Araucaria angustifolia is an environmentally threatened tree and the whole biota of the Araucaria Forest should be investigated with the aim of its preservation. Diazotrophic bacteria are extremely important for the maintenance of ecosystems, but they have never been studied in Araucaria Forests. In this study, diazotrophic bacteria were isolated from Araucaria roots and soil, when grown in semi-specific, semi-solid media. The diazotrophic character of some recovered isolates could be confirmed using the acetylene reduction assay. According to their 16S rRNA sequences, most of these isolates belong to the genus Burkholderia.

BurkfloJderia phenazinium (LMG2247T; U96936) 93 BurkholderiagJatllei(LMG14190T; U96935) 100 99 Burkholderia cepacia (M22518) I 74-~UtkflOlderia multívorans (Y18703) ~ Burkhofdería unamae{MTI-641; AY221956} 99 Burkho!deria tropica (Ppe8; AJ420332) Herbaspíríllum rubrísuba/bicans (ATCC 19308T; AB021424) rbaspir11lum seropedicae (DSM 6445, ATCC 35892; Y10146) Janthínobacterium fividum (DSM 1522T; Y08846) 100 S21316 (G4-JantllinotJacteríum Sp_) 50 Jantllinobacterium agaricidamnosum (W1r3T; Y08845) S31151 (G3-Xantllomonas Sp_)