Produção de carboidratos a partir do efluente de laticínios tratado por cianobactéria

Nesta tese foi demonstrado o potencial de produção de carboidratos por Aphanothece microscopica Nägeli cultivada no efluente oriundo de uma indústria de laticínios. Para tanto, o trabalho é composto de quatro artigos que objetivaram avaliar a produção de carboidratos em função da temperatura, inóculo e razões C/N e N/P do elfluente, bem como a possibilidade de reúso da água residuária. Foram utilizadas temperaturas de (10, 20 e 30ºC) e inóculo (100, 200 e 300 mg.L-1). A melhor condição indicada foi quando utilizou-se a temperatura de 30°C e 200 mg.L-1 de inóculo. Na sequência, considerando a temperatura e a concentração celular selecionada, foi estudada a influência das razões C/N e N/P na produção de carboidratos. Para tal, C/N (20, 40 e 60) e N/P (5, 10 e 15) na produção de carboidratos extracelulares foram avaliadas em cultivos a 30°C, tendo como inóculo 200 mg.L-1. Os melhores resultados obtidos, foram quando foi utilizado C/N 60 e N/P 10. Uma vez definidas as melhores condições de produção de carboidratos, foi estudado o processo de separação de biomassa do meio de cultivo, a partir dos coagulantes FeCl3, Al2(SO4)3 e tanino. O efeito dos coagulantes na separação da biomassa foram estudados, quanto ao pH (6,0, 7,0 e 8,0) e concentração de coagulantes (50, 300 e 550 mg.L-1), utilizando como parâmetro de medida, a eficiência de remoção de DQO, turbidez e sólidos suspensos (SS). Os resultados demonstraram que as concentrações de coagulantes influenciaram significativamente ao nível de significância de 5 %, na separação da biomassa, com eficiência significativa na remoção da DQO, turbidez e SS. A melhor condição avaliada foi a que utilizou tanino na concentração de 300 mg.L-1 e pH 7,0, o que resultou em uma água residuária com remoção média de 96 % da turbidez, com potencial de ser reutilizada. Por fim, foi realizada a identificação de carboidratos gerados por Aphanothece microscopica Nägeli. Os resultados evidenciaram uma biomassa com até 33,5 % de carboidratos totais, perfazendo uma fração de carboidratos extracelulares, na fase estacionária de crescimento celular, de aproximadamente 25 % e 8 % os carboidratos da parede celular. Ficou demonstrado ainda que a composição dos carboidratos extracelulares do microorganismo em estudo é constituído por mono e dissacarídeos perfazendo concentrações na ordem de 12,88 % de glicose, 3,54 % de rafinose, 3,43 % sacarose, 2,13 % de frutose e 2,45 % de ribose. Ficou demonstrado o potencial de produção de carboidratos por Aphanothece microscopica Nägeli quando cultivada no efluente da indústria de laticínios.

Dinâmica de nitrogênio em cultivo heterotrófico a partir de cianobactéria sob o escopo de biorrefinarias agroindustriais

O trabalho teve por objetivo avaliar a dinâmica de nitrogênio, em cultivo heterotrófico, a partir da cianobactéria Aphanothece microscopica Nägeli, sob o escopo de uma biorrefinaria. Neste sentido, foi avaliada a contribuição dos compostos nitrogenados não proteicos, na dinâmica de distribuição do nitrogênio, na biomassa gerada pelo micro-organismo em estudo, quando cultivado em sistema autotrófico e heterotrófico. Para o cultivo em condições autotróficas, foi utilizado o meio padrão BG-11, enquanto que, para o cultivo em condições heterotróficas, foi empregado o efluente da indústria de laticínios. Inicialmente, foi avaliada a contribuição dos pigmentos na fração nitrogenada não proteica tendo como base dois experimentos. No primeiro experimento foi selecionada a melhor condição para a produção de pigmentos, expressos pela clorofila-a em sistema heterotrófico, tendo como base os parâmetros C/N (20, 40 e 60), N/P (5, 10 e 15) e concentração de inóculo (100, 200 e 300 mg.L-1), mediante um planejamento fatorial 23 . Os experimentos foram conduzidos em biorreator heterotrófico a 20°C, pH 7,6 e aeração contínua de 1VVM. A melhor condição de produção de pigmento foi indicada como sendo a 200 mg.L-1 de concentração celular, razões C/N 20 e N/P 10. Com base nestes resultados, um segundo experimento foi delineado, visando avaliar a contribuição de pigmentos na fração de nitrogênio não proteico, bem como avaliar a produção de clorofila-a e ficobiliproteínas (ficocianina, aloficocianina e ficoeritrina), sob influência da luz e do meio de cultivo. Foi possível destacar teores superiores de ficobiliproteínas na biomassa gerada no cultivo heterotrófico. No entanto, com notada diferença (p≤0,05) nos teores de clorofila-a, quando são comparadas as concentrações na biomassa de meios autotróficos (10,7 mg.g-1) e heterotróficos (1,0 mg.g-1). Fato este compensado pelo menor tempo de cultivo registrado para atingir o final do experimento, quando o micro-organismo é cultivado em condições heterotróficas. Fica demonstrado assim, ainda, a importante contribuição dos pigmentos na fração de nitrogênio não proteico. Na sequência, um terceiro e quarto experimentos foram delineados, visando avaliar a influência do nitrogênio inorgânico intracelular na fração não proteica e na produção de proteína, assim como a caracterização da fração proteica quanto ao seu perfil aminoacídico. O estudo da dinâmica do nitrogênio intracelular demonstrou que o N-NH4 + foi a forma nitrogenada predominante, perfazendo importante fração de N-NP, sendo, portanto, os teores de N-NP significativamente dependente dos teores de pigmentos e nitrogênio intracelular. Os aminogramas das biomassas geradas pelos cultivos autotróficos e heterotróficos indicaram como aminoácidos majoritários o ácido glutâmico e aspártico, seguidos por valina, leucina e isoleucina, e como minoritários, lisina, glicina e metionina. O perfil aminoacídico caracterizou-se por apresentar aminoácidos essenciais como isoleucina, metionina + cisteína, fenilalanina + tirosina, valina e treonina em concentrações superiores ao preconizado pela FAO/WHO. A caracterização da fração proteica quanto ao perfil aminoacídico qualificou esta biomassa como fonte potencial de proteína. Os resultados obtidos neste trabalho demonstram a influência e dinâmica de distribuição dos compostos nitrogenados em Aphanothece microscopica Nägeli. Fica demonstrado, ainda, que a implementação do conceito de biorrefino, no tipo de agroindústria estudado, poderá representar importantes possibilidades de aproveitamento sustentável do efluente gerado.

Diversity and identification of heterotrophic bacteria from Antarctic Rocks of the McMurdo Dry Valleys (Ross Desert)

Diversity of endolithic Dry Valley rock microorganisms was studied by evaluating the presence of morphotypes in enrichments. Storage of rock samples for 16 h over dry ice affected the diversity of endolithic organisms, especially that of algae and fungi. Diversity in various samples depended on rock location and exposure, on the rock type, and to some extent on the pH of the pulverized rock samples. In most cases sandstone contained more morphotypes than dolerite or granite. Presence of many different phototrophs resulted in greater diversity of the heterotrophs in the enrichments. Samples from Linnaeus Terrace and Battleship Promontory had higher morphotype (MT) numbers than those from more exposed sites such as New Mountain, University Valley, Dais, or Mt. Fleming. Beacon sandstone (13 samples) from Linnaeus Terrace varied greatly with respect to MT numbers, although the pH values ranged only from 4.2-5.3. The highest MT number of 24 per sample was obtained from the upper surface of a flat boulder tilted to the North. Only two MT's were found in a hard sandstone sample from the wind-exposed and more shaded east side of the Terrace. 15 sandstone samples from Battleship Promontory contained more diverse populations: there occurred a total of 131 different MT's in these samples as compared to only 68 in Linnaeus Terrace samples. Cysts of colorless flagellates were found in some Battleship Promontory samples; rnost samples were populated with a wealth of different cyanobacteria. Studies on the distribution of actinomycete morphotypes in Linnaeus Terrace sandstone revealed great differences between individual boulders. Identification tests and lipid analyses made with representative strains of the isolated 1500 pure cultures led to genus names such as Caulobacter, Blastobacter, Hyphomicrobium, Micrococcus, Arthrobacter, Brevibacterium, Corynebacterium, Bifidobacterium, Mycobacterium, Nocardia (Amycolata), Micromonospora, Streptomyces, Blastococcus, and Deinococcus. Our data demonstrate the great diversity of Antarctic endolithic microbial populations.

N2 fixation in marine heterotrophic bacteria: dynamics of environmental and molecular regulation.

Molecular and immunological techniques were used to examine N2 fixation in a ubiquitous heterotrophic marine bacterium, the facultative anaerobic Vibrio natriegens. When batch cultures were shifted from aerobic N-replete to anaerobic N-deplete conditions, transcriptional and post-translational regulation of N2 fixation was observed. Levels of nifHDK mRNA encoding the nitrogenase enzyme were highest at 140 min postshift and undetectable between 6 and 9 h later. Immunologically determined levels of nitrogenase enzyme (Fe protein) were highest between 6 and 15 h postshift, and nitrogenase activity peaked between 6 and 9 h postshift, declining by a factor of 2 after 12-15 h. Unlike their regulation in cyanobacteria, Fe protein and nitrogenase activity were present when nifHDK mRNA was absent in V. natriegens, indicating that nitrogenase is stored and stable under anaerobic conditions. Both nifHDK mRNA and Fe protein disappeared within 40 min after cultures were shifted from N2-fixing conditions (anaerobic, N-deplete) to non- N2-fixing conditions (aerobic, N-enriched) but reappeared when shifted to conditions favoring N2 fixation. Thus, unlike other N2-fixing heterotrophic bacteria, nitrogenase must be resynthesized after aerobic exposure in V. natriegens. Immunological detection based on immunoblot (Western) analysis and immunogold labeling correlated positively with nitrogenase activity; no localization of nitrogenase was observed. Because V. natriegens continues to fix N2 for many hours after anaerobic induction, this species may play an important role in providing "new" nitrogen in marine ecosystems.

Dance dialogues : conversations across cultures, artforms and practices

These Proceedings, arising from the 2008 World Dance Alliance Global Summit, reflect both its spirit and diversity, re-appraising what dance is and might be in the 21st century. Through 53 papers from 14 countries in the Americas, Europe and the Asia-Pacific region, the authors — ranging from seasoned scholars to emerging artists publishing for the first time — span the perspectives of academics, educators, performance and community artists, health professionals and cognitive scientists; predominantly from dance but also from film, visual arts, science, performance and philosophy. The papers are grouped under the five Summit themes: Re-thinking the way we make Dance; Re-thinking the way we teach Dance; Mind/body connections; Transcultural conversations and Sustainability

Youth cultures, style and education

If our only sources of information were the newspapers and the television, the available evidence would suggest that youth is a terrible problem. Not only would we be convinced that most crime is committed by the social category of youth, but that young people are running out of control, that the streets are no longer safe, that all manner of standards are dropping, that the schools are in chaos, and that, as a consequence of these facts, society faces ruin. Fortunately, there is a considerable body of academic literature which rebuts these assertions, and via a more rigorous and objective analysis of society, it has sought to explain the practices, cultures and circumstances through and by which contemporary youth is formed.

Rethinking youth cultures : the case of the 'Gothics'

This paper has argued that subcultural social formations, such as the Gothics, did not evolve as resistance to a dominant culture. Instead, they are a response to the governmental construction of youth as an object of knowledge—the by-product of particular forms of government, generated by specific power/knowledge relations. Accordingly, attempts to account for the phenomenon of ‘subcultures’ should begin, not with notions of a shared, resistant class/generational consciousness, but rather with detailed investigations of specific forms of government, such as those involving conventions and customs within the fashion and music industries, the distribution of technologies of marketing and consumption, the adoption of various techniques of self-shaping, the prevalence of different journalistic practices, routines of policing, and so on. ‘Subcultural style’ is not an expression of relationship between a given social class, its material conditions and its economic and cultural aspirations. Rather, it constitutes the construction of particular habitus, shaped by fashion and leisure activities, through which certain youthful personae are given their form.

Negotiating selves: exploring cultures of disclosure

If identity is a construct—and, more critically, a construct defined and developed through relationships with others in public and private spheres—then an understanding of the processes, mechanisms and platforms by which individuals disclose information about themselves is crucial in understanding the way identity, community and culture function, and the way individuals can intervene in the functioning of culture.

Perceptions of aging across 26 cultures and their culture-level associates

College students (N = 3,435) in 26 cultures reported their perceptions of age-related changes in physical, cognitive, and socioemotional areas of functioning and rated societal views of aging within their culture. There was widespread cross-cultural consensus regarding the expected direction of aging trajectories with (1) perceived declines in societal views of aging, physical attractiveness, the ability to perform everyday tasks, and new learning, (2) perceived increases in wisdom, knowledge, and received respect, and (3) perceived stability in family authority and life satisfaction. Cross-cultural variations in aging perceptions were associated with culture-level indicators of population aging, education levels, values, and national character stereotypes. These associations were stronger for societal views on aging and perceptions of socioemotional changes than for perceptions of physical and cognitive changes. A consideration of culture-level variables also suggested that previously reported differences in aging perceptions between Asian and Western countries may be related to differences in population structure.

Leadership for creating cultures of sustainability

This chapter discusses the vital role of leadership in creating change for sustainability in an early childhood education and care setting. The author's experiences and perspectives as the past Director of Campus Kindergarten, a long day care centre that has had a Sustainable Planet Project for over a decade, are drawn upon as she explores the theoretical underpinnings that helped to shape her work as an innovative leader and a leader of innovation. Four frames of leadership, organisational culture, professional development and organisational change, and their contributions to creating and shaping the Sustainable Planet Project, are outlined. The style of educational and organisational leadership is highlighted as essential in creating a culture of sustainability. There is an emphasis on 'whole settings' approaches to change and the creating of 'learning communities' for sustainable living. Importantly, the recognition of children as leaders and change agents for sustainability is explored.