de purificação foi avaliada quanto ao número mais provável (NMP) de coliformes totais e Escherichia coli, em 100 mL. pela técnica dos tubos múltiplos. Todas as amostras colhidas foram avaliadas quanto ao número de mesófilos aeróbios totais (MAT), por meio da semeadura em profundidade em Ágar para Contagem (PCA). Todas as 18 amostras de água colhidas antes da purificação apresentaram <1,1 NMP.100 mL-1 de Escherichia coli. A média de MAT nas amostras de água variou entre 0,1 log UFC.mL-1 na água após-purificação da central E e 3,5 log.UFC.mL-1 na água antes da purificação da central F. Não houve diferença significativa (P>0,05) entre as contagens médias de MAT obtidas em diferentes tipos de amostra de água e entre as centrais de inseminação. A média de MAT nas amostras de diluente variou de 0,16 log UFC. mL-1 à 2,78 log UFC.mL-1. As centrais D e F apresentaram diluentes significativamente (P<0,05) mais contaminados. No sêmen, a média de MAT variou de 1,75 log. UFC.mL-1 à 3,79 log UFC.mL-1 e nas DIs entre 0,73 log.UFC.mL-1 e 2,88 log UFC.mL-1. A central de inseminação F apresentou média de MAT significativamente (P<0,05) maior que as demais centrais. Considerando os padrões existentes, conclui-se que a água captada, purificada e armazenada apresentou boa qualidade microbiológica em todas as centrais de inseminação e não influenciou a média de mesófilos aeróbios totais das DIs preparadas. O incremento de bactérias, quando observado, foi provavelmente resultante da contaminação de origem ambiental durante o preparo do diluente e das doses inseminantes. / The water employed in the production of insemination doses (IDs) of swine may be one of the vehicles for introduction of contaminant bacteria, and can lead to their quality loss. The objective of this study was to assess the number of total aerobic mesophilic (TAM) in water used in swine artificial insemination centers (SAIC) and its influence in the total bacterial counting of the IDs produced. Three cycles of sampling were conducted in six SAIC (A-F) intentionally included in the study according to the following criteria: to be located in the south of Brazil, to produce > 1.000 (IDs) monthly, and to agree in participating of the study. At each cycle, samples were collected from water before the purification, water after passage through the purification system, water after storage, extenders, fresh semen collected from three different boars and the respective (ID) prepared with the semen and extender sampled. The water collected before the purification system was evaluated for total coliforms and Escherichia coli most probable number (NMP) in 100 mL using the multiple tubes technic. All samples collected were evaluated for the number of total aerobic mesophilic (TAM) by the pour plate technic. All the 18 samples of water collected before the purification presented < 1.1 NMP. 100 mL-1 of Escherichia coli. The average of TAM in the water samples varied between 0.1 log.CFU. ml-1 in the water after purification of the central E and 3.5 log. CFU.mL-1 in the water before purification of the central F. There was no significant difference (P>0.05) among the average counting of TAM obtained in different water samples types and among SAICs. The average TAM in samples of diluents varied from 0.16 log.CFU.mL-1 to 2.78 log.CFU.mL-1; the SAICs D and F presented diluents significantly (P< 0.05) more contaminated. Among the semen samples, the TAM average varied from 1.75 log.CFU.mL-1 to 3.79 log CFU.mL-1 and in the DIs between 0.73 log.CFU.mL-1 and 2.88 log.CFU.mL-1. The SAIC F presented average of TAM significantly (P<0.05) higher than the others SAICs. Considering the available standards, it was concluded that water collected, purified and stored presented a good microbiological quality in all insemination centers and did not influence the number of TAM in the prepared IDs. The increase on bacterial population may have resulted from contamination of environmental origin during the preparation of the extender and insemination doses.

A água empregada na produção de doses inseminantes (DIs) de suínos pode ser um dos veículos de introdução de bactérias contaminantes, podendo levar à perda de qualidade das mesmas. O objetivo do presente estudo foi avaliar o número de mesófilos aeróbios totais (MAT) na água utilizada em centrais de inseminação de suínos e sua influência nas contagens bacterianas das DIs produzidas. Foram conduzidos três ciclos de amostragem em seis centrais de inseminação (A-F), intencionalmente incluídas no estudo de acordo com os critérios: estar localizada no sul do Brasil; produzir >1.000 DIs mensais; e concordar em participar do estudo. A cada ciclo, eram colhidas amostras de água antes da purificação, água após a passagem pelo sistema de purificação, água após armazenamento, diluente, sêmen in natura de três machos distintos de fertilidade comprovada; e das respectivas doses inseminantes preparadas com sêmen e diluente amostrados. A água colhida antes do sistema de purificação foi avaliada quanto ao número mais provável (NMP) de coliformes totais e Escherichia coli, em 100 mL. pela técnica dos tubos múltiplos. Todas as amostras colhidas foram avaliadas quanto ao número de mesófilos aeróbios totais (MAT), por meio da semeadura em profundidade em Ágar para Contagem (PCA). Todas as 18 amostras de água colhidas antes da purificação apresentaram <1,1 NMP.100 mL-1 de Escherichia coli. A média de MAT nas amostras de água variou entre 0,1 log UFC.mL-1 na água após-purificação da central E e 3,5 log.UFC.mL-1 na água antes da purificação da central F. Não houve diferença significativa (P>0,05) entre as contagens médias de MAT obtidas em diferentes tipos de amostra de água e entre as centrais de inseminação. A média de MAT nas amostras de diluente variou de 0,16 log UFC. mL-1 à 2,78 log UFC.mL-1. As centrais D e F apresentaram diluentes significativamente (P<0,05) mais contaminados. No sêmen, a média de MAT variou de 1,75 log. UFC.mL-1 à 3,79 log UFC.mL-1 e nas DIs entre 0,73 log.UFC.mL-1 e 2,88 log UFC.mL-1. A central de inseminação F apresentou média de MAT significativamente (P<0,05) maior que as demais centrais. Considerando os padrões existentes, conclui-se que a água captada, purificada e armazenada apresentou boa qualidade microbiológica em todas as centrais de inseminação e não influenciou a média de mesófilos aeróbios totais das DIs preparadas. O incremento de bactérias, quando observado, foi provavelmente resultante da contaminação de origem ambiental durante o preparo do diluente e das doses inseminantes. / The water employed in the production of insemination doses (IDs) of swine may be one of the vehicles for introduction of contaminant bacteria, and can lead to their quality loss. The objective of this study was to assess the number of total aerobic mesophilic (TAM) in water used in swine artificial insemination centers (SAIC) and its influence in the total bacterial counting of the IDs produced. Three cycles of sampling were conducted in six SAIC (A-F) intentionally included in the study according to the following criteria: to be located in the south of Brazil, to produce > 1.000 (IDs) monthly, and to agree in participating of the study. At each cycle, samples were collected from water before the purification, water after passage through the purification system, water after storage, extenders, fresh semen collected from three different boars and the respective (ID) prepared with the semen and extender sampled. The water collected before the purification system was evaluated for total coliforms and Escherichia coli most probable number (NMP) in 100 mL using the multiple tubes technic. All samples collected were evaluated for the number of total aerobic mesophilic (TAM) by the pour plate technic. All the 18 samples of water collected before the purification presented < 1.1 NMP. 100 mL-1 of Escherichia coli. The average of TAM in the water samples varied between 0.1 log.CFU. ml-1 in the water after purification of the central E and 3.5 log. CFU.mL-1 in the water before purification of the central F. There was no significant difference (P>0.05) among the average counting of TAM obtained in different water samples types and among SAICs. The average TAM in samples of diluents varied from 0.16 log.CFU.mL-1 to 2.78 log.CFU.mL-1; the SAICs D and F presented diluents significantly (P< 0.05) more contaminated. Among the semen samples, the TAM average varied from 1.75 log.CFU.mL-1 to 3.79 log CFU.mL-1 and in the DIs between 0.73 log.CFU.mL-1 and 2.88 log.CFU.mL-1. The SAIC F presented average of TAM significantly (P<0.05) higher than the others SAICs. Considering the available standards, it was concluded that water collected, purified and stored presented a good microbiological quality in all insemination centers and did not influence the number of TAM in the prepared IDs. The increase on bacterial population may have resulted from contamination of environmental origin during the preparation of the extender and insemination doses.

Made available in DSpace on 2014-08-20T13:42:09Z (GMT). No. of bitstreams: 1 Dissertacao_Tatiane_Kuka_Valente_Gandra.pdf: 6435400 bytes, checksum: eb0efa5223904e377b05e07ae3b1061e (MD5) Previous issue date: 2011-02-23 / Meat is one of the most important population diet items and has fundamental importance for the economy of the country. However, both for effective consoledation of Brazilian fresh beef exports to other markets, such as to offer domestic products with nutrition quality and food security is essential for maintaining an adequate shelf life and an acceptable microbiological quality of these products. In this context, this study was carried out to verify the microbiological quality by Salmonella spp., mesophilic aerobic microorganisms and Enterobacteriaceae quantification on bovine carcasses from two abattoirs-slaughterhouses with different levels of sanitary inspection (federal and state), located in southern Rio Grande do Sul and beyond, curtailments, equipment surfaces, utensils, and hands of food handlers, in the slaughterhouse for state inspection. Sixty cattle carcasses were evaluated two abattoirs-slaughterhouses, in four points in the slaughter line (after bleeding, after skinning, after evisceration, after washing and before cooling), totaling 240 samples. In the state inspection slaughterhouse the carcasses were sampled environmental surface slaughtering and processing (sawing open the breastbone, sawing the division of carcasses, table, knife and handlers) and two cuts (loin and fillet) totaling 52 samples. For statistical evaluation of results was carried out an analysis of variance followed by Tukey test and determining the correlation coefficients between microbial concentrations recorded in the sampled points. Among the points studied showed higher concentrations of mesophilic aerobic micro-organisms and Enterobactericeae as well as the presence of Salmonella spp. at the collection point after bleeding, indicating that the leather of cattle is a introduction source of microorganisms in the environment two abattoirs-slaughterhouses, and that the operations of hygiene and sanitation leather cattle before slaughter were not effective for prevent entry of these microorganisms in the environment of slaughter. From the scores of environmental surfaces found that the handlers are an important point of contamination in the state inspection slaughterhouse considering that showed significantly higher concentrations of mesophilic bacteria and Enterobactericeae in comparison with other items of the environment. Salmonella spp. was found in the leather of cattle, in the two abattoirs-slaughterhouses, however, was not detected in any other sample point of the slaughter line or in the environment and cuts, showing that the culling operations were effective to control contamination carcass and meat cuts for that microorganism. Finally, the slaughterhouses with different levels of sanitary inspection showed high correlation coefficients for the concentration of micro-organisms and aerobic mesophile (R=0,97) Enterobactericeae (R=0,91), and for the presence of Salmonella spp. no significant differences, indicating that the forms of contamination of carcasses during slaughter operations for these microorganisms are probably the same. / A carne é um dos itens mais importantes da dieta alimentar da população brasileira e possui fundamental importância para a economia do País. Contudo, tanto para consolidação efetiva da exportação brasileira de carne bovina in natura e de seus derivados a outros mercados, como para oferecer ao mercado interno produtos com qualidade nutricional e segurança alimentar é indispensável † manutenção de uma vida til adequada e de uma qualidade microbiológica aceitável para estes produtos. Neste contexto, este estudo foi realizado com intuito de verificar a qualidade microbiológica, através da pesquisa de Salmonella spp. e da quantificação de micro- organismos mesófilos aeróbios e de Enterobacteriaceae, em carcaças bovinas, provenientes de dois frigoríficos-matadouros com níveis de inspeção sanitária diferentes (estadual e federal), localizados na região sul do Rio Grande do Sul e, além destas, em cortes, superfícies de equipamentos, utensílios e m os de manipuladores, no frigorífico de Inspeção Estadual. Foram avaliadas 60 carcaças bovinas nos dois frigoríficos, em quatro pontos da linha de abate (após a sangria, após a esfola, após a eviscera€ o e após a lavagem pré-resfriamento), totalizando 240 amostras. No frigorífico com Inspeção Estadual, além das carcaças, foram amostradas superfícies do ambiente de abate e processamento (serra de abertura do esterno, serra de divisão das carcaças, mesa, faca e m os dos manipuladores) e dois cortes (alcatra e filé) que totalizaram 52 amostras. Para avalia€ o estatística dos resultados realizou-se uma análise de variância seguida do teste de Tuckey e determinaram-se coeficientes de correlação entre as concentrações microbianas verificadas nos pontos amostrados. Dentre os pontos avaliados verificaram-se maiores concentrações de micro-organismos mesófilos aeróbios e de Enterobactericeae, bem como a presença de Salmonella spp. no ponto de coleta ap‚s a sangria, indicando que o couro de bovinos Š fonte de introdu€ o de micro- organismos no ambiente de abate para dois frigoríficos, e que as opera€Žes de higiene e sanitiza€ o do couro de bovinos que antecedem o abate n o foram efetivas para impedir entrada destes micro-organismos no ambiente de abate. A partir das contagens das superfícies do ambiente constatou-se que as m os dos manipuladores s o um ponto importante de contamina€ o de mes‚filos aeróbios e de Enterobactericeae no frigorífico de Inspeção Estadual. Salmonella spp. foi encontrada no couro dos bovinos, nos dois Frigor‡ficos avaliados, entretanto, n o foi detectada em nenhum outro ponto de amostragem da linha de abate, do ambiente e nem nos cortes cŒrneos, demonstrando que as operações de abate foram efetivas para o controle da contaminação da carcaça e dos cortes cŒrneos, por esse micro- organismo. Os frigoríficos com diferentes n‡veis de inspeção sanitária apresentaram elevados coeficientes de correlação para a concentração de micro-organismos mesófilos aeróbios (R=0,97) e Enterobactericeae (R=0,91), e em relação à presença de Salmonella spp. n o apresentaram diferença significativa, indicando que as formas de contaminação das carcaças durante as operações de abate para estes micro-organismos s o provavelmente as mesmas.

Made available in DSpace on 2016-05-02T13:55:47Z (GMT). No. of bitstreams: 1 Norberto Bonamichi NetoDissertacao.pdf: 924328 bytes, checksum: 8e5270f5a465b88647392cac145ba780 (MD5) Previous issue date: 2013-05-29 / The goal of the experiment was to measure and assess the effects of lack of adequate cooling in obtaining and transporting the raw milk to dairy until his arrival by physical chemical and microbiological tests on hand milking and without milk coolers. The experiment was performed with milk coming from a single produceralso designed to evaluate the influence of the time of the year. For the tests were used 40 crossbred females, healthy lactating in a randomized block designand treatments were assembled in minutes elapsed to perform the analysis of quality of milk from milking until the end of the course of 150 minutes, being 30 minutes T1 after milking, 60 minutes T2 after milking, 90 minutes T3 after milking, 120 minutes T4 after milking and 150 minutes T5 after milking, during five days in the winter and five days in the spring. The days are repetitions of the treatment groups in minutes elapsed analyzed within each period (winter and spring). We measured pH tests, titratable acidity, density, freezing point, fat, total count of aerobic mesophilic, total solids and solids not. For the period of 30 minutes after milking, the difference was p<0.05 for the parameters acidity, fat, total solids and solids not fat, that result is repeated in periods of 60 and 90 minutes after milking, in periods of 120 and 150 minutes after milking the difference was p<0.05 for the parameters acidity, fat, aerobic mesophilic count, total solids and solids not fat. The milk collected at both stations during milking after 30 and 60 minutes is shown in better physical-chemical and microbiological, showing that the environmental factor was decisive for such results. The results of the analysis were submitted to Student's t test at a significance level of 5%, using statistical parametric Sisvar software version 5.1. / O objetivo do experimento foi mensurar e avaliar os efeitos da falta de refrigeração adequada na obtenção e transporte do leite cru até sua chegada ao laticínio pelos testes físicos químicos e microbiológicos na ordenha manual e sem resfrirador. O experimento foi realizado com leite oriundo de um único produtor com intuito de avaliar também a influência do período do ano.Para tanto utilizou 40 fêmeas mestiças, hígidas em lactação num delineamento em blocos casualizados e os tratamentos foram montados em minutos decorridos para realizar a análise de qualidade do leite entre o fim da ordenha até o decorrer de 150 minutos, sendo, T1 de 30 minutos pós ordenha, T2 de 60 minutos pós ordenha, T3 de 90 minutos pós ordenha, T4 de 120 minutos pós ordenha e T5 de 150 minutos pós ordenha, com cinco dias, no inverno e cinco dias na primavera. Os dias são as repetições dos grupos de tratamentos em minutos decorridos analisado dentro de cada período (inverno e primavera). Foram mensuradas os testes de pH, acidez titulável, densidade, crioscopia, gordura, contagem global de aeróbios mesófilos, sólidos totais e sólidos não gordurosos. Para o período de 30 minutos pós ordenha observou diferença p<0,05 para os parâmetros acidez, gordura, sólidos totais e sólidos não gordurosos, resultado que se repete nos períodos de 60 e 90 minutos pós ordenha, já nos períodos de 120 e 150 minutos pós ordenha observou diferença p<0,05 para os parâmetros acidez, gordura, contagem de aeróbios mesófilos, sólidos totais e sólidos não gordurosos. O leite colhido em ambas as estações, nos períodos pós ordenha de 30 e 60 minutos se mostraram em melhor estado físico-químico e microbiológico, mostrando que o fator ambiental foi decisivo para tais resultados. Os resultados das analises foram submetidos ao Teste t de Student ao nível de significância de 5%, utilizando o software estatístico paramétricoSisvar versão 5.1.