Search Results (93)

Utilizing bamboo residues for the cultivation of Stropharia rugosoannulata is an ecological practice grounded in the concept of agricultural waste recycling, aiming to improve soil microecology and enhance nutrient cycling in bamboo forests. However, a comprehensive and systematic evaluation of the ecological effects of using bamboo residues as cultivation substrates is lacking. To evaluate soil responses following the cultivation of S. rugosoannulata, a field experiment was conducted using bamboo residues pre-fermented with 4% rapeseed cake. The results showed that cultivating S. rugosoannulata with rapeseed cake-fermented bamboo residues significantly enhanced soil nutrient levels and enzyme activities. Notable increases were observed in soil organic carbon, total nitrogen, available nitrogen, and total potassium, as well as in the activities of sucrase, urease, peroxidase, polyphenol oxidase, and neutral protease. Both bacterial and fungal α-diversity were significantly enhanced, and substantial shifts occurred in the community structure and composition of soil microbiota. Metabolomic analysis revealed that significantly differential metabolites were primarily enriched in five key pathways, including purine metabolism, glycerolipid metabolism, biosynthesis of plant secondary metabolites, and starch and sucrose metabolism. Correlation analyses further revealed that specific microbial taxa (four bacterial genera and seven fungal genera) exhibited strong correlations with soil nutrient indicators, whereas another group of taxa (six bacterial phyla and eight fungal genera) was closely linked to soil enzyme activities. Furthermore, bacterial communities were significantly correlated with metabolite variations after substrate addition. Specifically, Firmicutes showed strong positive correlations with multiple metabolites, whereas Planctomycetes exhibited negative correlations with some of the same metabolites, indicating potential competitive interactions. Based on these findings, this study proposes a preliminary “Microbe–Enzyme–Metabolite–Nutrient” coupling cycle, driven by the synergistic interplay among bamboo residues, hypha–microbiome complex, soil enzymes, and functional metabolites. This mechanism provides a scientific explanation for the soil health improvements observed during S. rugosoannulata cultivation and offers theoretical support for the efficient utilization of bamboo waste and maintenance of forest ecosystem stability. Full article

The research hypothesis of this study assumes that nitrogen (N) from digestate has an equivalent productive effect as mineral fertilizer. Therefore, the use of digestate as a N carrier by farmers significantly reduces the energy costs of oilseed rape production. This hypothesis was verified in field experiments with rapeseed conducted in the 2015/2016, 2016/2017, and 2017/2018 growing seasons. The experiment consisted of three N fertilization systems (FSs)—mineral ammonium nitrate (AN) (AN-FS), digestate-based (D-FS), and ²/₃ digestate + ¹/₃ AN (DAN-FS)—and five N_f doses: 0, 80, 120, 160, and 240 kg N ha⁻¹. Maximum seed yields were 3.26, 3.32 and 3.66 t ha⁻¹ and were obtained for optimal N doses of 170, 186 and 189 kgNn ha⁻¹, respectively. Similar trends were observed for the following yields: straw, crude oil, and cake. The values of the Nitrogen Fertilization Replacement Value for the above yield categories slightly exceeded 100%, and for the mixed variant, they were in the range of 108–112% in relation to the mixture with ammonium nitrate. The contribution of straw, oil, and oilcake in the total energy harvested accounted for 64%, 22%, and 14%, respectively. The most favorable energy efficiency ratio, E_e = 8.15 (seeds + straw), was achieved under the mixed N fertilization variant (DAN-FS; 8.3 and 15.6 m³ ha⁻¹, respectively) and N fertilizer doses of 40 and 80 kg ha⁻¹. For the highest nitrogen doses, the digestate significantly stabilized the yields and energy output of winter rapeseed production. Overall, based on the results of the field experiment and calculations conducted, it is recommended that winter rapeseed biomass should be used entirely for liquid fuel (oil) and solid fuel (oilcake and/or straw) production. Full article

Moulds of the Rhizopus oryzae species exhibit high biotechnological potential due to their significant metabolic activity, which is influenced by cultivation conditions. The study aimed to evaluate the ability of R. oryzae DSM 2199 to synthesize extracellular lipolytic and proteolytic enzymes in solid-state fermentation (SSF) using rapeseed cake as a substrate. The effectiveness of the SSF method in stimulating the synthesis of hydrolytic enzymes by R. oryzae was confirmed. The effect of an additional carbon and nitrogen source with three different dilution variants of the solid substrate on lipase and protease activity was analyzed. No significant correlation was found between enzyme activity and the applied diluents. The extracellular enzyme solution obtained from R. oryzae in SSF was lyophilized. The freeze-dried raw preparation exhibited high lipolytic activity (111.59 U/g) compared to its low proteolytic activity (0.013 U/g). Demonstrated hydrolytic activity made the biocatalyst useful for the hydrolysis and esterification reactions. Full article

Background: Chinese Yellow Earth is a key subtropical agricultural resource in southwestern China; however, its productivity is limited by acidity and poor nutrient retention. This study examined how reduced nitrogen plus organic amendments affect its soil microbial structure and maize yield. Methods: A field experiment with four treatments evaluated reduced nitrogen fertilization amended with rice husk plus rapeseed cake (RS) or RS with biochar (BC). Soil properties (pH, nitrogen, organic matter) and maize yield were analyzed. Metagenomic analysis (NR database) characterized microbial communities, and correlation analysis with Mantel tests identified key relationships. Results: Combined organic amendments under reduced N significantly increased soil pH, nitrogen components, and organic matter, increasing maize yield by 4.41–8.97%. Metagenomics revealed enriched beneficial genera including Sphingomonas and Bradyrhizobium. Yield positively correlated with nitrate nitrogen and a beneficial microbial cluster containing Lysobacter and Reyranella, whereas Steroidobacter negatively correlated with key fertility indicators. Mantel tests revealed nitrate nitrogen as the primary correlate of functional gene community succession. Conclusions: This study reveals that reduced nitrogen with organic amendments promotes soil improvement and microbial modulation, demonstrating potential as a sustainable practice to maintain crop productivity in Chinese Yellow Earth. The observed trend toward yield improvement underscores its promise and warrants further validation through additional trials. Overall, the findings highlight the beneficial effects of these amendments on soil health and their role in supporting sustainable subtropical agriculture under reduced nitrogen input. Full article

The application of organic amendments is increasing in intensive modern agriculture. However, the impacts of organic amendments with distinct quality and quantity on soil mineral nitrogen (N) dynamics remain unclear. In this study, we performed a laboratory incubation experiment for 90 days to investigate the effects of organic amendments with different carbon-to-nitrogen ratios (C/N) (7, 119, 506) and application rates (2, 4, 6 g C kg⁻¹) on N mineralization–immobilization processes in calcareous cropland soil. The study showed that net N mineralization induced by low C/N amendment (rapeseed cake, 7) occurred in this soil. In contrast, net N immobilization was stimulated by glucose and high C/N organic amendments, including maize straw (C/N, 119) and cypress sawdust (C/N, 506). The immobilized N was in the order of glucose > maize straw > cypress sawdust regardless of application rates, which was ascribed to the discrepancy of their C availability. Both N mineralization and N immobilization increased with application rates during the incubation period. The net N mineralization from these organic amendments was significantly affected by C/N ratios (p < 0.001), application rates (p < 0.001), and their interaction (p < 0.001). The study indicated that organic amendments with a higher C/N ratio would promote soil N immobilization, which was further reinforced by higher application rates, thereby decreasing the risk of reactive N loss in calcareous soil. Full article

Microbial herbicides, recognized for their target specificity, environmental compatibility, and simple production processes, hold promising potential for sustainable agriculture. This study isolated a strain of Alternaria gaisen (designated GD-011) from infected Medicago sativa L. in Qinghai Province, China, and evaluated its herbicidal potential through systematic development and efficacy assessment. Using single-factor and orthogonal experimental designs, the optimal sporulation substrate was identified as wheat bran, and the fermentation medium was optimized to consist of 14.5 g wheat bran, 19.4 g wheat middlings, 1.5 g rapeseed cake, and 14.6 g corn flour. Based on colony diameter and OD₆₀₀ measurements, diatomite was selected as the most suitable carrier, while bentonite, humic acid, and polyvinyl alcohol were chosen as the stabilizer, protectant, and dispersant, respectively. Pot trials under controlled conditions demonstrated strong herbicidal activity of GD-011 against three common weed species: Chenopodium album L., Elsholtzia densa Benth., and Galium aparine L. The highest efficacy was observed against C. album, with disease incidence and fresh weight inhibition reaching 80.83% and 79.87%, respectively. Inhibition rates for both E. densa and G. asparine exceeded 60%. A wettable powder formulation developed from GD-011 showed particularly effective control of C. album and E. densa, providing a practical foundation for the application of GD-011 as a novel bioherbicide. Full article

This study aimed to evaluate the potential benefits of co-digesting rapeseed oil cake, a by-product of biodiesel production, with microalgal biomass. Anaerobic fermentation was carried out under mesophilic conditions using various doses of press residue as a co-substrate. The results demonstrate that the addition of rapeseed oil cake enhances biogas production. The highest biogas yield was achieved during co-digestion with 1 g VS·L⁻¹ of microalgal biomass and 0.5 g VS·L⁻¹ of rapeseed oil cake. The average methane content in the biogas was 62.42%. The average hydrogen sulfide concentration ranged from 400 to 700 ppm. The maximum energy yield of 3.76 kWh·kg⁻¹ DM was obtained from co-digesting microalgal and rapeseed oil cake biomass in a 2:1 ratio. Full article

This study aimed to investigate the influence of different organic fertilizers and their concentrations on the growth of ‘Orah’ (Citrus reticulata Blanco) seedlings, as well as on the mineral nutrient contents, chemical and biological properties, and microbial community of the soil. Five types of organic fertilizers and three concentrations were studied. The seedling growth indexes, leaf mineral elements, soil mineral elements, soil enzyme activity, and soil microorganisms were measured. The results showed that organic fertilization significantly increased the contents of eight mineral elements in leaves, depending on the types and concentrations used. Specifically, rapeseed cake fertilizer was found to significantly increase the content of iron (Fe), manganese (Mn), and zinc (Zn) in the leaves. Furthermore, compared with applying only chemical fertilizers or no fertilizers at all, the application of organic fertilizer significantly increased the content of soil organic matter (SOM) and several mineral elements in the soil. The bacterial species composition of soil treated with common organic fertilizer and bio-organic fertilizer, and sheep manure were similar; however, the bacterial composition was significantly different in the soil which been treated with rapeseed cake compared to these other three fertilizers. Additionally, PICRUSt function predicting indicates that the core microbial community in the rapeseed cake group could promote synthesis and the transport of sugar, iron and other substances. Organic fertilizer can change soil chemical and biological properties by affecting the core microbial community structure, and further promote accumulation of mineral elements in the leaves of citrus seedlings. Full article

The growing demand for sustainable biorefinery approaches calls for efficient, environmentally benign strategies to valorize agricultural residues and ensure their complete utilization. This study explores the combination of deep eutectic solvents (DESs) and microwave heating technology as a greener process for the selective fractionation of agri-food waste residues in a zero-waste perspective. Within this framework, five representative biomasses were thoroughly investigated, namely brewer’s spent grain, raw and parboiled rice husks, rapeseed cakes, and hemp hurds. DES formulation was selected for its ability to solubilize and separate lignocellulosic components, enabling the recovery of a polysaccharide-rich fraction, lignin, and bioactive compounds. DES extraction was performed using both microwave heating and conventional batch heating, enabling a direct comparison of the two methods, the optimization of a more sustainable fractionation process, and the maximization of yields while preserving the functional integrity of the recovered fractions. A comprehensive characterization of the separated fractions was carried out, revealing that the two fractionation methods do not yield significant differences in the composition of the primary components. Moreover, a ¹³C CP-MAS NMR analysis of the recovered lignins demonstrates how this analytical technique is a real fingerprint for the biomass source. The results demonstrate the great potential of microwave DES-mediated fractionation as a mild, tunable, and sustainable alternative to conventional methods, aligning with green chemistry principles and opening new approaches for the full valorization of waste byproducts Full article

Cake fertilizers are phosphorus-rich organic fertilizers that are commonly used in horticulture. Soil plays a crucial role in determining the effectiveness of phosphorus fertilizer. Comparative data on the relative phosphorus efficiency (rPE) of cake fertilizers across contrasting soils are scarce in the international literature. Information on the mechanisms that control phosphorus supply is also limited. This study examined the rPE of rapeseed and soybean cakes in three soils using ryegrass growth experiments and investigated the main factors affecting their phosphorus efficiency. The results showed that the rPE of rapeseed cake did not differ significantly among the three soils, with an average value of 71%. In contrast, the rPE of soybean cake showed a clear soil-dependent pattern, with the highest rPE in red soil (67%), followed by fluvo-aquic soil (47%), and the lowest in yellow-brown soil (32%). In red soil, there was no significant difference in rPE between the two cakes. Water-soluble phosphorus content of cake fertilizers and soil phosphatase activity are key factors affecting rPE. Owing to its low water-soluble phosphorus content, the phosphorus supplied by soybean cake is predominantly mobilized through soil phosphatase–mediated mineralization of organic phosphorus. In phosphorus fertilization practices, both cake water-soluble phosphorus content and soil phosphatase activity should be considered. In soils with low phosphatase activity, cake fertilizers with a higher water-soluble phosphorus content should be prioritized. Full article

Fertilizer integration is key for sustainable tea gardens, but the impacts of different plant- or animal-derived organic fertilizers on soil pH, nutrients, and carbon composition remain unclear. This study evaluated five fertilizer treatments: 50% chemical fertilizer combined with 50% of either compound fertilizer (CF), rapeseed cake (RC), soybean cake (SC), chicken manure (CD), or sheep manure (SD). Results indicate that both plant- and animal-derived organic fertilizers effectively increased soil pH and soil organic matter content. However, animal-derived fertilizers showed a more pronounced capacity to buffer soil acidity, albeit with the potential risk of exceeding the optimal pH range for tea cultivation. In terms of soil fertility, RC performed best, achieving the highest total nitrogen and phosphorus contents. Compared to CF, RC increased nitrogen by 27.98% and phosphorus by 89.04% in the first year, and by 51.21% (N) and 61.35% (P) in the second year. The CD demonstrated superior performance in available potassium, with increases of 52.01% in the first year and 86.09% in the second year compared to CF. Regarding soil organic carbon composition, including total organic carbon (TOC), particulate organic carbon (POC), and mineral-associated organic carbon (MAOC), both types of organic fertilizers enhanced TOC levels compared to CF. Animal-derived fertilizers were more effective in rapidly increasing TOC and POC, whereas plant-derived fertilizers promoted a more stable accumulation of POC, contributing to long-term soil fertility through sustained nutrient release. Dynamics of MAOC revealed initial enhancements under animal-derived fertilizers, but stability declined over time. In contrast, plant-derived treatments showed a steadier increase in MAOC. Ratios of POC/TOC and MAOC/TOC further indicated that RC favored a higher proportion of particulate organic carbon, which is crucial for sustained nutrient availability. In conclusion, this study highlights the importance of tailored fertilization strategies to optimize soil productivity and enhance carbon sequestration in tea gardens. Adapting fertilizer application to specific soil conditions is therefore critical for the effective management of modern sustainable tea garden systems. Full article

Oilseed cakes, by-products of oil extraction, represent an underutilized resource with significant potential for sustainable food and pharmaceutical applications. This comprehensive review examines the valorization strategies for oilseed cakes, focusing on their rich protein (up to 56%) and fiber (up to 66%) content. We analyze both conventional and innovative extraction methods, highlighting the advantages of ultrasound-assisted (96.64% phenolic compound yield), enzymatic (82–83% protein recovery), and subcritical water extraction techniques in improving efficiency while reducing environmental impact. This review demonstrates diverse applications of oilseed cake components from gluten-free bakery products and plant-based meat alternatives to advanced nanoencapsulation systems for bioactive compounds. Each major oilseed type (soybean, rapeseed, sunflower and flaxseed) exhibits unique nutritional and functional properties that can be optimized through appropriate processing. Despite technological advances, challenges remain in scaling extraction methods and balancing yield with functionality. This paper identifies key research directions, including the development of integrated biorefinery approaches and the further exploration of health-promoting peptides and fibers. By addressing these challenges, oilseed cakes can play a crucial role in sustainable food systems and the circular economy, transforming agricultural by-products into high-value ingredients while reducing waste. Full article

The increasing demand for sustainable agriculture and environmental protection has prompted the exploration of innovative methods to valorize byproducts from rapeseed oil production. This review focuses on the application of microorganisms as a promising approach to transforming rapeseed de-oiling residues, such as cake and meal, into valuable products. This review discusses traditional and modern methods of rapeseed oil extraction, the composition and challenges posed by rapeseed byproducts, and the presence of antinutritional components such as glucosinolates, erucic acid, and phytic acid. Microbial applications, including the production of industrial enzymes, enhanced digestibility, and the neutralization of antinutritional factors, are examined as key solutions for waste valorization. Additionally, the role of microbial consortia and genetic modification in optimizing transformation processes is discussed. This review underscores the potential of microorganisms in creating eco-friendly, scalable technologies that contribute to resource efficiency and environmental sustainability in the agricultural and biotechnology sectors. Full article

Rapeseed proteins, due to their quality and wide availability, have great potential for application in human nutrition. However, their high content of antinutritional compounds poses significant economic and environmental challenges for food industry applications. To overcome these obstacles, various extraction and modification techniques, including enzymatic and ultrasound-assisted methods, were used to enhance protein functionality and improve both nutritional and sensory properties. In this study, the effects of dephenolization on the structural, physicochemical, and functional properties of rapeseed protein isolate obtained from defatted rapeseed cake were investigated through four different protocols. All obtained protein isolates (PIs) exhibited high protein purity (above 65%), with a notable difference in extraction yield. Furthermore, the extraction process was optimized using an artificial neural network (ANN) model, which demonstrated high predictive performance. The optimal extraction conditions for the dephenolization of rapeseed oil cake were 84% ethanol concentration, a solid-to-liquid ratio of 1/60 w/v, and 15 min of ultrasound treatment, resulting in an impressive protein purity of 90.68% with a yield of 29.17%. The obtained proteins were further characterized and compared in terms of protein profile (FTIR and SDS-PAGE), amino acid composition, solubility, and digestibility. The protein isolate (PI) obtained under optimized conditions displayed superior functional properties, underscoring the relevance and necessity of a data-driven, mathematical approach for scale-up and industrial implementation. Full article

Oil cakes are biomass wastes created by pressing oil from oilseeds. Their chemical composition (including high fat or protein content, a favorable fatty acid profile, and a high proportion of unsaturated acids) makes them valuable raw materials not only in animal feeding but are increasingly gaining popularity in biotechnological processes. This article examines the possibility of valorizing oil cakes using the lipid fraction extracted from them or their raw form in a two-pot biosynthesis process of GDDL—a cyclic ester with a creamy-peach aroma. This study tested five types of oil cakes (hemp seeds, rapeseed, safflower, camelina, and flax), analyzing their physicochemical composition and the fatty acid profile of their lipid fraction. Due to the high content of oleic acid (over 62% lipid fraction) and the wide availability, rapeseed cake was used in the biotransformation process. The synthesis of GDDL involved a three-step process: hydrolysis of triacylglycerols, hydration of oleic acid (via lactic acid bacteria in anaerobic conditions), and β-oxidation (via Yarrowia yeast, aerobic process). The analysis showed that it is possible to produce because of the two-pot biotransformation of approximately 1.7 g of GDDL/dm³. These results highlight the process’s potential and justify the feasibility of waste valorization. The proposed biotransformation requires optimization and is a good example of the application of the circular economy in food processing and waste management. Full article