Solid and liquid waste utilization in fermentation process to get bacterial insecticide.

Proceeding of the 5th International Congress on Engineering and Food, 28 May and 3 June, 1989, Cologne, Federal Republic of Germany

Recent observations on bacterial insecticide production by semi-solid fermentation technique.

The practical use of entomopathogenic microorganism, to crop protection is possible when an industrial scale production of the organism is developed. That is the case of Bacillus thuringiensis (Bt), one of the most studied and commercially important entomopathogenic bacterium. In Brazil the feasibility of Bt production depends, to a large degree, on the cost at which this product can be obtained. So, the fermentation technology has to aim the production of new fermentation media and new fermentation processes to get such economical level. In search of new fermentation processes it was studied the production of Bt spores and gama-endotoxin in a low cost medium (using agroindustrial by-products) by the semi-solid fermentation in flasks. The fermented malt and the solid residues from pulp and paper industry could both be used as a complete medium for growth and sporulation of this bacterium. Furthermore, the humidification or the supplementation of the culture media with a low price mineral salt source increases the yield of the spores production. It was concluded that the semi-solid fermentation technique can be successfully used for Bt spores and gama-endotoxin production

Outlook on the use of semi-solid culture media for the production of Bacillus thuringiensis.

Based on the fact that wider use of Bacillus thuringiensis for the biological control of insect pests has been restricted by economic reasons, studies were initiated to explore the feasibility of producing Bt. endotoxin preparations using semi-solid fermentation with cheap components as substracts. Some agroindustrial by-products including solid residue from paper industry, residual fermented malt from beer industry, and a special kind of meal obtained from residual cookies and biscuits of bakery industry, were investigated for their abilities to support Bt. growth and spore production. The technique was based upon the employment of semi-solid type of fermentation in erlenmeyers whose culture medium was composed by each residue separated, or by the combinatio n of two residues. The incubations was done at 30. C., with one hand-shaking each day, and spore counts and pH measurement were done until the seventh day. The semi-solid process used takes nearly 168 hours to produce 10 10 - 10 13 spores/g. The submerged fermentation results are nearly 10 9 - 19 10 spores/ml, in about 48-71 hours. Economic studies are conducted to determine the advantageous process, but the low cost of residues, the availability of them in Brazil, the technological aspects of production in small scale in some regions of the country, seem to be sufficient reasons to adopt the semi-solid fermentation process for Bacillus thuringiensisi production

A first appraisal of the landing and mechanism of the Santos fishery

This paper summarizes and analyses the landing data collected at Santos, Brazil, during the 12 months period, July 1958-June 1959. These data are given in terms of weight landed of the more important fish and shrimp and also in terms of value. The distribution of the landings of each of the more important species is shown both according to the type of fishing gear used and fishing area. The fishing area is given in the form of statistical rectangles of 60 miles square. The landings are broken down to obtain a figure for the landing per hour of fishing for each species, for each gear and for each rectangle fished. This figure of landing per unit fishing time is used to compare one area with another, one gear with another, and one month with another for each of the important species. In this way, comparisons of the available density of a species by time, area and fishing gear are made.Êste trabalho sintetiza e analisa os dados coletados em Santos, Brasil, sobre o desembarque de pescado durante o período de 12 meses, de julho de 1958 a junho de 1959. Estes dados são apresentados em termos de peso desembarcado, para as espécies de peixes mais importantes e camarões e, também, em termos de valor econômico. A distribuição dos desembarques de cada uma das espécies mais importantes é apresentada tanto em relação ao tipo de aparelho de pesca usado, como em relação à área de pesca. Essa área é dada sob forma de retângulos estatísticos de 60 milhas quadradas. Os desembarques são classificados para se obter o valor do desembarque por hora de pesca para cada espécie, para cada aparelho e para cada retângulo pescado. Este valor do desembarque por unidade de tempo de captura é usado para comparar as áreas entre si, os aparelhos de captura entre si e os meses do ano entre si, em relação a cada espécie importante. Deste modo são feitas as comparações da densidade disponível de uma espécie no tempo, na área de pesca e por aparelho de pesca

Produção de inseticida biológico com Bacillus thuringiensis.

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Analise citogenetica de suínos intersexuados.

Esclarecer a etiologia da interssexualidade devido aos fatores geneticos, foram observados os produtos de 350 fêmeas em um plantel suíno, nascidos num período de 11 meses

Dificuldades de professores de física em início de carreira

Neste trabalho, procuramos, através de uma pesquisa qualitativa, realizada por meio de entrevistas e narrativas, identificar as principais dificuldades encontradas por três professores de física em início de carreira. Percebemos nos casos estudados, que, ao se depararem com a realidade de sala de aula em suas primeiras experiências, os professores se chocam com questões básicas do ensino, como a indisciplina, a motivação dos estudantes, como se portar em sala e que, nos momentos iniciais, estas questões fazem parte do seu desenvolvimento profissional assim como muitas vezes determinam a continuidade ou não de alguns professores em suas carreiras. Apresentamos nossos dados, relacionando, classificando e analisando as principais dificuldades encontradas por estes professores, a luz de algumas teorias relacionadas à formação de professores