The Sustainable Production of a Novel Laccase from Wheat Bran by Bordetella sp. JWO16: Toward a Total Environment

Laccase is increasingly adopted in diverse industrial and environmental applications, due to its readily accessible requirements for efficient catalytic synthesis and biotransformation of chemicals. However, it is perceived that its industrial production might incur some unfavorable overhead, which leads to expensive market products, and the corresponding negative environmental feedback, due to the use of capital-intensive and precarious chemicals. To this end, this study was designed to evaluate the performance indicators of the valorization of wheat bran by a novel Jb1b laccase and its subsequent application in waste minimization and water management, on a laboratory scale. Optimal Jb1b laccase was produced in submerged fermentation medium containing wheat bran, an agroindustrial residue, through response surface methodology (RSM) algorithm, and was applied in dye decolorization and denim bioscouring, respectively. Results showed that the resultant enzyme manifested unique biochemical properties, such as enhanced tolerance at certain physicochemical conditions, with a residual activity of at least ca. 76%. Furthermore, phenomenally high concentrations of synthetic dyes (0.2% w v−1) were decolorized over 56 h, and a 6 h mediator-supported simultaneous denim bleaching and decolorization of wash effluent was observed. The sustainability of the production and application processes were inferred from the reusability of the fermentation sludge as a potential biofertilizer, with subsequent prospects for the biostimulation and bioaugmentation of contaminated soils, whereas the decolorized water could be adopted for other uses, amongst which horticulture and forestry are typical examples. These phenomena therefore authenticate the favorable environmental feedbacks and overhead realized in this present study.

Agroindustrial residue of carnauba as substrate alternative for seedling production of watermelon

Substrates is an important pillar of seedling production, when it seeks to establish vigorous plants with a uniform pattern and lower possible production costs. The objective of this work was to evaluate the use of the carnauba agroindustrial residue (RC) in the alternative substrate composition for the formation of watermelon seedlings. The experiment was conducted at the Campus Professor Cinobelina Elvas, Federal University of Piauí, Bom Jesus, Piauí. A randomized block design with five treatments was used: RC and sand, in the proportions: 20/80, 40/60, 60/40, 80/20 and 100/0, with four replications and eight plants per plot, 160 plants. The variables evaluated were: emergence percentage, emergence speed index, plant height, leaf area, leaf number, shoot dry mass, neck diameter, root density, root area, root mean length and root dry mass. The seedlings with 100% RC provided higher height (4.43 cm), leaf area (16.13 cm2), number of leaves (2.0) and shoot dry mass (0.13 g / plant). The use of 80% CR and 20% sand resulted in a larger diameter of the neck (mean), root area (mean) and root mean (average) length. Already in the proportions of 60 and 40% of CR plus sand respectively, they promoted higher root density (mean). However, to produce seedlings of Citrullus lanatus with adequate quality standard, it is recommended to use 100% RC substrate because it is more responsive to aerial part and substrate with 80% RC / 20% sand, which promotes greater growth of the system root.

Hydrothermal–Microwave Processing for Starch Extraction from Mexican Avocado Seeds: Operational Conditions and Characterization

Avocado seeds are an agroindustrial residue widely produced in Mexico that are causing various environmental problems due to their accumulation. The evaluation of avocado residues to recover biopolymers by microwave-assisted extraction (MAE) and the characterization of avocado starch properties were studied in the present work. A central-composite design was used to optimize the MAE process. Moreover, a comparison was performed between MAE non-isothermal mode (NO–ISO) and conventional extraction. Starch optimization by MAE was obtained at 161.09 °C for 56.23 min with an extraction yield of 49.52% ± 0.69%, while with NO–ISO at 161 °C was obtained 45.75% ± 2.18%. Conventional extraction was 39.04% ± 2.22%. Compared with conventional starch, MAE starch showed similar proprieties and molecular spectra. In contrast, MAE starch showed high solubility, low water absorption capacity, a non-granular structure with small particle size (<2 µm) and polydispersity of fragments at different sizes of polymers. Therefore, MAE is a viable technology to extract the starch, and avocado seed can be considered an excellent starch source for the development of novel functional foods, contributing to promoting sustainability across the food chain.

Optimization of extraction conditions of volatile compounds from pequi peel (Caryocar brasiliense Camb.) using HS-SPME

The pequi is a native specie from the Brazilian Cerrado that has great economic importance for the population of the region. The pericarp is considered an agroindustrial residue despite corresponding to approximately 80% of the total fruit mass. Informations about the chemical composition of pericarp would allow better utilization of this portion of the fruit. The objective of this study was to identify the best conditions of agitation, extraction time and extraction temperature to maximize the extraction of volatile organic compounds present in pequi pericarp (Caryocar brasiliense Camb.) using two types of solid phase microextraction fibers. The extraction of the volatile compounds was using the headspace solid-phase microextraction method with subsequent separation and identification by CG-MS. Polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was statistically more efficient than divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. The both fibers enabled the extraction and identification of 35 compounds, mainly terpenes (65.71%) and esters (14.29%). An increase in the extraction temperature and time allowed greater extraction of volatile compounds by both fibers. However, in relation to agitation, the best condition for using DVB/CAR/PDMS was 100 rpm, while agitation was not necessary for an efficient extraction using the PDMS/DVB fiber.