Decomposition Of Substrates Research Articles

Characterization of the Agronomic Properties of Different Vermicompost from the Co-composting of Oil Palm Empty Fruit Bunches and Green Waste

The accumulation of palm oil industries waste is one of the causes of environmental pollution that is becoming an increasingly concern in Côte d'Ivoire. However, this waste, combined with other simple plant substrates, can be used in the vermicomposting process. That is the context in which this study is conducted, with the aim of determining the agronomic properties of different vermicompost made of oil palm empty fruit bunches combined with green waste (Chromolaena odorata leaves and grass clippings). For this purpose, plastic boxes of 1.5 L in volume were first filled with 800 g of soil. Then, 300 g of the different pre-composted substrates and 4 earthworms were added. In total, 4 treatments of 25 repetitions each were carried out. For all the treatments, treatments T3 (oil palm empty fruit bunches + Grass cutting + earthworms) and T4 (oil palm empty fruit bunches + Chromolaena odorata + Grass cutting + earthworms) presented the best values of the substrate decomposition capacity and physicochemical properties. The same is true for the mineral materials obtained. For these two treatments mentioned, the C/N ratio was around 15 and significantly higher than those of treatments T1 (oil palm empty fruit bunches + earthworms) and T2 (oil palm empty fruit bunches + Chromolaena odorata + earthworms), which were around 12. The pH values being variable at the beginning of vermicomposting were close to neutral at the end, thus indicating the maturity of the different vermicompost produced. Vermicompost resulting from co-composting of empty fruit bunches of oil palms and green waste appears to improve nutrient availability, structure and microbial activity of the vermicompost to promote good development of cultivated plants.

Direct Conversion of Minimally Pretreated Corncob by Enzyme-Intensified Microbial Consortia

The presence of diverse carbohydrate-active enzymes (CAZymes) is crucial for the direct bioconversion of lignocellulose. In this study, various anaerobic microbial consortia were employed for the degradation of 10 g/L of minimally pretreated corncob. The involvement of lactic acid bacteria (LAB) and a CAZyme-rich bacterium (Bacteroides cellulosilyticus or Paenibacillus lautus) significantly enhanced the lactic acid production by Ruminiclostridium cellulolyticum from 0.74 to 2.67 g/L (p < 0.01), with a polysaccharide conversion of 67.6%. The supplement of a commercial cellulase cocktail, CTec 2, into the microbial consortia continuously promoted the lactic acid production to up to 3.35 g/L, with a polysaccharide conversion of 80.6%. Enzymatic assays, scanning electron microscopy, and Fourier transform infrared spectroscopy revealed the substantial functions of these CAZyme-rich consortia in partially increasing enzyme activities, altering the surface structure of biomass, and facilitating substrate decomposition. These results suggested that CAZyme-intensified consortia could significantly improve the levels of bioconversion of lignocellulose. Our work might shed new light on the construction of intensified microbial consortia for direct conversion of lignocellulose.

Interspecies Interactions in Dual Cultures of Selected Fungi Species and Their Influence on the Decomposition of Scots Pine and Norway Spruce Wood Substrates

Interspecies Interactions in Dual Cultures of Selected Fungi Species and Their Influence on the Decomposition of Scots Pine and Norway Spruce Wood Substrates

Colonization & Decomposition Pattern of Water Borne Conidial Fungi in Freshwater Stream of Central Himalaya

In the freshwater streams the leaf litter substrate is colonized by early fungal colonizer and helps in decomposition of leaf litter and makes the substrate more suitable for the recruitment of late successional species. The study was carried out at Central Himalayan stream (Vinayak) to examine the colonization and decomposition pattern of Water Borne Conidial Fungi as all the streams are naturally subjected to great spatial and temporal variability, which is likely to affect the distribution and activity of organism in aquatic ecosystem. In this study nylon-mesh bags technique was used for the period of twelve months, using Angiospermic and Gymnospermic leaves as leaf litter substrate. Decomposition (weight loss) of different substrates in different months of submergence was analyzed statistically and was found that species number significantly affect the weight loss of tested leaf litter. KEY WORDS: Water Borne Conidial Fungi, Fresh Water Streams, Colonization, Decomposition.

Bakteryjna redukcja siarczanów jako odpowiednia metoda usuwania siarczanów z kwaśnych wód kopalnianych

The aim of this work was to investigate of the sulfates removal from acid mine drainage (AMD) by biological method using sulfate-reducing bacteria (SRB). A sample of AMD out-flowing from the Pech shaft of the abandoned and flooded Smolník deposit in Slovak Republic was studied. The untreated AMD (with contents metals) and treated AMD i.e. after of the metals removing by the synthetic sorbent Slovakite were used. The base of the biological sulfates elimination was the sulfates bacterial reduction under influence of SRB genera Desulfovibrio. These bacteria realize the sulfates reduction to hydrogen sulfide at the simultaneously oxidation of energetic substrate. Standard selective nutrient medium DSM-63 and modified selective nutrient medium DSM-63 (without sulfates contents) with standard amount of sodium lactate (as energetic substrate) were used in the experiments with untreated AMD. Standard selective nutrient medium DSM-63 and modified selective nutrient medium DSM-63 with standard, double and triple amount of sodium lactate were used in the experiments with treated AMD. In the case of untreated AMD has been reached low removing of sulfates - 20% efficiency (standard medium) and 26% (modified medium). The formation of heterogeneous precipitates containing metals pointed to the need for treatment of AMD by the initial removal of metals by sorption on Slovakite sorbent and subsequent removal of sulfates by bacterial reduction. The results of experiments with AMD treated in this way showed 49%, 70% and 88% efficiency of sulfate removal when using sodium lactate in standard, double and triple amounts. The results of this work suggest that ratio of substrate quantity and sulfate concentration is one of the key parameter of sulfate reducing condition. However, the price of the energy substrate is also an important factor. Therefore, subsequent experiments will be focused on the use of the more affordable substrates (e.g. whey) or mixed bacterial culture of SRB, which will also be able to use the products of decomposition of basic energetic substrates.

The effect of laser post-treatment on the microstructure and properties of Al coating on the PEEK substrate

To improve the bonding strength and electrical conductivity(σ) of cold-sprayed Al coatings on polyetheretherketone(PEEK) substrates, laser post-treatment was employed as an effective strengthening method without decomposition of the polymer substrates. Optical and electron microscopy observations were used to examine the microstructures and tensile fracture surfaces of the Al coatings fabricated with various laser powers. X-ray diffraction and electron backscatter diffraction were employed to investigate the phase composition and grain information of each coating. Hardness, pull-out adhesion, and electrical conductivity tests were performed to investigate the effect of laser power on the mechanical and physical properties of cold-sprayed Al coatings. The results revealed that despite the formation of several hundred micrometer-sized pores on the PEEK side, the porosity of the laser post-treated Al coatings significantly decreased, and the particle–particle interfaces were greatly healed with increasing laser power. The heat input induced large-scale recrystallization and significantly reduced the dislocation density in the samples. The XRD pattern revealed that no oxidation phase appeared following the laser treatment under the protection of Ar. The electrical conductivity and bonding strength of the Al coatings increased by up to 40 % and 167.4 %, respectively, after the laser post-treatment.

Effect of substrate moisture content during cultivation of Hericium erinaceus and subsequent vermicomposting of spent mushroom substrate in a continuous feeding system

Cultivation of Hericium erinaceus depends on various factors, one of which is water content in the substrate. This parameter influences not only the growth rate of the mushroom but also enzymatic activity, which is important for substrate decomposition and for the later usage of spent mushroom substrate (SMS). This study compared parameters, such as mycelial growth, pH and enzymatic activity in substrates with different initial water content. During cultivation, the water content and pH decreased in all variants, but the activity of hydrolytic enzymes increased with time and was higher in variants with higher water content (70% and 75%); however, the activity of ligninolytic enzymes decreased during cultivation. The production of 1 kg of mushrooms generates about 5 kg of SMS. Vermicomposting is a natural method for processing SMS, as it involves a combination of earthworms, microorganisms and enzymatic activity; thus, we compared the differences between variants with and without earthworms using continuous feeding vermicomposters. The C:N ratio in the variant with earthworms radically decreased from 153.7:1 to 16.5:1. The ratio of bacteria to fungi in both variants was highest in the oldest compost layer in the vermicomposters. The variant without earthworms exhibited the highest enzymatic activity of β-D-glucosidase and Mn-peroxidase, but the highest activity of cellobiohydrolase and laccase occurred in the variant with earthworms. The vermicomposting process is ideal for this type of biowaste, as it produces a fertilizer rich in beneficial microorganisms and enzymatic activity.

Crystallization Assisted Dynamic Kinetic Resolution for the Synthesis of (R)-β-Methylphenethylamine.

This study explores a combination of the concept of enantioselective enzymatic synthesis of β-chiral amines through transamination with in situ product crystallization (ISPC) to overcome product inhibition. Using 2-phenylpropanal as a readily available and easily racemizing substrate of choice, (R)-β-methylphenethylamine ((R)-2-phenylpropan-1-amine) concentrations of up to 250 mM and enantiomeric excesses of up to 99 % are achieved when using a commercially available transaminase from Ruegeria pomeroyi in a fed-batch based dynamic kinetic resolution reaction on preparative scale. The source of substrate decomposition during the reaction is also investigated and the resulting unwanted byproduct formation is successfully reduced to insignificant levels.

Highly Conjugated Nanozyme with Non Coordination Saturation for Cascaded Enhanced POD Reaction Driving Antibacterial Therapy

AbstractThe misuse of antibiotics leads to emergence of drug‐resistant bacteria. Developing artificial nanozymes with high stability and excellent catalytic performance is desirable to substitute for antibiotics, but still remains huge challenge. Herein, the study reports a new strategy for cascaded enhanced peroxidase (POD) reaction driving antibacterial therapy via constructing 2D conjugated metal‐organic frameworks (MOFs) with non coordination saturation as nanozyme. It is demonstrated that the non coordination saturation Cu atom promotes the adsorption of H2O2, followed by the Cu‐HHTP MOFs with high conjugated structure can enhance the photogenerated electron transfer for ·OH generation in POD reaction. The sequential enhancement of substrate adsorption and decomposition endows the as‐made Cu‐HHTP MOFs with outstanding antibacterial property of >99.9999% elimination with a concentration only 1/133 that of traditional nanozyme. In addition, the study also certifies its excellent in vivo antimicrobial activity and biocompatibility, indicating the therapeutic potential for infections by drug‐resistant bacteria.

Effects of turning aeration and the initial carbon/nitrogen ratio on the biodegradation of polylactic acid under controlled conditions

Plastic pollution is primarily caused by the accumulation of petroleum-derived plastics, as they tend to degrade slowly. Sustainable alternatives to these materials are bio-based and biodegradable plastics, such as polylactic acid (PLA). In this study, we assessed how turning aeration and the initial carbon/nitrogen (C/N) ratio impact PLA biodegradation. The study was carried out under controlled composting conditions, over 180 days, with the aim of decreasing the biodegradation time of the PLA. Apple pomace, rice husk, grape pomace compost, and PLA were used as substrates in the composting process. The experiments were conducted using three types of turning aeration: without turning, one turn per week, and two turns per week. Three initial C/N ratios were used: 20, 30, and 40. A stepwise temperature ramp was designed and implemented to simulate industrial composting conditions, which influence microbial activity and thus the rate of decomposition of substrates, including PLA. The data showed behavior; hence, a nonlinear regression model based on the logistic growth equation was used to predict the PLA biodegradation at the end of the composting process. The results showed that two turns per week with an initial C/N ratio of 30 or 40 led to a 90 % biodegradation of the PLA in 130 days. This degradation was verified by Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM).

Mycorrhizal fungi modify decomposition: a meta-analysis.

It has been proposed that ectomycorrhizal fungi can reduce decomposition while arbuscular mycorrhizal fungi may enhance it. These phenomena are known as the 'Gadgil effect' and 'priming effect', respectively. However, it is unclear which one predominates globally. We evaluated whether mycorrhizal fungi decrease or increase decomposition, and identified conditions that mediate this effect. We obtained decomposition data from 43 studies (97 trials) conducted in field or laboratory settings that controlled the access of mycorrhizal fungi to substrates colonized by saprotrophs. Across studies, mycorrhizal fungi promoted decomposition of different substrates by 6.7% overall by favoring the priming effect over the Gadgil effect. However, we observed significant variation among studies. The substrate C : N ratio and absolute latitude influenced the effect of mycorrhizal fungi on decomposition and contributed to the variation. Specifically, mycorrhizal fungi increased decomposition at low substrate C : N and absolute latitude, but there was no discernable effect at high values. Unexpectedly, the effect of mycorrhizal fungi was not influenced by the mycorrhizal type. Our findings challenge previous assumptions about the universality of the Gadgil effect but highlight the potential of mycorrhizal fungi to negatively influence soil carbon storage by promoting the priming effect.

High-temperature annealing effects on epitaxial TiN films on 4H-SiC

To gain deeper insights into the impact of very high-temperature annealing on TiN film quality and thermal diffusion phenomena, the deposited TiN films underwent annealing in an induction heating furnace across a temperature range from 1150 °C to 1700 °C. Our findings indicate that TiN films remain stable, and the full-width at half-maximum (FWHM) of TiN (111) noticeably reduced by about 30 % when annealed at 1250 °C. However, as the annealing temperature rises to 1400 °C, the film composition gradually enriches with carbon as TiCxN1-x with x up to 0.5. After annealing at 1700 °C, the film is further enriched with x larger than 0.5. For a long time annealing at 1700 °C, the decomposition of SiC substrate with void formation is verified from observations by cross-sectional transmission electron microscopy.

Effects of micro-nano bubble water addition on maturation degree and microbial community during aerobic composting

In order to explore the effects of micro-nano bubble water (MNBW) on compost maturation and the microbial community in cow manure and straw during aerobic composting, we conducted composting tests using tap water with 12 mg/L (O12), 15 mg/L (O15), 18 mg/L (O18), and 21 mg/L (O21) dissolved oxygen in MNBW, as well as tap water with 9 mg/L dissolved oxygen as a control (CK). The results showed that O21 increased the maximum compost temperature to 64 °C, which was higher than the other treatments. All treatments met the harmless standards for compost. The seed germination index (GI) was largest under O21 and 15.1% higher than that under CK, and the non-toxic compost degree was higher. Redundancy analysis showed that the temperature, C/N, pH, and GI were important factors that affected the microbial community composition. The temperature, C/N, and pH were significantly positively correlated with Firmicutes and Actinobacteria (p < 0.05). Firmicutes was the dominant phylum in the mesophilic stage (2–6 days) and it accounted for a large proportion under O21, where the strong thermophilic metabolism increased the production of heat and prolonged the high temperature period. The bacterial genus Ammoniibacillus in Firmicutes accounted for a large proportion under O21 and it accelerated the decomposition of substrates. Therefore, the addition of MNBW changed the microbial community to affect the maturation of the compost, and the quality of the compost was higher under O21.

Legacy effects of long‐term autumn leaf litter removal slow decomposition rates and reduce soil carbon in suburban yards

Societal Impact StatementAs cities grow, it is essential to understand how landscape management decisions in urban spaces alter ecosystem function. This study demonstrates that the ubiquitous practice of long‐term leaf litter removal in suburbs, even in relatively small patches of a yard, reduces the soil's ability to cycle nutrients in plant litter and results in lower amounts of carbon stored in the soil. Even two years of retaining leaves where they previously were removed is insufficient to restore decomposition rates or carbon pools. This research is an important step in creating best practices for litter management to maintain essential ecosystem functions, like carbon sequestration, water holding capacity, and soil fertility.Summary Seasonal senesced leaf litter removal eliminates considerable organic material from suburban soils annually. We test if this disturbance alters decomposition and carbon cycles and depletes soils of organic matter over time, creating persistent legacy effects. We used a factorial experimental design to implement 1–2 years of current leaf litter manipulations (remove or retain fallen leaves) within historically raked and unraked areas in suburban Maryland yards. We then compared total organic soil carbon and decomposition using a standardized substrate decomposition methodology (Tea Bag Index) across treatment plots. Long‐term litter removal in suburban yards reduced decomposition rates by 17% and total soil organic carbon concentration by up to 24% compared to areas where leaf litter was retained in situ. In contrast, short‐term management changes (1–2 years) did not significantly impact decomposition rates or total organic soil carbon concentrations. Our findings suggest that long‐term suburban litter raking creates legacy effects that alter decomposition and carbon storage process trajectories that are not easily reversed. This is important in understanding urban ecosystem function and sustainable management.

Immobilised Ruthenium Complexes for the Electrooxidation of 5-Hydroxymethylfurfural.

Abundantly available biomass-based platform chemicals, including 5-hydroxymethylfurfural (HMF), are essential stepping stones in steering the chemical industry away from fossil fuels. The efficient catalytic oxidation of HMF to its diacid derivative, 2,5-furandicarboxylic acid (FDCA), is a promising research area with potential applications in the polymer industry. Currently, the most encouraging approaches are based on solid-state catalysts and are often conducted in basic aqueous media, conditions where HMF oxidation competes with its decomposition. Efficient molecular catalysts are practically unknown for this reaction. In this study, we report on the synthesis and electrocatalysis of surface-bound molecular ruthenium complexes for the transformation of HMF to FDCA under acidic conditions. Catalyst immobilisation on mesoporous indium tin oxide electrodes is achieved through the incorporation of phosphonic acid anchoring groups. Screening experiments with HMF and further reaction intermediates revealed the catalytic route and bottlenecks in the catalytic synthesis of FDCA. Utilising these immobilised electrocatalysts, FDCA yields of up to 85 % and faradaic efficiencies of 91 % were achieved, without any indication of substrate decomposition. Surface analysis by X-ray photoelectron spectroscopy (XPS) post-electrocatalysis unveiled the desorption of the catalyst from the electrode surface as a limiting factor in terms of catalytic performance.

Soil Properties and Forest Decline in the North-Western Part of Romania

The paper presents the study of the soil quality and health expressed by the chemical and biological properties in a research field placed at Varciorog, Bihor County, Romania. The soil samples were collected from 3 soil variants in March 2023. In each soil variant, some soil chemical parameters and the abundance of bacteria were determined. The frequency and intensity of colonization, along with arbuscules and vesicles, were scored to determine the mycorrhizal potential of each soil. The community-level physiological profile was used to determine the functional microbiome and its ability to decompose a specific set of substrates. In the control variant (CTRL), which is a functional forest cultivated with beech in a proportion of 90%, the soil properties were compared with those determined from Site 1 (a declined mixed forest) and from Site 2 (chestnut forest in a stage of complete drying). The data were statistically processed with a one-way ANOVA test, followed by the Duncan post-hoc test, which revealed significant variation in the potential of microbial functional communities across the analyzed sites. Also, the soil parameters that significantly varied in the 3 soil variants were bacterial number, pH, humus, exchangeable aluminum, coarse sand, dust, and fine sand. The Pearson correlation was computed to study the links between bacterial numbers and chemical parameters. The results showed strong correlations between most of the studied soil properties. The Ecoplates approach to soil functional microbiome highlighted various differences between the microbial communities of the three tested sites. Mycorrhizal colonization shows different potentials for symbiosis formation. The peak of mycorrhizal colonization was in declined forest, with 43.36% colonization frequency and 24.56% intensity. Arbuscules reached 11.36% in declined forest, while in control and decayed sites, the indicator was under 4%. Vesicles are more associated with control and decayed forests, with values of presence over 1.30%. As an indicator of microbial general activity, the sum of recorded activities was higher in declined and decayed forests. At these sites, the activity of the functional microbiome was amplified. The decline process activates a higher diversity of functional groups and is associated with a larger area of substrate decomposition capacity, which indicates a more extensive range of microbial functions related to breaking down organic matter.

Molecular and morphological diversity, qualitative chemical profile and antioxidant activity of filamentous fungi of the digestive tract of Phylloicus sp. (Trichoptera: Calamoceratidae).

This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.

Fungi are more important than bacteria for soil carbon loss through priming effects and carbon protection through aggregation

Plant inputs from root exudates and litter can improve soil aggregation and enhance soil organic carbon (SOC) content, but they can also increase SOC decomposition referred to as the priming effect. While bacteria and fungi are considered as key microbes for organic matter decomposition, their role in decomposing plant inputs and SOC, and their contribution to forming aggregates and SOC protection is still not fully understood. We conducted a 16-day incubation study to investigate the role of bacteria and fungi on decomposition and protection of C derived from glucose (labile C as a surrogate for root exudates) and wheat root biomass added to soil. Bronopol and captan were used to suppress bacterial and fungal activity, respectively, in the soil. Because glucose and wheat root biomass were enriched in 13C, we were able to estimate their decomposition and priming effect, microbial C use efficiency (CUE), and recovery in different aggregate size classes. As expected, the decomposition of both substrates was reduced significantly when biocides were added, and the decomposition rate of glucose was significantly higher than of wheat root biomass. Fungi were more important than bacteria in causing a priming effect, as indicated by the reduced SOC decomposition in the presence of substrates when captan was added. The mean weight diameter of aggregates at the end of the incubation was significantly reduced when captan was added, either alone or in combination with bronopol, independent of substrate type, suggesting that fungi also played an important role in soil aggregation. However, recovery of C derived from wheat root biomass in macroaggregates was highest when both biocides were added, suggesting that decomposition by both bacteria and fungi may have outweighed the protection of wheat C in new macroaggregates. While we observed variation in the microbial CUE among substrate and biocide treatments, we found no relationship with soil aggregation. We conclude that both bacteria and fungi were important for decomposition of added substrates to the soil, but that fungi can play a larger role in both soil C loss through priming effects and C protection through aggregation.

Pilot-scale biogas and in-situ struvite production from pig slurry: A novel integrated approach

Excess ammonia produced during the decomposition of nitrogen-rich substrates inhibits the anaerobic digestion (AD) process while it increases the concentration of ammonium nitrogen (NH4+) in the digestate. Digestate is commonly applied to farmland, causing nitrogen loss via runoff and volatilization. Therefore, developing an integrated strategy to promote the overall efficiency of AD systems susceptible to ammonia toxicity events, is worthy of consideration. Herein, a step-feeding approach to combat ammonia toxicity in AD process in which, intermittent rather than continuous substrate feeding was tested. A pilot-scale, mesophilic (37 ± 1 °C), fed-batch AD reactor (working volume ∼ 6.67 m3), was operated as the biomethanation step in a novel biorefinery concept, to recover bioenergy and nutrients (struvite) from pig slurry. The results showed that methane production yield achieved was 89.7 % of the theoretical at high ammonia levels (4.44 g NH4+-N L−1), indicating an efficient AD process under strong ammonia stress. The production rate of precipitate was 4.0 kg t−1 feedstock, while X-Ray Diffraction analysis revealed that purity of struvite crystal was 98 % w/w. Orthorhombic crystals and homogeneous distribution of significant elements (O, P, N, and Mg) in the precipitate were observed through scanning electron microscopy coupled with energy dispersive X-ray analysis. Recoveries of nitrogen and phosphorus were 48.5 % and 68.5 % from the digestate, respectively. Furthermore, the chemical and sanitary (i.e., Escherichia coli, Enterobacteriaceae and Salmonella) indicators of the precipitate were in line with the EU Fertilizer Regulation. Overall, the obtained results indicate that it is possible to establish an integrated efficient nutrient and energy recovery process for the simultaneous production of high-yield biogas and high-purity struvite fertilizer from pig slurry, which could yield a gross profit of 5.79 € t−1 feedstock.

Characterization of the physicochemical Properties, bacterial community and non-volatile profiles of fermented Yu jiangsuan by Weissella cibaria and Lactobacillus plantarum

Yu jiangsuan (YJS) is a unique traditional fermented condiment in China. Physicochemical, bacterial communities, and non-volatile properties were examined in inoculation Autochthonous Weissella cibaria and Lactobacillus plantarum. The results indicated that inoculation samples did well in shortening fermentation time; amino acid nitrogen (AN) and TCA-soluble peptide contents of fermented YJS were 10.8% and 17.4% higher than those of naturally fermented YJS, respectively. However, its total volatile base nitrogen (TVB-N), thiobarbituric acid (TBARS), and nitrite were only 74.3%, 87.2% and 83.6% of those of naturally fermented YJS. In addition, the dominant bacterial genera were Lactobacillus, Weissella and Pectobacterium, whose contributions were 41.2%, 20.3% and 5.5%, respectively. Moreover, 26 significantly differential metabolites were identified, and involved in 10 metabolic pathways. The decomposition of substrates and the formation of differential metabolites in YJS were primarily centered on the TCA cycle and the metabolism of carbohydrates. Therefore, this study is conducive to discovering the bacterial community structure and metabolite composition of probiotic inoculated YJS fermentation, as well as the potential value of core functional bacteria genera in controlling YJS production in industry.