Is next generation sequencing an alternative to cultivation-based methods for investigating fungal diversity in indoor air samples?

Abstract

The direct effect of fungi on human health makes the fungal diversity in the air an important and necessary subject for examination. Studies that determine fungal diversity generally depends on culture methods. Developed culture-independent methods eliminate many disadvantages of existing culture-dependent methods. In our study, duplicate air samples were collected on 5 different days at a Microbiology Research Laboratory to compare these methods. Samples were collected in 3 different groups: (A) culture method and ITS-targeted Sanger DNA sequencing with 100 L samples, (B) culture method and ITS-targeted Sanger DNA sequencing with 1000 L samples, (C) filter method and next generation sequencing with 1000 L air sample. The Groups A, B and C defines culture, isolation and SANGER DNA-based methods, culture and next generation sequencing methods and directly next generation sequencing methods, respectively. Method-A failed to represent real fungal diversity. Method-B did represent the diversity but did not truly represent relative abundance of the species. Method-C can be completed in 2 days whereas Method-A and B can be completed in 2 weeks and 1 week, respectively. In conclusion, we recommend direct DNA isolation which is followed by ITS-targeted NGS in order to study fungal diversity in indoor air environments.