Paenibacillus favisporus sp. nov. a xylanolytic and phosphate-solubilizing bacterium isolated from cow faeces

E. Velázquez¹, Trinidad de Miguel², Raúl Rivas¹, Margarita Poza², Ramón Rosselló-Mora³ and Tomás G. Villa².

¹ Departamento de Microbiología. Fac. Farmacia. Univ. Salamanca. SPAIN.

² Dpto. Microbioloxía e Parasitoloxía. Fac. Farmacia. Univ. Santiago de Compostela. Campus Sur, Santiago de Compostela. SPAIN.

³ Institut Mediterrani d’Estudis Avancats and Departament de Biologia Ambiental, Universitat de les Illes Balears (CSIC-UIB), Crtra. Valldemossa Km 7.5, 07071 Palma de Mallorca, SPAIN.

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Bacilli is one of the groups of bacteria that contain more species able to solubilize phosphates. This group has been separated in several genera and families and the most known phosphate solubilizing species, Bacillus polymyxa, has been reclassified in a new genus, Paenibacillus, currently included in the Family Paenibacillaceae. In this work we analysed the ability to solubilize phosphate in plates of three strains isolated from cow faeces that are able to hydrolyze several polymers, including xylan and cellulose. These strains are Gram negative in the most of growth phases and endospore forming. The spores are terminal and have honeycomb form. The analysis of its 16S rDNA sequence showed a similarity of 98.8% with respect to Paenibacillus azoreducens. The strains are aerobic and facultative anaerobic and produce catalase and oxidase. They produce acid from xilose and glucose but were no able to ferment glucose. The optimal growth temperature is 37°C and the optimal growth pH is 7. Nitrate is reduced to nitrite. The strains grow in 2% NaCl but not in 5% NaCl. Type strain is GMP01. The three strains isolated as well as the type strain of P. azoreducens showed a moderate ability to solubilize phosphates in plates containing bicalcium phosphate.