Search Results (1,593)

This study analyzed the anaerobic co-digestion of inoculum (I), rubber plant effluent (RPE) and Gliricidia leaves slurry (GLS) at different mixing ratios for the simultaneous production of methane and organic fertilizer. The results were analyzed for volatile fatty acids, pH, C/N ratio, and methane production. The organic quality of the substrate mixture before and after anaerobic digestion was analyzed for total organic carbon, total nitrogen, potassium, and phosphorus contents. This study concluded that the inoculum, rubber plant effluent (RPE), and Gliricidia leaves slurry (GLS) mixed at the ratio of 10:2:2 showed higher methane production than other experiments conducted at different mixing ratios. The nitrogen, potassium, and phosphorus contents of the substrates were increased after anaerobic digestion. However, the organic carbon content in the substrate decreased in all experiments. This research recommends the planting of rubber trees and Gliricidia maculata to promote energy sustainability and the socio-economic development of Mauritania. Full article

Dissolved hydrogen is a critical factor in maintaining the delicate balance among microbial species that drive anaerobic digestion. Since previous findings have demonstrated a correlation between dissolved hydrogen concentration and volatile fatty acid (VFA) levels, we propose to evaluate the use of dissolved hydrogen concentration in digestate as an alternative to traditional VFA measurements. The aim is to determine whether dissolved hydrogen could serve as a faster, more accurate, and more efficient indicator of process instability in anaerobic digestion. An integral part of this task also involves addressing the technical challenge of identifying a suitable sensor that meets our requirements. In this study, we evaluated the ratio of dissolved hydrogen concentration to Total Inorganic Carbon as a potential alternative to the traditional stability indicator, Volatile Fatty Acids/Total Inorganic Carbon (VFA/TIC), also referred to as Flüchtige Organische Säuren/Totales Anorganisches Carbonat (FOS/TAC). The single-stage anaerobic digestion process was carried out in a Terrafors IS rotary drum bioreactor for 150 days at an average temperature of 40 °C and an organic volatile load of 0.092 kg m⁻³ d⁻¹. Corn silage was dosed on weekdays as the substrate. With a theoretical retention time of 45 days, a biogas production of 0.219 $\mathrm{N}{\mathrm{m}}^3\mathrm{k}\mathrm{g}\mathrm{V}{\mathrm{s}}^{-1}$ with a CH₄ content of 31.6% was achieved. The values of the determined VFA/TIC stability indicator ranged from 0.22 to 5.66, with the highest values obtained when the reactor was overloaded. The dissolved hydrogen concentration ranged 0.005–0.196 $\mathrm{m}\mathrm{g}\mathrm{d}{\mathrm{m}}^{-3}$. The Pearson correlation coefficient was 0.337 and the Spearman correlation coefficient was 0.468. The amperometric microsensor has proven to be unsuitable for field applications due to its lack of sensitivity and short lifetime. The proposed ratio of dissolved hydrogen concentration to TIC did not prove to be significantly more effective than the established VFA/TIC indicator. Full article

This research investigated the effects of hydrothermal depolymerization with Fe/Ni loaded C catalysts on the anaerobic digestion (AD) performance of corn stover (CS). CS was depolymerized at 140 °C for 20 min with Fe/C or Ni/C catalysts, and then anaerobically digested. The results showed that the biomethane yield with Fe/C-600 increased by 36.6% compared to that of the control. This increase could be attributed to effective CS depolymerization with catalysts (DC), indicated by modified structures of solid fraction and enriched available components of liquid fraction. SEM analyses showed that CS microphysical structure after DC was obviously disrupted, resulting in more accessibility of cellulose and hemicellulose. The crystallinity index (CrI) of depolymerized CS was significantly reduced from 32.5% to 23.5%, allowing for a more easily biodegradable non-crystalline area to be available for enzymes. Meanwhile, the DC group produced 4.7 times more reducing sugar (RS), and a 3.4 times increase in total volatile fatty acids (VFAs) as compared to the control. Furthermore, these enhancements in DC led to an increased relative abundance of cellulolytic bacteria (Hydrogenispora and Fermentimonas) and anaerobic methanogenic archaea (Methanosarcina) in following the AD process. This could explain the reason for the biomethane yield increase with DC from microbial perspectives. This study demonstrated that hydrothermal depolymerization with Fe/C or Ni/C could provide an effective approach for obtaining more biomethane from CS via AD. Full article

This study was developed with the goal of exploring the impact of capsaicin on ruminal fermentation and ruminal bacteria in beef cattle affected by high-grain diet-induced subacute ruminal acidosis (SARA). In total, 18 healthy Simmental crossbred cattle were randomized into three separate groups (n = 6/group): (1) control diet (CON; forage-to-concentrate ratio = 80:20); (2) high-grain diet (SARA; forage-to-concentrate ratio = 20:80); and (3) high-grain diet supplemented with capsaicin (CAP; 250 mg/cattle/day). The study was conducted over a 60-day period. The results showed that the SARA model was successfully induced in the SARA group with a high-grain diet. Relative to the SARA group, the addition of capsaicin elevated the ruminal pH from 5.40 to 6.36 (p < 0.01), and decreased the total volatile fatty acids (VFAs) from 133.95 to 82.86 mmol/L (p < 0.01), aligning closely with the levels observed in the CON group. The addition of capsaicin increased the alpha diversity of ruminal bacteria relative to the SARA group, as evidenced by a lower Simpson index (p < 0.05), together with increases in the Ace, Chao, and Shannon indices (p < 0.05). Bacteroidota and Firmicutes were the most common phyla across all treatment groups, while Prevotella was the predominant genera. The unique bacterial genera (LDA scores > 4) identified within the SARA group comprised Succinivibrionaceae_UCG-001, Succinivibrio, NK4A214_group, Lachnospiraceae_NK3A20_group, and Ruminococcus, which may serve as potential biomarkers for the diagnosis of SARA. The unique genera associated with the CON group included Rikenellaceae_RC9_gut_group, Prevotellaceae_UCG-003, and U29-B03, while those for the CAP group included Succiniclasticum and Prevotellaceae_UCG-004. In summary, these results suggest that dietary capsaicin supplementation can limit the adverse effects of SARA through the modulation of bacterial communities within the rumen, thus altering ruminal fermentation in beef cattle. Full article

Microplastics (MPs) are widely distributed in the environment, and they inevitably enter animal bodies during livestock and poultry farming, leading to their presence in livestock and poultry manure. However, there is limited research on the effects of different types of MPs on the anaerobic digestion (AD) performance of livestock and poultry manure. Herein, we investigated the impact of four types of MPs (polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), and polyhydroxyalkanoate (PHA)) on AD performance using cattle manure as a substrate. Results demonstrated that the cumulative methane production in the PE group reached 5568.05 mL, exhibiting an 11.97% increase compared to the control group. Conversely, the cumulative methane production was decreased by 5.52%, 9.69%, and 14.48% in the PP, PVC, and PHA groups, respectively. Physicochemical analyses showed that MPs promoted organic matter hydrolysis on day 4 of AD, leading to the accumulation of volatile fatty acids (VFAs) in the initial stage. Specifically, the acetic acid content of PE was 44.48–92.07 mL/L higher than that of the control during the first 8 days. PE MPs also enriched microorganisms associated with methane production. The abundance of Firmicutes was enhanced by 2.89–17.57%, Methanosaeta by 8.42–12.48%, and Methanospirillum by 10.91–16.89% in comparison to the control; whereas PHA MPs decreased the abundance of Methanosaeta by 8.14–31.40%. Moreover, PHA MPs inhibited methane production by suppressing acetate kinase activity while promoting lactate dehydrogenase release from microorganisms involved in the AD process. Based on changes observed in key enzyme functional gene abundances, PHA MPs reduced acetyl-CoA carboxylase functional gene abundance, negatively affecting the acetone cleavage methanogenesis pathway. Meanwhile, PE MPs significantly increased acetate-CoA ligase abundance, thereby promoting the acetic acid methanogenesis pathway. The results provide novel insights into the influence exerted by MPs on AD performance when applied to livestock manure. Full article

This study aimed to investigate the nutritional value and potential for herbal tea production of two species Eryngium. The analysis includes the quantification of lipids, proteins, organic acids (HPLC-MS), sugars (HPLC-MS), phenolic compounds (HPLC-MS-MS), volatile compounds (GC-MS), fatty acids (GC-MS), amino acids (HPLC-MS-MS), some minerals (ICP-MS), total phenolic content, and antioxidant activities of Eryngium billardieri flowers (EBF) and thorns (EBT), as well as Eryngium planum flowers (EPF) and thorns (EPT). The results indicate that EPF and EPT exhibit elevated levels of protein (11.2%) and sugars (224.2 mg/gdw), respectively. Whereas, EBF demonstrates a higher concentration of amino acids (7.13 mg/100 gdw) and total phenolic content (19.25 mg GAE/gdw), which correlates with pronounced antioxidant properties. Oleic acid was notable in E. billardieri, while linoleic and α-linolenic acids were predominant in E. planum. Furthermore, essential minerals such as Fe, Mn, Zn, Mg, K, Ca, and P were also determined. Sensory evaluations by panelists confirmed that tea derived from the studied species possesses favorable taste and flavor profiles, attributed to its rich volatile compounds. These findings highlight the nutritional value of Eryngium species as a functional ingredient in the food industry. Additionally, their antioxidant properties suggest promising uses in pharmaceutical applications. Full article

This study aims to explore anaerobic co-digestion (AcoD) of cassava (EUM) and poultry (FP) effluents using one inoculum/substrate ratio (30%) and three EUM vs. FP substrate composition ratios (25:75, 50:50, and 75:25). The AcoD process was therefore designed for 20 L batch digesters, under mesophilic conditions, with less than 5% total solids for 66 days. The results showed that EUMs were highly resistant to degradation, while FPs were the most easily degradable. Kinetic analysis indicated specific organic matter (MO) reduction rates of 0.28% per day for EUM and 0.76% per day for FP. EUM alone produced 45.47 mL/g MO, while the 50:50 substrate produced 1184.60 mL/g MOV. The main factors contributing to EUM inefficiency were the inability to tame acidic conditions and the accumulation of volatile fatty acids. AcoD produced 23 to 50 times more methane than EUM alone, 2 to 5 times more than FP alone, and 2 to 4 times more than inoculum. As a result, the AcoD of both types of waste had a qualitative and quantitative effect on biogas production. CH₄ content increased from around 2 to 75%, depending on the amount of organic nitrogen added. The addition of nitrogen by AcoD, even under mesophilic conditions, improves the kinetics and quality of anaerobic digestion of low-nitrogen substrates. Its impact on thermophilic and psychrophilic conditions needs to be verified. Full article

This study aimed to investigate the effects of different storage times of the mixed inoculum on in vitro rumen fermentation characteristics, microbial diversity, and community composition. The experiment was divided into five groups, with mixed inoculum composed of fresh rumen fluid and culture medium being stored at 39 °C for 0 h (H0), 12 h (H12), 24 h (H24), 36 h (H36), and 48 h (H48). After 48 h of in vitro fermentation, the fermentation fluid was collected to assess rumen fermentation characteristics and microbial community composition. The H24 group showed higher total gas production, ammoniacal nitrogen levels, and total volatile fatty acids, as well as higher concentrations of individual volatile fatty acids except propionate, compared to the H0 and H48 groups (p < 0.05). The Shannon and Simpson evenness indices were significantly higher in the H0, H12, and H24 groups than in the H48 group (p < 0.05). A total of nine phyla and sixteen genera involved in starch and fiber degradation were found to be more abundant in the H24 or H48 groups (p < 0.05). Moreover, nine predicted metabolic pathways were observed to be significantly enriched in either the H24 or H48 group (p < 0.05). Both principal coordinates analysis (PCoA) and non-metric multidimensional scaling (NMDS) analysis revealed distinct clustering patterns among the H0, H12, H24, H36, and H48 groups, and analysis of similarities (ANOSIM) confirmed these significant differences (R = 1.00, p < 0.05). This study demonstrates that the storage time of mixed inoculum influences rumen fermentation characteristics and microbial community composition in a time-dependent manner. It is recommended to use a mixed inoculum that has been stored within 24 h in an anaerobic environment at 39 °C for in vitro rumen fermentation tests. This study offers valuable microbial insights into the storage strategies for mixed inoculum, thereby improving the methodologies for variable control in in vitro rumen fermentation techniques. Full article

This study compares Dalmatinski pršut, an EU Protected Geographical Indication (PGI)-labelled smoked dry-cured ham from the Dalmatia region in Croatia, with non-PGI hams from the same area, focusing on the impact of PGI certification on the product quality. The investigation is prompted by the increasing presence of dry-cured hams lacking the PGI label on the market, aspiring to compete with esteemed high-value PGI products. Samples of 28 smoked dry-cured hams (12 PGI and 16 non-PGI) were analysed for chemical properties, fatty acid composition, volatile compounds, PAH content and sensory characteristics. The results showed that PGI and non-PGI hams differ in their chemical and physical properties, with non-PGI hams having a lower water content and a higher salt content, which was also confirmed by the saltier taste in the sensory evaluation. PGI hams had a lower b* colour value, and, while the differences in texture were minimal, non-PGI hams had slightly more monounsaturated fatty acids. The aroma analysis revealed that PGI hams contained more aldehydes and alcohols, while non-PGI hams had a higher content of phenolic compounds and aromatic hydrocarbons, probably due to differences in smoking practices. PAH levels, however, were within the EU limits, indicating controlled smoking of both type of hams. Overall, these results show that the quality of smoked dry-cured ham can be distinguished by the PGI designation. The study illustrates how the traditional production methods prescribed by the PGI production protocols shape the sensory and chemical profiles of Dalmatinski pršut, with the PGI certification playing a crucial role in maintaining product quality and certifying its typicality, to distinguish it from non-PGI products. Full article

Mercury pollution is a significant environmental issue, primarily resulting from industrial activities, including gold mining extraction. In this study, 333 microorganisms were tested in increasing mercury concentrations, where 158 bacteria and 14 fungi were able to grow and remain viable at concentrations over 5.0 mg/L of mercuric chloride (II). One of the bacterial strains, Stenotrophomonas sp. INV PRT0231, isolated from the mouth of the San Juan River in the Chocó region in Colombia, showed a high mercury resistance level (MIC₉₀ of 27 ± 9 mg/L), with a removal rate of 86.9%, an absorption rate of 1.2%, and a volatilization rate of 85.7% at pH 6.0 and 30.0 °C. The FTIR analysis showed changes in the functional groups, including fatty acid chains and methyl groups, proteins, and lipopolysaccharides associated with the carboxylate group (COO⁻), suggesting an important role of these biomolecules and their associated functional groups as mechanisms employed by the bacterium for mercury detoxification. Our study contributes to the understanding of the mechanisms of mercury biotransformation in microbial environmental isolates to help develop bioremediation strategies to mitigate mercury pollution caused by anthropogenic activities. Full article

This study analyzed the nutritional composition, physicochemical properties, and volatile profiles of three major bovine head muscles—medial pterygoid, masseter, and buccinator—to reduce byproduct resource waste and increase the utilization rate of bovine head to establish a foundation for its industrial use. Compared to tenderloin, which is popular among consumers, these head muscles were found to be rich in collagen (4.90–13.1 mg/g), low in fat (0.39–1.61%), and abundant in free amino acids (143.93–223.00 mg/100 g). Their compact fiber structures, with minimal gaps between myocytes, resulted in lower cooking and press losses, making them suitable for various production processes. Notably, the medial pterygoid and masseter muscles contained high levels of polyunsaturated fatty acids (PUFAs) and lower saturated fatty acids (SFAs), with a PUFA/SFA ratio exceeding 0.45. The buccinator muscle, while containing more volatile organic compounds associated with undesirable odors and bitter amino acids, was not indicative of spoilage. Overall, this study confirmed that bovine head muscles possess high collagen, low fat, and diverse nutritional qualities, making them suitable as premium raw materials for value-added meat products, and their returns will be most economically equal to the meat derived from cattle. Full article

When vegetable waste (VW) is used as a sole substrate for anaerobic digestion (AD), the rapid accumulation of volatile fatty acids (VFAs) can impede interspecies electron transfer (IET), resulting in a relatively low biogas production rate. In this study, Chinese cabbage and cabbage were selected as the VW substrates, and four continuous stirred tank reactors (CSTRs) were employed. Different concentrations of biochar-loaded nano-Fe₃O₄(Fe₃O₄@BC) (100 mg/L, 200 mg/L, 300 mg/L) were added, and the organic loading rate (OLR) was gradually increased during the AD process. The changes in biogas production rate, VFAs, and microbial community structure in the fermentation tanks were analyzed to identify the optimal dosage of Fe₃O₄@BC and the maximum OLR. The results indicated that at the maximum OLR of 3.715 g (VS)/L·d, the addition of 200 mg/L of Fe₃O₄@BC most effectively promoted an increase in the biogas production rate and reduced the accumulation of VFAs compared to the other treatments. Under these conditions, the biogas production rate reached 0.658 L/g (VS). Furthermore, the addition of Fe₃O₄@BC enhanced both the diversity and abundance of bacteria and archaea. At the genus level, the abundance of Christensenellaceae_R-7_group, Sphaerochaeta, and the archaeal genus Thermovirga was notably increased. Full article

Lipoxygenase (LOX) is involved in the oxidation of fatty acids in plants and is a ubiquitous oxygenase that plays an important role in the process of plant resistance to adversity. In this study, the LOX gene family in the sweet cherry genome was identified by bioinformatics methods, the chromosomal mapping of different LOX genes was carried out, and the homology alignment and functional domain analysis of the encoded proteins were performed. The results showed that there were nine LOX gene sequences in the sweet cherry LOX gene family, and the subcellular localization was mainly located in the cytoplasm, chloroplast, or plasma membrane, and was concentrated on chromosomes 1, 2, 3, 4, 6, and 8. During the ripening process of sweet cherry fruits, the LOX gene family showed five different expression patterns, the expression peak of different LOX genes reached the peak of expression at a specific development period, all LOX genes jointly promoted the growth and development of fruits, the enzyme activities of LOX in different varieties of early and late ripening cherries exhibited great differences during the development process, and the results of volatile content in the later stages also showed that different varieties of cherries had their specificity. The results of this study provide a theoretical basis for further revealing the specific functions of LOX gene family members in sweet cherry. Full article

The gradual decline in feed resources for livestock needs alternate ways to ensure non-stop feed supply throughout the year. The objective of this study was to evaluate the impact of vegetable waste and rice straw silage (VTRS) on immune response, antioxidant status, and microbial changes in duodenum and caecum in Hu sheep. Eight healthy male Hu sheep were randomly distributed into control (fed farm roughage) and VTRS (fed vegetable waste silage) groups for 35 days. Results had shown that silage had less mycotoxin content (p < 0.05). The VTRS increased butyrate content in duodenal digesta, while acetate, butyrate, total volatile fatty acids (TVFA), and valerate were enhanced in caecal digesta (p < 0.05). The VTRS also increased amylase activity in duodenum and ileum tissues, along with GLUT2 and SGLT1 expressions. In serum, Interleukin-10 (IL-10) concentration and total antioxidant capacity (T-AOC) were increased while malondialdehyde (MDA) was decreased. An increase in T-AOC and GSH-Px activity was also observed, along with increased IL-6, immunoglobulin A (IgA), and catalase in duodenum tissue (p < 0.05). Prevotella was increased in the duodenum and caecum, with Prevotellacae UCG-001 and Christensenellacae R-7 group representing the VTRS group in the duodenum (p < 0.05). KEGG pathway prediction also indicated the enrichment of energy metabolism-related pathways. Significant microbes had shown a significant correlation with immune parameters. It can be concluded that vegetable waste silage has the ability to improve antioxidant status, enhance energy metabolism, and balance intestinal microbiota in Hu sheep. Full article

Biochar-based additives can enhance the ability to produce methane during anaerobic digestion (AD), and biogas residues (BRs) are solid waste that can cause environmental pollution. Therefore, in this work, BRs were used as raw material to prepare biochar, and Fe³⁺ was used to modify biochar for use in the AD process, generating pig manure water (PMW). The results showed that biogas residue biochar (BRB) showed good pore size and had a “honeycomb structure” on its surface. The commercially available iron–carbon composite material (Fe-C) showed the greatest cumulative methane production (CMP), the greatest removal rates of chemical oxygen demand (COD), and the greatest degradation rate of volatile fatty acids (VFAs), with the order of Fe-C > Fe³⁺-modified biogas residue biochar (FBRB) > BRB > control group. Fe³⁺ and Fe⁰ showed similar effects, where both could enhance the methanogenesis performance of anaerobic digestion by promoting direct interspecific electron transfer, and Fe⁰ was slightly more effective than Fe³⁺. Bacteroidotas and Firmicutes were the predominant phyla, and Clostridium_sensu_stricto_1 was the predominant genus. The addition of biochar and Fe³⁺ promoted the transformation of microorganisms from the conventional metabolic mode into an efficient metabolic mode. Extracellular electron transfer played a crucial role in this. Full article