Homoacetic fermentation in the cyanobacterium Nostoc sp. strain Cc from Cycas circinalis

Authors

  • Maria Cristina Margheri,

    Corresponding author
    1. Centro di Studio dei Microrganismi Autotrofi, CNR, Florence, Italy
      Correspondence to: M.C. Margheri, Centro di Studio dei Microrganismi Autotrofi, CNR, P. le delle Cascine, 27, 50144 Florence, Italy.
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  • Graziella Allotta

    1. Centro di Studio dei Microrganismi Autotrofi, CNR, Florence, Italy
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Correspondence to: M.C. Margheri, Centro di Studio dei Microrganismi Autotrofi, CNR, P. le delle Cascine, 27, 50144 Florence, Italy.

Abstract

Abstract The dark anaerobic metabolism of Nostoc sp. strain Cc, isolated from coralloid roots of Cycas circinalis, was studied. As soon as cells were transferred to dark anaerobic conditions, exogenous glucose was actively metabolized to yield acetate as the sole fermentation product. The absence of other fermentation products and the stoichiometric ratio of about 3 mol of acetate per mol of glucose consumed strongly suggested that strain Cc is able to perform homoacetic fermentation. The same type of fermentation was also observed at the expense of endogenous carbohydrates as well as under reduced partial pressure of O2. The homoacetic fermentation allowed the strain to survive but not to grow.

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