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

Bacillus thuringiensis production using cassava liquid waste (manipueira) as a fermentation substrate.

In developing countries the search for inexpensive substrates to grow useful microorganisms is a desirable way to get new and safe products to protect man against insect pest losses. Bacillus thuringiensis is an entomopathogenic bacteria, which by fermentation produces endo- or exotoxins to be used against Lepidoptera or Diptera, resp. These are insect pests of economic importance in developing countries, mainly in Brazil, where 60% losses in agriculture are caused by this type of pest. Our research group has been working with B. thuringiensis since 1970; and many papers have been published on the processes, culture media composition and available substrates, culture and operational conditions, equipment and so on. Many residues and waste waters were tried forthe fermentation culture medium. This paper reports the possibility of using manipueira, a residual waste water from cassava processing as a substrate to produce B. thuringiensis by fermentation. The culture medium was composed of 75% manipueira & 25% water. Operational conditions considered agitation and aeration rate, as well as initial pH and optimum growing temperature. Microbial growth and sporulation behavior were accomplished by optical density determination, pH variation and sugar consumption. Results are promising

Anticarsia gemmatalis como inseto-teste para Bacillus thuringiensis.

O CNPDA/EMBRAPA, com a colaboração da Faculdade de Engenharia de Alimentos/UNICAMP, desenvolveu um processo de produção do Bacillus thuringiensis por fermentacao semissólida visando o barateamento do meio de cultura associado a diminuição do custo de produção. Para esse tipo de fermentação foram testados resíduos agro-industriais como farelos e tortas de oleaginosas, malte de cervejarias e leveduras filtradas, entre outros, que são facilmente encontrados na região e de custo baixissimo. Para verificação da atividade do B. thuringiensis, foram realizados bioensaios com Anticarsia gemmatalis Hubner, 1918 (Lepidoptera, Noctuidae) que e considerada a principal especie desfolhadora da soja, Glycine max, sendo de ocorrência em todas as áreas desta cultura no Brasil. Outro ponto para a escolha desta lagarta foi o fato de existir uma metodologia para sua criação em laboratório. Quando foi usada a dieta artificial sem anticontaminantes, o B. thuringiensis foi oferecido as lagartas colocando-o sobre a dieta ou se misturando a mesma, que foi colocada em copos plásticos, tipo cafezinho, onde foram postas duas lagartas por copo. O comportamento das lagartas foi observado diariamente ate o sétimo dia. O parâmetro usado foi a mortalidade e a resposta do bioensaio e representada em % da mortalidade no período

Characteristics of precipitation in the Santarém study region.

Abstract ID: 80. Publicado também on-line

Estratégia para a obtenção de cultivares de arroz com resistência genética à bicheira-da-raiz.

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