Abstract

This research focuses on the activity of the desert truffle Terfezia boudieri Chatin against its associated microflora. It consists of the enumeration and pre-identification of soil microflora associated with ascocarps of T. boudieri Chatin, in contact with fungus ascocarps and at 10 cm deep. Enumeration reveals that the number of some microorganisms is higher when in contact with ascocarps of T. boudieri than at 10 cm deep. Also, bacteria are more dominant than fungi and actinomycetes (especially Bacillus sp., Pseudomonas sp., Micrococcus sp., Streptococcus sp., Proteus sp.). The number of bacteria is estimated to be 8.3 - 8.6x10⁷ ± 0.5x10⁷ CFU/g of dry soil, while fungal genera (with a dominance of Penicillium sp., Aspergillus sp., Mucor sp. and Alternaria sp.) are between 8.6x10⁴ ± 0.8x10⁴ and 4.5x10⁵±0.8x10⁵ CFU/g and actino-mycetes (especially Streptomyces sp.) are between 8.2x10² ± 0.3x10² and 2.2 x 10³ ± 0.3 x 10³ CFU/g. Microorganisms included in the nitrogen cycle are represented by free nitrogen fixing bacteria (Azotobacters) (2.2x10¹ ± 0.8x10¹MPN/g), ammonifying bacteria (4x10³ ±1.0 x 10¹ MPN/g), nitric bacteria (between 6.8X10³ ±1.0x10³ and 0.6x10¹ ±1.0x10¹ MPN/g), and nitrous bacteria (between 4x10¹ ±1.0x10¹ and 0.3X10¹ ±1.0x10¹ MPN/g). Bacteria included in the degradation of organic matter are mainly proteolytic (between 1.2x10⁶ ±0.8 x 10⁶ and 2.4X10⁴ ±0.8 x 10⁴ CFU/g), amylolytic (between 6.8 x 10³ ± 0.2 x 10³ and 0.6 x 10¹ ± 0.2 x 10¹ CFU/g) and cellulolytic bacteria (between 1.3x10⁴ ±0.7x10⁴ and 1.5x10³ ±0.7x10³ MPN/g) but lipolytic and denitrifying bacteria are absent. These results suggest that T. boudieri Chatin stimulate soil microflora in contact with their ascocarps.

Key words: Terfezia boudieri Chatin, terfez soil, microorganisms, enumeration.