RHIZOSPHERE FUNGAL DIVERSITY IN OIL AND BRINE CONTAMINATED SOILS

Wes Colgan III*
D. Ross Patrick
Milan Vavrek
Louisiana Tech University
School of Biological Sciences
PO Box 3179
Ruston, LA 71270
Voice: 318-257-4573
Fax: 318-257-4574
E-mail: wcolgan@ans.latech.edu

To determine the fungal diversity in regenerating oil/brine spill sites; soils were collected from six sites to serve as an inoculum. Sorghum vulgare var. sudanese (Sudan grass) served as the host for rhizosphere fungi. DNA was extracted, and the fungal internal transcribed spacer region was amplified with fungal specific primers via the polymerase chain reaction and cloned into competent E. coli. Restriction fragment length polymorphism analyses were performed on 25 randomly selected clones from each clone library. Each unique fingerprint was considered an operational taxonomic unit and sequenced. Comparison to the GenBank database revealed a predominance of ascomycetes, although at least one representative from each major fungal phyla was returned. Seventeen sequences were found to be related to Chrysosporium pseudomerdarium, seven related to Paecilomyces inflatus, and 6 found to be related to Bipolaris spicifera. Subsequent phylogenetic analysis of the 5.8S region of the sequences, and its two closest GenBank matches revealed a similar pattern, with a large number of the Ascomycete sequences belonging to the order Pezizomycota. Of particular interest was one individual which was closely related to the genus Monascus, because of the genus' ability to digest hydrocarbons.