Maria Inez de Moura Sarquis

Production of L-asparaginase by filamentous fungi

L-asparaginase production was investigated in the filamentous fungi Aspergillus tamarii and Aspergillus terreus. The fungi were cultivated in medium containing different nitrogen sources. A. terreus showed the highest L-asparaginase (activity) production level (58 U/L) when cultivated in a 2% proline medium. Both fungi presented the lowest level of L-asparaginase production in the presence of glutamine and urea as nitrogen sources. These results suggest that L-asparaginase production by of filamentous fungi is under nitrogen regulation.

DIVERSITY OF MICROFUNGI IN THE SANDY SOIL OF IPANEMA BEACH, RIO DE JANEIRO, BRAZIL

The mycobiota of the sandy soil of Ipanema Beach, Rio de Janeiro, Brazil, was investigated in 144 sand samples collected at four different sites along the sea coast, divided into three subsites. for a period of one year. A total of 4285 yeast colonies and of 6956 of colonies filamentous fungi were isolated using conventional media and techniques. Representatives of the filamentous fungi corresponding to a total of 1334 colonies were identified and assigned to 34 genera and 170 species. The genera of highest incidence and their respective numbers of species were as follows: Aspergillus, 30.4%, 32 spp.; Penicillium, 16.2%, 35 spp.; Fusarium, 12,6%, 33 spp.: Trichoderma, 6.4%, 7 spp.; Paecilomyces, 3.7%, 10 spp.: Cladosporium, 3.1 %, 8 spp. and Acremonium, 1.0%, 8 spp. Several other genera and species were detected at quite low occurrences. Non‐sporulating fungi (18.3%) and Coelomycetes (Sphaeropsidales) (1.9%) were also detected. Most of the genera detected belonged to the Deuteroycotina, with fewer proportions belonging to the Ascomycotina and Zygomycotina. Moniliaceae was represented by the largest number of species and Dematiaceae was represented by the largest number of genera. In terms of seasonal distribution, the largest number of filamentous fungi was isolated during the winter and the smallest number the Summer.

Isolation of Beauveria bassiana and Metarhizium anisopliae var. anisopliae from Boophilus microplus tick (Canestrini, 1887), in Rio de Janeiro State, Brazil

The objective of this work were to isolate and identify strains of entomopathogenic fungi from ingurgitated female Boophilus microplus ticks, collected from the soil in the municipality of Paracambi, Rio de Janeiro State, Brazil. The ingurgitated females were inoculated in the selective medium oat dodine agar (oda), where 49 colonies of Beauveria bassiana (71%) and 20 of Metarhizium anisopliae var. anisopliae (29%) were isolated. These isolated strains characterize for the first time in Brazil the natural occurrence of these species of fungi in this tick, and will be used to conduct bioassays to evaluate the pathogenicity and virulence of these strains for ticks of the genus Boophilus microplus.

Fusarium species in sandy soil from Ipanema Beach, Rio de Janeiro, Brazil

The presence of the genus Fusarium was investigated in sandy soil from Ipanema Beach, Rio de Janeiro, RJ, Brazil during a period of one year in order to determine the diversity, and seasonal distribution of species. A total of 123 strains were isolated, for a total of 34 different species, with higher incidence in spring and winter. The species detected in greater numbers during the various seasons of the year were, in decreasing order, F. solani var. solani, F. oxysporum var. oxysporum and F. sacchari var. subglutinans, described in the literature (GUARRO and GENÉ 1992) as infectious agents for humans and animals. Few species were detected in summer and fall, probably due to the higher rainfull occurring during these seasons.