Sweet sorghum bagasse (SSB) provides a raw material rich in polysaccharides that can be converted into biofuel and other high-value-added bioproducts under the biorefinery concept. The aim of this study was to evaluate the effect of hydrothermal pretreatment on the availability of SSB fermentable sugars for bioethanol production, considering the energy balance of the process. For this, the biomass was subjected to one process, pre-saccharification simultaneous and fermentation (PSSF). Previously, the temperature, time, and particle size effect were determined, as well as the enzymatic load for the more significant release of monomeric sugars. It was observed that the increase in the pretreatment severity, defined by the severity factor [log(R_o)], resulted in a more significant release of sugar and energy consumption. In the PSSF, bioethanol production was 22.17 g/L, with a total energy consumption of 2.46 MJ/g of processed biomass, of which 79.14% was by concept of electricity.

The growing global demand for energy and the reduction of energy based on oil are driving the search for new sources of energy that are environmentally friendly. To achieve this goal, it is also necessary to optimize the related processes. In this study, the behavior of the agronomic parameters of, and the energy invested in, production systems based on a new variety of sweet sorghum (Sorghum bicolor (L.) Moench) called ROGER were determined to define the optimal production conditions. To this end, three methods of tillage (minimum, traditional, and traditional tillage with rupture of the plow layer) and three types of fertilizers (inorganic, organic, and without fertilizer) were established, and to estimate the energy efficiency, the inputs and the energy outputs of each system were considered. The traditional tillage with breaking of the plow layer and the organic fertilizer showed the highest values of plant height (2.45 and 2.39 m, respectively); total fresh weight of the plant (51.66 and 50.77 t·ha⁻¹, respectively), of the stem (42.7 and 41.05 t·ha⁻¹, respectively), and of the juice (21.89 and 22.57 t·ha⁻¹, respectively); the volume of the juice (20,783.12 and 22,529.59 L·ha⁻¹, respectively); and Brix degrees (16.04% and 15.01%, respectively). However, the highest energy efficiency was registered in the production system that used the minimum tillage, with a value of 15.11, as well as when no fertilizer was applied with 18.68.

Laccases have attracted a great deal of interest because of their remarkable ability for the degradation of synthetic dyes present in wastewaters. New laccase producing sources with robust operational and functional properties are being continuously explored. In this work, the potential for the decolorization and detoxification of synthetic dyes was evaluated in two Mexican strains of the genus Trametes. The decolorization capacity of Trametes maxima LE130 and Trametes sp. LA1 was tested in solid and liquid media. The phytotoxicity of the degradation products was determined using Raphanus sativus and Pisum sativum seeds. In solid media, both strains showed a higher decolorization capacity (p ≤ 0.05) than Phanerochaete chrysosporium ATCC 24725, which is known to be very efficient in lignin and dye-degradation. They produced laccase as the main ligninolytic enzyme; T. maxima LE130 secreted a single isoform of 43.9 kDa, while Trametes sp. LA1 produced three isoforms of 67.3, 58.6 and 52.7 kDa, respectively. Trametes sp. LA1 culture fluids were capable of decolorizing and detoxifying chemically diverse dyes (anthraquinonic dye Remazol Brilliant Blue R, azoic Reactive Black 5 and triphenylmethane Crystal Violet) without the addition of redox mediators. Therefore, this could be considered as a new laccase source which could be potentially competitive in the bioremediation of dye-containing wastewaters.