Brazilian açaí berry seeds: an abundant waste applied in the synthesis of carbon-based acid catalysts for transesterification of low free fatty acid waste cooking oil.

Residues of açaí seeds (Euterpe oleracea Mart.) were a novel source for the synthesis of the acid heterogeneous catalyst applied in the conversion of low free fatty acid waste cooking oil (WCO) to biodiesel. Yield of activated carbon (AC) and catalyst (CAT), as well as density of SOH groups and total acidity, was analyzed in an entirely random designed experiment using multiple linear regression, one-way ANOVA, and Tukey's post hoc test.

Myxobolus sp. (Myxozoa; Myxosporea) causing asymptomatic parasitic gill disease in Astyanax aff. bimaculatus (Characiformes; Characidae) in the Tocantins river basin, amazon region, Brazil.

The middle course of the Tocantins river is located in the eastern portion of the "Legal Amazon" region of Brazil and the Dantas river is one of its tributaries. Among the components of the aquatic biota, eukaryote microparasites establish direct relationships with several species of fish and have zoonotic potential that is still little known. Myxozoans stand out among these parasites: they cause myxosporidiosis, a disease that gives rise to high mortality rates worldwide.

Biosorption Cu (II) by the yeast .

With the industrial and population advances, the generation of effluents containing heavy metals has grown a lot. In this work, the commercial biomass of the yeast Saccharomyces cerevisiae Perlage BB were carried out as Cu (II) ion biosorbent. The influence of some variables such as metal concentration, pH range, equilibrium time and biomass concentration were evaluated.