The word cybernetics has its roots in the Greek word \kybernetes" or \steers-man" and was coined by Norbert Wiener in 1948 to describe \the science of control and communication, in the animal and the machine". The discipline focuses on the way various complex systems (animals/machines) steer towards/maintain their goals utilizing information, models and control actions in the face of various disturbances. For a given animal/machine, cybernetics considers all the possible behaviors that the animal/machine can exhibit and then enquires about the constraints that result in a particular behavior. The thesis focuses on the application of principles of cybernetics to the modeling and optimization of bioreactors and lies at the interface of systems engineering and biology. Specifically, it lies at the interface of control theory and the growth behavior exhibited by microorganisms. The hypothesis of the present work is that the principles and tools of control theory can give novel insights into the growth behavior of microorganisms and that the growth behavior exhibited by microorganisms can in turn provide insights for the development of principles and tools of control theory. Mathematical models for the growth of microorganisms such as stoichiometric, optimal and cybernetic assume that microorganisms have evolved to become optimal with respect to certain cellular goals or objectives. Typical cellular goals used in the literature are the maximization of instantaneous/short term objectives such biomass yield, instantaneous growth rate, instantaneous ATP production rate etc. Since microorganisms live in a dynamic world, it is expected that the microorganisms have evolved towards maximizing long term goals. In the literature, it is often assumed that the maximization of a short term cellular goal results in the maximization of the long term cellular goal. However, in the systems engineering literature, it has long been recognized that the maximization of a short term goal does not necessarily result in the maximization of the long term goal. For example, maximization of product production in a fed-batch bioreactor involves two separate phases: a first phase in which the growth of microorganisms is maximized and a second phase in which the production of product is maximized. An analogous situation arises when the bacterium E. coli passes through the digestive tract of mammals wherein it first encounters the sugar lactose in the proximal portions and the sugar maltose in the distal portions. Mitchell et al. (2009) have experimentally shown that when E. coli encounters the sugar lactose, it expresses the genes of maltose operons anticipatorily which reduces its growth rate on lactose. This regulatory strategy of E. coli has been termed asymmetric anticipatory regulation (AAR) and is shown to be beneficial for long term cellular fitness by Mitchell et al. (2009). The cybernetic modeling framework for the growth of microorganisms, developed by Ramakrishna and co-workers, is extended in the present thesis for modeling the AAR strategy of E. coli. The developed model accurately captures the experimental observations of the AAR phenomenon, reveals the inherent advantages of the cybernetic modeling framework over other frameworks in explaining the AAR phenomenon, while at the same time suggesting a scope for the generalization of the cybernetic framework. As cybernetics is interested in all the possible behaviors that a machine (which is, in the present case, microorganism) can exhibit, a rigorous analysis of the optimal dynamic growth behavior of microorganisms under various constraints is carried out next using the methods of optimal control theory. An optimal control problem is formulated using a generalized version of the unstructured Monod model with the objective of maximization of cellular concentration at a fixed final time. Optimal control analysis of the above problem reveals that the long term objective of maximization of cellular concentration at a final time is equivalent to maximization of instantaneous growth rate for the growth of microorganisms under various constraints in a two substrate batch environment. In addition, reformulation of the above optimal control problem together with its necessary conditions of optimality reveals the existence of generalized governing dynamic equations of the structured cybernetic modeling framework. The dynamic behavior of the generalized equations of the cybernetic modeling framework is analyzed further to gain insights into the growth of microorganisms. For growth of microorganisms on a single growth limiting carbon substrate, the analysis reveals that the cybernetic model exhibits linear growth behavior, similar to that of the unstructured Contois model at high cellular concentrations, under appropriate constraints. During the growth of microorganisms on multiple substitutable substrates, the analysis reveals the existence of simple correlations that quantitatively predict the mixed substrate maximum specific growth rate from single substrate maximum specific growth rates during simultaneous consumption of the substrates in several cases. Further analysis of the cybernetic model of the growth of S. cerevisiae on the mixture of glucose and galactose reveals that S. cerevisiae exhibits sub-optimal dynamic growth with a long diauxic lag phase and suggests the possibility for S. cerevisiae to grow optimally with a significantly reduced diauxic lag period. Since cybernetics is interested in understanding the constraints under which a particular machine (microorganism) exhibits a particular behavior, a methodology is then developed for inferring the internal constraints experienced by the microorganisms from experimental data. The methodology is used for inferring the internal constraints experienced by E. coli during its growth on the mixture of glycerol and lactose. An interesting question in the study of the growth behavior of microorganisms concerns the objective that the microorganisms optimize. Several studies aim to determine these cellular objectives experimentally. A similar question that is relevant to the optimization of fed-batch bioreactors is \what are the objectives that are to be optimized by the feed flow rate in various time intervals for the optimization of a final objective?" It was mentioned previously that the maximization of product production in a fed-batch bioreactor involves maximization of growth of microorganisms first and the maximization of product production later. However, such guidelines can only be stated for relatively simple bioreactor optimization problems and no such guidelines exist for sufficiently complex problems. For complex problems, the answer to the above question requires the formulation and solution of a genetic programming problem which can be quite challenging. An alternative numerical solution methodology is developed in the present thesis to address the above question. The solution methodology involves the specification of bioreactor objectives in terms of the bioreactor trajectory in the state space of substrate concentration-volume. The equivalent control law of the sliding mode control technique is used for finding the inlet feed ow rate that tracks the bioreactor trajectory accurately. The search for the best bioreactor trajectory is carried out using the stochastic search technique genetic algorithm. The effectiveness of the developed solution methodology in determining the optimal bioreactor trajectory is demonstrated using three challenging bioreactor optimization problems.

Os resíduos de pescado são descartados, em sua maioria, gerando um alto impacto ao ambiente; ou subutilizados em co-produtos de baixo valor agregado. O presente estudo objetivou a obtenção de hidrolisados proteicos a partir de resíduos sólidos oriundos do processamento industrial de tilápia vermelha (Oreochromis niloticus var.), avaliando sua capacidade antioxidante e eficiência como fonte suplementar de nitrogênio para o crescimento de bactérias e leveduras. Um total de 30 carcaças inteiras não evisceradas, sem filé e pele, com peso médio de 741,53g, foram mecanicamente homogeneizadas. A composição centesimal apresentou 54,34±0,31g/100 g de umidade, 8,46±0,72 g/100 g de cinza, 27,03±2,94 g/100 g de proteína e 10,17±0,65 g/100 g de lipídeos, assim como a carga microbiana do homogeneizado estava dentro dos limites de tolerância preconizados pela legislação vigente para consumo humano. Foram otimizadas as condições de hidrólise proteica quanto à concentração de substrato, enzima e tempo de hidrólise, dos resíduos sólidos de tilápia vermelha, resultando na obtenção de modelos preditivos para o grau de hidrólise (GH) produzido tanto pelas enzimas endógenas como pelas enzimas comerciais neutrase e papaína. OGH diminuiu significativamente (p < 0,05) com o incremento da concentração de substrato, exceto na hidrólise produzida pelas enzimas endógenas sob condições ótimas para papaína. Não obstante, o GH produzido pelas enzimas endógenas aumentou significativamente (p < 0,05) com o incremento do tempo de hidrólise, enquanto que o incremento na concentração de papaína também aumentou significativamente (p <0,05) o GH nos resíduos. Rendimento de 80,95 ± 3,12%, e GH de 45,33 % foram alcançados sob condições ótimas para neutrase (22 g substrato/100 mL e 0,277 g enzima/100 g proteína durante 3 min), enquanto que a papaína teve um rendimento de 82 ± 2,21% e GH de 42,37% sob condições ótimas (18,5 g substrato/100 mL e 0,570 g enzima/100 g proteína durante 3 min). As peptonas produzidas apresentaram atividade antioxidante quanto à capacidade de sequestro dos radicais livres ABTS e DPPH, sendo esta incrementada significativamente (p < 0,05) com o aumento da concentração de peptona. As peptonas também foram altamente eficientes para o crescimento das bactérias Escherichia coli, Listeria monocytogenes e Staphylococcus aureus, e para a levedura Saccharomyces cerevisiae, sendo similares ou mesmo superiores quando comparadas às três peptonas comerciais. Os resultados obtidos no presente trabalho demonstraram, portanto, que os hidrolisados proteicos obtidos a partir de resíduos sólidos de tilápia vermelha podem ser uma fonte alternativa de antioxidantes e de nitrogênio para crescimento de microrganismos. / Fish wastes are mostly discarded in Brazil, causing a high environmental impact, or underused in low-valuable coproducts. The present study aimed to obtain protein hydrolysates from solid wastes of red tilapia (Oreochromis niloticus var.), evaluating their antioxidant activity as well as their efficiency as supplemental source of nitrogen for the growth of bacteria and yeasts. Thirty carcasses with viscera of red tilapia (i.e. tilapia without fillet and skin), with an average weight of 741.53 g, were mechanically homogenized. Proximate composition and microbial quality were determined, containing 54.34±0,31g/100 g of moisture, of ash, 27.03±2,94 g/100 g of protein and 10.17±0,65 g/100 g of lipids, as well as microbial levels in concordance with the legal limits in force. Conditions for the proteolysis of solid wastes of red tilapia (concentration of substrate, concentration of enzyme and time of hydrolysis) were optimized. Predictive models for the degree of hydrolysis (DH) generated by both endogen enzymes and thecommercial enzymes neutrase and papain were obtained. DH decreased significantly (p < 0.05) with the increase of the concentration of substrate, except in the hydrolysis caused by the endogen enzymes under optimal conditions for papain. However, DH produced by the endogen enzymes increased significantly (p < 0.05) with the increment of the time of hydrolysis. Meanwhile, DH increase significantly (p < 0.05) with the increase of the concentration of papain. A yield of 80.95 ± 3.12% and a DH of 45.33 % were achieved under optimized conditions for neutrase (i.e. 22 g substrate/100 mL and 0.277 g enzyme/100 g protein for 3 min). Moreover, proteolysis with papain reached a yield of 82 ± 2.21% and a DH of 42.37% under optimized conditions (i.e. 18.5 g substrate/100 mL and 0.570 g enzyme/100 g protein for 3 min). Obtained peptones showed antioxidant activity in terms of inhibition of free radicals of ABTS and DPPH, being increased significantly (p < 0.05) with the increment of the concentration of peptone. Peptones also had a high efficiency for the growth of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Saccharomyces cerevisiae, being comparatively similar or higher than commercial peptones. Therefore, results obtained in the present study demonstrated that protein hydrolysates from solid wastes of red tilapia could be an alternative source of antioxidants and nitrogen for the use in bioprocess.

Zur Beschreibung von realen Prozessen werden oft Differentialgleichungen herangezogen. Liegen nun Messdaten von diesen Prozessen vor, so sollen auch die Parameter im mathematischen Modell so gewählt werden, dass diese den Messungen entsprechen. Dieser Vortrag zeigt, wie dies in Mathcad mit der Funktion genfit realisiert werden kann.

The problem of segmenting linearly ordered data is frequently encountered in time-series analysis, computational biology, and natural language processing. Segmentations obtained independently from replicate data sets or from the same data with different methods or parameter settings pose the problem of computing an aggregate or consensus segmentation. This Segmentation Aggregation problem amounts to finding a segmentation that minimizes the sum of distances to the input segmentations. It is again a segmentation problem and can be solved by dynamic programming. The aim of this contribution is (1) to gain a better mathematical understanding of the Segmentation Aggregation problem and its solutions and (2) to demonstrate that consensus segmentations have useful applications. Extending previously known results we show that for a large class of distance functions only breakpoints present in at least one input segmentation appear in the consensus segmentation. Furthermore, we derive a bound on the size of consensus segments. As show-case applications, we investigate a yeast transcriptome and show that consensus segments provide a robust means of identifying transcriptomic units. This approach is particularly suited for dense transcriptomes with polycistronic transcripts, operons, or a lack of separation between transcripts. As a second application, we demonstrate that consensus segmentations can be used to robustly identify growth regimes from sets of replicate growth curves.

Microrganismos fotossintetizantes têm sido utilizados por muitos anos como alimento humano devido ao seu alto conteúdo de proteína e valor nutricional. A Spirulina platensis pode ser uma fonte alternativa de proteína para a alimentação, bem como pode possibilitar a obtenção de outros produtos, como pigmentos, vitaminas e lipídios, principalmente ácidos graxos polinsaturados, como o &#947;-linolênico. Neste trabalho, foram estudadas as influências da concentração de cloreto de amônia no meio de alimentação (N0) e da vazão específica de alimentação (D) no cultivo de Spirulina platensis por processo contínuo, avaliando parâmetros cinéticos de crescimento bem como a composição das biomassas obtidas. A produtividade em células máxima obtida (63,9 mg.L-1.dia-1) foi comparável àquelas obtidas em processos descontínuos e descontínuos alimentados, para nitrato de potássio e cloreto de amônia como fontes de nitrogênio, respectivamente. O máximo conteúdo de proteína na biomassa foi de 72,5 %, obtido em experimento conduzido com N0 = 10 mmolar e D = 0,083 dia-l. Os melhores resultados em termos do teor do ácido &#947;-linolênico na fração lipídica da biomassa foi empregando vazão específica de alimentação de 0,110 dia-1 e concentração de cloreto de amônio no meio de alimentação de 1mmolar. / Photosynthesizing microorganism has been used for many years as human food because of its high protein content and nutritional value. Spirulina platensis can be an alternative source of protein for food purpose, as well as the possibility of obtaining other products like pigments, vitamins and lipids, mainly polyunsaturated fat acids like &#947;-linolenic. In this work, they were studied the influence of the ammonium chloride concentration in the feeding nutrient medium (N0) as well as the dilution rate (D) on the Spirulina platensis cultivation by continuous process, evaluating the kinetics parameters of the growth as well as the composition of the biomasses obtained. The maximum cell productivity obtained (63.9 mg.L-1.day-1) was c¬omparable with that ones obtained using batch and fed-batch processes for nitrate and ammonium chloride as nitrogen sources, respectively. The highest protein biomass content was 72.5 %, obtained in experiment carried out with N0 = 10 mmolar and D = 0.083 day-1. The best result in terms of the &#947;-linolenic acid content in the lipid fraction of the biomass was employing dilution rate of the 0.110 day -1 and 1 mmolar of the ammonium chloride in the feeding nutrient medium.

Microrganismos fotossintetizantes têm sido utilizados por muitos anos como alimento humano devido ao seu alto conteúdo de proteína e valor nutricional. A Spirulina platensis pode ser uma fonte alternativa de proteína para a alimentação, bem como pode possibilitar a obtenção de outros produtos, como pigmentos, vitaminas e lipídios, principalmente ácidos graxos polinsaturados, como o &#947;-linolênico. Neste trabalho, foram estudadas as influências da concentração de cloreto de amônia no meio de alimentação (N0) e da vazão específica de alimentação (D) no cultivo de Spirulina platensis por processo contínuo, avaliando parâmetros cinéticos de crescimento bem como a composição das biomassas obtidas. A produtividade em células máxima obtida (63,9 mg.L-1.dia-1) foi comparável àquelas obtidas em processos descontínuos e descontínuos alimentados, para nitrato de potássio e cloreto de amônia como fontes de nitrogênio, respectivamente. O máximo conteúdo de proteína na biomassa foi de 72,5 %, obtido em experimento conduzido com N0 = 10 mmolar e D = 0,083 dia-l. Os melhores resultados em termos do teor do ácido &#947;-linolênico na fração lipídica da biomassa foi empregando vazão específica de alimentação de 0,110 dia-1 e concentração de cloreto de amônio no meio de alimentação de 1mmolar. / Photosynthesizing microorganism has been used for many years as human food because of its high protein content and nutritional value. Spirulina platensis can be an alternative source of protein for food purpose, as well as the possibility of obtaining other products like pigments, vitamins and lipids, mainly polyunsaturated fat acids like &#947;-linolenic. In this work, they were studied the influence of the ammonium chloride concentration in the feeding nutrient medium (N0) as well as the dilution rate (D) on the Spirulina platensis cultivation by continuous process, evaluating the kinetics parameters of the growth as well as the composition of the biomasses obtained. The maximum cell productivity obtained (63.9 mg.L-1.day-1) was c¬omparable with that ones obtained using batch and fed-batch processes for nitrate and ammonium chloride as nitrogen sources, respectively. The highest protein biomass content was 72.5 %, obtained in experiment carried out with N0 = 10 mmolar and D = 0.083 day-1. The best result in terms of the &#947;-linolenic acid content in the lipid fraction of the biomass was employing dilution rate of the 0.110 day -1 and 1 mmolar of the ammonium chloride in the feeding nutrient medium.

Made available in DSpace on 2016-08-17T18:39:30Z (GMT). No. of bitstreams: 1 2145.pdf: 2206472 bytes, checksum: 5295597725f34bdf5560d6cda8af7446 (MD5) Previous issue date: 2008-03-27 / Financiadora de Estudos e Projetos / Streptococcus pneumoniae (pneumococo) is a pathogenic bacterium that causes several infections which are aggravated by the increase of serotypes with antibiotics resistance. The development of an effective vaccine against this pathogen is crucial for the prevention of the neumococcal illnesses. Conjugated vaccines, consisting of the capsular polysaccharide joined to a carrier protein, are more efficient in the stimulation of the immunologic memory. The capsular polysaccharide (PS) is present in the capsule that involves the cell. Thus, the conjugated vaccine elaboration involves bacterial cells cultivation for its production. As the organism is cultivated in the oxygen absence, the lactate production is inevitably high, leading to growth inhibition due to lactate accumulation in the medium. To minimize the inhibitory effects of the lactate accumulation and to increase the PS production it is necessary to monitor the process and adequately control the addition of supplementary medium along with the withdrawal of saturated medium. This kind of operation can be performed by carrying out a fed-bath cultivation in a bioreactor connected to a perfusion system. The success on the monitoring, control and optimization of this bioprocess depends on the efficiency of the modeling and simulation resources employed. This research work considers the uses intelligent computational techniques, specifically the technique of heuristical search called simulated annealing (SA) combined with neural networks for the state inference and the optimization of S. pneumoniae cultivations. The proposal was implemented as a computational system that: a) uses the SA for the identification of the values for a set of parameters associated to unstructured models and; b) uses neural networks (individually and grouped as a committee) for the state inference of a culture. The work presents and discusses the results of the system for data sets experimentally obtained and highlights the importance of the proposal for achieving a higher efficiency in the culture control processes. / Streptococcus pneumoniae (pneumococo) é uma bactéria patogênica causadora de várias infecções que são agravadas pelo aumento de cepas com resistência aos antibióticos. O desenvolvimento de uma vacina efetiva contra este patógeno é crucial para a prevenção das doenças pneumocócicas. Vacinas conjugadas, constituídas pelo polissacarídeo capsular ligado a uma proteína carregadora, são mais eficientes no estímulo da memória imunológica. O polissacarídeo capsular (PS) está presente na cápsula que envolve a célula e, desta forma, a elaboração de vacinas conjugadas envolve o cultivo da bactéria para a produção do mesmo. Como o microrganismo é cultivado na ausência de oxigênio, a produção de lactato é inevitavelmente elevada e o seu acúmulo no meio provoca a inibição do crescimento. Para minimizar os efeitos inibitórios da acumulação de lactato e aumentar a produção de PS é necessário monitorar o processo e controlar adequadamente a adição de meio suplementar e a retirada de meio saturado em cultivos operados em batelada alimentada, utilizando biorreatores acoplados a sistema de perfusão. O sucesso no monitoramento, no controle e na otimização deste bioprocesso depende da utilização de recursos de modelagem e de simulação que sejam eficientes. Este trabalho de pesquisa propõe o uso de técnicas computacionais inteligentes, especificamente a técnica de busca heurística chamada de simulated annealing (SA) aliada a redes neurais, para a inferência de estado e a otimização de cultivos de S. pneumoniae. A proposta foi concretizada via desenvolvimento de um sistema computacional que: a) faz uso do SA para a identificação do conjunto de valores de parâmetros associados a modelos não estruturados e; b) usa redes neurais (individualmente e em regime de comitê) para a inferência de estado de um cultivo. O trabalho apresenta e discute os resultados do sistema em conjuntos de dados obtidos experimentalmente e evidencia a importância da proposta para uma maior eficiência no controle de processos de cultivo.

Trenden i byggbranschen är att efterfrågan på täta, energisnåla byggnader ökar. Passivhus och andra lågenergikonstruktioner blir vanligare och vanligare. Riskerna med att bygga in organiskt material som trä i dessa konstruktioner har fått branschen att börja titta på alternativa material. Lättbetong är ett material som både har bärande och isolerande egenskaper. Dessutom är det inte organiskt vilket gör det okänsligt för mikrobiell påväxt. Det som är intressant med lättbetong, ur fuktsynpunkt, är att materialet levereras från tillverkare med en stor mängd byggfukt. Våren 2014 färdigställde Bollnäs Bostäder passivhus- projektet Sundsbro i Bollnäs, där lättbetong ingår i utfackningsväggarna. Sett inifrån består väggen av ett tunt lager kc-puts, lättbetong, cellplast, mineralull, kc-baserad grovputs och ytputs. I detta arbete användes projektet i Bollnäs som referensobjekt och en risk- och känslighetsanalys av väggkonstruktionen utfördes. Arbetet utreder risken för fuktrelaterade problem med väggen vid de extra uttorkningsinsatser som vidtogs i referensobjektet och vid normala uttorkningsbetingelser. Vidare utreds vilka parametrar som är viktiga för väggens fuktfunktion och vad man behöver tänka på när man projekterar och bygger i lättbetong. Arbetet har genomförts i samarbete med AK-Konsult Indoor Air AB och deras senior konsult Anders Kumlin. Fuktberäkningsprogrammet WUFI Pro 5.3 har använts för simuleringar. Beräkningarna gjordes endimensionellt på väggkonstruktionen. Resultaten med den ökade uttorkning som utfördes i referensobjektet visar inget högre fuktinnehåll längst ut i väggen på grund av byggfukt från lättbetongen som vandrar utåt. Farhågan var att så skulle kunna ske och att det skulle kunna leda till mögelproblem. Däremot visar resultaten att bygg-fukt från putsen kan fukta upp mineralullen. Det finns dock inga kända skadefall av detta slag och därför dras ändå slutsatsen att konstruktionen är riskfri. Tack vare en förutseende fukt-projektering och väl utförd uttorkning eliminerades risken för mögel. Hade inte dessa åtgärder vidtagits så visar resultaten att en liten mängd byggfukt hade kunnat vandra utåt och kondensera i mineralullen under första vintern. Då hade det funnits risk för mikrobiell påväxt. Detta visar att det är av största vikt att utföra en noggrann fuktprojektering vid byggnation av välisolerade hus i allmänhet och i synnerhet när lättbetong används. Lyckligtvis gjordes detta på ett bra sätt i referensprojektet. Känslighetsanalysen visar att isoleringens diffusionstäthet är avgörande för hur stor del av bygg-fukten som kan vandra utåt och därmed hur stor risken för problem blir. Lägre täthet ger större risk och högre täthet reducerar risken. Resultaten visar också att det är viktigt att inte montera täta skikt på insidan för tidigt. Den allmänna rekommendationen från leverantör är att lättbetongen skall torkas till 15 % fuktkvot på 50 millimeters djup innan målning och tapetsering på insida vägg får ske. Studien visar att detta är ett för högt fukttillstånd om det skikt som appliceras på insida vägg är tätt. Lättbetongen bör torkas till 5 % på 50 millimeters djup innan helt täta skikt kan monteras utan mögelrisk. / The trend in the construction industry is that the demand for tight, energy-saving buildings is rising. Passive houses and low energy constructions are becoming more and more common. The risk with using organic material in this type of constructions has made the industry look at alternative materials. Aerated concrete is a material that has both load-bearing and insulating properties. In addition to that it is not organic, which makes it insensitive to microbial growth. What is interesting with aerated concrete, from a moisture point of view, is that the material is delivered from the producer with a large amount of construction moisture. In the spring of 2014, the passive-house project Sundsbro in Bollnäs with aerated concrete in the wall construction, was finished by Bollnäs Bostäder. In this study the project in Bollnäs was used as reference object and a risk- and sensitivity analysis was made. The study examines the risk of moisture related problems with the wall construction during normal dehydration conditions and after the increased dehydration efforts that were taken in the reference project. The study also examines which parameters are important for the moisture function of the wall construction and what you need to think about when you project and build with aerated concrete. The job has been done in cooperation with AK-Konsult Indoor Air AB and their senior consultant Anders Kumlin. The moisture calculation program WUFI Pro 5.3 has been used for simulations. The results with the increased dehydration that was used in the reference project show no increased moisture content in the outer parts of the construction due to construction moisture from the concrete that wanders outwards. The concern was that so could happen and that it would lead to mould problems. However the results show that construction moisture from the exterior plaster can moisten the mineral wool. There are no known damage cases of this sort and therefore the conclusion is that the construction is free of risk. Thanks to a foreseeing moisture projection and a well performed dehydration the risk of mould was eliminated. If these measures would not have been taken, the results show that a small amount of construction moisture could have wandered outwards and condensed inside the mineral wool during the first winter. Then there would have been a risk of microbial growth. This shows that it is very important to carry out a detailed moisture projection when constructing well insulated houses in general and when using aerated concrete in particular. Fortunately this was properly done in the reference project. The sensitivity analysis shows that the diffusion resistance of the insulation decides how much of the construction moisture that can wander outwards and consequently the size of the problem risk. Results also show that it is crucial not to apply sealing layers on the inside of the wall too early. The general recommendation from the supplier is that the aerated concrete should be dried to 15 % moisture ratio on 50 millimeter depth before painting and paper hanging on the interior surface of the wall can be done. The study shows that the concrete still is too damp at that stage if the layer applied on the inside of the wall is impermeable. The concrete should be dried down to 5 % moisture ratio before sealing layers can be applied without mould risk.

Cyanobakterien sind die einzig bekannten Prokaryoten, die in der Lage sind oxygene Photosynthese zu betreiben. Sie besitzen ein großes Potenzial als nachhaltige Ressourcen für die Herstellung zahlreicher industriell und medizinisch relevanter Wirkstoffe. Trotz ihrer essentiellen Bedeutung ist jedoch das Wachstum von Cyanobakterien bis jetzt nur unzureichend verstanden. Im Rahmen dieser Arbeit habe ich daher ein mathematisches Modell entwickelt, das das Wachstum von Cyanobakterien auf der Grundlage von intrazellulärer Proteinverteilung beschreibt. Dabei wurde das Proteom in wenige relevante Protein-Klassen unterteilt, die an fundamentalen zellulären Prozessen beteiligt sind, darunter Kohlenstoffaufnahme, -fixierung und -stoffwechsel, sowie Photosynthese und Proteintranslation. Besonders interessant sind die aus dem Modell resultierenden sogenannten mikrobiellen Wachstumsgesetze, sprich die Korrelationen zwischen der Wachstumsrate und der Proteinverteilung, die im stationären Zustand des Wachstums beobachtet werden. Das Modell prognostiziert eine charakteristische Krümmung für die Wachstumsgesetze jener Proteine, welche mit Lichtabsorption und Proteintranslation assoziiert werden. Verursacht wird diese Krümmung durch hohe Lichtintensitäten, die eine Abnahme der Wachstumsrate zur Folge haben. Die prognostizierten Wachstumsgesetze werden durch Proteindaten, die mittels Massenspektrometrie erhoben wurden, vom Cyanobakterium Synechocystis sp. PCC 6803 gestützt. Des Weiteren bietet das Modell einen geeigneten Ausgangspunkt für die Erweiterung von der Charakterisierung von Einzelzellen zu einer Population von Zellen in einem lichtlimitierten Chemostat. Das erweiterte Modell stellt einen Zusammenhang her zwischen intrazellulärer Proteinverteilung, Wachstum der Population und Kultivierungseigenschaften, und bietet somit einen neuartigen Ansatz zur Untersuchung und Verbesserung der Kultivierung von phototrophen Organismen und die Optimierung der photosynthetischen Produktivität. / Cyanobacteria are the only known prokaryotes that perform oxygenic photosynthesis, and therefore, hold significant potential as sustainable resources for the production of numerous industrially and medically relevant compounds. Despite their importance, however, the (molecular) limits and cellular economy of photoautotrophic growth are still insufficiently understood. In this thesis, I present a mathematical model based on a coarse-grained description of cellular protein allocation to describe cyanobacterial growth. The model describes cellular trade-offs considering only proteins that are involved in key cellular processes (carbon uptake, fixation, and metabolism, as well as photosynthesis and protein translation). Of particular interest are the resulting microbial growth laws, i.e., correlations between the growth rate and the protein distribution observed during balanced growth. The model predicts a characteristic kink for the growth laws of the light harvesting components and the translational machinery induced by photoinhibition, a decrease in growth rate due to high light intensities. The resulting growth laws are supported by quantitative mass spectrometry-based proteomics data of the cyanobacterium Synechocystis sp. PCC 6803. The proteomics data shows that the mathematical model has intrinsic predictive power, and thus, provides a suitable starting point for extending it from describing single cells to describe a growing population in a light-limited chemostat. The extended modeling framework goes beyond current models using phenomenological growth equations and establishes a mechanistic link between intracellular protein allocation, population growth and cultivation properties. The extended model provides a novel approach to study and guide phototrophic cultivation improvements that maximize photosynthetic productivity.

[Truncated abstract] Acidic mine lakes are formed as a result of the oxidation and dissolution of metal sulfide minerals and are primarily characterized by low pH values of 2 – 4. Many strategies for the bioremediation of acidic mine lakes depend on the alkalinity generation capabilities of microbial ferric and/or sulfate reducing bacteria. However nearly all mine lakes are oligotrophic, with very low concentrations of available organic carbon and nutrients; all required for healthy microbial growth. There is also an unusual class of mine lakes characterized by low concentrations of organic carbon and also very low concentrations of dissolved iron and sulfate. Our ability to promote microbial activity in these systems is especially challenging. This study focuses on one of these systems, Lake Kepwari, a coal mine lake in Western Australia. Numerical modeling of remediation strategies is an efficient way of testing scenarios prior to expensive in-field trials. However such modeling relies on good descriptions of microbial processes, including kinetic parameterizations of ferric and sulfate reduction. There has been little research to date on the study of kinetic parameterizations of the chemical and biological alkalinity generation in acidic mine lakes. The objectives of this thesis were to investigate the viability of microbial ferric and sulfate reduction in an ultraoligotrophic, acidic mine lake, to assess the impact of these microbial processes on water quality and to parameterize the Dual Monod kinetics of neutralization under dual limitation conditions. Molecular analyses including most probable number, DNA extraction, polymerase chain reaction, polymerase chain reaction – denaturing gradient gel electrophoresis were used to examine the microbial communities in the lake sediments. ... The Monod maximum specific microbial growth rates with respect to dissolved organic carbon and ferric, and as determined in batch experiments, were 0.07 ± 0.01 and 0.048 ± 0.02 day-1, respectively, and their corresponding Monod half saturation constants and were 14.37 and 5.6 mmol L-1. The Monod maximum consumption rates under ferric and OC limitation were also estimated. The Monod maximum specific microbial growth rates with respect to dissolved organic carbon and sulfate, , and were 0.05 ± 0.01, 0.08 ± 0.01 and 0.07 ± 0.02 day-1, respectively, and their corresponding Monod half saturation constants, and were 75.5, 131.8 and 10.2 mmol L-1. The Monod maximum consumption rates under sulfate and OC limitation were also estimated. The results of this study suggest that strategies for the remediation of ultraoligotrophic, acidic mine lakes may rely on microbial ferric and sulfate reduction, however additions of both organic carbon and sulfate/ferric are essential. These results can be immediately applied to mesocosm studies in outdoor enclosures and to the management of acidic mine lakes. Furthermore, this thesis has provided a new, valuable understanding on the Dual Monod kinetic parameterizations of neutralization for an ultraoligotrophic, acidic mine lake environment. These parameterizations are essential for the lake ecological models that will be used to investigate remediation scenarios for acidic mine lakes.