Molecular Characterization of Fungi Associated with Dump Site Soil

Aims: A study was conducted to identify fungal species isolated from dumpsite soil in University of Port Harcourt using molecular techniques. Methodology: Molecular methods for determining the species of a fungus based on the amplification and sequencing of the internal subscribed spacer (ITS) region of the fungal rRNA operon using molecular markers was applied. Soil sample was collected from a dumpsite in the University of Port Harcourt, Rivers State, Nigeria. Isolation of fungi associated with the dumpsite soil was carried out using spread plate method. Fungal genomic DNA was extracted using Quick-DNA Fungal/Bacterial Miniprep kit. The ITS1-2 gene of the isolates was amplified by Polymerase Chain Reaction (PCR) using the primer pair; ITS4 and ITS5. Results: The sequences of the amplified ITS region were blasted against known sequences on the National Centre for Biotechnology Information (NCBI) database. Nucleotide sequence analysis revealed the species identity of the fungal isolates to be: Aspergillus fumigatus, Trichoderma harzianum, Aspergillus felis, Aspergillus templicola, Aspergillus flavipes, Aspergillus fumigatus and Cunninghamella binariae. Phylogenetic analysis was carried out to ascertain the relationship between the isolates and other closely-related isolates on GenBank. Isolates 2 (Trichoderma harzianum) and 7 (Cunninghamella binariae), 3 (Aspergillus felis) and 6 (Aspergillus fumigatus), and 4 (Aspergillus templicola) and 5 (Aspergillus flavipes) were found to be more closely related to each other. Conclusion: The molecular techniques employed successfully identified the organisms to the species level as these techniques are based on the genetic constitution of organisms. The result obtained from this study will complement the information on the fungal organisms associated with dumpsite soil.

Asperflamides A and B from Aspergillus flavipes DZ-3, an Endophytic Fungus of Eucommia ulmoides Oliver

The fungus strain DZ-3 was isolated from twigs of the well-known medicinal plant Eucommia ulmoides Oliver and identified as Aspergillus flavipes. Two new alkaloids, named asperflaloids A and B (1 and 2), together with 10 known compounds (3–12) were obtained from the EtOAc extract of the strain. Interestingly, the alkaloids 1–4 with different frameworks are characterized by the presence of the same anthranilic acid residue. The structures were established by detailed analyses of the spectroscopic data. The absolute configuration of asperflaloids A and B was resolved by quantum chemistry calculation. All compounds were screened for their inhibitions against α-glucosidase and the antioxidant capacities. The results were that compound 3 had an IC50 value of 750.8 μM toward α-glucosidase, and the phenol compounds 7 and 8 exhibited potent antioxidant capacities with IC50 values 14.4 and 27.1 μM respectively.