Analysis Of Culturable Airborne Fungi In Tianjin University Campus And First Record Of Clonostachys Rosea As Entomopathogenic Fungus Of Coleoptera In China

Airborne fungi have significant influence on air quality and may pose adverse effects on human health directly or indirectly due to their allergy,toxicity,or infection capabilities.In this study,we carried out a one-year systematic survey on the airborne fungal diversity and concentration across six different sampling sites,including indoor and outdoor environments,within the Tianjin University,Weijin road campus.Airborne fungi were sampled using an HAS-100B air sampler.Isolated fungal strains were identified based on morphological and molecular analysis.The fungal concentration and diversity at each site were analyzed and correlated with the environmental factors(temperature and relative humidity)and human activities.A total of 641 fungal strains belonging to 173 species and 74 genera were identified in this study.Among the identified culturable fungi,the dominant genera were Cladosporium(29.49%),Alternaria(25.9%),and Epicoccum(5.93%).The most frequently occurring fungal species were Alternaria alternata(15.44%),Cladosporium cladosporioides(11.86%),and Epicoccum nigrum(5.62%).The mean fungal concentration at different sites through the one year ranged from 0 to 420 CFU/m~3which is lower than the permissive standard level.There was a seasonal variation in the airborne fungal community at the investigated sites.We found that temperature and relative humidity were positively correlated with the fungal concentration and diversity at almost all the sites.Human traffic in terms of peak and off-peak also turned out to be another key factor that influenced the fungal diversity and community in most sampling locations.Higher fungal diversity was recorded in peak period at the two canteens,whereas the two dormitories showed higher fungal diversity in off-peak period.Our study provides the first report on the diversity and concentration of airborne fungal species within different Tianjin University campus environments and clarifies the role played by environmental factors,including human activities,on the analyzed fungal community.The dominant presence of fungi such as Alternaria alternata and Cladosporium cladosporioides in the analyzed environment deserves further attention since these fungal species have been reported as common allergens and associated with many human and animal infections.Our results represent valuable information for air quality monitoring and microbial pollution control in university of campus environments.Clonostachys rosea is an ascomycetous fungal species commonly found in tropical and subtropical regions as soil saprotroph,plant decomposer,and endophyte.This fungus is also well-known as a mycoparasite,exhibiting strong biological control ability against numerous fungal plant pathogens,nematode,and insect parasite.In this study,we isolated for the first time C.rosea as entomopathogen of the Coleoptera species Ophrida xanthospilota(Chrysomelidae)in China.This finding increases our knowledge of the ecology and distribution of C.rosea.