A new genus, Desertispora, and a new species, Diversispora sabulosa, in the family Diversisporaceae (order Diversisporales, subphylum Glomeromycotina)

Phylogenetic analyses of sequences of the SSU-ITS-LSU nrDNA segment and the RPB1 gene showed that the arbuscular mycorrhizal fungus originally described as Diversispora omaniana does not belong to the genus Diversispora, but represents a separate clade at the rank of genus in the family Diversisporaceae of the order Diversisporales. The closest natural relatives of the fungus proved to be species of the genera Corymbiglomus and Redeckera. Consequently, the new genus was named Desertispora, and Di. omaniana was renamed De. omaniana comb. nov. In addition, the morphological and histochemical features of spores and mycorrhizal structures of a new Diversispora sp., Di. sabulosa, were described and the closest relatives of the species were determined based on phylogenetic analyses of sequences of the two loci mentioned above. The new fungus was grown in single-species cultures established from spores extracted from a trap culture inoculated with a mixture of the rhizosphere soil and root fragments of Ammophila arenaria that had colonized maritime sand dunes of the Curonian Spit located in the north of Lithuania. Diversispora sabulosa was never found before in many different sites of the world which were sampled during the last 34 years by the last author of the paper. Also, the lack of molecular sequences in public databases of identity ≥ 97% to sequences of Di. sabulosa suggests that the fungus is rare on the Earth

Achromobacter xylosoxidans as a new microorganism strain colonizing high-density polyethylene as a key step to its biodegradation

This study presents results of research on isolation new bacteria strain Achromobacter xylosoxidans able to effect on the structure of high-density polyethylene (HDPE), polymer resistant to degradation in environment. New strain of A. xylosoxidans PE-1 was isolated from the soil and identified by analysis of the 16S ribosome subunit coding sequences. The substance to be degraded was HDPE in the form of thin foil films. The foil samples were analyzed with Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) as well as scanning electron microscope (SEM), and the results revealed degradation of chemical structure of HDPE. About 9 % loss of weight was also detected as a result of A. xylosoxidans PE-1 effect on HDPE foil. On the basis of comparative spectral analysis of the raw material before the bacteria treatment and the spectrum from a spectra database, it was assumed that the HDPE was the only source of carbon and energy for the microorganisms. No fillers or other additives used in the plastic processing were observed in HDPE before experiments. This is the first communication showing that A. xylosoxidans is able to modify chemical structure of HDPE, what was observed both on FTIR, in mass reduction of HDPE and SEM analysis. We also observed quite good growth of the bacteria also when the HDPE was the sole carbon source in the medium. These results prove that A. xylosoxidans is an organism worth applying in future HDPE biodegradation studies