During the evolution some groups of organisms have become coevolutionary associated with other groups, as is the case of host symbiont systems. To explore coevolutionary history of hosts and their associated symbionts, phylogenetic reconstruction of symbionts and phylogenetic reconstruction of hosts are usually compared. Coevolution is described by coevolutionary events (cospeciation, host switch, duplication, failure to diverge events and linage sorting events). The aim of this work was to test the suitability of MLST method for the complex of entomopathogenic nematodes from the genus Steinernema (with detailed analysis of Steinernema feltiae) and their symbiotic bacteria Xenorhabdus bovienii and subsequently use cophylogenetic comparative analysis to determine their level of cospeciation.

Since the introduction of advanced molecular methods the research on insect bacterial symbioses underwent a major focus shift towards large scale phylogenetics and comparative genomics. These new fields provided answers to several fundamental questions of symbiont evolution, functional capabilities of the host-associated bacteria, and the role of symbionts in the host?s biology. However, the vast diversity and complexity of symbiotic relationships still leaves gaps in our understanding to a rich mosaic of various symbiont types, effects and transitions from facultative association to obligate mutualism. The presented study focuses on distribution, diversity, phylogenetic patterns, evolutionary transitions and genome evolution of two less known but ecologically diverse bacterial genera, Arsenophonus and Sodalis. The thesis also takes advantage of the knowledge on a well established symbiotic model between aphids and Buchnera and reveals several evolutionary patterns in the host and symbiont.

We studied asymbiotic and symbiotic propagation of terrestrial orchids. There wasn´t found statistical effect of organic nitrogen in the form of pepton for examined species of orchid in the asymbiotic propagation. There wasn?t confirmed the positive effect of microelements and addition of carbohydrates (sucrose, glukose and maltose) on the germination of Habenaria dentata. Effects of various iron salts weren´t striking to stimulate seed of Cypripedium calceolus. The effect of different isolates of mycorrhizal fungi in the symbiotic propagation wasn´t statistically proven on investigated species of orchids. The effect of examined substrates (Akadama, volcanic sand and substrate Lukscheiter Orchid) wasn´t statistically confirmed on growth of species Spiranthes odorata and Bletilla striata, when seedling of them were moved to ex vitro conditions.

Orientador: Claudio Cabello / Banca: Rogério Lopes Vieites / Banca: Luis Fernando Barbisan / Banca: Maria José Queiroz de F. Alves / Banca: Eliane Maria Ravasi S. Simionato / Resumo: Atualmente, o consumidor está cada vez mais exigente por alimentos nutritivos e higienicamente seguros. Estudos têm sido conduzidos para o desenvolvimento de novos produtos e para assegurar as propriedades e os efeitos dos alimentos funcionais sobre o organismo humano. O yacon pode ser considerado alimento funcional pelo seu teor de frutooligossacarídeos (FOS), os quais não são digeridos pelo organismo humano, passando inertes através do trato digestório, fornecendo poucas calorias. Diante da crescente exigência do consumidor e da importância de se obter produto de valor agregado (simbiótico = yacon e bifidum), este estudo teve por objetivos verificar os adequados procedimentos para a extração e purificação de frutanos de yacon na utilização da funcionalização de alimentos definindo um protocolo dos procedimentos para produção de uma base alimentar contendo frutanos consorciados com probióticos Bifidobacterium bifidum e avaliar qualitativa e quantitativamente a ação funcional da base alimentar projetada em modelo experimental. O processo de aquecimento do yacon foi feito à 90°C por 10 minutos, utilização de 0,5% de ácido cítrico e pré-capa com diatomácea CA/150 e CA/500 resultando na secagem em um produto de coloração clara. O controle das condições de temperatura na entrada (250°C) e saída (110°C) resultou em menor gasto de energia, clareamento do produto e baixa porcentagem de umidade. Para a avaliação do efeito do extrato desidratado de yacon com Bifidobacterium bifidum sobre desenvolvimento ponderal, glicemia, colesterol total, triglicérides, alanina amino transferase (ALT), aspartato amino transferase (AST), histologia do fígado, 24 ratos Wistar foram tratados por 59 dias. O ensaio foi conduzido com 8 animais (sendo 4 machos e 4 fêmeas) para cada grupo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : Nowadays, consumers demand more nutritional and hygienically safe food products. Studies have led to the development of new products, guaranteeing the properties e effects of functional food products on humans. Yacon may be considered a functional product, owing to its fructooligosaccharides (FOS) content, which is not metabolized by the human organism, passing inertly through the digestive tract, providing a few calories. Before the growing consumer's demand and the importance of an aggregated- value product (symbiotic = yacon and bifidum), this study aimed at verifying the suitable procedures for the extraction and purification of yacon fructans to functionalization in food products, thus defining a protocol for the production of a food basis containing fructans along with probiotic Bifidobacterium bifidum, and assess both qualitatively and quantitatively the functional action of the food basis projected in an experimental model. Yacon was heated at 90°C, for 10 minutes, with 0,5% of citric acid and Diatomacea CA/150 and CA/500 pre-cover, resulted, in the drying, in a clear coloration product. The control of temperature conditions at the beginning (250°C) and at the end (110°C) resulted in less energy expenditure, whitening of the product and low humidity percentage. To asses the effect of dehydrated extract of yacon with Bifidobacterium bifidum on ponderal development, glycemia, total cholesterol, triglycerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver histology, 24 Wistar rats were treated for 59 days. The experiment was carried out with 8 animals (4 males and 4 females) for each group: control, dehydrated extract of yacon and dehydrated extract of yacon with bifidum. The animals were sacrificed on the 60th day, and the blood was collected through exsanguination... (Complete abstract click electronic access below) / Doutor

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-12T14:09:32Z No. of bitstreams: 2 Dissertação - Kellen Cristhina Inácio Sousa - 2012.pdf: 5012340 bytes, checksum: 5d359d0996e1d7af5f7a16ae553d8b85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-12T14:26:47Z (GMT) No. of bitstreams: 2 Dissertação - Kellen Cristhina Inácio Sousa - 2012.pdf: 5012340 bytes, checksum: 5d359d0996e1d7af5f7a16ae553d8b85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-12T14:26:47Z (GMT). No. of bitstreams: 2 Dissertação - Kellen Cristhina Inácio Sousa - 2012.pdf: 5012340 bytes, checksum: 5d359d0996e1d7af5f7a16ae553d8b85 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2012-06-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In Brazil, 2500 to 3000 species of orchids have been reported to occur, of which 300 are found in the “cerrado” region. The orchids Cyrtopodium saintlegerianum (epiphyte) and Epidendrum nocturnum (rupicola) occur in areas anthropized of cerrado and cerrado rupestre, respectively. The orchids posses mycorrhizal association with rhizoctonia-like and endophytic fungi. The identification of these fungi can be done by microscopic and morphological characters. Root infecting fungi also are utilized for in vitro symbiotic germination of orchid seeds, aiming the conservation of plant species and fungi. The objective of the present investigation was isolation and morphological characterization of mycorrhizal and endophytic fungi originating from roots of C. saintlegerianum and E. nocturnum, as well as symbiotic in vitro seed germination. Three isolates of Epulorhiza sp. from each one of C. saintlegerianum, and E. nocturnum and two of Rhizoctonia sp. from E. nocturnum were obtained. Also, two isolates of Xylaria sp. were obtained from roots of C. saintlegerianum. There were, however, differences among isolates Epulorhiza sp. of C. saintlegerianum and of the E. nocturnum, in relation to morphological and enzymatic characters. The fungus was localized in root tissues of both species by optical and scanning electronic microscopes. The seed viability was tested by tetrazolium chloride and found 80.3 and 32.33% viable embryos of C. saintlegerianum and E. nocturnum, respectively. There was no in vitro symbiotic germination of E. nocturnum due to low seed viability. Two experiments of symbiotic germination of C. saintlegerianum seeds were conducted, both under photoperiods of 16/8 h (light/dark) at 26°C ± 2°C. The treatments were two isolates of Xylaria sp., three plant pathogens (Rhizoctonia solani of common beans and R. oryzae of rice ), and three mycorrhiza of C. saintlegerianum, two of Cyrtopodium vernum, and one ofE. nocturnum. Of three culture media tested, germination was obtained only in oat meal agar culture. The isolate En07 of Rhizoctonia sp. from E. nocturnum was found better for seed germination with 81.64 and 90.73% of germination of experiments 1 and 2, respectively. One non-specific isolate, two plant pathogenic isolates and one specific isolate were efficient for seed germination of C. saintlegerianum. On the other hand, for symbiotic in vitro seed germination of C. saintlegerianum, there was no specificity between this orchid and only one rhizoctonia-like fungus. These results showed that C. saintlegerianum can be propagated utilizing different root infecting fungi, which facilitates future programs of reintroduction and commercialization of species. / O Brasil possui entre 2500 e 3000 espécies de orquídeas, das quais cerca de 300 são encontradas em áreas de Cerrado. Cyrtopodium saintlegerianum (epífita) e Epidendrum nocturnum (rupícola) ocorrem em áreas antropizadas de Cerrado e Cerrado Rupestre, respectivamente. As orquídeas possuem associação micorrízica com fungos rizoctonioides, e fungos endofíticos também podem ser encontrados nessas plantas. Os fungos rizoctonioides são utilizados para a germinação simbiótica in vitro de sementes de orquídeas, tendo em vista a conservação das espécies vegetais e fúngicas. O presente trabalho objetivou o isolamento e a caracterização morfológica de fungos oriundos do sistema radicular de C. saintlegerianum e E. nocturnum, visando a germinação simbiótica in vitro de suas sementes. Foram obtidos três isolados de Epulorhiza sp. para C. saintlegerianum, e para E. nocturnum obteve-se três de Epulorhiza sp. e dois de Rhizoctonia sp. Das raízes de C. saintlegerianum também foram obtidos dois isolados de Xylaria sp. Houve diferença entre os isolados de Epulorhiza sp. oriundos de C. saintlegerianum e os originários de E. nocturnum quanto as características morfológicas e enzimáticas. Os fungos micorrízicos foram histolocalizados, por microscopia óptica e eletrônica de varredura, em raízes de ambas as espécies. A viabilidade de sementes foi realizada pelo teste do cloreto de tetrazólio e verificou-se 80,3 e 32,33% de embriões viáveis para C. saintlegerianum e para E. nocturnum, respectivamente. Não houve germinação simbiótica in vitro de E. nocturnum devido a baixa viabilidade das sementes. Para as sementes de C. saintlegerianum foram realizados dois experimentos de germinação simbiótica, ambos em fotoperíodo de 16/8 h (Luz/Escuro) a 26°C ± 2°C. Os tratamentos foram dois isolados de Xylaria sp., três fitopatogênicos (Rhizoctonia solani de feijão e R. oryzae de arroz), e três micorrízicos de C. saintlegerianum, dois de Cyrtopodium vernum Rchb.f. & Warm., e um de E. nocturnum. Foram testados três meios de cultivo, mas somente o meio agar aveia padrão proporcionou a germinação. Verificou-se que o isolado En07 de Rhizoctonia sp. oriundo de E. nocturnum foi o melhor para germinar as sementes com 81,64 e 90,73% de germinação nos experimentos 1 e 2, respectivamente. Observou-se que um isolado não específico, dois isolados fitopatogênicos e um específico foram eficientes em germinar as sementes de C. saintlegerianum. Portanto, para a germinação simbiótica in vitro de C. saintlegerianum não houve especificidade entre esta orquídea e um único fungo rizoctonioide. Estes resultados indicam que C. saintlegerianum pode ser propagada utilizando fungos rizoctonioides, o que facilita futuros programas de reintrodução e comercialização da espécie.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-09-20T12:13:55Z No. of bitstreams: 1 Amanda Cordeiro de Melo Souza.pdf: 353123 bytes, checksum: fafead9a2ad6ac1a30c9e9716b2a3d7e (MD5) / Made available in DSpace on 2016-09-20T12:13:55Z (GMT). No. of bitstreams: 1 Amanda Cordeiro de Melo Souza.pdf: 353123 bytes, checksum: fafead9a2ad6ac1a30c9e9716b2a3d7e (MD5) Previous issue date: 2015-02-23 / The cowpea [Vigna unguiculata (L.) Walp] is a autogamous plant that presents cleistogamy, widely cultivated in the North and Northeast regions of Brazil. It’s rusticity and phenotypic plasticity allow it’s cultivation in adverse weather conditions and soil and it is capable of establishing symbiosis with rhizobia, with biological nitrogen fixation (BNF). BNF fixes atmospheric N2 by an enzymatic complex called nitrogenase. Rhizobia strains, to fix nitrogen with plants, depend on factors intrinsic to the bacteria-legume symbiosis process and on environmental factors that affect the survival of the plant. The objective was to evaluate symbiotic compatibility and efficiency of isolates obtained from the soils semi-arid region of Pernambuco and the recommended strain BR 3262, and its symbiotic stability in cultivars BR 17-Gurguéia, IPA 206 and BRS Novaera selected for different regions of Brazil. A greenhouse experiment was conducted with these cultivars, 25 isolates, the recommended strain and uninoculated treatments with and without N. Harvest was 45 days after inoculation and dry matter of shoots, roots and nodules, nodule number, dry weight of nodules by number of nodules, N accumulated in shoots dry matter by nodules, N content in the shoot, N accumulation in the shoots on the recommended efficiency strain based on the accumulation of nitrogen, on the recommended efficiency strain based on dry matter of shoots were determined. The plants of all inoculated treatments nodulated. Sixteen isolates did not differ from BR 3262 nodules dry matter. For dry weight of nodules by number of nodules, 20 isolates did not differ from BR 3262, and 18 isolates were similar to nitrogen accumulated in the shoot dry matter by the nodules. The nitrogen treatment with and without inoculation were among the lowest average for N content in shoot and relative efficiency of N accumulation compared to the inoculated treatments. The strains with improved stability and adaptability to cultivar with high potential for biological nitrogen fixation are G7.85 and BR 3262. / O feijão-caupi [Vigna unguiculata (L.) Walp] é uma planta autógama, que apresenta cleistogamia, amplamente cultivado nas regiões Norte e Nordeste do Brasil. Sua rusticidade e plasticidade fenotípica permitem cultivá-lo em condições de clima e solo adversas e é capaz de estabelecer simbiose com rizóbios, ocorrendo a fixação biológica de nitrogênio (FBN). A FBN fixa o N2 atmosférico através de um complexo enzimático chamado nitrogenase. As estirpes de rizóbios, para fixar nitrogênio nas plantas, dependem de fatores intrínsecos do processo da simbiose bactéria-leguminosa e de fatores ambientais que afetam a sobrevivência da planta. O objetivo do trabalho foi avaliar a compatibilidade simbiótica e a eficiência de isolados obtidos a partir de solos da região semiárida de Pernambuco e da estirpe recomendada BR 3262, e sua estabilidade simbiótica nas variedades BR 17- Gurguéia, IPA 206 e BRS Novaera selecionadas para diferentes regiões do Brasil. Um experimento foi conduzido em casa de vegetação com as três variedades de caupi e 25 isolados, tratamentos sem inoculação com e sem N e inoculação com a estirpe referência BR 3262. A colheita foi aos 45 dias após a inoculação, determinando matérias secas da parte aérea, raiz e nódulos, número de nódulos, matéria seca de nódulos por número de nódulos, N acumulado na parte aérea pela matéria seca de nódulos, teor de N na parte aérea, acúmulo de N na parte aérea, eficiência relativa à estirpe recomendada baseada no acúmulo de nitrogênio, eficiência relativa à estirpe recomendada baseada na matéria seca da parte aérea. As plantas de todos os tratamentos inoculados nodularam. Para matéria seca dos nódulos, 16 isolados não diferiram de BR 3262. Para a matéria seca de nódulos por número de nódulos, 20 isolados não diferiram da BR 3262, e 18 isolados não diferiram para nitrogênio acumulado na parte aérea pela matéria seca de nódulos. Os tratamentos com e sem N e sem inoculação estiveram entre as menores médias para teor de N na parte aérea e eficiência relativa à recomendada baseada no acúmulo de N em comparação com os tratamentos inoculados. As estirpes com melhor estabilidade e adaptabilidade a variedades com alto potencial para fixação biológica de nitrogênio são G7.85 e BR 3262.

O cenário de constante transformação do mundo contemporâneo aponta para uma necessidade urgente de novas descrições da realidade, capazes de sintetizar as complexas relações vivenciadas nos sistemas socioeconômicos e direcionar os tomadores de decisão para ações que garantam a sustentabilidade dos mesmos. Uma das propostas para lidar com tal questão no ambiente da estratégia é a hipótese da Dinâmica Simbiótica. Esta tratativa teórica a despeito de já oferecer uma opção consistente em outras áreas do conhecimento, ainda carecia de ampliação conceitual e validação de certas premissas que as legitimassem na área gerencial. Neste sentido, este esforço de pesquisa objetiva validar tais premissas e determinar os princípios que possibilitam a emergência e manutenção de sistemas socioeconômicos sustentáveis. Para tanto, foi desenvolvida uma pesquisa baseada em experimentos de etologia sintética, construídos especificamente com o fim de validar as hipóteses em pauta. Com este procedimento, foi possível constatar que as organizações, como sistemas sociotécnicos, possuem uma dinâmica autopoiética, onde a incorporação de novos componentes e o porte das mesmas, se apresentam como fatores de grande influência em sua sobrevivência. Quando interconectadas com outros agentes, inclusive de mesmo tipo, estas organizações compõem um ambiente socioeconômico sujeito a rupturas que o levam a diferentes patamares qualitativos. Neste contexto, o trabalho destas estruturas em prol da estabilidade do ambiente, buscando estabelecer um equilíbrio adequado entre consumo e regeneração de recursos, se mostrou promissor para aumentar as chances, tanto individuais como do próprio sistema socioeconômico, de se perpetuarem ao longo do tempo. / The constant transformation of the contemporary world points to an urgent need for new descriptions of reality, able to synthesize the complex relationships between direct decision makers in socioeconomic systems and point to actions that ensure their sustainability. One proposal to deal with this issue in a strategic environment is the hypothesis of symbiotic dynamics. This theoretical approach, despite providing consistent option in other areas of knowledge, still lacked conceptual expansion and validation of certain assumptions to legitimize it in management. This research aims to validate this effort and determine the principles that make the emergence and maintenance of sustainable socioeconomic systems. Therefore, a search based on synthetic ethology experiments was built specifically to validate the hypotheses in question. This method found that organizations such as socio-technical systems have autopoietic dynamics, where the incorporation and size of new components are the most influential factors in their survival. When interconnected with other agents, including those of the same type, these organizations make up a socioeconomic environment subject to disruptions that lead to different quality levels. In this context, the work of these frameworks to support the environmental stability, seeking to establish an appropriate balance between consumption and resource regeneration, promises to increase the chances of a socioeconomic system perpetuating it over time.

Time to market can be a decisive factor when bringing a new product or a new company to the market. Sometimes, for not defining strategic plans during the new product development phase, companies fail. According to the Lean Start Up Methodology (LSM), testing market-fit as early as possible and customer focused product development are important to increase the chances of a successful commercialization. The definition of a value proposition based on the market needs is seen as a central point to orchestrate key activities such as teamwork, efficient product development and marketing and finally the commercialization. In Sweden, the nutraceutical industry today represents a dynamic sector that offers novel opportunities to converge scientific discovery with growing consumer interest in health-improving foods.This study discourses on functional food segment, with a focus on probiotic, prebiotic and symbiotic-based products. It included a case study in a new company active in the nutraceutical sector in Sweden (TSL). Their actual strategy for commercializing a symbiotic-based weight loss program will be evaluated, and a new strategy built inspired on LSM Methodology is proposed, with a special focus on value proposition design.

La zone latérale des filaments branchiaux des bivalves Codakia orbiculata et Lucina pensylvanica est le lieu d'une symbiose chimioautotrophe avec des bactéries sulfo-oxydantes hébergées dans des cellules spécialisées, appelées bactériocytes. Dans cette étude, nous nous sommes proposés de déterminer les mécanismes qui sous-tendent la plasticité cellulaire et tissulaire observée au cours des processus de décolonisation et de recolonisation bactérienne. Pour ce faire, des individus collectés dans leur milieu naturel, ont été maintenus au laboratoire dans des bacs d'eau de mer filtrée en absence de nourriture et de soufre réduit, afin de provoquer la décolonisation bactérienne des filaments branchiaux. Lorsque la branchie apparaissait purgée de ses symbiotes, les individus ont été remis dans leur habitat naturel afin de provoquer sa recolonisation. L'analyse des branchies au cours de ces processus a fait appel à des techniques variées (histologie, immunohistochimie, hybridation in situ, cytométrie en flux, dosage des protéines et spectrométrie de fluorescence X). Les résultats obtenus ont permis de montrer que l'acquisition environnementale mise en évidence chez les juvéniles des Codakia se poursuivait tout au long de la vie des adultes. Cette étude a également permis une meilleure compréhension des mécanismes tissulaires sous-jacents à la plasticité du filament branchial en mettant en évidence les processus d'apoptose et de prolifération cellulaire qui ont lieu au cours des processus de décolonisation et de recolonisation. Ces processus s'accompagnent d'une variation de la teneur en soufre élémentaire, ainsi que de la taille relative et du contenu génomique des symbiotes / The lateral zone of gills filaments of coastal bivalves Codakia orbiculata and Lucina pensylvanica is the site of chemoautotrophic symbiosis with sulfur-oxidizing bacteria, housed in specialized cells called bacteriocytes. The objective of this thesis is to determine the mechanisms underlying cel1 plasticity and tissue plasticity observed in the lateral zone of gills filaments during the processes of bacterial decolonization and recolonization. In order to do this, the individuals collected in their natural habitat were maintained at the laboratory in seawater filtered tanks, without food and reduced sulfur, to cause bacterial decolonization. When the gills seemed to be purged, the individuals were returned to their natural habitat in order to cause the bacterial recolonization of gills filaments. The analysis of the gills during these processes involves several techniques (histology, immunohistochemistry, molecular hybridization, flow cytometry, total protein assays, protein sulfur assays, X-ray fluorescence spectrometry).This study shows that symbiont acquisition can occur during the entire life of Codakia bivalves. It also allows a better understanding of gills filaments plasticity by highlighting apoptosis and cell proliferation during decolonization and recolonization processes.Theses processes are accompanied with of elemental sufur, relative size and genomic content of symbiontes.

Heme proteins carry out a diverse array of functions in vivo while maintaining a well-conserved 3-over-3 α-helical structure. Human hemoglobin (Hb) is well-known for its oxygen transport function. Type 1 non-symbiotic hemoglobins (nsHb1) in plants and bacterial flavohemoglobins (fHb) from a variety of bacterial species have been predicted to carry out a nitric oxide dioxygenase function. In nsHb1 and fHb this function has been linked to protection from nitrosative stress. Herein, I combine photoacoustic calorimetry (PAC), transient absorption spectroscopy (TA), and classical molecular dynamics (cMD) simulations to characterize molecular mechanism of diatomic ligand interactions with a hexa-coordinate globin from plant (rice hemoglobin), bacterial flavohemoglobins and human hemoglobin. In rice type 1 non-symbiotic hemoglobin (rHb1), the dynamics and energetics of structural changes associated with ligand photodissociation is strongly impacted by solvent and temperature, namely CO escape from the protein matrix is slower at pH = 6.0 compare to neutral pH (ns) due to the CD loop reorganization which forms a pathway for ligand escape. In human hemoglobin, exogenous allosteric effectors modulate energetics of conformational changes associated with the CO and O2 escape although the effectors impact on rate constants for ligand association is small. The conformational dynamics associated with ligand photorelease from fHbs from Cupriavidus necator (FHP) and Staphylococcus aureus (HMPSa) are strongly modulated by the presence of azole drugs indicating that drug association modulates structural properties of the heme binding pocket. In addition, we carried out a study of the formation of the DNA intercalated motif (i-motif). The formation of the structure is strongly favored at acidic pH; therefore, PAC was combined with a 2-nitrobenzaldehyde pH-jump to probe formation of the i-motif on fast timescales. i-Motif folding is two-step process with the initial protonation of cytosine residues being endothermic with ΔHfast=8.5 ± 7.0 kcal mol-1 and ΔVfast=10.4 ± 1.6 mL mol-1 and subsequent nucleation/i-motif folding (τ = 140 ns) with ΔHslow=-51.5 ± 4.8 kcal mol-1 and ΔVslow=-6.6 ± 0.9 mL mol-1. The above results indicate that PAC can be employed to study diverse biochemical reactions such as DNA folding, drug binding and ligand photorelease from proteins.