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Evaluation Of Biodeterioration In Nemrut Mount Monument And Temple Of Augustus By Using Various TechniquesSirt, Elif 01 September 2011 (has links) (PDF)
Different techniques were studied to evaluate the presence of different microorganisms that played important roles in decay processes of historic stones. In that scope, limestones and sandstones from Nemrut Mount Monument, and marbles and andesites from Temple of Augustus were studied. For measurement of enzymatic activity, fluorescein diacetate (FDA) hydrolysis method previously applied to assess soil microbial activity was carried out. Total microflora method based on countings of colony number was conducted for determination of the level of bacterial and fungal activity of stones. ATP bioluminescence method, developed for the field of hygiene monitoring, was carried out in order to detect global metabolic activity degree in historic stones. Most probable number (MPN) method was carried out to detect the number of microbial cells, namely nitrifying and sulphur oxidising bacteria which could take part in the decay processes. Moreover, fungi identification was done for determining occurance of detrimental species.
Presence of lichenic and algal zones existed on stones of Nemrut Mount Monument and the presence of black discolorations on stones of Temple of Augustus was common. Results have shown that the bacterial and fungal activity was low, however considerable quantity of FDA hydrolyses has shown the importance of algal population in the stones of two studied historical sites. This study has proved that FDA hydrolyses, total microflora and MPN method were efficient for the evaluation of biodeterioration in historic stones.
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Report of an internship with the Ohio River Valley Water Sanitation Sommission (ORSANCO) in Cincinnati, OhioSundar, Naveen. January 2004 (has links)
Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2004. / Title from first page of PDF document. Includes bibliographical references (p. 33).
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Improvement of the quantitation method for the tdh+ Vibrio parahaemolyticus in molluscan shellfish based on most-probable- number, immunomagnetic separation, and loop-mediated isothermal amplification / 最確数法、免役磁気分離法、およびloop-mediated isothermal amplification 法に基づく軟体動物貝類中のtdh+ 腸炎ビブリオの定量検査法の改良Escalante, Maldonado Oscar Roberto 23 March 2016 (has links)
Final publication is available at: http://journal.frontiersin.org/article/10.3389/fmicb.2015.00270/full / 付記する学位プログラム名:グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19619号 / 医博第4126号 / 新制||医||1015(附属図書館) / 32655 / 京都大学大学院医学研究科医学専攻 / (主査)教授 中川 一路, 教授 木原 正博, 教授 松林 公蔵 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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REPORT OF AN INTERNSHIP WITH THE OHIO RIVER VALLEY WATER SANITATION COMMISSION IN CINCINNATI, OHIOSundar, Naveen 10 August 2004 (has links)
No description available.
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Comparing the mannitol-egg yolk-polymyxin agar plating method to the three tube most probable number method for enumeration of bacillus cereus spores in raw and high-temperature-short-time pasteurized milkHarper, Nigel Murray January 1900 (has links)
Master of Science / Food Science Institute- Animal Sciences and Industry / Kelly J. K. Getty / The Food and Drug Administration’s Bacteriological Analytical Manual recommends two enumeration methods for Bacillus spp.: 1) standard plating method using mannitol-egg yolk-polymyxin (MYP) agar and 2) most probable number (MPN) method with tryptic soy broth supplemented with 0.1% polymyxin sulfate. Preliminary research evaluated three inoculum preparation methods using EZ-Spore™ B. cereus pellets. Two methods involved EZ-Spore™ B. cereus pellets that were dissolved in deionized (DI) water, grown in brain heart infusion broth with manganese sulfate, and then heated to produce spores. The third inoculum preparation method of dissolving EZ-Spore™ pellets only in DI water was the most efficient due to 100% spores being present in the inoculum. Preliminary research also determined that MPN method recovered greater (p<0.05) B. cereus populations than MYP method in inoculated ultra-high temperature pasteurized skim and 2% milk. The objective of the main study was to compare the MYP and MPN method for detection and enumeration of B. cereus in raw and high-temperature-short-time pasteurized skim, 2%, and whole milk at 4 °C for 96 h. Milk samples were inoculated with B. cereus EZ-Spores™ dissolved in DI water and sampled at 0, 48, and 96 h after inoculation. No differences (p>0.05) were observed among sampling times so data was pooled for overall mean values for each treatment. The overall B. cereus population mean of pooled sampling times for MPN method (2.59 log CFU/mL) was greater (p<0.05) than MYP plating method (1.89 log CFU/mL). B. cereus populations ranged from 3.40 log CFU/mL to 2.40 log CFU/mL for inoculated milk treatments for MYP and MPN methods, which is well below the necessary level for toxin production. Even though MPN method enumerated more B. cereus, the MYP method should be used by industry for enumeration of B. cereus due to its ease of use and rapid turnover time (2 d compared to 5 d with MPN). However, MPN method should be used for validation research due to its greater populations recovered. EZ-Spore™ B. cereus pellets were found to be an acceptable spore inoculum for validation research because the inoculum consists of 100% spores and does not contain vegetative cells.
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Emprego de microscopia de fluorescência para a quantificação microbiana em amostras salinas da indústria do petróleo / Use of fluorescence microscopy for microbial quantification in the saline samples of the petroleum industryDenise da Piedade Silva 09 December 2010 (has links)
Os micro-organismos constituem um grande problema em termos econômicos para a indústria petrolífera. Estes são responsáveis pela produção de substâncias corrosivas e a formação de biofilmes, que causam deterioração dos materiais metálicos. Os principais grupos microbianos presentes em amostras ambientais da indústria do petróleo são as bactérias anaeróbias heterotróficas totais (BANHT) e as bactérias redutoras de sulfato (BRS). Atualmente, a quantificação desses grupos microbianos é realizada através da técnica do Número Mais Provável (NMP) que estima o resultado em aproximadamente 28 dias. Neste trabalho foi otimizada uma metodologia para a microscopia de fluorescência de amostras salinas provenientes de tanques de armazenamento de água/óleo. As condições testadas foram o tipo de óleo de imersão, o tipo de diluente, o volume do corante, o volume da amostra corada e a concentração do fixador (glutaraldeído) numa tentativa de correlacionar com resultados de quantificação de BANHT e BRS através da técnica convencional do NMP. Nesse caso, as células totais foram quantificadas por microscopia de fluorescência utilizando o corante fluorescente laranja de acridina (AO). Verificou-se que houve uma correlação entre os resultados da quantificação de células totais por microscopia de fluorescência e os resultados de BANHT pela técnica do NMP, devido a pouca variação de valores expressos em ambas as quantificações. Entretanto, não foi possível correlacionar os resultados da quantificação de células totais com os resultados de BRS por NMP devido à grande variação dos valores de quantificação de BRS. Na microscopia de fluorescência, foi possível, quantificar os micro-organismos em aproximadamente 30 minutos e através das fotografias, verificou-se ainda que as amostras apresentaram-se nítidas e os micro-organismos com uma boa fluorescência / Microbial cells constitute a severe problem, from the economic point of view, for the petroleum industry. They are responsible for the production of corrosive metabolites and for the formation of biofilms, causing deterioration in the surface of metallic materials. The main microbial groups present in environmental samples from the petroleum industry include total anaerobic heterothrophic bacteria (TANHB) and sulfate-reducing bacteria (SRB). Nowadays, the quantification of those microbial groups is performed through the use of the most probable number technique (MPN), providing the final quantification after 28 days. In the present work a new methodology, based on fluorescence microscopy, was optimized on saline samples from water/oil storage tanks. The conditions tested were the type of immersion oil, type of diluent, the volume of the dye, the stained sample volume and concentration of fixative (glutaraldehyde) in order to quantify total cells, in an attempt to correlate with TANHB and SRB quantification through MPN. In that case, total cells were quantified with the help of acrydine orange as fluorescent dye. It could be observed a clear correlation between the results obtained for total cells quantification by fluorescence microscopy and the results obtained for TANHB through MPN technique, due to the negligible differences observed in both quantifications. However, when a correlation with SRB cells was tried results of total cells through fluorescence microscopy did not fit entirely. With the use of fluorescence microscopy, it was possible to quantify microbial cells in around 30 minutes and with the help of photographic reports obtained, it could be observed that the samples were clearly observed and the microbial cells indicated a good fluorescence
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Βακτηριακή & ιογενής ρύπανση των οστρακοειδώνΤσιμπουξή, Ανδρομάχη 01 August 2008 (has links)
Στα πλαίσια αυτής της διδακτορικής εργασίας μελετήθηκαν οι εμπορικά σημαντικότερες περιοχές καλλιέργειας και συγκομιδής οστρακοειδών του Ελλαδικού χώρου.
Κατά τη διάρκεια περιόδου 18 μηνών πραγματοποιήθηκε μηνιαία συλλογή δειγμάτων στρειδιών (Οstrea edulis) και μυδιών (Mytilus galloprovincialis), τα οποία συλλέχθηκαν από έξι (6) διαφορετικά σημεία του Ελλαδικού χώρου και αναλύθηκαν για τους εντεροϊούς (EV), τους αδενοϊούς (Adv), τον ιό της ηπατίτιδας Α (HAV), τους ιούς Noro I και II (NLVI και NLVII), για το βακτήριο Ε. coli, καθώς και για σωματικούς κολιφάγους, τους F-sperific RNA βακτηριοφάγους και τους βακτηριοφάγους του Β. fragilis. Επιπλέον αναπτύχθηκαν μέθοδοι τόσο για την ανίχνευση παθογόνων ιών ανθρώπινης προέλευσης στα οστρακοειδή, όσο και για την ανίχνευση των "πιθανών δεικτών" αυτών των ιών. Οι μέθοδοι εξετάστηκαν προκειμένου να αξιολογηθεί η απόδοση καλής ποιότητας από όλα τα εργαστήρια μέσω διεργαστηριακών αναλύσεων.
Η μέθοδος που εφαρμόστηκε σε αυτή τη μελέτη για την ανίχνευση των ιών στα οστρακοειδή βασίζεται στην εξαγωγή και την ομογενοποίηση του πεπτικού αδένα με χρήση διαλύματος γλυκίνης, pH 10, απομόνωση των νουκλεϊνικών οξέων και ενίσχυση του γονιδιώματος των ιών που αναλύονται.
Για την ανίχνευση του βακτηρίου E. coli χρησιμοποιήθηκε η μέθοδος των πολλαπλών σωλήνων, ενώ για την ανίχνευση των βακτηριοφάγων χρησιμοποιήθηκε η μέθοδος καλλιέργειας διπλοστιβάδας.
Για το βακτήριο E. coli, σε σύνολο 138 δειγμάτων, 110 δείγματα (ποσοστό 79,7%) βρέθηκαν να ανήκουν στην κατηγορία Α (MPN/100g σάρκας = <20 έως 220), δηλαδή χαρακτηρίζονται σαν δείγματα χαμηλής μόλυνσης, 25 δείγματα (ποσοστό 18,1%) βρέθηκαν να ανήκουν στην κατηγορία Β (MPN/100g σάρκας = 220 έως 3500), οπότε χαρακτηρίζονται σαν δείγματα μεσαίας μόλυνσης, ακατάλληλα προς κατανάλωση χωρίς να προηγηθεί διαδικασία εξυγίανσης, ενώ μόνο 3 δείγματα (ποσοστό 2,2%) βρέθηκαν να ανήκουν στη κατηγορία C (MPN/100g σάρκας =3500 έως >18000), δηλαδή είναι δείγματα υψηλής μόλυνσης.
Οι ιοί που εμφανίζονται με μεγαλύτερη συχνότητα στα οστρακοειδή της Ανατολικής Μεσογείου είναι οι αδενοϊοί (34% των δειγμάτων βρέθηκαν θετικά για τους αδενοϊούς) και ακολουθούν οι εντεροϊοί (16,7% των δειγμάτων βρέθηκαν θετικά για τους εντεροϊούς). Αντίθετα, ο ιός της ηπατίτιδας Α (ποσοστό θετικών δειγμάτων = 4,34%), καθώς και οι ιοί Noro I (ποσοστό θετικών δειγμάτων = 2,1%) και Noro II (ποσοστό θετικών δειγμάτων = 1,47%%) εμφανίζονται σε μικρό ποσοστό δειγμάτων.
Τέλος, 80 δείγματα (58%) βρέθηκαν θετικά (παρουσία πλακών βακτηριοφάγων) για τους σωματικούς κολιφάγους, με τον αριθμό των πλακών να κυμαίνεται από 71,4 έως 584800 pfp/100g, 52 δείγματα (37,7%) βρέθηκαν θετικά για τους F-specific RNA βακτηριοφάγους (αριθμός των πλακών από 76,2 έως 17051 p100g) και 33 δείγματα (24%) βρέθηκαν θετικά για τους βακτηριοφάγους του Bacteroides fragilis (αριθμός των πλακών από 194.5 έως 5266,25 pfp/100g).
Τόσο για το βακτήριο E. coli όσο και για τους βακτηριοφάγους πραγματοποιήθηκαν διεργαστηριακές αναλύσεις προτύπων, οι οποίες οδήγησαν στο συμπέρασμα ότι οι αντίστοιχες μέθοδοι χαρακτηρίζονται ως αξιόπιστες.
Η στατιστική ανάλυση έδειξε ότι το βακτήριο E. coli παρουσιάζει θετική συσχέτιση με τους σωματικούς κολιφάγους, αλλά δεν δείχνει στατιστικά σημαντική συσχέτιση ούτε με τους F-specific RNA βακτηριοφάγους, ούτε με κανέναν από τους ιούς εντερικής προέλευσης. Επίσης, θετική συσχέτιση παρουσίασαν οι αδενοϊοί με τους εντεροϊούς, καθώς και οι σωματικοί κολιφάγοι με τους βακτηριοφάγους του B. fragilis.
Η μοναδική συσχέτιση μεταξύ ιών εντερικής προέλευσης και βακτηριοφάγων βρέθηκε για τους αδενοϊούς και τους βακτηριοφάγους του B. fragilis. Εάν αυτό επιβεβαιωθεί σε περαιτέρω μελέτες, τότε η συγκεκριμένη κατηγορία βακτηριοφάγων θα μπορούσε να αποτελέσει έναν καλό δείκτη πρόβλεψης της παρουσίας αδενοϊών σε δείγματα οστρακοειδών.
Επιπλέον μελετήθηκε η σχέση που μπορεί να υπάρχει μεταξύ των φυσικοχημικών παραμέτρων και των μικροοργανισμών που εξετάστηκαν. Η επεξεργασία αυτή οδήγησε στο συμπέρασμα ότι το βακτήριο E. coli ανιχνεύεται σε μεγαλύτερα ποσά όταν το διαλυμένο οξυγόνο και η περιεκτικότητα σε άλας του ύδατος είναι αυξημένα. Αντίθετα, αύξηση της θερμοκρασίας οδηγεί σε μείωση της ανίχνευσης του βακτηρίου. Επίσης, η περιεκτικότητα σε άλας φαίνεται να επηρεάζει θετικά και τον ιό της ηπατίτιδας Α, αν και ο μικρός αριθμός θετικών δειγμάτων γι’αυτόν τον ιό δεν μπορεί να επιτρέψει την εξαγωγή ασφαλών συμπερασμάτων. Το pH και το διαλυμένο οξυγόνο των υδάτων οδηγεί σε αύξηση της ανίχνευσης των βακτηριοφάγων του B. fragilis, χωρίς όμως να μπορούμε να ισχυριστούμε ότι κάτι τέτοιο ισχύει, λόγω του μικρού αριθμού θετικών δειγμάτων γι’αυτούς τους βακτηριοφάγους. Τέλος, η αύξηση της θερμοκρασίας των υδάτων φαίνεται να οδηγεί και σε αύξηση της παρουσίας των F-specific RNA βακτηριοφάγων, και το ίδιο παρατηρήθηκε και με την αύξηση του διαλυμένου οξυγόνου στο νερό.
Η παρούσα μελέτη αποτελεί την πρώτη διεξοδική έρευνα για την ιογενή κοπρανώδη μόλυνση τον οστρακοειδών στην Ελλάδα. Επιπλέον, αντιπροσωπεύει την πρώτη μελέτη σχετικά με τη αποτελεσματικότητα των οργανισμών - δεικτών ιϊκής μόλυνσης, καθώς και για τη συσχέτιση της μικροβιολογικής επιβάρυνσης των οστρακοειδών με τις φυσικοχημικές παραμέτρους του περιβάλλοντος ύδατος. Η μελέτη κατάλληλων δεικτών που σχετίζονται με την παρουσία εντερικών ιών στα οστρακοειδή οδήγησε σε χρήσιμα συμπεράσματα για τη χρήση της ανίχνευσης των βακτηριοφάγων ως δεικτών ιϊκής μόλυνσης. Εντούτοις, απαιτείται περαιτέρω μελέτη προκειμένου να προσδιοριστεί και η χρήση των βακτηριοφάγων ως δεικτών που θα μαρτυρούν την προέλευση (ανθρώπινη ή ζωική) των εντερικών ιών που ανιχνεύονται στα οστρακοειδή. / In this doctorate investigation, important shellfish growing areas of Greece have been defined and studied.
Oysters (Ostrea edulis) and mussels (Mytilus galloprovincialis) were obtained on a monthly basis over an 18 month sampling period. These samples were collected by six (6) different points of Greece and were analyzed for enteroviruses (EV), adenoviruses (Adv), virus of hepatitis A (HAV), Noro viruses I and II (NLVI and NLVII ), bacterium E. coli, as well as for somatic coliphages, F-sperific RNA bacteriophages and bacteriophages of B. fragilis. Moreover, methods were developed for the detection of pathogenic viruses of human origin in the shellfish, as well as for the detection of potential "viral indicators". The methods were examined in order to validate the good quality performance from all the laboratories via interlaboratory analyses.
The method that used in this study for the detection of human enteric viruses in the shellfish is based on the export and homogenisation of digestive gland with glycine buffer at pH 10, viral nucleic acid extraction and amplification of the genomes of the analysed human viruses.
The procedure applied for detection of E. coli consists on a five tube, three dilution most probable number (MPN) method, while the method for the detection of bacteriophages was the double-agar-layer method.
For E. coli analysis, in a total number of 138 samples, 110 samples (79,7%) were found to belong in category A (MPN / 100 g of flesh = < 20 until 220), that it means these samples are characterized as samples of low pollution, 25 samples (18,1%) were found to belong in category B (MPN / 100 g of flesh = 220 until 3500), therefore are characterized as samples of intermediate pollution, inadequate to consumption without precedes process of cleansing, while only 3 samples (2,2%) were found to belong in category C (MPN / 100 g of flesh = 3500 until > 18000), that it means they are samples of high pollution.
The viruses that are presented with higher frequency in the shellfish of Eastern Mediterranean are the adenoviruses (34% of samples were found positive for adenoviruses) and follow enteroviruses (16,7% samples they were found positive for enteroviruses). On the contrary, virus of hepatitis A (percentage of positive samples = 4,34%), as well as the Noro I viruses (percentage of positive samples = 2,1%) and Noro II viruses (percentage of positive samples = 1,47%%) are presented in small number of samples.
Finally, 80 samples (58%) were found positive (presence of plaques of bacteriophages) for somatic coliphages, with the number of plaques between 71,4 and 584800 pfp / 100 g, 52 samples (37,7%) were found positive for F - specific RNA bacteriophages (number of plaques from 76,2 to 17051 pfp/ 100 g) and 33 samples (24 %) were found positive for the bacteriophages of B. fragilis (number of plaques from 194,5 to 5266,25 pfp / 100 g).
Interlaboratory studies involved the testing of reference materials of E. coli and bacteriophages were used as part of the good quality performance assessment program to be applied all over the study, and led to the conclusion that the corresponding methods are characterized by good reliability.
According to the statistical analysis of the results, the presence of E. coli seems to be significantly related with the presence of somatic coliphages. However, E. coli do not present significant statistical relation neither with F - specific RNA bacteriophages, nor with all of the viruses of intestinal origin. Also, adenoviruses were significantly related with enteroviruses, as well as somatic coliphages with the bacteriophages of B. fragilis.
The unique significant relation between viruses of intestinal origin and bacteriophages was found for the adenoviruses and bacteriophages of B. fragilis. If this is confirmed in further studies, then this category of bacteriophages could constitute a good indicator of forecast of presence adenoviruses in samples of shellfish.
Moreover, we studied the relation that can exist between the physic-chemical parameters and the micro-organisms that were examined. This analysis led to the conclusion that E. coli is detected in higher levels when the dissolved oxygen and the salinity of water are increased. On the contrary, increase of temperature leads to reduction of detection of E. coli. Also, the salinity appears to influence positively also virus of hepatitis A, even if the small number of positive samples of this virus cannot allow the export of sure conclusions. The pH and the dissolved oxygen of waters lead to increase of detection of bacteriophages of B. fragilis, but the small number of positive samples for these bacteriophages can’t give safe conclusions. Finally, the increase of temperature of waters appears to lead also to increase of presence of F - specific RNA of bacteriophages, and the same was also observed with the increase of dissolved oxygen in water.
This study constitutes the first extensive research for the fecal viral pollution of shellfish in Greece. Moreover, it represents the first study with regard to the effectiveness viral indicators, as well as for the correlation of microbiological parameters of shellfish with the physical-chemical parameters of water. The study of suitable indicators that are related with the presence of enteric viruses in the shellfish led to useful conclusions on the use of detection of bacteriophages as indicators of viral pollution. Nevertheless, further study is required in order to determine also the use of bacteriophages as indicators that will testify the origin (human or animal) of the enteric viruses that are detected in the shellfish.
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Emprego de microscopia de fluorescência para a quantificação microbiana em amostras salinas da indústria do petróleo / Use of fluorescence microscopy for microbial quantification in the saline samples of the petroleum industryDenise da Piedade Silva 09 December 2010 (has links)
Os micro-organismos constituem um grande problema em termos econômicos para a indústria petrolífera. Estes são responsáveis pela produção de substâncias corrosivas e a formação de biofilmes, que causam deterioração dos materiais metálicos. Os principais grupos microbianos presentes em amostras ambientais da indústria do petróleo são as bactérias anaeróbias heterotróficas totais (BANHT) e as bactérias redutoras de sulfato (BRS). Atualmente, a quantificação desses grupos microbianos é realizada através da técnica do Número Mais Provável (NMP) que estima o resultado em aproximadamente 28 dias. Neste trabalho foi otimizada uma metodologia para a microscopia de fluorescência de amostras salinas provenientes de tanques de armazenamento de água/óleo. As condições testadas foram o tipo de óleo de imersão, o tipo de diluente, o volume do corante, o volume da amostra corada e a concentração do fixador (glutaraldeído) numa tentativa de correlacionar com resultados de quantificação de BANHT e BRS através da técnica convencional do NMP. Nesse caso, as células totais foram quantificadas por microscopia de fluorescência utilizando o corante fluorescente laranja de acridina (AO). Verificou-se que houve uma correlação entre os resultados da quantificação de células totais por microscopia de fluorescência e os resultados de BANHT pela técnica do NMP, devido a pouca variação de valores expressos em ambas as quantificações. Entretanto, não foi possível correlacionar os resultados da quantificação de células totais com os resultados de BRS por NMP devido à grande variação dos valores de quantificação de BRS. Na microscopia de fluorescência, foi possível, quantificar os micro-organismos em aproximadamente 30 minutos e através das fotografias, verificou-se ainda que as amostras apresentaram-se nítidas e os micro-organismos com uma boa fluorescência / Microbial cells constitute a severe problem, from the economic point of view, for the petroleum industry. They are responsible for the production of corrosive metabolites and for the formation of biofilms, causing deterioration in the surface of metallic materials. The main microbial groups present in environmental samples from the petroleum industry include total anaerobic heterothrophic bacteria (TANHB) and sulfate-reducing bacteria (SRB). Nowadays, the quantification of those microbial groups is performed through the use of the most probable number technique (MPN), providing the final quantification after 28 days. In the present work a new methodology, based on fluorescence microscopy, was optimized on saline samples from water/oil storage tanks. The conditions tested were the type of immersion oil, type of diluent, the volume of the dye, the stained sample volume and concentration of fixative (glutaraldehyde) in order to quantify total cells, in an attempt to correlate with TANHB and SRB quantification through MPN. In that case, total cells were quantified with the help of acrydine orange as fluorescent dye. It could be observed a clear correlation between the results obtained for total cells quantification by fluorescence microscopy and the results obtained for TANHB through MPN technique, due to the negligible differences observed in both quantifications. However, when a correlation with SRB cells was tried results of total cells through fluorescence microscopy did not fit entirely. With the use of fluorescence microscopy, it was possible to quantify microbial cells in around 30 minutes and with the help of photographic reports obtained, it could be observed that the samples were clearly observed and the microbial cells indicated a good fluorescence
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Storage of Pine Tree Substrate Influences Plant Growth, Nitrification, and Substrate PropertiesTaylor, Linda Lea 05 December 2011 (has links)
Pine tree substrate (PTS) is a relatively new substrate for container crop production. There are no detailed studies that elucidate how storage time impacts PTS chemical, physical, and biological aspects. The objective of this research was to determine how PTS storage time influenced PTS chemical and physical properties, nitrification, and plant growth. Pine tree substrate was manufactured by hammer-milling chips of loblolly pine trees (Pinus taeda L.) through two screen sizes, 4.76 mm (PTS) and 15.9 mm amended with peat (PTSP). PTS and PTSP were amended with lime at five rates. A peat-perlite mix (PL) served as a control treatment. Prepared substrates were placed in storage bags and stored in an open shed in Blacksburg, Virginia. Subsamples were taken at 1, 42, 84, 168, 270, and 365 days. At each subsampling day, twelve 1-L containers were filled with each substrate. Six containers were left fallow and six were planted with marigold (Tagetes erecta L. "Inca Gold") seedlings. Substrate was also collected from select treatments for Most Probable Number assays to estimate density of nitrifying microorganisms, and for chemical and physical property analyses. Pour-through extracts were collected from fallow containers at 0, 2, and 4 weeks, and from marigold containers at harvest for determination of pH, electrical conductivity, ammonium-N and nitrate-N. At harvest, marigold height, width, and dry weight were measured. At least 1 kg·m-3 lime for PTS, and 2 to 4 kg·m-3 lime for PTSP were needed to maintain pH values ≥ 5.5 for 365 days. Bound acidity of unlimed PTS increased but cation exchange capacity for unlimed PTS and PTSP decreased over 365 days. Carbon to nitrogen ratio and bulk density values were unchanged over time in all treatments. There were minor changes in particle size distribution for limed PTS and unlimed and limed PTSP. Marigold growth in PTS and PTSP was ≥ PL in all limed treatments, except at day 1. Nitrite-oxidizing microorganisms were present and nitrification occurred in PTS and PTSP at all subsampling days. Pine tree substrate is relatively stable in storage, but pH decreases, and lime addition may be necessary to offset this decrease. / Ph. D.
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