Search Results (1,341)

Propionic acid (PA) is an important organic acid with applications in food preservation, feed additives, and bio-based chemical production. While industrial PA is mostly derived from petrochemical processes, sustainable microbial alternatives are gaining attention. In this study, we explored a co-fermentation strategy using lactic acid bacteria (LAB) with complementary metabolic capabilities to enhance PA biosynthesis via the 1,2-propanediol (PDO) pathway. Genome-based screening identified a metabolic division between strains capable of producing PDO (e.g., Carnobacterium maltaromaticum IBB3447) and those converting PDO to PA (e.g., Levilactobacillus brevis IBB3735). Notably, we discovered that C. maltaromaticum IBB3447 is capable of PDO 24 biosynthesis, a function previously undescribed in this species. Phenotypic assays confirmed glycerol metabolism and acid tolerance among strains. In co-culture fermentation trials, the highest PA concentration (6.87 mM) was achieved using simultaneous fermentation in a fructose–sorbitol–glucose (FRC-SOR-GLC) medium, accompanied by prior PDO accumulation (up to 13.13 mM). No single strain produced PA independently, confirming that metabolic cooperation is required. These findings reveal a novel LAB-based bioprocess for sustainable PA and PDO production, using cross-feeding interactions and the valorization of industrial waste streams. The study supports future optimization and scale-up for circular bioeconomy applications. Full article

This study evaluated how fruit fermentation liquid (FFL) enhances the conversion of chicken manure by black soldier fly larvae (BSFL) and modulates their gut microbiota. Three groups were tested: control (A: 300 g manure + 50 g water), low-dose FFL (B: 300 g manure + 25 g FFL + 25 g water), and high-dose FFL (C: 300 g manure + 50 g FFL). The results show that the dry matter conversion rate significantly increased by 9.5% (p < 0.05), while the feed-to-larvae ratio was reduced by 1.02 (p < 0.01) in group C. NH₃ emissions in group C decreased by 24.48 mg·kg⁻¹·DM (dry matter substrate) day⁻¹ (24.48 mg per kilogram of dry matter substrate per day) (p < 0.01), with suppressed H₂S release. Gut microbiota analysis revealed that FFL reduced the abundance of Proteobacteria (6.07% decrease in group C) while enriching Actinobacteriota (4.68% increase) and beneficial genera (Corynebacterium, Gallicola). Substrate microbial diversity in group C improved, with Proteobacteria and Firmicutes increasing by 11.07% and 4.83%, respectively, and pathogenic Sphingobacteriaceae declining by 21.16% by day 7. FFL likely introduced organic acids and nutrients, enhancing larval digestion and nutrient absorption while inhibiting the production of harmful gases. These findings demonstrate that FFL optimizes BSFL-driven waste conversion efficiency through modulation of the microbiota, offering a sustainable strategy for organic waste management and contributing to circular agricultural systems. Full article

This study explored the prevalence and types of microplastic (MP) pollution in three fish species—Labeo rohita, Wallago attu, and Cirrhinus mrigala—collected from the Panjnad Barrage in South Punjab, Pakistan. MPs were analyzed from the gastrointestinal tracts (GITs), gills, and muscles of 90 fish samples. Advanced analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy/Energy-Dispersive X-Ray Spectroscopy (SEM/EDX), and Gas Chromatography/Mass Spectrometry (GC/MS), were deployed, confirming the polymeric composition and presence of various additives. Quantitative and qualitative analyses revealed significant variations in MP accumulation across tissues, with the GIT consistently showing the highest MP count, the gills having the highest concentration per gram, and the muscles exhibiting the lowest amount of accumulation. Wallago attu was found to have accumulated the highest concentration of microparticles among all three species due to its feeding habits and habitat. Fibers and fragments were the predominant types of MPs, with yellow and red being the most frequent colors. Polypropylene (PP) and polyethylene (PE) were the primary polymers identified, alongside other types like polyethylene terephthalate (PET) and polyvinyl chloride (PVC). The MP size distribution indicated that mid-sized particles (150–50 µm) were most abundant in the GIT and gills, while smaller particles (<50 µm) accumulated in the muscles, suggesting different levels of bioavailability and tissue penetration. Overall, the results suggest that agricultural activities are a major contributor to plastic pollution in the Panjnad Barrage. These findings highlight the ecological and health impacts of MP contamination, stressing the importance of targeted mitigation strategies to eliminate plastic waste in aquatic environments. Full article

Methylparaben (MP) is an important member of the paraben family of aromatic compounds, which is under great demand in the industrial market as an antibacterial agent, preservative, and feed additive, and also has potential application value in the preparation of bio-based polyetherester materials. However, the current chemical production method of MP has various problems, such as serious environmental pollution, its dependence on petrochemical resources, and the generation of different types of waste. It is of great significance to develop an environmentally friendly MP synthesis method via synthetic biology. In this work, Saccharomyces cerevisiae was used as the host to construct the biosynthetic pathway of MP and various metabolic engineering strategies were applied to break the bottlenecks in the synthesis process, including the regulation of the rate-limiting steps in the endogenous shikimate pathway, the enhancement of central carbon flux via knocking out competitive pathways and promoting precursors synthesis, and the improvement of the exogenous enzyme expression using promoter engineering. The final engineered S. cerevisiae could produce 68.59 mg/L MP in shake flasks, which was the highest titer of MP synthesized by S. cerevisiae so far. It was indicated that the strategies applied in our work were effective in promoting the synthesis of MP, which not only laid an important foundation for the industrial production of MP, but also provided a platform for the synthesis of other aromatic compounds. Full article

Microplastics (MPs) have been extensively studied in the marine environment, but reliable data on their sources and pathways in freshwater ecosystems, which are the main sources of such pollutants, are still limited. In this study, we investigated the spatiotemporal variations, characteristics, and sources of MPs in Nakivubo catchment, which drains waste and stormwater from Kampala city (Uganda) and empties it into Lake Victoria through the Nakivubo channel. Surface water samples (n = 117) were collected from thirteen sites in the Nakivubo catchment (S1 to S13) during the dry and wet seasons in 2022. The MPs were recovered by wet peroxide oxidation protocol, followed by salinity-based density separation, stereomicroscopy, and micro-attenuated total reflectance Fourier-transform infrared spectroscopy. All the samples had MPs, with mean concentrations ranging from 1568.6 ± 1473.8 particles/m³ during the dry season to 2140.4 ± 3670.1 particles/m³ in the wet season. Nakivubo catchment discharges an estimated 293.957 million particles/day into Lake Victoria. A Two-Way ANOVA revealed significant interactive effects of seasons and sampling sites on MPs abundance (p < 0.05). Spatially, the highest mean concentrations of MPs (5466.67 ± 6441.70 particles/m³) were in samples from site S3, which is characterized by poor solid waste and wastewater management practices. Filaments (79.7%) and fragments (17.9%) made of polyethylene (75.4%) and polyethylene/polypropylene co-polymer (16.0%) were the most common MPs. These are likely from single-use polyethylene and polypropylene packaging bags, water bottles, and filaments shed from textiles during washing. These results highlight the ubiquity of MPs in urban drainage systems feeding into Lake Victoria. To mitigate this pollution, urban authorities need to implement strict waste management policies to prevent plastic debris from entering drainage networks. Full article

Management of sewage sludge is of ongoing concern because this waste product is generated continuously and contains high levels of harmful constituents. Among these constituents, fungal pathogens are of increasing concern. Vermicomposting can reduce the amounts of bacterial pathogens in sewage sludge; however, information about the effects of earthworms on fungal pathogens is limited or non-existent. We therefore aimed to determine whether vermicomposting can control fungal pathogens present in sewage sludge. Using next-generation sequencing techniques, we characterized fungal communities in sewage sludge from eight wastewater treatment plants (WWTPs) and in casts (feces) of earthworms feeding on sewage sludge. Fungal communities in earthworm casts primarily included taxa that were absent from sewage sludges, indicating a significant change in fungal composition. Changes in fungal diversity depended on the source of sewage sludge (WWTP). All of the sewage sludges contained low levels of fungal pathogens, most of which were significantly reduced or eliminated by earthworms, such as Armillaria, Cystobasidium, Exophiala and Ophiosthoma. Moreover, earthworm gut transit enhanced beneficial (saprotrophic) fungi like Arthrobotrys, Aseroe, Crepidotus and Trichurus. Overall, digestion of sewage sludge by earthworms alone generated a mainly pathogen-free fungal community with a high proportion of saprotrophic taxa, which would enhance nutrient cycling rates. Full article

Sustainable livestock production is a critical component of global food security and environmental stewardship. Agricultural crop residues, such as cereal straws, stovers, and hulls, as well as agro-industrial by-products, including oilseed meals, distillery wastes, and fruit/vegetable processing residues, are generated in large quantities worldwide, and these residues can be used in the diet of the animals to reduce the feed production cost and sustainability. In this review, we found that the use of treated crop residues in the diet of animals increased the production performance without causing any side effects on their health. Additionally, we also noticed that using these crop residues also mitigates the methane production in ruminants and feed costs, particularly for harvesting the feed crops. Traditionally, these materials have often been underutilized or even disposed of improperly, leading to wastage of valuable nutrients and potential environmental pollution. By incorporating these materials into animal feed formulations, livestock producers can benefit from several key advantages. The review further discusses the challenges and considerations involved in the effective utilization of these alternative feed resources, such as variability in nutrient composition, anti-nutritional factors, and the need for appropriate preprocessing and formulation strategies. Emerging technologies and innovative approaches to optimize the integration of crop residues and by-products into sustainable livestock production systems and also reduce global warming, particularly methane, CO₂ and other particles that affect the environment after burning these crop residues, are also highlighted. By synthesizing the current knowledge and exploring the multifaceted benefits, this review underscores the vital roles that agricultural crop residues and agro-industrial by-products can play in fostering the sustainability and resilience of livestock production, ultimately contributing to global food security and environmental stewardship. Full article

This paper investigated pre-concentration of a low-grade Upper Group 2 (UG2) ore to assess the possibility of rejecting waste at a typical discard Platinum Group Metals (PGMs) grade of <0.4 g/t at mass rejection to floats greater than 16% by comparing feed prepared by High pressure grinding rolls (HPGR) to Conventional crushers (Cone crushers). Heavy Liquid Separation (HLS) was conducted as a benchmark test to Dense Medium Separation (DMS) to determine the expected grade, recovery, and mass yield for various size classes and crusher. The comparison between fine size classes −9.5 + 1.18 mm and −6.7 + 1.18 mm crushed by HPGR and conventional crushing showed that, under the conditions tested, the conventional crusher outperformed HPGR in terms of high sinks grade and a higher percentage of material exposed to pre-concentration. Looking at coarser size fractions (+12 mm), HLS results showed that under the conditions tested, size fraction −20 + 1.18 mm crushed by a conventional crusher at an optimum density of 3.4 g/cm³ is an optimized size fraction to run the DMS plant. The pilot DMS cyclone testwork showed that 61.1% by mass could be rejected to the floats stream based on Run of Mine (ROM) feed at 1.12% Cr₂O₃ and 0.42 g/t Total PGMs + Au grade, a typical discardable PGMs grade. Full article

The increasing global population, projected to exceed 9.1 billion by 2050, presents a critical challenge for sustainable food production. Edible insects have emerged as a promising alternative protein source due to their high nutritional value, low environmental footprint, and efficient resource utilization. This review explores the opportunities and challenges of integrating edible insects into food systems. Benefits include their high protein content and quality, low greenhouse gas emissions, low-cost production, and ability to thrive on organic waste. Furthermore, edible insect cultivation requires significantly less land and water compared to traditional livestock. Edible insects are nutritionally rich, containing substantial amounts of essential amino acids, unsaturated fatty acids, and minerals. However, barriers to widespread adoption persist, such as cultural perceptions, regulatory hurdles, potential allergenicity, and biological and chemical contamination. Furthermore, standardizing rearing practices and ensuring food safety are critical for broader adoption. While edible insects represent a nutritious, low-cost food and feed, there are a lot of variables that have not been fully investigated. Only after further research, promising results, and solutions that are relatively easy to apply might edible insects be considered a sustainable food source. Considering the challenges that may arise by 2050, more intensive research is highly advised. Full article

Straw has been used as a building material since time immemorial and has been considered as a waste product from the agricultural sector, usually used for feed, bedding, or fertilization. Nowadays, the construction industry strives to reduce greenhouse gas emissions and is focusing on renewable materials; hence, straw seems to be an attractive, low-energy option. Straw bales or blown insulation are common uses, with limited detailed knowledge regarding the properties of different straw types. Straw is made up of the dry stems of crops. Straw’s chemical composition will differ with different crops and can have a great impact on its effectiveness. As a renewable material, straw also has the potential to be used in buildings, enhancing thermal insulation and reducing environmental impacts. This study considers four kinds of straw: barley, oats, oilseed rape, and triticale, regarding their possible usage in insulation materials. The thermal conductivity, bulk density, and dust generation of each type were tested in the laboratory. Among them, the best performance was shown by the barley straw treated with mechanical pulping using a knife mill at 4000 rpm for 60 s, which showed the lowest bulk density and thermal conductivity and generated the least dust. It is thus proven to be an environmental insulation material with significant implications for sustainable construction and energy-efficient building design, further helping in maintaining environmental sustainability in building construction. Full article

This study assessed the performance of black soldier fly larvae (BSFL) fed different tomato plant residues (fruit, leaves, and stems) at doses ranging from 100 to 350 mg/larva/day over ten days. Most doses resulted in 100% survival, except for the leaf residue at the highest dose (300 mg/larva/day), which had an 88% survival rate. Growth varied by substrate, with the highest increase observed in larvae-fed tomato fruit, followed by stems and leaves. However, no doses exceeded the control diet regarding biomass accumulation, although fruit tomatoes produced the highest wet biomass (13.71 g). Larvae-fed fruit tomatoes also showed the best performance in waste reduction index (WRI) with 7.56, substrate reduction (SR) of 75%, and a feed conversion rate (FCR) of 3.29. Furthermore, the fruit tomato was the most efficient at converting organic waste into larval biomass. This study demonstrates the potential of using tomato plant residues as a sustainable substrate for BSFL, offering an effective way to manage agricultural waste and produce valuable larval biomass. Full article

More than one billion tons of the food produced in the world ends up being wasted every year, accounting for about one-third of the food produced globally. For this reason, the problem of food waste management has been the focus of the different actors intervening in the food supply chains, who recognize that food waste has not only environmental but also economic and social impacts. This review focuses on foods of plant origin wasted at different stages of their life, namely primary production, transformation/processing, transportation, sales, catering and the domestic level. It addresses the subject from multiple angles, considering the environmental, economic and social perspectives. The review was based on a search carried out within scientific databases, for example, ScienceDirect, Scopus and the Web of Science. The results highlighted that in the generation and management of food waste from plant origin, there is a clear difference between developed and developing countries, with these last showing higher losses in production, principally the transportation and storage of the foods. Contrarily, in developed countries, excess food produced and not consumed is the strongest contributor to food waste. Valorization of agricultural waste and industrial residues for application into animal feed or agricultural fertilizers, or through the recovery of valuable compounds for industrial purposes, are some of the ways to deal with food waste while generating additional economic value and reducing environmental impact. However, there is still a need to modify processes and behaviors to reduce food waste and improve the sustainability of supply chains. Therefore, it is crucial to conduct research to identify and report food waste so that stakeholders can contribute positively to solving this problem. Full article

CFD simulations of annular coolers have often been performed on a single trolley, making it difficult for the method to provide reliable and accurate data for the optimum design of annular coolers. The present paper establishes a three-dimensional model of the entire annular cooler, uses sliding mesh to approach the actual working conditions, and through UDF, realizes the simulations of the continuous feeding process of the annular cooler, and obtains complete data for one run of the annular cooler. By comparing the simulated data with the actual measured data, the reliability of the model was verified. The temperature distribution inside the annular cooler and the temperature variation at the outlet of the waste heat recovery as well as the flow rate are also explored in detail. Subsequently, the temperature distribution inside the annular cooler, the flue gas flow, and the changes in temperature at each outlet were studied under different material layer thicknesses, and the discharge temperature under different thicknesses was obtained. Based upon the proposed method, a lot of data that cannot be obtained by traditional calculation methods can be obtained, thus shortening the cycle of optimizing the design and development of the structure and operating parameters of annular coolers. Full article

Although the adverse health effects of consuming ultra-processed foods (UPFs) are well-documented, limited evidence exists on their impact during lactation. This study examined the association between maternal UPF consumption, feeding practices, and malnutrition in breastfed infants. A cross-sectional analysis was conducted with 111 mother–child pairs up to 150 days postpartum. Infant feeding practices were assessed using WHO indicators, and malnutrition was evaluated by length-for-age and BMI-for-age. Maternal dietary intake was estimated using two 24 h recalls, and UPF consumption was classified by the Nova classification. Dyads were grouped based on the highest UPF consumption quartile, and adjusted binary logistic regression was applied. UPFs accounted for 26% of the maternal diet on average. While 71.2% of infants were exclusively breastfed, one-third were overweight, and 11.7% were stunted. High maternal UPF consumption (>32% of energy) was associated with increased odds of malnutrition by BMI-for-age (wasting or overweight) (OR 3.38; 95% CI: 1.29–8.83) and stunting (OR 3.89; 95% CI: 1.04–14.58). Feeding practices showed no association. These findings highlight that maternal UPF consumption is associated with malnutrition odds in breastfed infants in the population assessed, emphasizing the need for dietary guidance during lactation to improve infant health outcomes. Full article

The main disadvantages of using soybean oil extraction waste as a raw feed material are its high contents of fiber, fat, and anti-nutritional factors. Therefore, several processing methods such as extrusion and hydrolysis are used to overcome these disadvantages and increase the availability of high-quality proteins to animals from this by-product. This study is concerned with the hydrolysis of extruded soybean meal in the presence of bacterial alkaline proteases. The effects of various process parameters were investigated to determine the optimal process parameters for hydrolysis in terms of the total free amino acid and amine nitrogen contents. The experiment included two sets of parameters that were selected for comparison: the temperature and pH in ranges of t 45–50 °C, pH 8–11, compared to the temperature and pH ranges of t = 40–45 °C and pH 7–9, using three enzyme/substrate ratios (1:10, 1:20, and 1:30). The protein hydrolysate was stored for three months after it was treated with two different preservatives (sorbic acid and thymol). Based on the results, it was found that the total free amino acid content was higher when the temperature range was 45–50 °C, the pH range was 8–11, and sorbic acid was used as a preservative. Full article