Application of methylotrophic yeast Pichia pastoris in the field of food industry - A review

Since ancient times, the utilization of yeasts by the man has a great impact on the socio-economic development. After the advent of the technology of recombinant DNA, great advances have occurred due to the acquisition of strains of mutant yeasts in the field of applied research, and Saccharomyces cerevisiae has soon been outstanding as an interesting candidate for the expression of heterologous proteins of biotechnological interest. As the time goes by other alternative systems of expression have been shown because they have advantages over Saccharomyces cerevisiae. Among those new systems, Pichia pastoris is outstanding as methylotrophic yeast capable of growing in a culture medium containing methanol as the only source of carbon and energy. The induction of production of glycerol-3-phosphate dehydrogenase (GPD, NAD(+): oxido-redutase EC 1.1. 1.8) by Pichia pastoris was accomplished in the medium containing methanol. One of the most important key parameters in Pichia pastoris expression system is the methanol concentration. Bibliographic reviews on the Pichia pastoris production system have shown that the best culture conditions vary according to the strain used and/or kind of heterologous protein desired to be expressed. Therefore, we have sought to develop a system, involving expression of glycerol-3-phosphate dehydrogenase in the yeast Pichia pastoris, for generating sufficient quantities of the enzyme in order to asses its potential value for use in various food bioanalytical determination. Dehydrogenases have been widely used in the enzymatic assays of diverse composites of industrial interest, being enclosed among them glycerol and a number of important bioanalytical applications.

Larval aggregation and competition for food in experimental populations of Chrysomya putoria (Wied.) and Cochliomyia macellaria (F.) (Dipt., Calliphoridae)

In blowflies, larval aggregation in patches of food can be both intra- and interspecific, depending upon the degree to which competitors are clumped among the patches. In the present study, the implications of spatial aggregation for larval competition was investigated in experimental populations of the introduced blowfly Chrysomya putoria and the native Cochliomyia macellaria, using data from survival to adulthood in a range of single- and double-species larval cultures. The reduction in C. macellaria survival rate in the presence of C. putoria suggests that the former species is the inferior competitor. The results on survival to adulthood for both species in single- and double-species cultures can be explained in the light of the relationship between the level of intra- and interspecific aggregation and the efficiency of the larval feeding process. The possible implications of these results for the population biology of both species in natural environments are discussed.

Expanded food choice as a possible factor in the evolution of sociality of Vespidae (Hymenoptera)

A recent theory suggests that economic considerations are more important than genetic ones in the emergence and maintenance of social behavior. Evolution of social behavior in wasps, thus, could be based on the development of worker castes, which increase the efficiency of brood care and energy use of the colony. If so, social wasps should collect a larger range of prey, favoring polyethism, as social behavior should increase the adaptive value of social species among wasps by increasing the range of prey accessible. We explored the literature and showed that the Eumeninae, which are mostly solitary, draw prey from significantly fewer orders of arthropods than wasps in the subfamily Vespinae and Polistinae, which are mainly social, supporting the hypothesis that social behavior may have emerged as a more efficient way to feed and care for the young by opening a wider range of food sources, increasing the amount of food and quality of care provided to the young. Two alternative explanations of this data are also discussed.

Cuticular Hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): Analyses and Electrophysiological Studies

Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes. Difference in the composition appears to relate with the type of habitat of specie.

An alternative LC-UV procedure for the determination of prochloraz residues in fruits

An alternative method using liquid chromatography with UV detection for the determination of prochloraz as 2,4,6-trichlorophenol in mango, papaya and orange is described. Ethyl acetate, acetone and dichloromethane were tested for extraction of prochloraz from the fruits. After extraction the residue of prochloraz was derivatized with pyridine hydrochloride. The analysis was carried out using liquid chromatography with UV detection and gas chromatography with electron-capture detection. Average recoveries of prochloraz from spiked fruits (0.1 and 0.2 mg kg-1) ranged from 80% to 94% with relative standard deviations between 5.6% and 12.6% (n=8). Detection and quantification limits were 0.05 and 0.1 mg kg-1, respectively. The LC-UV method was applied to mango and papaya samples submitted to dip treatment with a prochloraz formulation under laboratory conditions. In addition, fruit samples obtained from local markets were analysed. ©2005 Sociedade Brasileira de Química.

Ação de óleos essenciais no controle de sigatoka-negra (Mycosphaerella fijiensis) Morelet de bananeiras (Musa sp)

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Desenvolvimento e análise de um protótipo automatizado para dosagem pontual de fertilizantes sólidos em taxas variáveis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Extratos vegetais e produtos naturais com potencial de uso no controle de Tetranychus urticae Koch (Acari: Tetranychidae) na cultura da videira

Pós-graduação em Agronomia - FEIS

Use of nicarbazin, salinomycin and zinc oxide as alternative molting methods for commercial laying hens

An experiment was carried out to evaluate the performance, egg quality and morphometry of the reproductive tract, liver, pancreas and tongue of laying hens submitted to different molting methods. Two hundred and eighty eight 72-week-old Isa brown layers were distributed according to a completely randomized design with six treatments (molting methods) and six replicates of eight birds each. Layers were fed diets containing 3000 ppm zinc oxide, 60 ppm or 120 ppm nicarbazin, 30 ppm or 60 ppm salinomycin, or were submitted to feed fasting. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% probability level. Molting methods alternative to feed fasting were effective to induce molting in layer and provided good performance results in the second laying cycle.

Contributions of the old urban homegardens for food production and consumption in Rio Claro, Southeastern Brazil

Urban homegardens are green areas of households within the city limits and they have the potential to provide families with a cheap alternative for diet improvement, and to complement the income of the families who sell cultivated products. This research analyzes the contributions of old urban homegardens on food consumption and household economy. Data related to homegardens composition were collected by interviews and by collecting cultivated plants. Diets were assessed through a retrospective method (last 24 hours food recall) and administered every two months, during a year, to include seasonal variations. The diet of the sampled population was found to be dependent on certain foods, indicating a narrow food niche (Levins index = 25.9; Levins standardized index = 0.23). Variations in interviewees' diet are related to the consumption of fruits and vegetables, which are partly supplied by homegardens. Spices and teas consumed were obtained from homegardens, revealing its importance in food consumption and health. Among the 98 species found in homegardens, only 38% appeared in the interviewees' diet, indicating an under-exploitation of these homegardens. Our study found that the main role of homegardens is to supply variation in the diet, contributing to the consumption of different types of products.

Coagulase-negative staphylococci strains resistant to oxacillin isolated from neonatal blood cultures

Coagulase-negative staphylococci (CoNS) are the microorganisms most frequently isolated from clinical samples and are commonly found in neonatal blood cultures. Oxacillin is an alternative treatment of choice for CoNS infections; however, resistance to oxacillin can have a substantial impact on healthcare by adversely affecting morbidity and mortality. The objective of this study was to detect and characterise oxacillin-resistant CoNS strains in blood cultures of newborns hospitalised at the neonatal ward of the University Hospital of the Faculty of Medicine of Botucatu. One hundred CoNS strains were isolated and the mecA gene was detected in 69 of the CoNS strains, including 73.2% of Staphylococcus epidermidis strains, 85.7% of Staphylococcus haemolyticus strains, 28.6% of Staphylococcus hominis strains and 50% of Staphylococcus lugdunensis strains. Among these oxacillin-resistant CoNS strains, staphylococcal cassette chromosome mec (SCCmec) type I was identified in 24.6%, type II in 4.3%, type III in 56.5% and type IV in 14.5% of the strains. The data revealed an increase in the percentage of CoNS strains isolated from blood cultures from 1991-2009. Furthermore, a predominant SCCmec profile of the oxacillin-resistant CoNS strains isolated from neonatal intensive care units was identified with a prevalence of SCCmec types found in hospital-acquired strains.

Influence of the combination of probiotic cultures during fermentation and storage of fermented milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cell cultures of Maytenus ilicifolia Mart. are richer sources of quinone-methide triterpenoids than plant roots in natura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DEVELOPMENT OF A BIOMIMETIC SENSOR MODIFIED WITH HEMIN AND GRAPHENE OXIDE FOR MONITORING OF CARBOFURAN IN FOOD

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of alternative drying aids on water sorption of spray dried mango mix powders: a thermodynamic approach

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)