Journal of Bioprocessing & Biotechniques

Autochthonous microorganisms as probiotics are a novel alternative to antibiotics. The genus Bacillus is highly used by its ability to survive on adverse conditions. Piaractus mesopotamicus, a native fish, is the most produced specie in Argentinian aquaculture. The low level of knowledge, high stress conditions and demand of animals led to a deficit in the number of larvae and fry. The aim of this study was to evaluate the probiotic effect of previously selected autochthonous Bacillus on biometrical parameters of P. mesopotamicus larvae when administered together in a combined suspension in different doses and stages. Results showed that the bacterial administration did not cause significant effects on the variables evaluated. However, the dose containing 6 × 107 CFU L-1 of each strain showed the highest average values of P. mesopotamicus biological parameters, regardless the stage of administration. Histological evaluations of animals administered with this dose did not showed adverse effects and indicated the capability of this dose, administered in a particularly period of time, to stimulate the early appearance of gastric glands, vestiges of what would be the pylorus and a higher development of liver. Thus, we proposed the safe use of this dose in a combined probiotic mixture to be studied in further assays.

This work aims the functionalization of reduced graphene oxide nanoplatelets with chitosan (G-chitosan) and also with poly(styrenesulfonic acid) (GPSS), thus forming stable, dispersed aqueous solutions. G-chitosan and GPSS solutions allowed the layer-by-layer (LbL) film formation with glucose oxidase (GOx), establishing multilayered nanostructures with elevated control in thickness and morphology. The graphene nanoplatelets were characterized by UV-vis and FTIR spectroscopies, resulting in good adherence and linear deposition of the graphene nanoplatelets with GOx in the LbL structures. Cyclic voltammetry shows an enlargement in the current intensity with increasing number of deposited LbL layers, possibly owing to the formation of conducting paths by the graphene nanoplatelets in the tailored multilayer nanomaterial formed.

The increase of global biofuel production is supported mainly by energetic policies adopted by important energy markets that aim to promote the production and use of biofuels, including the promising cellulosic-derived biofuels. Brazil is facing a challenge to attain sustainability in ethanol sector and to maintain its position as a major supplier of ethanol to world market in this new era of sustainable biofuel policies. In this paper we carried out a structural path analysis on sugarcane-derived ethanol sector and on a hypothetical bagasse-derived ethanol sector in order to identify the input paths that most influencing their economic and environmental performance. We make an empirical application to the Brazilian economy, using existing data from ethanol sector for 2005 and estimating data for the hypothetical sector. The fuel burned in the transport sector and on-site transport tasks is identified as important element for the environmental performance of both sectors. Also, sugarcane sector is identified to have relevant role in the economic performance of ethanol sector, as enzyme production has in second generation ethanol sector. The results present in this article can provide valuable information for decision-making in both biofuels to address new initiative for effective economic and environmental policies efforts.