Sobrevivência de Rhizobium japonicum em turfa esterilizada com raios gama

Survival of Rhizobium japonicum in irradiated peat

NOTAS

Sobrevivência de Rhizobium japonicum em turfa esterilizada com raios gama¹

Survival of Rhizobium japonicum in irradiated peat

Eli Sidney LopesI, ²; Antonio Roberto GiardiniI, ²; Luiz Sanches^{II, III}

^ISeção de Microbiologia do Solo, Instituto Agronômico, IAC

^IIPontifícia Universidade Católica de Campinas, IAC

^IIIFísico Nuclear - IBRAS-CBO e Professor da Pontifícia Universidade Católica de Campinas, IAC

SUMMARY

Peat like substrate, ready for use by inoculant industry was gama irradiated at 2.25 and 5.10⁸ megarads in sealed plastic bags. Non sterilized, and autoclaved peat were also packed and sealed. Broth of strain SMS-313 (RS/SEMIA 566) was insected to give 33% humidity into each peat treatment and 2.3 x 10⁸ rhizobia/g of wet inoculants.

The bags were maintained at room temperature, and six samples of each treatment were collected at different intervals, during 290 days, to count the number of bacteria. In both dosis of irradiation there was a sharp increase in rhizobia. Maximum numbers in the period were reached in between 32 and 60 days. At the second sampling (32 days) population in both irradiated treatment had circa 1.8 x 10⁹ rhizobia/g wet peat. In the non sterilized and autoclaved peat treatments the maximum numbers of rhizobia were much lower (3.0 x 10⁸).

A gradual decrease in number of rhizobia, in the irradiated treatment was observed, but a higher number of rhizobia was maintained throughout the experiment, as compared to the non sterilized, or autoclaved peat.

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Recebido para publicação a 13 de novembro de 1979.

1

Trabalho apresentado na 9.a Reunião Latino-americana sobre Rhizobium, 1978, México. Projeto FAPESP 72/ 1464.

2

Com bolsa de suplementação do CNPq.

Datas de Publicação

• Publicação nesta coleção
  21 Dez 2007
• Data do Fascículo
  1980