Revista Brasileira de Ciências Ambientais (RBCIAMB)

Transforming orange waste with yeasts: bioprocess prospects

Gabriel do Amaral Minussi — 2024-04-10

It is mandatory to make the circular economy a reality, developing ways of transforming waste into valuable products. In this context, investigating the biotechnological potential of different residues is most welcome. This review analyzes how orange waste can be used as biorefinery feedstock to produce different bioproducts using yeasts as the major biocatalysts. In addition to the current orange market, its pectin-rich biomass is described in detail, aiming to elucidate how yeast cells can convert it into ethanol, xylitol, polyphenols, and organic acids (some of them, volatile compounds). Genetic, metabolic, and evolutionary engineering are also analyzed as biotechnological tools to improve the existing processes. Finally, this review also addresses the potential employment of fruit-dwelling yeasts in biorefining pectin-rich biomasses such as orange wastes. All the data presented herein lead to the conclusion that these residues could already be used for noble purposes.

Recent advances in xylitol production in biorefineries from lignocellulosic biomass: a review study

Jéssyka Ribeiro Santos — 2024-04-04

The progression of sustainable practices in biorefineries is pivotal in mitigating carbon emissions and optimizing the utilization of natural resources, thereby preserving the environment. Biorefineries, which convert lignocellulosic biomass into a variety of products, distinguish themselves by efficiently transforming waste into high-value products. Xylitol stands out among biorefinery products. Derived from the conversion of xylose present in lignocellulose, it not only offers health benefits but is also considered an intermediate molecule in the production of valuable chemical products. Microbiological methods for xylitol production are increasingly acknowledged as efficient and environmentally friendly alternatives. These are some of the main factors discussed in this review, which aims to demonstrate the biotechnological route for producing xylitol through lignocellulosic materials. Several studies were observed to characterize various lignocellulosic residues, and it was noted that Eucalyptus globulusand banana leaves exhibit high levels of xylose. By analyzing the most recent researches related to xylitol production, the possibility of co-production of bioethanol using the same biotechnological route of xylitol production was identified. For instance, studies have shown that a combination of bagasse and sugarcane straw, as well as rice straw residue, are capable of producing substantial levels of xylitol and ethanol. The yields reached 30.61 g/L of xylitol and 47.97 g/L of ethanol, and 34.21 g/L of xylitol and 2.12 g/L of ethanol, respectively. These innovations not only promote sustainability but also have the potential to generate positive impacts on the global economy.

Sustainable valorization of Moringa oleifera Lam. co-products and zoo waste

Fernanda Rubio — 2024-03-05

Moringa oleifera (moringa) stands out as a promising plant in several segments, being produced worldwide. However, its co-products, particularly valves and seed husks, which represent more than 70% of its fruit, remain underutilized. Therefore, this work aimed to assess the use of parts of the moringa fruit in conjunction with sediment from an artificial pond in a zoo enclosure inhabited by Tapirus terrestris (tapir), exploring the potential treatment of these wastes, using Eisenia foetidaearthworms. Five experimental conditions were analyzed, whose waste proportions were varied. The vermicomposts were not phytotoxic and differed regarding the C/N ratio; those that received parts of the moringa fruit had a higher C/N ratio. As commonly observed in stabilization processes, the contents of P, K, Ca, and electrical conductivity increased, while carbon and pH decreased during stabilization. Plant development of Catharanthus roseus was evaluated using, in addition to the vermicomposts, two commercial composts. The vermicomposts provided better development of C. roseus than the commercial composts, with T2 (65% sediment+35% fruit valves) and T3 (50% sediment+35% valves+15% seed husks) standing out as the best treatments. Vermicomposting associated with moringa co-products and zoo waste is a viable alternative via aerobic treatment, favoring waste management and the search for sustainability.

Primacy of the real and interdisciplinarity: contradictions in theoretical production

José Henrique Faria — 2024-04-10

The purpose of this text is to assert the thesis that scientific work, manifested in the production of analyses, theories, and concepts, irrespective of their disciplinary, multidisciplinary, or interdisciplinary origins, only unfolds when rooted in the primacy of the real. The complexity of scientific objects cannot be fully addressed exclusively within disciplinary confines. Discussions centered solely on theoretical, conceptual, or explanatory models, while assisting in transcending disciplinary limitations, do not propel the advancement of scientific knowledge. Contradictions in theoretical-conceptual and analytical production, explicit within disciplinary fields, arise not only from the limitations of disciplines but from how reality is conceptualized as concrete thought. Regardless of the discipline, theory and concept divorced from reality amount to mere speculation.

A bibliometric review of ecosystem services and coastal zones: diagnoses and trends

Nivaldo Lemos de Souza — 2024-03-12

Bibliometric analysis is an instrument used to quantify scientific production on a given topic. This type of analysis can be applied to show trends in an area of study. This review aims to examine how scientific production on ecosystem services, coastal zones, and ports is being carried out, identifying trends and gaps. The guiding questions of the work focused on the growth of production, the ports as focal points, the ecosystems studied, the methodologies used, and which ecosystem services were the focus of discussion. Searches on catalog platforms were made to determine how many articles would be considered for analysis, and after filtering, 91 articles were examined. The main results show that the years 2014 and 2018 were the peak of publications; the United States of America is the country that presented most publications with 19 papers; ports appear in just over 20% of the analyzed works, and beaches and marine environments, such as the continental shelf and slopes, are focus of discussion. More than 50 ecosystem services were found in the analysis, with “food” and “recreational values” being the most studied services. With the decade of the oceans, there is a tendency for the growth of scientific production, maintaining the relevance of the themes, particularly when studied together.

Microcrystalline cellulose: an alternative to increase the resistance of kraft packaging with recycled fiber

Yankha Myllena da Silva Van Tienen — 2024-03-09

The consumption of paper packaging is increasing. On the contrary, the planted areas of Pinus spp. are showing a trend tendency of imbalance between supply and demand. Therefore, many companies are prioritizing the use of recycled fiber (RF). However, its inclusion can influence the quality of the product. This study aimed to evaluate whether the combination of RF with microscale cellulose will enable the production of resistant paper. The first step involved producing bench-scale samples of Kraft paper (with different percentages of virgin and RF) and characterized it physically (grammage, moisture, Gurley porosity, Z-traction, SCT, and Mullen). The second stage involved replicating the first stage with the inclusion of microcrystalline cellulose (MCC) and the elimination of Pinus spp. (LF). All formulations were approved for the physical characterization tests, except for the porosity analysis and grammage for F5. In the first test (MCC=0%), there was a reduction in tensile, compression, and burst index of 13.2, 7.3, and 19.5%, respectively, showing that the higher the percentage of RF, the lower the paper’s strength. In the second test for Formulation 3 (MCC=6%), there was an increase in the tensile, compression, and burst index of 9.5, 2.6, and 2.7%, respectively, when compared with Formulation 2 (LF=MCC=0%). This study demonstrates that the addition of up to 6% MCC strengthens the RFs and decreases the dependence on Pinus spp., making it a promising alternative for the production of sustainable and resistant packaging.

Sustainable reduction of sulfate contained in gypsum waste: perspectives and applications for agroforestry waste and sanitary sewage

Gilka Maria da Silva Paiva — 2024-03-05

This review article explores sustainable biotechnological strategies for converting sulfate compounds and lignocellulosic waste, focusing on using sulfate-reducing bacteria (SRB) and the valorization of agroforestry residues and sanitary sewage. SRB show potential in effluent treatment, mine drainage, and the removal of sulfate and heavy metals from wastewater, with their metabolic activity being influenced by factors such as pH, temperature, and chemical oxygen demand/sulfate (COD/SO4=) ratio. In the context of a sustainable bioeconomy, the challenge of converting lignocellulosic waste into value-added products is addressed through physical pretreatment techniques such as milling, extrusion, microwave irradiation, and ultrasound, which are efficient in valorizing waste from urban tree pruning. The article highlights the importance of bioreactors in transforming raw materials into desirable biochemical products, discussing different types of bioreactors, such as batch, continuous stirred tank, airlift, fluidized bed, upflow anaerobic sludge blanket (UASB), and bubble column, and their specific advantages and disadvantages. Sustainable sulfate reduction is the central focus, integrating the application of SRB and the conversion of lignocellulosic waste in a way that complements the objectives of the work and promotes a more cohesive flow in the summary. Thus, the interrelationship between effluent treatment strategies and waste valorization is emphasized from an environmental sustainability perspective, highlighting the relevance of this study in the broader context of a sustainable bioeconomy.

Improvements in the regulation and implementation of extended producer responsibility systems: analysis from the e-waste case study in the State of São Paulo from 2012 to 2021

Raissa Silva de Carvalho Pereira — 2024-03-05

The strategy adopted for the implementation of the extended producer responsibility (EPR) in the State of São Paulo was conceived in three phases, the first and second of which have already been completed, while the third is in progress. The aim of this paper is to evaluate the response of EPR systems to the advancement of regulation, based on the case study of waste electrical and electronic equipment in the State of São Paulo. An evaluation of the behavior of these systems was carried out from 2012 to 2021, between the first and second phase of EPR implementation, considering the following variables: established goals, participating companies and results achieved, with two approaches: a) comparative analysis between the two engagement agreements established with entities in the electronics sector, signed, respectively, in the first and second phase; b) analysis of the aggregate results of the systems whose reverse logistics plans were presented to the state environmental agency in compliance with the regulation, between 2018 and 2021. Advances were noted from the first to the second phase, regarding the variety of waste covered, quantity and diversity of actors in the production cycle involved, significance of goals, geographic scope of waste collection points and quantities collected. From 2018 to 2021, the total number of collection points increased 37.4 times, and the amount collected almost quadrupled. The decisive factor for this advance was the publication of an innovative regulation between the two phases, binding the compliance with the EPR to environmental licensing at the state level.

Challenges for the implementation of the jurisdictional REDD+ in the Brazilian state of Amazonas

Abdulai Ismail Seca — 2024-02-01

The forestry sectors of developing countries can contribute to the fight against climate change through financial negotiations, which include the REDD+ mechanism. The jurisdictional REDD+ (J-REDD+) approach has emerged as an option for large countries, such as Brazil, which have profound regional idiosyncrasies that can influence the dynamics of the implementation of a REDD+ system. The study analyzes the implementation of a J-REDD+ system in the Brazilian state of Amazonas, between 2005 and 2022, based on the analysis of official documents and academic studies. The data were used to compile a SWOT matrix, which was employed to identify the strengths, weaknesses, opportunities, and threats involved in implementing the J-REDD+ in the state. This analysis revealed that the principal forces include public policy, the combat of deforestation, governance, monitoring, and the targets for reducing deforestation rates. The primary weaknesses include the lack of a state REDD+ plan, recent increases in deforestation rates, strategic challenges, the limited representation of traditional and indigenous peoples on advisory councils, and the lack of adequate transparency mechanisms. External opportunities lie in the potential for increasing the funding for projects, although the external threats include a lack of continuous funding, changes in the composition of working bodies, and the discontinuous nature of local government programs. These findings indicate that implementation of J-REDD+ at both state levels will be crucial to ensure that this approach provides an effective mechanism for the mitigation of climate change, as well as achieving present and future goals for conservation and sustainable development.

Effects of changes in use and soil cover on real evapotranspiration from the creation of a remote sensing product in the Xingu basin

Sarah Christina Ribeiro Antunes — 2024-03-05

Several studies have shown that changes in land cover within a given watershed significantly affect the hydrological cycle and its variables. In the Xingu basin, many areas had their vegetation replaced by agricultural crops and pastures, while deforestation has been particularly prevalent in the region known as the Arch of Deforestation. Using remote sensing techniques enable the estimation of biophysical variable ETr for extensive areas, as exemplified in the study basin. Evapotranspiration data used in this work were obtained by creating a product that returns the combined median of the MOD16A2, PML_V2, Terra Climate, GLEAM_v3.3a, FLUXCOM, SSEBop, FLDAS, and ERA5-Land models, with subsequent application of the data provided by Collection 6 of the MapBiomas network, allowing the integration of land use and land cover information with real evapotranspiration estimates for the transition ranges: Forest to Pasture; Forest to Agricultural Land; Cerrado to Pasture; Cerrado to Agricultural Land. The interval defined for the study corresponds to the years 1985 to 2020, according to the historical series available on MapBiomas. After applying programming languages to filter the data, the results underwent statistical analysis to elucidate the effects of soil changes on evapotranspiration. Over the total data period (1985-2020), there was a decrease in forest areas (-16.23%), with conversion to pasture areas, in the order of +12.51%, and agricultural areas, reaching +5.5%. In the same timeframe, evapotranspiration in conversion bands underwent minimal changes, notably from 2009 to 2020, where a decreasing trend was reported of 0.095 mm/month for the “forest to pasture” substitution, and 0.090 mm/month in “Cerrado for pasture".

Nutritional quality of Brazil nuts from different trees and under different storage conditions

Ediglei Gomes — 2024-03-09

The Amazon nut is a naturally organic food, considered a functional food for promoting good nutrition and health of the body. Its regular consumption has already been associated with reducing several diseases due to the high antioxidant and anti-inflammatory activities of some phytochemicals, mainly Selenium (Se). The objectives of this study were: 1) to evaluate whether Brazil nut trees that present higher fruit production also have higher Se content, 2) to check for alterations in Brazil nut (2021 harvest) seeds after one year of storage under different controlled conditions; 3) to check for alterations in the proximate composition of seeds (2022 harvest) after pre-drying and storage in the field. The average Se content was 143 mg kg^-1, varying from 33 to 544 mg kg-¹, with higher values in Brazil nuts collected from trees with lower fruit production. Seeds stored in their fruit for one year had higher moisture content (21%) and water activity (0.91) than those in the climate-controlled cold room and laboratory room, in addition to more carbohydrates and less lipids. This proved the efficiency of seed storage in fruit to maintain germination viability. In general, no significant changes were found in the proximate and nutritional composition of Brazil nuts taken to storehouse of pre-drying and the local buyer’s warehouse, proving that these conditions enable the quality maintenance of fresh Brazil nuts. These results can support commercialization, improvement, and valorization actions in the Brazil nut production chain that favor its quality as a functional and nutraceutical food.

Plant growth-promoting bacteria in sorghum development in coppercontaminated soil

Juliano Cesar da Silva — 2024-03-09

Copper (Cu) is a metal that can become toxic to sorghum when present in high concentrations in the soil. The use of plant growth-promoting rhizobacteria can be an alternative for the development of sorghum [Sorghum bicolor (L.) Moench] in soil contaminated with copper. The objective of this study was to determine the effect of Azospirillum brasilense inoculation on the development and copper levels of sorghum cultivated in soil contaminated with Cu, enabling the reuse of these areas. The experimental design was randomized blocks in a factorial arrangement (9 × 2), with nine doses of copper [(0: natural content of the soil), 30, 60, 90, 120, 150, 180, 240, and 300 mg of copper kg-1 of soil] with and without A. brasilense inoculation, with six replicates. In the treatment without inoculation, a dose of 200 kg-1ha was applied. Plant height (PH), stem diameter, dry mass of the air part (DMAP), volume, length, and root dry mass (RDM), relative index of chlorophyll a and b, and copper contents in DMAP and RDM were evaluated. The inoculation with A. brasilense allows a higher index of chlorophyll a and b and the development of the aerial part of the sorghum, reducing copper content in the aerial part, enabling the reuse of soil containing 52.5% clay, contaminated with up to 300 mg of copper kg-1 of soil. Inoculation with A. brasilense increases the specific surface area (SSA) of sorghum roots compared with non-inoculated plants grown only with nitrogen fertilization in soil contaminated with copper.

Fire effect on bamboo-dominated forests in Southwestern Amazon: impacts on tree diversity and forest structure

Izaias Brasil da Silva — 2024-02-04

Severe droughts increase the forest flammability, especially if fires are recurrent. Considering that fires tend to alter the forest structure and reduce biological diversity, we analyzed the fire effect on the tree plant community and forest structure over a 10-year post-fire period. The study was carried out in two tropical forest fragments located in the eastern Acre State in southwestern Brazilian Amazon. In each fragment, we established three plots of 250 × 10 m² in an unburned forest and three in a burned forest. In these plots, we collected all tree individuals with DBH≥10 following the RAINFOR protocol, with censuses made in 2011, 2014, 2016, 2017, 2019, 2020 and 2021. The fire significantly reduced the abundance, basal area, and aboveground biomass of tree species, and altered the species composition along the post-fire temporal gradient. The absence of differences in the species richness and species diversity between unburned and burned forests is probably related to the life cycle of bamboo. The results suggest that, 10 years after the fire, the structure and phytosociology of the forest have not yet fully recovered.