Modern, large scale Cheddar cheese manufacture is dependent on reliable acid production by Lactococcus lactis subspecies cremoris and subspecies lactis starter cultures. Any inhibition of acid production may affect cheese quality, disrupt production schedules and reduce profitability. The presence of antibiotic residues in manufacturing milk resulting from the treatment of mastitis in lactating cattle is a potential source of starter culture inhibition. Therefore, a range of antibiotic concentrations was assessed for measurable inhibitory effects on acid production and compared to the minimum detectable concentrations by approved screening test procedures. Antibiotics were selected from formulations approved for use on lactating cattle for the treatment of mastitis. Novobiocin, lincomycin, oleandomycin and oxytetracyline HCl, all non-b-lactam antibiotics, inhibited acid production of one or more L. lactis strains at antibiotic concentrations below the detectable limit of standard screening procedures. / Depending on the antibiotic, either or both the Bacillus stearothermophilus (var. calidolactis) disk assay and/or the Delvo SP assay were ineffective at detecting the antibiotics at concentrations required to inhibit the starter strains. Consequently, antibiotic residues below the detectable limits of these testing procedures could cause significant starter culture inhibition, disrupting cheese making schedules. Another potential source of starter culture inhibition is related to raw milk quality and the practice of refrigerated storage prior to processing. Previous studies differed as to whether the growth of psychrotrophic organisms would have a detrimental impact on subsequent acid production by starter bacteria employed in cheese manufacture. In this study, no inhibition of acid production by a commercial L. lactis subsp. cremoris strain was evident when grown in milk that had undergone short term temperature abuse. Antimicrobial systems native to bovine milk may also have an adverse impact on starter culture performance. The present study assessed the inhibitory effect of an activated lactoperoxidase system (LPS) on a range of L. lactis cultures. All of the strains were significantly inhibited when grown on reconstituted skim milk in the presence of an active LPS. Inhibition of acid production by strains grown on glucose was also observed, leading to further investigations to describe the inhibitory process. A non-phosphoenolpyruvate phosphotransferase (PEP/PTS) dependent glucose transport system, first observed in 1980 in one L. lactis subsp. lactis strain, was hypothesised as a link in strain variations in LPS sensitivity. However, the LPS sensitive L. lactis subsp. cremoris strains tested did not take up glucose in a PEP depleted state, most likely due to their inability to utilise arginine as an ATP generating energy source. The questions remain unanswered whether cremoris strains possess this glucose transport mechanism and whether it could contribute to strain variations in LPS sensitivity. / In a subsequent investigation, galactose phosphotransferase system (PTS) deficient L. lactis strain ATCC 7962 demonstrated log phase growth inhibition when grown on galactose in the presence of the model LPS. Previously reported LPS mediated effects on the glycolytic enzyme hexokinase do not appear to explain this result. The present study confirmed strain variability in sensitivity to the model LPS among both Lactococcus lactis subspecies lactis and subspecies cremoris strains. Further, the observation that dithiothreitol significantly alleviated the inhibition of a highly sensitive cremoris strain, implicated the involvement of sulphydryl groups as the target of the transient inhibitory factors. Data collected excluded the possibility that portions of the metabolic pathways involved in fructose and galactose metabolism are sensitive to the LPS in cells possessing PEP/PTS capability. This study also identified potential directions of further work to elucidate the mechanism(s) of LPS inhibition.

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on June 18, 2009. Major professor: Phillip S. Tong, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Agriculture, with Specialization in Dairy Products Technology." "May 2009." Includes bibliographical references (p. 79-93). Also available on microfiche.

AN ABSTRACT OF THE THESIS OF JESSE MILLER, for the Master of Science degree in PLANT, SOIL, and AGRICULTURAL SYSTEMS, presented on May 13, 2016 at Southern Illinois University Carbondale. TITLE: THE EFFECTS OF STARTER FERTILIZER ON SOYBEAN INFESTED WITH FUSARIUM VIRULIFORME OR RHIZOCTONIA SOLANI MAJOR PROFESSOR: Dr. Jason Bond Fusarium virguliforme (Aoki), the fungus that causes sudden death syndrome of soybeans (SDS), is prevalent in most of the soybean (Glycine max L. Merr.) production regions throughout the United States. Sudden death syndrome management has been limited to cultural practices and host resistance. Rhizoctonia solani (Kühn) is a fungus responsible for pre-emergence and post emergence damping off. Control methods include seed treatments and cultural practices. Several companies have advocated the use of in-furrow starter fertilizers in soybean production. Promoting root growth and emergence are a couple of the alleged benefits. It is unknown if the increased fertility in the root zone may actually increase or decrease the severity of root or seedling diseases. An objective of this study is to determine if the starter fertilizers (2-6-16), (7-12-11), (3-10-13) Nachurs Alpine Solutions™ impacts seedling disease caused by Rhizoctonia solani and soybean yield. A second objective is to determine if starter-fertilizer influences the incidence and severity of SDS and soybean yield. One trial was infested with R. solani at the rate of 0.9 g of inoculum/30.5 centimeters of row. A second trial was infested with F. virguliforme at the rate of 2.25 g/30.5 centimeters of row. Inoculum consisted of sterilized white sorghum inoculated with either pathogen. Plots were 3.04 meters wide by 6.1 meters in length with row spacing of 0.76 meters. Trials took place during the growing season of 2014 and 2015. In 2014, a randomized complete block design consisted of 4 treatments that were replicated 6 times and planted into 4 row plots. Treatments consisted of treated (Metalaxl™, Fluxapyroxad™, Pyraclostrobin™, and Imidacloprid™) or non-treated seed (‘Asgrow 4730’) combined with either fertilizer (2-6-16) or non-fertilizer. Across both trials, there were no seed treatment and fertilizer rate interactions. In the R. solani trial, stand counts were similar between the fertilizer and non-fertilizer treatments. Stand counts were higher when the seed treatment was used. There was no significant difference in soybean yield regardless of treatment. In the F. virguliforme trial, stand counts were reduced in the fertilizer treatment when compared to the non-fertilizer treatment. Foliar symptoms of SDS and soybean yield were not affected by treatment. In 2015, there were changes in treatment structure due to additions of fertilizer treatments 7-12-11 and 3-10-13. Seed treatments and randomized complete block design remained for 2015. Stand counts were higher in plots that received fertilizer treatments in the R. solani trial. Stand counts were lower in R. solani plots with treated seed. Yield was not influenced by seed treatment but was increased by 3-10-13 and 7-12-11 fertilizer treatments. For the F. virguliforme trial, reduced stand counts were found in the plots with seed treatments. Seed treatments did not influence yield. Fertilizer did not impact stand or yield. Foliar symptoms of SDS were not influenced by seed treatment or fertilizer.

The thesis was processed in cooperation with Pribina s.r.o. The aim of the thesis was the monitoring of the starters of cheeses with the white fungus on the surface. The thesis was engaged in the monitoring process of a souring curve of used starters. This monitoring was based on temperature, titrating acidity and pH measured in the time interval. The souring curve was evaluated as the indirect measurement change of acidity of the starter in the time period. Further, the activity of detached starters was measured. The measurement was based on the change of pH measured in the time period. The influence of the culture medium was monitored by changes in behaviour of the bacterial cultures. The monitored starters were compounded of mezophilic and termophilic bacterial strains.

<p>Starter fertilizer applied with or near the seed at planting often enhances early season maize growth (<i>Zea mays</i> L.) but does not always result in higher grain yield. Other responses to starter fertilizer, such as reduced thermal time to reach silking, which suggests accelerated plant development, have been documented. The objective of this study was to examine the relationship between dry matter production and accelerated plant development with respect to 5x5 cm starter (ST) and in-furrow popup (PU) fertilizer. A field experiment was conducted in 2016 with three at-planting treatments consisting of one single rate and formulation of ST (53 N and 21 P kg ha^-1) or PU (4 N and 6 P kg ha^-1), and an untreated control. In 2018, the study included four additional site-years with treatments consisting of an intermediate (ST) or high (STH) starter fertilizer rate, and an untreated control. For ST treatments, depending on location, nitrogen (N) and phosphorus (P) fertilizer rates ranged between 26-28 and 6-10 kg ha^-1, respectively, and for STH treatments N and P fertilizer rates ranged between 47-56 and 12-20 kg ha^-1, respectively. In 2016, as new leaf collars appeared, dry matter increased exponentially, but at an equal number of leaf collars ST and PU had similar dry matter as the control. In 2018, dry matter for ST, STH, and control was also similar when normalized for leaf collar number at each site. Overall, these results suggest that enhanced dry matter at a given point in time from ST, STH, or PU was a function of accelerated leaf development as opposed to physically more robust plants of the same leaf collar number. Grain yield was unaffected by ST, STH, or PU treatments at any site-year.</p> <p>Methods used to study roots in crop fields have included extracting soil cores, excavating entire root systems, using radioactive and non-radioactive chemical tracers, or using mini-rhizotrons. However, due to the intensive nature, level of difficulty, and cost associated with these methods, their use in crop fields has been minimal. We developed an alternative method to quantify maize rooting density over time. The method involved perforated cylinders installed vertically into the soil at different distances from the row, which made roots growing into the cylinder voids visible from the soil surface and possible to count [root number density (RND)] at different depths using a video recording device (1m-long borescope). The objective of this study was to determine if the cylinder method could quantify rooting density throughout the growing season (V3, ~V7, and R2-R3) similar to the more intensive soil core method, compared in two starter fertilizer trials [continuous maize (M/M) and maize/soybean (M/S) rotation]. Cylinders were constructed with perforated (49% voids) polypropylene resin to an inside diameter of 2.58 cm and a length of 30 cm. Cylinders were painted with red and green alternating markings (5 cm) on the outside and inside walls to visually aid in identifying depth from the soil surface. After plants emerged, cylinders were inserted vertically into the soil after drilling a 3.5 cm diameter borehole. Ten perforated cylinders were installed in a parallel line 13 or 25 cm away from, and on both sides of, the planted row. Soil cores were also collected at the same relative locations for conducting root extractions and subsequent calculation of length density (RLD). At V3, methods frequently resulted in the same significant (<i>p≤</i>0.10) or insignificant (<i>p></i>0.10) main and interaction effects in both fields, whereas at ~V7 and R2-R3, there were several instances where the cylinder method failed to detect the same effects as the soil core method. At times both the cylinder method and the soil core method detected significant main or interaction effects, but the direction of the effect was opposite.</p> <p>In-furrow biological (BIO) and plant growth regulator (PGR) products, otherwise known as biostimulants, are becoming increasingly available in the commercial maize market. The objective of this study was to compare the effects of several commercially available in-furrow biostimulant products on maize growth and development, nutrient uptake, and grain yield to starter fertilizer in large-plot field trials. The study was conducted across five locations in 2016, and three locations each in 2017 and 2018 at Purdue University research farms. At each location, treatments consisted of four different BIO or PGR products plus starter fertilizer, starter fertilizer only, and an untreated control. Compared to the control, starter-only increased grain yield at 7 of 8 site-years in 2016 and 2018 ranging from 125 to 753 kg ha^-1, depending on location, but no increase was found at any of the 3 locations in 2017. Grain yield was increased (3 of 11 site-years) or decreased (2 of 11 site-years) by some of the BIO or PGR products, but in 6 of 11 site-years none of the products affected yield compared to starter-only.</p>

The proteolytic system of Lactococcus lactis starter cultures influences both flavor and the characteristic body and texture of cheese. The ability to further understand and control how different components of this proteolytic system work together to hydrolyze milk proteins would be of immense importance to the dairy industry. The goal of this research was to characterize Lactococcus lactis subsp. lactis starter bacteria with varying prt operon compositions by proteinase specificity, aminopeptidase and lipase activities, growth, and influence on cheese flavor. By using a cheese slurry system, a statistical model to predict milk protein hydrolysis patterns was developed. Lactococcus lactis subsp. lactis C20 has five plasmids of 55 (pJK550), 48 (pJK480), 43 (pJK430), 3.7 (pJK037), and 2.1 (pJK021) kilo bases. Two of these plasmids (pJK550 and pJK430) are necessary for full proteolytic capability, i.e., clotting milk in 16 h at 20°C. Plasmid pJK550 codes for a proteinase that catalyses the first step in casein degradation. Plasmid pJK430 codes for an oligopeptide transport system, which further transports peptides across the membrane for bacterial metabolism. Strains were constructed containing twelve different combinations of proteolytic phenotypes, such as Lac+PrtP+Opp+, Lac+PrtP+Opp-, Lac+PrtP-Opp+, Lac+Prt-Opp-, Lac-PrtP+Opp+, Lac-PrtP+Opp-, Lac-Prt-Opp+, and Lac-Prt-Opp-. The proteinase specificities of these strains toward milk proteins were dependent on the genotypes present. Genetically all strains showed a P1-type proteinase. Enzymatically C20 had group g proteinase specificity, whereas the rest of the strains containing the proteinase gene showed mixed group specificity. a a-Casein was only slightly hydrolyzed by all strains. B-Casein had a variable pattern, as did mixed casein and milk. K-Casein hydrolysis showed similar degradation patterns in all strains except CB06, which varied in its profile from the other strains. Sensory evaluation showed that culture had a significant effect on rancidity but not on acidity or bitterness. It also showed that the proteolytic system was associated with lipase activity in these strains. A statistical prediction model was developed that allowed strains to be classified according to their amino acid hydrolysis patterns. Mixed casein solution proved to be the best substrate for this analysis. Relationships among strains were seen more easily with canonical analysis and distance tables than by looking only at amino acid hydrolysis patterns.

Within commercial broiler production, feed and feed manufacturing costs account for 60 to 70% of production costs. Of these feed costs specifically, ingredients that supply energy and protein represent the highest expenditure, verifying the importance of knowing the nutrient requirements of current broiler strains to ensure accurate least-cost formulation. To reduce these production costs and optimize performance, primary breeder companies and nutritionists continuously strive to improve nutrient utilization of commercial broiler strains. As a result of this, a great magnitude of work is conducted to determine the nutrient requirements for broilers, especially amino acids. Therefore, the overall objective of this dissertation was to utilize processing measurements, multiple statistical models, and economics as a whole to determine the optimal percent digestible Isoleucine:digestible Lysine ratio (dIle:dLys) for Ross 708 x Ross YP male broilers to improve growth performance and economic return. Chapter 2 determined the optimal dIle:dLys ratio for the starter phase (d 0-18), while Chapter 3 determined the optimal ratio for the grower phase (d 14-28), and Chapter 4 determined the optimal ratio for the finisher phase (d 28-42). All experimental diets for each respective growth phase were created from a common deficient corn and soybean meal-based diet. After manufacturing, half was retained to create the summit diet through the addition of crystalline Ile. The remaining five experimental diets for each respective growth phase were obtained by blending proportions of the deficient and summit diets. All dIle:dLys ratios were estimated using quadratic regression (QR; 95% of the asymptote), as well as linear and quadratic broken line models (LBL; QBL). Regression analysis from d 0-18 using multiple regression models estimated the ratios to range from 63-73% for BW and BWG and 68-74% for FCR. Based on the data from the grower phase and using multiple regression models, the estimated ratios ranged from 62-68% for BW and BWG and 67-70% for FCR and are similar to the current breeder nutrient specifications. Data from the finisher phase and once again using multiple regression models estimated the ratios to range from 62-66% for BW and BWG and 63-66% for FCR.

Little research has been done in the humid mid-Atlantic region to develop full-season N fertilizer recommendations for dryland no-tillage grain sorghum (Sorghum bicolor L. Moench) production. The objectives of this study were: (i) to determine the optimum rate of band-placed starter N fertilizer needed in combination with side-dress N applications to achieve economic grain yields, (ii) to investigate if pre-plant broadcast N applications are as efficient as band-placed plus side-dress N applications, (iii) to evaluate the response of grain sorghum yield to partitioned side-dress N applications, and (iv) to study the influence of residual soil profile mineral-N (nitrate and ammonium) on sorghum response to applied N fertilization. Multi-location field studies were conducted over three years. A range of N treatments of various starter-band and side-dress N rates were applied. The experimental data indicate that an optimum rate of N fertilization depends on residual soil mineral-N. Little or zero starter-band-N in conjunction with side-dress-N applications of 130 kg of N ha-1 for soils testing high in mineral-N ( 50 kg N ha-1 in the top 0.3m of surface soil) at planting, and a starter-band-N supplement of 40 kg N ha-1 in conjunction with 130 kg N ha-1 side-dress N for soils testing low in mineral-N at planting, optimized the grain sorghum yields in these experiments. Broadcast N applications were observed to be as efficient as band placed N applications when followed by rainfall soon after application. Grain sorghum yields did respond to the partitioned side-dress N applications. However, partitioning of side-dress N application again depends on the residual mineral-N level present in the soil. In order to consider residual soil mineral-N in making N fertilizer recommendations "Associated Nitrogen Fertilizer Equivalency" (ANFE) values were calculated. ANFE is the amount of applied N that has potential to produce the same yield as that produced by the residual soil mineral-N. The N fertilizer recommendations based on ANFE values were quite close for two out of four sites as compared to the N rates at which the maximum yields were obtained in this study. / Ph. D.

Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 Resumo - Rogerio Pinho Dias.pdf: 124846 bytes, checksum: 695e36f2af2139d1d4a624a0e573473f (MD5) Previous issue date: 2008-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a study for implementation of the control of limitation of electromagnetic torque develops for three-phase induction motor in soft-starters applications. The proposed method is based on the electromagnetic torque estimation from the measurement of stator currents and the stator voltages. The related problems to the stator flux estimation by pure integration of the equation of the stator voltages are minimized with use of low pass filters in the place of pure integrators and high pass filter at the analogical input to eliminate the measurement offset error. The amplitude and phase errors resultant of the filtering process are reduced with the use of a factor of correction in the final stage of integration. Gotten experimental results validate the proposed method showing its viability in applications where the objective is to control only the start or stop process of three-phase induction motors and possibility the applications with soft-starter - to any type of load that does not need speed variation in permanent regimen. / Este trabalho apresenta um estudo para implementação de um controle de limitação do torque eletromagnético produzido pelo motor de indução trifásico para aplicação em chaves eletrônicas de partida suave. O método proposto é baseado na estimação do torque eletromagnético através da medição das correntes e tensões estatóricas. Os problemas relacionados à estimação do fluxo estatórico através da integração da força contra eletromotriz são minimizados com a utilização de filtros passa baixa no lugar dos integradores puros e de filtros passa alta nas leituras analógicas das tensões e correntes estatóricas. Os erros de amplitude e fase devidos aos processos de filtragem são reduzidos com a utilização de um fator de correção na etapa final de integração. Resultados experimentais validam o método proposto mostrando a viabilidade de sua aplicação no controle dos processos de partida e parada do motor de indução trifásico, possibilitando assim, a aplicação das chaves eletrônicas de partida suave - a qualquer tipo de carga - que não necessite da variação de velocidade em regime permanente

<p>Kombuha je tradicionalni napitak koji se dobija fermentacijom zaslađenog crnog<br />ili zelenog čaja, fiziolo&scaron;kom aktivno&scaron;ću čajne gljive, koja predstavlja simbiozu<br />autohthonih vrsta kvasaca i bakterija sirćetnog vrenja. Cilj rada je bio da se ispita<br />biolo&scaron;ka aktivnost konzumnih kombuha napitaka (titrabilne kiselosti 3,5-4 g/L) od<br />crnog čaja (<em>Camellia sinensis</em> L), čaja ehinacee (<em>Echinacea purpurea</em> L.) i<br />rtanjskog čaja (<em>Satureja montana</em> L.). Za ispitivanje antimikrobne aktivnosti<br />kombuha napitaka upotrebljeni su sledeći sojevi bakterija, kvasaca i plesni:<br /><em>Pseudomonas aeruginosa</em>, <em>Staphylococcus aureus</em>, <em>Bacillus sp.</em>, <em>Salmonella<br />enteritidis, Proteus mirabilis, Escherichia coli, Sarcina lutea, Saccharomyces<br />cerevisiae, Candida pseudotropicalis, Rhodotorula sp., Penicillium<br />aurantiogriseum, Aspergillus niger i Aspergillus flavus</em>. Antioksidativna aktivnost<br />kombuha napitaka ispitana je na DPPH i OH radikale ESR spektralnom metodom.<br />Antiproliferativna aktivnost čajeva i kombuha napitaka od crnog i rtanjskog čaja<br />ispitana na tri ćelijske linije humanih karcinoma: HeLa (epitelni karcinom<br />cerviksa), MCF-7 (adenokarcinom dojke) i HT-29 (adenokarcinom debelog<br />creva). Pored istraživanja biolo&scaron;ke aktivnosti kombuha napitaka, cilj rada je bio da<br />se ispitaju i neki od osnovnih parametara kombuha fermentacije &ndash; optimalna<br />količina izvora ugljenika i azota u medijumu za kultivaciju, geometrijske<br />karakteristike fermentora, inokulacija starter kulturama. Definisanje kritičnih<br />parametara kombuha fermentacije je bio osnov za izvođenje matematičkog<br />modela za scale-up fermentativnog procesa.</p> / <p>Kombucha is a traditional beverage obtained by fermenting sweetned black or<br />green tea with tea fungus, which represents a symbiotic combination of acetic acid<br />bacteria and autochthonous yeast species. In this study, the antimicrobial,<br />antioxidative and antiproliferative activity of kombucha beverages (titratable<br />acidity 3,5-4 g/L) obtain from black tea (<em>Camellia sinensis</em> L), echinacea tea<br />(<em>Echinacea purpurea</em> L.) and rtanj tea (<em>Satureja montana</em> L.) were tested.<br /><em>Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus sp., Salmonella<br />enteritidis, Proteus mirabilis, Escherichia coli, Sarcina lutea, Saccharomyces<br />cerevisiae, Candida pseudotropicalis, Rhodotorula sp., Penicillium<br />aurantiogriseum, Aspergillus niger i Aspergillus flavus</em> were used as test<br />microorganisms for examination of antimicrobial activity. The antioxidant activity<br />of differently prepared kombucha beverages was examined agains DPPH and OH<br />radicals by ESR-spectrometry. Antiproliferative activity of black tea kombucha<br />and Satureja montana kokmbucka was measured by sulforhodamine B<br />colorimetric assay on HeLa (cervix epitheloid carcinoma), HT-29 (colon<br />adenocarcinoma), and MCF-7 (breast adenocarcinoma) cells line. Also, same<br />parametars of kombucha fermentation &ndash; optimal quantity of source of carbon and<br />nitrogen in cultivation medium, geometric characteristics of reactors and<br />inoculation by starter culture &ndash; were tested. Definition of critical parameters of<br />kombucha fermentation is important for derivation of mathematical model for<br />scaling-up fermentation process.</p>