AbstractÐSix dierent species of non-living Sargassum biomass were compared on the basis of their equilibrium Cd and Cu uptake in order to evaluate potential variability in the sorption performance of dierent Sargassum species. Biosorption uptakes for Cd at the optimal pH of 4.5 ranged from q max =0.90 mmol/g for Sargassum sp. 1 to 0.66 mmol/g for S. ®lipendula I representing a 36% dierence. Three species were evaluated for their Cu uptake where q max =0.93 mmol/g for S. vulgare; 0.89 mmol/g for S. ®lipendula I, and 0.80 for S.¯uitans, representing a 16% dierence between the lowest and highest values. Potentiometric titrations were carried out on S. vulgare, S.¯uitans and S. ®lipendula I and yielded the similar results of 1.5 mmol/g weakly acidic sites for S. vulgare and S.uitans, and 1.6 mmol/g for S. ®lipendula I. Estimates of 0.3 mmol/g of strongly acidic sites for S. uitans and S. ®lipendula I and 0.5 mmol/g for S. vulgare were obtained. The total number of active sites averaged 1.9 2 0.1 mmol/g. The elution eciency for Cu-desorption from S. ®lipendula was determined for CaCl 2 , Ca(NO 3 ) 2 , and HCl at various concentrations and solid:liquid ratios (S/L). The highest elution eciency was >95% for Cu for all elutants at S/L=1 g/l and decreased for both calcium salts with increasing S/L to less than 50% at S/L=10 g/l as a new batch sorption equilibrium was reached quickly. CaCl 2 was chosen to be the most suitable metal-cation desorbing agent. 7

The study indicates a promising potential for aqueous and ethanolic Moringa leaf extracts as alternative treatment of infections caused by the tested strains.

SUMMARYAntibacterial effects of aqueous and ethanolic extracts of seeds of moringa (Moringa oleifera) and pods of soursop (Annona muricata) in the concentration of 1:5 and 1:10 in volumes 50, 100, 150 and 200 μL were examined against Staphylococcus aureus, Vibrio cholerae, Escherichia coli (isolated from the organism and the aquatic environment) and Salmonella Enteritidis. Antibacterial activity (inhibition halo > 13 mm) against S. aureus, V. cholerae and E. coli isolated from the whiteleg shrimp, Litopenaeus vannmaei, was detected in aqueous and ethanolic extracts of moringa. E. coli isolated from tilapiafish, Oreochromis niloticus, was sensitive to the ethanolic extract of moringa. The aqueous extracts of soursop showed an antibacterial effect against S. aureus and V. cholerae, but the antibacterial activity by the ethanol extracts of this plant was not demonstrated.

SUMMARYGuava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.

Out of the twenty-four samples of shrimp and fish muscle used for this study, twelve were collected near a large marine sewer for waste disposal, 3 km off the coast of Fortaleza (Brazil) and used for the isolation of E. coli. Other twelve were collected at the Mucuripe fresh fish market (Fortaleza, Brazil) and used for the isolation of Staphylococcus aureus. Ethanol, water and acetone-diluted extracts of guava and papaya leaf sprouts were tested on the bacteria in order to verify their microbicidal potential. The E. coli strains used in the trials were rated LT positive. The papaya leaf extracts (Carica papaya Linn) showed no microbicidal activity while the guava sprout extracts (Psidium guajava Linn) displayed halos exceeding 13 mm for both species, an effect considered to be inhibitory by the method employed. Guava sprout extracts by 50% diluted ethanol most effectively inhibited E. coli (EPEC), while those in 50% acetone were less effective. It may be concluded that guava sprout extracts constitute a feasible treatment option for diarrhea caused by E. coli or by S. aureus-produced toxins, due to their quick curative action, easy availability in tropical countries and low cost to the consumer.