Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 82-87.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Evolution of adaptation requires both generation of novel phenotypic variation and retention of a locally beneficial subset of this variation. Such retention can be facilitated by genetic assimilation, the accumulation of genetic and molecular mechanisms that stabilize induced phenotypes and assume progressively greater control over their reliable production. A particularly strong inference into genetic assimilation as an evolutionary process requires a system where it is possible to directly evaluate the extent to which an induced phenotype is progressively incorporated into preexisting developmental pathways. Evolution of diet-dependent pigmentation in birds-where external carotenoids are coopted into internal metabolism to a variable degree before being integrated with a feather's developmental processes-provides such an opportunity. Here we combine a metabolic network view of carotenoid evolution with detailed empirical study of feather modifications to show that the effect of physical properties of carotenoids on feather structure depends on their metabolic modification, their environmental recurrence, and biochemical redundancy, as predicted by the genetic assimilation hypothesis. Metabolized carotenoids caused less stochastic variation in feather structure and were more closely integrated with feather growth than were dietary carotenoids of the same molecular weight. These patterns were driven by the recurrence of organism-carotenoid associations: commonly used dietary carotenoids and biochemically redundant derived carotenoids caused less stochastic variation in feather structure than did rarely used or biochemically unique compounds. We discuss implications of genetic assimilation processes for the evolutionary diversification of diet-dependent animal coloration.

Lutein is a principal constituent of the human macular pigment. This study is composed of two projects. The first studies the conformational geometries of lutein and its potential adaptability in biological systems. The second is a study of the response of human subjects to lutein supplements. Using semi-empirical parametric method 3 (PM3) and density functional theory with the B3LYP/6-31G* basis set, the relative energies of s-cis conformers of lutein were determined. All 512 s-cis conformers were calculated with PM3. A smaller, representative group was also studied using density functional theory. PM3 results were correlated systematically to B3LYP values and this enables the results to be calibrated. The relative energies of the conformers range from 1-30 kcal/mole, and many are dynamically accessible at normal temperatures. Four commercial formulations containing lutein were studied. The serum and macular pigment (MP) responses of human subjects to these lutein supplements with doses of 9 or 20 mg/day were measured, relative to a placebo, over a six month period. In each instance, lutein levels in serum increased and correlated with MP increases. The results demonstrate that responses are significantly dependent upon formulation and that components other than lutein have an important influence serum response.

The evolutionarily persistent and widespread use of carotenoid pigments in animal coloration contrasts with their biochemical instability. Consequently, evolution of carotenoid-based displays should include mechanisms to accommodate or limit pigment degradation. In birds, this could involve two strategies: (i) evolution of a moult immediately prior to the mating season, enabling the use of particularly fast-degrading carotenoids and (ii) evolution of the ability to stabilize dietary carotenoids through metabolic modification or association with feather keratins. Here, we examine evolutionary lability and transitions between the two strategies across 126 species of birds. We report that species that express mostly unmodified, fast-degrading, carotenoids have pre-breeding moults, and a particularly short time between carotenoid deposition and the subsequent breeding season. Species that expressed mostly slow-degrading carotenoids in their plumage accomplished this through increased metabolic modification of dietary carotenoids, and the selective expression of these slow-degrading compounds. In these species, the timing of moult was not associated with carotenoid composition of plumage displays. Using repeated samples from individuals of one species, we found that metabolic modification of dietary carotenoids significantly slowed their degradation between moult and breeding season. Thus, the most complex and colourful ornamentation is likely the most biochemically stable in birds, and depends less on ecological factors, such as moult timing and migration tendency. We suggest that coevolution of metabolic modification, selective expression and biochemical stability of plumage carotenoids enables the use of unstable pigments in long-term evolutionary trends in plumage coloration.

Orientador: Adilma Regina Pippa Scamparini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T16:03:30Z (GMT). No. of bitstreams: 1 Maldonade_IrianiRodrigues_D.pdf: 4259808 bytes, checksum: a80eab15ad28ff36edff81d33fd716be (MD5) Previous issue date: 2003 / Resumo: Este trabalho teve como objetivo isolar e selecionar leveduras produtoras de carotenóides de ecossistemas brasileiros. As leveduras pigmentadas foram isoladas de amostras de solos, flores, folhas, frutos da região de Campinas-SP e de alimentos processados. As amostras foram colocadas em frascos de erlenmeyer de 50 mL, contendo 20 mL de meio de Extrato de Malte e Levedura (YM), e incubadas a 30° C por 48 horas. Após 48 horas, as amostras foram inoculadas em placas de petri contendo meio ágar-YM e incubadas a 30°C, por 120 horas. As colônias de leveduras que apresentaram coloração entre amarelo e vermelho, foram transferidas para tubos de ensaio contendo meio ágar YM inclinado e incubadas a 30°C até crescimento satisfatório. Estas leveduras foram reisoladas, pelo método de estrias de esgotamento, em placas de petri contendo meio ágar YM (30°C por 72 horas) e, posteriormente, transferidas para tubos de ensaios contendo ágar GYMP inclinado. As culturas pigmentadas foram codificadas do seguinte modo: L12, isolada como contaminante em massa de tomate; L108, isolada de solo da região da Universidade Estadual de Campinas; L125, isolada a partir de folhas da cana-de-açúcar; L135 e L137 isoladas de solo em Holambra-SP. Através das características morfológicas, de reprodução, testes fisiológicos e bioquímicos as leveduras foram identificadas como: L12, L108, L135 e L137 como Rhodotorula mucilaginosa, e L125 como Rhodotorula graminis. A composição de carotenóides, das leveduras isoladas no Brasil, foi estudada. As culturas de leveduras foram cultivadas em 200 mL de meio YM a 200 rpm em shaker, a 25°C por 5 dias. Cromatografia de coluna aberta, cromatografia de camada delgada e cromatografia líquida de alta eficiência foram utilizadas para separar os carotenóides obtidos das leveduras, a fim de identificá-los e quantificá-los. A linhagem de Rhodotorula glutinis foi a que apresentou maior concentração total de carotenóide (881 mg/L), seguido por Rhodotorula graminis (594 mg/L), Rhodotorula mucilaginosa-137 (590 mg/L) e Rhodotorula mucilaginosa-135 (545 mg/L). Rhodotorula minuta e Sporobolomyces tiveram a menor concentração de carotenóides (168 mg/L and 237 mg/L, respectivamente). Os principais pigmentos encontrados nestas linhagens foram toruleno e b-caroteno. b-Caroteno foi o carotenóide predominante em Rhodotorula grarninis-125, Rhodotorula glutinis e Sporobolornyces, enquanto que o toruleno foi o carotenóide principal nas leveduras de Rhodotorula rnucilaginosa. Em termos de produção específica de cartenóides (_g/g de células secas), Rhodotorula glutinis foi a que obteve maior concentração de carotenóides 132 mg/g. Duas linhagens foram selecionadas para otimização da produção de carotenóides, R. mucilaginosa-137 e R. glutinis. Estas duas culturas foram cultivadas em shaker a 200 rpm, a 25°C por 5 dias, sem iluminação. Utilizou-se planejamento experimental e análise de superfície de resposta para estudar o efeito do pH inicial, concentração de glicose, extrato de levedura, sais de fosfato e sulfato de magnésio na produção de carotenóides, de biomassa e proteína celular. Para cada linhagem, foram realizados 2 planejamentos fatoriais, sendo 1 fracionário e 1 completo.Para a linhagem de R. mucilaginosa-137, o extrato de levedura foi a variável de maior influência na produção de carotenóides, enquanto que os sais de sulfato e fosfato tiveram efeito negativo. O pH inicial não teve efeito significativo tanto na produção de carotenóides como na biomassa. Através dos resultados obtidos pelo planejamento completo, observou-se que a máxima concentração de carotenóides foi de 745 mg/L com 15 g/L de extrato de levedura e 20 g/L de glicose. Em relação a produção específica de carotenóides, a máxima concentração foi de 152 mg/g com 5 g/L de extrato de levedura e 15 g/L de glicose. A concentração de extrato de leveduras e glicose também foram importantes na produção da biomassa, que atingiu o valor máximo de 8 g/L, na faixa de concentração de 15 a 17,1 g /L de extrato de levedura e de 15 a 20 g/L de glicose. Para a linhagem de Rhodotorula glutinis as variáveis de maior influência na produção de carotenóides foram pH inicial, extrato de levedura e glicose. Os sais de sulfato e fosfato não tiveram efeito significativo. Através do planejamento fatorial completo 23 com três pontos centrais, observou-se que na produção de carotenóides, apenas a glicose teve efeito positivo significativo. Na produção específica de carotenóides, o pH inicial, glicose e extrato de levedura tiveram efeito positivo. A máxima concentração de carotenóides obtida foi de 1.269 mg/L com pH inicial 4, 4 g/L de extrato de levedura e 17 g/L de glicose. Na produção específica de carotenóides, a máxima concentração foi de 337 mg/g com pH inicial 4, a 4 g/L de extrato de levedura e 7 g/L de glicose. O crescimento celular foi afetado pelo pH inicial, concentração de extrato de levedura e glicose. Entretanto, o modelo matemático referente a biomassa não apresentou uma regressão satisfatória, devendo ser utilizado apenas para estabelecer tendência da resposta / Abstract: Pigmented yeasts were collected from soils, flowers, leaves, fruits from Campinas-SP region and industrialized foods. The samples were put in 50 mL erlenmeyers flasks, containing YM broth, and they were incubated at 30°C for 48 hours. After 48 hours, these samples were inoculated in Petri plates with YM agar, and incubated at 30°C for 120 hours. The yeasts colonies that had color between red and yellow were transferred to tubes, containing YM agar, and incubated at 30°C. These yeasts were reisolated by screening in Petri plates with YM agar (30°C for 72 hours) and then, transferred into tubes containing GYMP agar. After the selection, the pigmented yeasts were identified by a code: L12, was isolated from tomato sauce; L108, from soils of State University of Campinas; L125, from leaves of sugar cane; L135 e L137, from soils of Holambra-SP. The yeasts were identified by their morphology characteristics, reproduction characteristics, physiology and biochemical tests. The yeasts L12, L108, L135 and L137 were identified as Rhodotorula mucUaginosa and L125 as Rhodotorula graminis. The carotenoid composition of yeasts isolated in Brazil was studied. The yeasts were cultured in 200 mL broth yeast malt at 200 rpm in rotary shaker, 25°C for 5 days without illumination. Open column, thin layer chromatography and high performance liquid chromatography were used to separate, identify and determine carotenoid concentrations. The yeast Rhodotorula glutinis had the highest total carotenoid concentration (881 mg/L), followed by Rhodotorula graminis (594 mg/L), Rhodotorula mucUaginosa-137 (590 mg/L) and Rhodotorula mucilaginosa-135 (545 mg/L). Rhodotorula minuta and Sporobolomyces had the lowest carotenoid contents (168 mg/L and 237 mg/L, respectively). The principal pigments found in these yeasts were torulene and b-carotene. b-Carotene predominated in Rhodotorula graminis-125, Rhodotorula glutinis and Sporobolomyces, while torulene was the major carotenoid in Rhodotorula mucilaginosa. In specific carotenoid production (mg/g of dried cells), Rhodotorula glutinis had a total carotenoid concentration of 132 mg/g. Two of these strains were selected to optimize the carotenoid production, Rhodotorula mucilaginosa-137 and Rhodotorula glutinis. The cultures were cultivated into 200 mL broth yeast malt at 200 rpm in rotary shaker, 25°C for 5 days without illumination. Response surface design was used to study the effects of initial pH and concentrations of glucose, yeast extract, magnesium sulfate and potassium phosphate. Two statistical designs were used for each strain. For the strain of Rhodotorula mucilaginosa-137, the yeast extract the most important variable in terms of enhancing carotenoid formation; magnesium sulfate and potassium phosphate had a negative influence. The initial pH had no significant effect on carotenoid formation or on cell production. Analysis of the quadratic surfaces showed that after 5 days of cultivation at 25°C, the maximum carotenoid concentration of 745 mg/L appeared at 15 g/L of yeast extract and 20 g/L of glucose. The maximum concentration of specific carotenoid production was 152 mg/g at 5 g/L of yeast extract and 10 g/L of glucose. The concentrations of yeast extract and glucose were also important on biomass production, which reached maximum value of 8.0 g/L at a range of 15 to 17.1 glL of yeast extract and 15 to 20 g/L of glucose. The variables that had most influence on carotenoid production by Rhodotorula glutinis were initial pH, yeast extract and glucose. Magnesium sulfate and potassium phosphate had no influence. The carotenoid production was described by second order p01ynomial equation. Analysis of the 23 factorial design surfaces showed that after 5 days of cultivation at 25°C, the maximum carotenoid concentration of 1,269 mg/L with initial pH 4, 4 g/L of yeast extract and 17 g/L de glucose. The maximum specific carotenoid production was 337 j..tglg with initial pH 4, 4 g/L of yeast extract and 7 g/L of glucose. Moreover, carotenoid production in mg/g per liter was more sensitive to changes in yeast extract than to changes in glucose concentrations, in the vicinity of the optimum point of carotenoid production. The growth of the microorganism was affected by initial pH and concentration of yeast extract and glucose. However, the model obtained for biomass from the experimental designs had not a good correlation and because of that it should be used only to study the tendency of response / Doutorado / Doutor em Ciência de Alimentos

Carotenoids are precursors of hormones and signaling molecules across all kingdoms of life. An increasing body of evidence suggests the presence of yet unidentified carotenoid-derived metabolites (apocarotenoids) with developmental and regulatory functions, besides the known plant hormones abscisic acid (ABA) and strigolactones (SLs). Generally, apocarotenoid synthesis is initiated by carotenoid cleavage dioxygenases (CCDs), which constitute a ubiquitous family of non-heme iron enzymes. In SL biosynthesis, an iron-binding cis/trans-isomerase, DWARF 27 (D27) converts all-trans-β-carotene into 9-cis-β-carotene. This reaction is followed by a double bond cleavage at 9, 10 position, mediated by the stereospecific CCD7. The cis-configured cleavage product of CCD7, 9-cis-β-apo-10’-carotenal, is simultaneously cleaved, triple-oxygenated and rearranged by CCD8, to produce carlactone (CL). CL is a central metabolite and the precursor of a wide range of SLs. The aim of this work is to investigate whether CCD8 synthesize CL-like compounds from other 9-cis-configured apocarotenoids to confirm their presence and synthesis in planta. We showed that CCD8 enzymes from different plants produce a hydroxylated carlactone (3-H-CL) from 9-cis-3-OH-β-apo-10’-carotenal in vitro. In addition, we detected 3-H-CL in Nicotiana benthamiana leaves transiently expressing the CL biosynthesis enzymes from rice and Arabidopsis. 3-H-CL is biologically active, as shown by Striga hermonthica seed germination assay and by its effect on the high-tillering phenotype of the rice d10 mutant. We also confirmed that 3-H-CL is a natural metabolite by detecting it in roots of the rice SL perception mutant d14. In a second project, we investigated the activity of three rice CCDs in vitro and showed that one of them (zaxinone synthase; ZAS) is an apocarotenoid cleavage enzyme with a clear preference for the substrate all-trans-3-OH-β-apo-10’-carotenal, as suggested by a kinetic study. ZAS produces two products, the C18 ketone zaxinone and an unstable C9 dialdehyde that could be identified by LC-MS after derivatization. Activity tests were performed with crude lysates of overexpressing Escherichia coli cells and with purified enzyme. We established that zaxinone is a natural metabolite present in planta. Investigations of a corresponding rice mutant (zas) and activity bioassays performed by our group demonstrate that zaxinone a novel signaling molecule required for normal rice growth and development.

Carotenoids are important industrial pigments present practically in all living organisms. The aim of presented work is the study of regulation of carotenoid production in yeasts of the genus Cystofilobasidium in presence of exogenous stress factors. Growth curve of C. capitatum exhibited typical two-stage course with prolonged stationary phase similar to other carotenogenic yeasts. Maximal production of biomass and beta-carotene occurred in 103rd hour. Applied stress factors (2-5% NACl, 2-5 mM H2O2, 0,01-1 mM Se(IV), 0,1-5 mM Cr(III)) exhibited no significant influence on biomass production, which reached on average 8-9 g/l. Positive effect was observed in presence of 5mM Cr where 10 g/L of biomass was produced. Beta-carotene formation was positively influenced by many applied stress factors, the highest yield (695 g/g) was reached in presence of 0,1 mM Se(IV). No simultaneous regulation of ergosterol and carotenes was observed in Cystofilobasidium cells. Production properties of yeast strain C. capitatum CCY 10-1-1 wee compared with those of other carotenogenic yeasts of the genes Rhodotorula and Sporobolomyces. C. capitatum produced similar biomass yield as Rhodotorula sp. in presence of salt. Production of beta-carotene by C. capitatum was slightly higher than in Rhodotorula glutinis, but lower than in Sporobolomyces strains which exhibited substantially lower biomass production. Karyotype of C. capitatum is relatively different when compared with karyotype of other carotenogenic yeasts. Based on summary of our results in seems that yeasts C. capitatum exhibit similar physiological as well as production properties as some Rhodotorula strains. Thus, yeasts of the genus Cystofilobasidium could be potentially used to industrial production of carotenoid pigments as well as yeast biomass rich in carotenoids and some biogenic elements.

Carotenoids are naturally occurring pigments of plants also produced by microbes. The area of their application concerns mainly food industry; however, they are used in chemical, pharmaceutical, and cosmetics industry as well. Currently, the isolation of carotenoids from plants is markedly regulated by legislation, so the study of their production is greatly emphasised, where the microbiological, instead of the synthetic, production of carotenoids is being prioritized. This work was made as a comparative study of carotenogenic yeasts of the genes Rhodotorula, Sporobolomyces, and Cystofilobasidium. Their ability to use various waste substrates as a carbon and nitrogen source and source of other nutrition factors was tested. In this work, conditions of random mutagenesis were optimized. Particular yeast strains were also subjected to the effect of mutagen ethyl methanesulfonate (EMS) in order to increase the production of biomass and specific metabolites – carotenoids and other lipid-soluble substances. Random mutagenesis and mutant strain selection was performed using waste subtrates as glycerol, pasta and some pasta hydrolyzed by fungal extracellular enzymes. Subsequently, a control of specific DNA sequences in pigments overproducing mutants was analyzed by PCR/DGGE (denaturating gradient gel electrophoresis). Increased production of -carotene was achieved in a mutant of Sporobolomyces roseus strain growing on glycerol, pasta, and hydrolyzed pasta. Overproduction of carotenoids by mutant strain of Rhodotorula glutinis was observed in glucose medium only. Mutants of Cystofilobasidium capitatum exhibited a decrease of biomass production; on the other hand, the production of carotenoids increased especially in pasta medium hydrolyzed by enzyme preparative from Fusarium solani. In this work it was confirmed that using random mutagenesis strains capable to utilize waste substrates can be selected. In mutant strains increased carotenoids biosynthesis was observed, which enables effective use of cheap substrates and reduction of the negative effects of wastes on the environment.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / Microfiche copy available in Archives and Science / Vita. / Includes bibliographies. / by Daniel James Repeta. / Ph.D.