Os volumes da produÃÃo de leite estÃo crescendo a uma taxa mÃdia de 2% ao ano em todo o mundo. Este aumento da quantidade de leite està sendo canalizado para a produÃÃo de queijo, caseÃna, caseinato e outros produtos lÃcteos, resultando no aumento do volume de soro de leite. Ele representa cerca de 85-95% do volume do leite e retÃm cerca de 55% de seus nutrientes, no entanto, seu alto poder poluente levou ÃrgÃos ambientais e outras autoridades reguladoras a proibir o descarte do soro de leite nÃo tratado no ambiente. A partir de estudos sobre os componentes do soro de leite e a descoberta das propriedades tecnolÃgicas e funcionais de suas proteÃnas, a visÃo de resÃduo poluidor mudou, sendo hoje, considerado um co-produto da produÃÃo de queijo. Um dos processos que promove a melhoria de suas propriedades consiste na hidrÃlise protÃica. Este tratamento pode ser realizado pelo emprego de Ãcidos, bases ou enzimas, contudo, a hidrÃlise enzimÃtica apresenta diversas vantagens sobre a quÃmica, como a especificidade, o controle do grau de hidrÃlise (GH), as condiÃÃes moderadas do processo e a formaÃÃo mÃnima de subprodutos. O objetivo deste trabalho foi promover a hidrÃlise das proteÃnas do soro de leite, atravÃs da aÃÃo de proteases sintetizadas pelo Aspergillus oryzae IV e a secagem deste por atomizaÃÃo. Avaliou-se o efeito da temperatura e tempo de incubaÃÃo, relaÃÃo enzima:substrato (E:S), e posteriormente do pH. Determinou-se os parÃmetros que permitiram maior grau de hidrÃlise. A faixa de temperatura de incubaÃÃo estudada foi entre 30 e 50 ÂC, a relaÃÃo E:S variou nas proporÃÃes de 0,5:100 a 3,0:100. A melhor condiÃÃo de hidrÃlise (GH = 70%) obtida à 50 ÂC por 12 horas, empregando a relaÃÃo E:S de 2,0:100. Avaliou-se a influÃncia da hidrÃlise no perfil peptÃdico realizando uma anÃlise eletroforÃtica, em que confirmou-se a necessidade de estudar a hidrÃlise em diferentes valores de pH. Desta forma o pH do soro de leite foi ajustado entre 4,0 e 8,0 antes da reaÃÃo para avaliar a influÃncia deste parÃmetro sobre o grau de hidrÃlise. A amostra hidrolisada foi concentrada atà um teor de sÃlidos entre 14 e 28 ÂBRIX antes do processo de atomizaÃÃo. NÃo houve diferenÃa significativa entre as amostras atomizados avaliados quanto ao rendimento, umidade e atividade de Ãgua. AtravÃs da anÃlise eletroforÃtica, a partir dos gÃis corados em soluÃÃo de prata, foi possÃvel confirmar a aÃÃo das proteases sobre proteÃnas de diversos pesos moleculares com exceÃÃo a β-lactoglobulina. / Worldwide milk production is growing at a average rate of 2% per year. This increased amount of milk has been related to the production of larger volumes of cheese, casein, caseinate and other milk products, resulting in increased volume of whey. It represents about 85-95% of milk volume and retains about 55% of its nutrients, however, its high power pollutant led environmental bodies and other regulatory authorities to prohibit the discharge of whey into the environment untreated. From studies about whey components and with the discovery of technological and nutritional properties the status of polluter waste changed, then, nowadays, whey is considered a co-product of cheese production. One processes that promote improvement of whey properties is protein hydrolysis, characterized by the disruption of bonds of molecules protein chains releasing different sizes peptides and free amino acids. The hydrolytic treatment can be done by acids, bases or enzymes, however, enzymatic hydrolysis show many advantages in relation to chemical processes, as specificity, control of hydrolysis degree, the moderated conditions of the process and minimal formation of residual products. The objective of this study was to promote whey protein hydrolysis through the action of proteases synthesized by Aspergillus oryzae IV and spray drying this product. We evaluated the effect of temperature and time of incubation, enzyme: substrate ratio (E: S), and subsequently the pH. The parameters which have enabled higher degree of hydrolysis were determined. The temperature range studied was incubated between 30 and 50  C, the ratio E: S ranged in the proportions of 0,5:100 3,0:100. The best condition of hydrolysis (DH = 70%) was obtained at 50  C for 12 hours, employing the ratio E: S 2,0:100. An electrophoretic analysis was performed to obtain the hydrolysis influence on the peptide profile, in which confirmed the need to study the hydrolysis at different pH values. Thus, the whey pH was adjusted between 4.0 and 8.0. The hydrolyzed sample was concentrated to a solids content between 14 and 28 Brix before the atomization process. There was no significant difference regarding yield, moisture and water activity between the spray dried samples. Through the eletrophoretic analysis, from gels stained with silver solution, was possible to verify the action of proteases on proteins of different molecular weights with exception β-lactoglobulin.

Orientador: Luciana Francisco Fleuri / Resumo: Resíduos e subprodutos agroindustriais são extensivamente estudados a fim de se reaproveitar seu potencial biológico e agregar valor. A fermentação em estado sólido (FES) é uma das formas de utilizar estes resíduos e subprodutos para obtenção de enzimas, como as proteases. Este trabalho objetivou estudar a produção de proteases fúngicas por FES utilizando farelo de soja e farinhas de banana, caracterizar bioquimicamente as proteases mais promissoras e, por fim, aplicar na hidrólise da farinha de grilo (Gryllus assimilis), avaliando os produtos de hidrólise. O estudo da composição do meio de cultivo foi conduzido através de um delineamento experimental, o planejamento de misturas, para definir a proporção ótima de parte sólida dos substratos de fermentação. Posteriormente, realizou-se a cinética de produção de protease por FES, a caracterização bioquímica das proteases mais promissoras quanto ao pH e temperatura ótimos de atuação, bem como a influência de íons metálicos e L-cisteína em diferentes concentrações. Por meio de relargagem (salting-out), fez-se a purificação parcial das enzimas, seguida de diálise e liofilização, para então serem aplicadas na hidrólise da farinha de grilo. O fator de hidrólise, a atividade antioxidante e o perfil eletroforético dos produtos de hidrólise foram avaliados. O planejamento de misturas resultou em duas proporções com altas atividades proteolíticas, 50 % de farelo de soja (FS) e 50 % de farinha de casca de banana madura (FCBM) e um terço d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Agro-industrial waste and by-products are extensively studied aiming to add value and explore their full biological potential. Solid state fermentation (SSF) is a technique that use agro-industrial waste and by-products and may be used to obtain enzymes, such as proteases. This study aimed to produce fungal proteases by SSF using soybean bran and banana flours as substrate, characterize biochemically and apply most promising proteases to hydrolysis of cricket flour (Gryllus assimilis), and evaluate the hydrolysis products. The composition of the culture medium was evaluated through an experimental design to define the optimal proportion of solid part of the fermentation substrates. Subsequently, the protease production kinetics were performed by SSF, the most promising proteases were characterized biochemically according to the optimal pH and temperature, as well as according to the influence of metal ions and L-cysteine ​​in different concentrations. Proteases were partially purified by salting-out, followed by dialysis and lyophilization and applied in hydrolysis of the cricket flour. The hydrolysis factor, the antioxidant activity and the electrophoretic profile of the hydrolysis products were evaluated. The mixture design resulted in two combinations with high proteolytic activities, 50% soybean bran (SB) and 50% ripe banana peel flour (RBPF) and one third of each component (soybean bran, ripe banana peel flour and green banana flour) for the microorganisms Trichoderma ko... (Complete abstract click electronic access below) / Mestre

Thesis by publication. / "August 2006" / Thesis (PhD)--Macquarie University, Division of Environmental & Life Sciences, Dept. of Biological Sciences & Dept. of Chemistry & Biomolecular Sciences), 2007. / Bibliography: leaves 157-183. / 1. Introduction -- 1.1. Proteomics and two-dimensional electrophoresis -- 1.2. A proteomic approach to study the filamentous fungus Trichoderma -- 1.3. Aims of the thesis -- 2. Materials and methods -- 3. Results and discussion -- 3.1. Method development for the display and identification of fungal proteins by 2DE and mass spectrometry -- 3.2. Discovery of novel determinants in the biological control of phytopathogens by Trichoderma atroviride -- 3.3. Summary and concluding remarks. / Trichoderma harzianum and T. atroviride are filamentous fungi commonly found in soil. Both display biocontrol capabilities against a range of phytopathogenic fungi including Rhizoctonia solani and Botrytis cinerea which are known pests of hundreds of commercially important crops including tomatoes, potatoes, beans, cucumber, strawberries, cotton and grapes. These Trichoderma species secrete a combination of enzymes degrading cell walls and antibiotics to overgrow and kill fungal phytopathogens. They are seen as an environmentally friendly alternative to chemical fungicides currengly used on crops. / A proteomic approach was taken to separate and identify proteins from a strain of T. harzianum with well established biocontrol properties. Several methods were developed in this thesis to display the whole proteome content and several subcellular proteome fractions from T. harzianum. Proteins were separated by two-dimensional electrophoresis and identified by mass spectrometric methods. The resulting proteomic maps represent the first extensive array of cellular and sub-cellular proteomes for T. harzianum. / Cellular protein patterns of T. atroviride (T. harzianum P1) grown on media containing either glucose or R. solani cell walls were compared by differential gel electrophoresis to identify a suite of new proteins involved in the biological control response. Twenty four T. atroviride protein spots up-regulated in the presence of the R. solani cell walls were identified by mass spectrometry and N-terminal sequencing. Proteins identified from this study included previously implicated enzymes degrading cell walls and three novel proteases, vacuolar serine protease, vacuolar protease A and trypsin-like protease. The genes encoding two of these proteases, vacuolar protease A and vacuolar serine protease have been cloned by degenerate primer PCR and genomic walking PCR and sequenced. The gene sequences and protein sequences derived from these genes have been partially characterised. / Mode of access: World Wide Web. / 194 leaves ill