Antonio Azeredo

Organochlorine compounds in sharks from the Brazilian coast

We are grateful to Prof. An. Subramanian, Ehime University, for critical reading of this manuscript. Financial assistance was provided by ‘‘21st Century COE Program” and ‘‘Global COE Program” from the Ministry of Education, Culture, Sports, Science and Technology, Japan. This study was supported also by Grants-in-Aid for Scientific Research (S) (No. 20221003) from Japan Society for the Promotion of Science (JSPS).

Persistent toxic substances in the Brazilian Amazon: contamination of man and the environment

The organochlorine insecticide DDT was extensively used in Brazil since 1945, both for agricultural purposes and for vector control measures. In 1986 its uses were forbidden in agriculture and in 1997 it was also phased-out in vector controls programs. However, the presence of DDT in urban and forested soils, breast milk and aquatic biota is still common, especially at the Amazon region. The results gathered since the middle of the 90s indicate that environmental contamination with this pesticide is still relatively high. Due to the high fish consumption by traditional riverside populations, human breast milk may represent an important source of DDT exposure to newborns. New results on DDT and PCBs in red dolphin (Inia geoffrensis), an endemic aquatic mammal of the Amazon region, is also reported.

Polygalacturonase secreted by yeasts from Brazilian semi-arid environments

Microbial pectinolytic enzymes are known to play a commercially important role in a number of industrial processes. The objective of this study was to investigate the extracellular polygalacturonases of yeasts isolated from Brazilian semi-arid environments. Among the 250 colonies tested, only 33 produced extracellular polygalacturonases: Aureobasidium pullulans (18 isolates), Candida boidinii (one isolate), Trichosporonoides sp. (three isolates), Kluyveromyces marxianus (one isolate), Cryptococcus liquefaciens (one isolate), Pseudozyma sp. (four isolates), and yeast-like related to fungal endophyte (five isolates). The highest activity of polygalacturonase was observed in Pseudozyma sp. CCMB 300 (14.17±0.08 µmol acid galacturonic released/min/mg protein). This study shows the potential of yeasts and yeast-like organisms isolated from Brazilian semi-arid environments to produce pectinolytic enzymes.