Gustavo Hitzschky Fernandes Viera

Bio: Gustavo Hitzschky Fernandes Viera is an academic researcher from Universidade Estadual do Vale do Acaraú. The author has contributed to research in topics: Moringa & Annona muricata. The author has an hindex of 1, co-authored 1 publications receiving 133 citations.

Antibacterial effect (in vitro) of Moringa oleifera and Annona muricata against Gram positive and Gram negative bacteria

Abstract: Antibacterial 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 microL 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.

Headway on natural polymeric coagulants in water and wastewater treatment operations

Abstract: Metal and polymer based materials are the conventional coagulants used in water and wastewater treatment operations. Despite the wide applicability of these genera of coagulants, the challenges associated with the usage have engendered research efforts towards the development of green biobased coagulants, whose applications are capable of obviating the challenges synonymous with the usage of these conventional coagulants. Taking into cognizance the goals that informed the development of green technology, perspectives on the promising non-conventional coagulants that are green and biobased are presented in this treatise. The perspectives on these green biobased coagulants were anchored on the background information of the material, the economic importance, mode of application of the extract as coagulant, underlying coagulating mechanism and the shortcomings of the usage in water and wastewater treatment operations. On the basis of the information provided by different researchers, on the appraisals of these green biobased coagulants for water and wastewater treatment operations, the factors militating against the transition of the applications of these non-conventional coagulants from bench-scale to real life applications were discussed.

Isothiocyanates: An Overview of Their Antimicrobial Activity against Human Infections

Abstract: The use of plant-derived products as antimicrobial agents has been investigated in depth. Isothiocyanates (ITCs) are bioactive products resulting from enzymatic hydrolysis of glucosinolates (GLs), the most abundant secondary metabolites in the botanical order Brassicales. Although the antimicrobial activity of ITCs against foodborne and plant pathogens has been well documented, little is known about their antimicrobial properties against human pathogens. This review collects studies that focus on this topic. Particular focus will be put on ITCs’ antimicrobial properties and their mechanism of action against human pathogens for which the current therapeutic solutions are deficient and therefore of prime importance for public health. Our purpose was the evaluation of the potential use of ITCs to replace or support the common antibiotics. Even though ITCs appear to be effective against the most important human pathogens, including bacteria with resistant phenotypes, the majority of the studies did not show comparable results and thus it is very difficult to compare the antimicrobial activity of the different ITCs. For this reason, a standard method should be used and further studies are needed.