Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India

Similipal Biosphere Reserve (SBR) is a tropical moist deciduous forest dominated by the species Shorea robusta. To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1–6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 104–2.1 × 105 and 5.1 × 104–4.7 × 105 cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI) was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher’s alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (%) of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium.

Endophytic fungi occurring in Ipomoea carnea tissues and their antimicrobial potentials

The aim of this work was to study the endophytic fungi associated with the tissues of Ipomoea carnea, a common invasive plant of India. A total of 69 isolates belonging to ten taxa comprising 1.45% Zygomycetes, 10.14% Coelomycetes, 62.32% Hypomycetes, 18.84% sterile mycelia and 7.25% unidentified species were obtained. Species of Curvularia, Aspergillus, Fusarium, Colletotrichum and sterile fungus were isolated as dominant endophytes. Colonization frequency of Curvularia (7.25%) was highest which was isolated from all the tissues. The samples collected during the monsoon harbored more endophytes and showed higher species richness than the samples obtained in summer season. Of the total isolates, 15 isolates (21.74%) displayed antimicrobial activity, inhibiting at least one of the test microorganisms that comprised of pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi, Pseudomonas fluorescens, Shigella dysentriae) and fungi (Trichophyton rubrum, Aspergillus fumigatus, Trichophyton sp). The results provided promising baseline information on the endophytic fungal diversity associated with I. carnea tissues and their potential exploitation as antimicrobial agents.