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The efficient utilization of all of the key lignocellulosic biomass residues is important for the development of an integrated biorefineries uassing this as its feedstock. In this study, a process involving a simultaneous pre-treatement process with anaerobic digestion (AD) were implemented for processing oil palm empty fruit bunches (OPEFB) in order to produced both vanillin and methane. Before and after treatment with the dry rot fungus (Serpula lacrymans) the biomass was analyzed for total reducing sugar (TRS), total soluble phenols (TSP), pH, and weighed. Change in the physical characteristic and morphology of untreated and OPEFB following fungal culture was observed using scanning electron microscopy (SEM). The biomethane potential (BMP) of pretreated OPEFB significantly increased (62.07%) compared to untreated sample and in addition. The amount of vanillin extracted reached 3.48ug mL−1. This study therefore confirms that multiple products can effectively be isolated using a fungal preatreatment of lignocellulosic OPEFB followed by anerobic fermentation of biomass residual thus maximizing the potential returns and reducing environmentally impacts compared to other pretreatments. [ABSTRACT FROM AUTHOR]

Purpose: Combining thermal treatment and composting with bulking agents is a safe and effective method to dispose of penicillin mycelial dreg (PMD), but the effects of adding thermally treated PMD (HT-PMD) on lignocellulose degradation, fungal diversity, and fertilizer efficiency are still unclear. Methods: The mixture of maize straw and cattle manure was composted alone (CK) or with HT-PMD at low (T1) and high levels (T2). Samples during the 52 days of composting were taken for the analysis of physicochemical parameters, fungal diversity, and fertilizer efficiency using a pot experiment. Results: Adding HT-PMD significantly decreased the K, Ca, hemicellulose, cellulose, and lignin contents and C/N ratio (P < 0.05), but increased the PO43−, SO42−, and Zn contents. The cellulose content of CK kept decreasing throughout the 52 days of composting, but that of T1 and T2 increased before 19 and 26 days, respectively. The rapid degradation of hemicellulose and cellulose in CK and T1 was between 19 and 26 days, but that of T2 began after 26 days. Mycothermus, Remersonia, Coprinopsis, and Aspergillus dominated the samples of CK on day 19, and Sodiomyces and Microascus were the main genera of T1. In the pot experiment, composts of T1 resulted in the highest stem diameter, plant height, leaf number, and dry weight of maize, which increased by 65.9%, 77.8%, 46.2%, and 351.9%, respectively. Conclusion: Adding HT-PMD balanced the composition of nutrient elements and improved the fertilizer efficiency, but decreased the degradation rate of cellulose and hemicellulose. [ABSTRACT FROM AUTHOR]

Purpose: A large proportion of the European Union's tomato crop is discarded during harvesting and there is a valorisation potential to recover proteins from this waste. Methods: Cherry tomatoes were segregated into three separate components: juice, pomace (peels and skins), and seeds. The peels and skins, and seeds were separately hydrolyzed with carbohydrases to determine whether protein recovery could be increased. In addition, a strategy to fractionate the seeds was developed using sequential washing of milled tomato seeds, followed by low-speed centrifugation to remove the denser seed hulls and to collect the protein rich kernels remaining in suspension. Results: The protein content of the seeds was highest with 27.4% while the peels and skins contained 7.6%. Carbohydrase mediated hydrolysis resulted in a minor increase in protein recovery of 10% from seeds using Filta 02L (cellulase, xylanase and β-glucanase), and the quantity of protein recovered from peels and skins increased by 210% using Tail 157 (pectinase, hemicellulase). The strategy to separate the seeds into two fractions, revealed that a higher proportion of the fibre (65%) was associated with the hull fraction compared with the original seeds (47%). A significant proportion of the fibre in this fraction was composed of lignin although the protein contents between both fractions was similar ranging from 27.4 to 29.9%. Conclusions: These results reveal that carbohydrases were quite effective in protein extraction from peels and skins, but not from seeds. An alternative strategy was developed to remove the seed hulls from the milled seeds and to collect a fraction containing protein and dietary fibre where oil could be removed at this stage. [ABSTRACT FROM AUTHOR]

Composting is a promising process for green waste (GW) management. However, reducing the processing time and increasing end-product quality are aspects to be improved. A strategy to optimize GW composting is using bacterial strains and microbial consortia that stimulate lignocellulose degradation. This work systematically analyses the research trends on the use of those bacterial inoculants and microbial consortia. The information was analyzed according to three topics: (i) microbial role in the process; (ii) process optimization; and (iii) end-product quality. Research needs identified by our research include: (i) selection of bacterial consortia and optimization of inoculum concentration; (ii) correlation between enzymatic activity of indigenous and exogenous bacteria and nitrogen availability during the process; and (iii) stimulation of lignocellulose degradation and formation of humic substances considering end-product quality. This research contributes to planning future research endeavors related to the use of microbial inoculants to optimize GW composting. [ABSTRACT FROM AUTHOR]

Nanocellulose (NC) has a wide variety of emerging applications, including enzyme immobilization, drug delivery, and imaging diagnosis. On the other hand, derivatives of hydrazinonicotinic acid (HYNIC) have been used as coordination-agents for their binding to 99mTc in the development of potential radiopharmaceuticals. To this end, we studied and developed NC-HYNIC-99mTc for diagnostic imaging using NC obtained from rice husk using Trichoderma reseii and Phanaerochaete chrysosporium in a semi-solid fermentation system to generate a potential nanoradiopharmaceutical agent. In this work, we performed the separation of nanosilica, microcellulose, and nanocellulose using the TAPPI T203 os-74 technique. The synthesis of conjugate NC-HYNIC was performed following a one-pot procedure. The NC and the conjugate NC-HYNIC were characterized by Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and atomic force microscopy (AFM). We obtained NC with a structure of laminar-like nanofibers. The yield of NC was 55% and the conjugate NC-HYNIC was obtained with a yield of 36%. The TGA and FTIR analyses showed that the NC functionalized with HYNIC had similar characteristics to those of NC. In addition, the AFM analysis of the functionalized NC showed an average height of 8 ± 3 nm, while the NC showed an average height of 10 ± 4 nm. The subsequent binding to 99mTc was assayed, and the purity of the radiolabeled product and the efficiency of the process was studied by ITLC chromatography. The radiolabeling process was very efficient with a radiochemical purity of 98 ± 1.2%, which opens the possibility of a new potential-imaging agent. [ABSTRACT FROM AUTHOR]

The agri-food sector creates a significant waste stream, mainly due to inefficiencies arising from damage and loss of product throughout the supply chain. Therefore, a thorough utilization of food waste via a bio-refinery approach could play a crucial role in sustainable and zero-waste global development. This article focuses on the current status of valorization routes of selected agri-food processing waste and byproducts within an integrated biorefinery concept. First, the state-of-art extraction technologies for food-waste valorization are described, focusing on apple, tomato, grape, and defatted olive oil pomace as representative substrates. Second, the article investigates a cascade of treatments suitable for the extraction of various useful chemicals. Viable options of integrated biorefineries applied to food waste streams are presented. Selected agri-food processing side streams were divided into two different categories that, in turn, can be valorized through two different integrated combinations. Highly wet residues can be firstly treated by subcritical water to release fermentable saccharides and then valorized by hydrothermal carbonization. Conversely, oily residues can be initially treated using supercritical fluids to extract oils and subsequently converted through anaerobic digestion. [ABSTRACT FROM AUTHOR]

A significant example of circular economy application concept is the recycling of wastes through co-composting to obtain techno-soils and composts. The objective of this paper was to demonstrate that the co-composting of Posidonia oceanica residues with decontaminated sediments is an effective method to manage two kinds of waste and transform them in a suitable material for the preparation of growth substrates. To demonstrate the effectiveness of the co-composting process, a protocol, involving physical–chemical, biochemical, and toxicological parameters, has been followed. Moreover, to evaluate the quality of the different Posidonia-based composts, the characteristics have been compared with threshold values proposed in the Italian regulation for plant growth substrates and to specific parameters from the scientific literature. All the obtained composts responded to the main characteristics for composting and growing media preparation provided in national and international regulations, in terms of pH (6.7–7.6), electrical conductivity (0.13–0.30 dS/m), and total organic carbon content (6.62–27.9 C%). Moreover, results about humic carbon (16.6–21.9 C%), germination index (139–158%), enzymatic activities (B-glucosidase: 3538–5367 mmol MUB/kg ds H), bulk density (0.30–0.83 g/cm3), and cation exchange capacity (43.3–126 meq/100 g ds) proved the quality of the P. oceanica and sediment based composts. These results are an endorsement of Posidonia with sediment-based composts use as a constituent of techno-soils and, as a component for the preparation of nursery growth substrate. It is possible to claim that the co-composting process is an alternative management strategy for decontaminated sediments and P. oceanica residues to be recommended. Adequate policies are needed in order to recycle Posidonia oceanica residues and decontaminated sediments, namely two kinds of waste, into a secondary raw material, namely techno-soil, thus implementing the concept of the circular economy. [ABSTRACT FROM AUTHOR]

The opportunity of tomato peel waste exploitation for simultaneous recoveries of high value compounds, such as pectin, polyphenols and fatty acids (FAs) is presented in this work. Prior to polyphenols and FAs extraction, the pectin removed from tomato cuticle was evaluated as possible tin corrosion inhibitor using electrochemical impedance spectroscopy. Subsequently, de-pectinized tomato peels are evaluated as appropriate bio-substrate for polyphenols and FAs recovery, using chromatographic analyses. Corrosion tests (24 h) showed that pectin (4 g/L) isolated from tomato peel act as more efficient tin corrosion inhibitor (η = 65.8%) than commercial apple pectin (η = 52.3%), which points out that it could be used as natural corrosion inhibitor. The polyphenols data showed that de-pectinized samples contained higher amounts of total phenols (2485.68–4064.46 mg/100 g, in 96% ethanol) and chlorogenic acid derivative (86.13–454.34 109 mg/100 g, in 70% ethanol) than samples with pectin incorporated in tomato cuticle. In addition, de-pectinized samples contained more polyunsaturated FAs (~ 45%) than samples with pectin (~ 26). Furthermore, both types of peels contained linoleic, palmitic and oleic acids as three dominants, and thus represented valuable source of nutritive oils. Their presence was also confirmed by FTIR and NMR spectroscopy. Therefore, obtained findings revealed that already exploited tomato peel for pectin production could be effectively re-used for polyphenols and FAs recoveries, providing valuable benefits, either for producers and consumers, such as decreasing the waste disposal costs and take opportunity that isolated compounds could be reintroduced into food. [ABSTRACT FROM AUTHOR]

Purpose: Tobacco stalk contained large amount of lignin, which is resistant to microbial degradation and limit the composting efficiency during composting. The purpose of this study is to enhance the lignin degradation efficiency, and consequently improve the composting efficiency and product quality. Methods: Lignin degrading microorganisms (LDMs) were screened and inoculated to tobacco stalk compost, lignin degradation enzyme activities and lignin degradation rate were measured to evaluate the lignin degradation efficiency, other physico-chemical characters were determined as well to evaluate the composting efficiency and product quality. Results: Two white-rot fungi Trametes hirsuta S13 and Pleurotus ostreatus S18 were screened as LDM according to their high lignin degradation efficiency. After inoculation, lignin peroxidase, manganese peroxidase and laccase were raised from (U g−1) 105.9, 372.9 and 460.68 to 374.7, 1095.6 and 1420.8, respectively. Consequently, lignin degradation rate increased nearly 2-fold (from 23.7 to 41.1%). In addition, organic matter degradation rate was increased from 26.5 to 31.2% with the addition of fungal inoculants. Degree of polymerization, humification index and germination index were also elevated, from 2.0, 17.8% and 108.3% to 3.5, 24.2% and 123.8%, respectively. Conclusions: In this study, T. hirsuta S13 and P. ostreatus S18 were used as LDM and inoculated to tobacco stalk composting. After inoculation, the lignin degradation rate was increased, with the composting efficiency and the quality of composting product was improved as well. [ABSTRACT FROM AUTHOR]

Anaerobically digested slurry is well known for its use as a bio-fertilizer because of its high macro-nutrient content (e.g. N, P, K), which is essential for plant growth. The suppressive effect of slurry land application on pathogenic fungal growth due to the presence of bioactive and antimicrobial substances generated during anaerobic digestion has recently been reported. However, knowledge about the identification, characterization, and subsequent antimicrobial activity evaluation of various bioactive compounds in the anaerobically digested slurry is still insufficient. Ultrasound-assisted extraction using three solvents, ethyl acetate (EA), dichloromethane (DM), and n-butanol (NB), was employed for extraction of bioactive compounds. After extraction and characterization, antifungal activity against Fusarium oxysporum was assessed. EA was found to be a more efficient extractant with less evaporating time (4 min), irrespective of temperature. DM was found to be efficient in the extraction of O-heterocycles, while N-heterocycles were enriched in EA extracts. Furthermore, the bioactive compounds, 1,2-benzenedicarboxylic acid, butyl 2-methylpropyl ester (54.9%), and 9-octadecenamide, (Z)-(2.51%) were detected in the EA extract, while tetrahydro-2-furanmethanamine (1.32%), cyclic octatomic sulfur (1.17%), squalene (4.06%), and cholestan-3-ol (9.06%) were detected in the DM extract. The EA extract achieved approximately 84% inhibition of F. oxysporum, while only 63% inhibition was observed with the DM extract. Collectively, these findings indicate that in addition to its role as a fertilizer, digested slurry may also contribute to the control of phytopathogens upon land application because of the presence of various bioactive compounds. However, further work is needed to explore the diversity of bioactive compounds in digested manures and evaluate their antimicrobial potential. [ABSTRACT FROM AUTHOR]

Composting is a process that converts organic materials including solid wastes into humus-like substances. Additives play an important role in regulating composting performances. This work investigated the influences of flue gas desulphurization gypsum (FGDG) on the properties and evolution of dissolved organic matter (DOM) during the co-composting of dairy manure, sugarcane leaf and pressmud (the sludge from sugar factory effluent) with the combination techniques of elemental analysis, particle size, zeta potential, UV–Vis spectroscopy and FT-IR technology. The results revealed that FGDG amendment reduced carbon loss and facilitated nitrogen emission in compost DOM, increased the aromaticity of DOM and compost maturity, enhanced the absorbance of –OH, –CHO, –COOH and C–O in polysaccharides. Additionally, the adding of FGDG was an inhibitive factor to the whole bacterial diversity during composting. These findings provided new insights into the evolution and properties of DOM and the microbial community during the composting process with FGDG amendment. [ABSTRACT FROM AUTHOR]

The purpose of this study is to assess the maturity and stability of the lagooning sludge (LS) with green waste (GW) during semi-industrial composting. Physico-chemical parameters, spectroscopy analysis and germination test were monitored. After 105 days, the decomposition rate of about 33.6; 39 and 36%, a stabilization of pH around neutrality; NH4+/NO3− ratio decreased to 0.922, 0.974 and 1.038; the C/N ratio decreased to 9.47, 9.24 and 10.10 respectively for mixture 1 (M1), mixture 2 (M2) and mixture 3 (M3). This reduction is explained by the bio-oxidation of organic matter. The intense microbial activity was characterized by the rise of temperature (between 40 and 50 °C) during the first weeks. Humification process was characterized by the increase of humification index (HI), which was approximately 62.1%; 73.6%; 61.5% respectively for M1, M2 and M3. The progress of humification process was determined by the decrease of aliphatic absorbance bands and the increase of aromatic absorbance bands. The increase in germination index (GI) (> 50%) for the four seeds: cress, alfalfa, turnip and radish, at the end of composting indicated that the composts are phytotoxic-free and are rich in stable organic compounds and nutrients. The results show that all three composts are mature, which opens the way for their application in agriculture without risk for the soil–plant system. [ABSTRACT FROM AUTHOR]

Organic matter degradation and bacterial communities associated to the thermophilic phase of composting were compared using two different types of anaerobic digestates, one from a sewage sludge digester (SD), and the other from an agricultural digester (AD). The composting process exhibited similar variations in temperature, pH, moisture content and bacterial profiles, despite the inherent feedstock differences along with distinctive initial bacterial composition. According to the data obtained from 16S rRNA gene amplicon sequencing, SD constituted more than 20 bacterial phyla with Proteobacteria (21%) and Chloroflexi (21%) being predominant, meanwhile AD was represented by only 7 phyla in which Firmicutes was the most abundant phylum (73%). Nevertheless, bacterial community profiles of the two composting systems became more similarly represented at the phylum level, both dominated by Proteobacteria (65% in AD and 61% in SD), whereas Chromatiaceae and Sphingomonadaceae were the most abundant families in AD and SD, respectively. Highly diverse but similar bacterial communities were detected during the composting of different anaerobic digestates at the thermophilic phase. [ABSTRACT FROM AUTHOR]

This investigation was carried out on the effects of compost-born thermophilic complex microbial consortium (TCMC) composed of Ureibacillus suwonensis (TB42), Geobacillus thermodenitrificans (TB62) and Bacillus licheniformis (TA65) on co-composting of dairy manure and sugarcane leaves. The study assessed the TCMC influence on physicochemical parameters and dissolved organic matter (DOM) properties. Compared to the control (CP), the inoculated pile (CPT) showed a longer thermophilic phase, a faster organic matter degradation, a better Kjeldahl nitrogen preservation as well as a greater aromaticity and stability of DOM. Consequently, the inoculation with TCMC agent was effective in reducing the loss of nitrogen and accelerating maturity of compost. [ABSTRACT FROM AUTHOR]

Green waste (GW) represents a large fraction of municipal solid waste (MSW) and has increased significantly with the rapid development of urban green areas in some countries. Composting is an appropriate method for the treatment and recovery of these wastes. However, the high content of lignocellulosic substances in GW is known to slow down the decomposition process. This research evaluated the effect of introducing processed food waste (PFW) and unprocessed food waste (UPFW) on composting of GW, it monitored the process itself and assessed the end-product quality. A field-scale experiment was developed using three treatments: Treatment A (100%GW), Treatment B (40%UPFW + 60%GW) and Treatment C (50%GW + 30%UPFW + 20%PFW). Treatment C reached thermophilic temperatures in a shorter time than the other treatments and maintained those temperatures for longer periods. In addition, treatment C reached ambient temperatures during curing in a shorter time compared to treatments A and B. An improved product quality was observed in treatment C compared to other treatments. For example, products from treatment C had lower ash content, higher concentrations of TOC and PTotal and lower EC values compared to treatments A and B. The final fertility index of the end-product from treatment C was 4.8-5.0, which indicates that the product can be suitable for agricultural use. [ABSTRACT FROM AUTHOR]

To study the biochemical and microbiological properties during co-composting of chicken feather and spent mushroom substrates, chicken feather by incubation of multiple microorganisms were co-composted for 28 days with Pleurotus geesteranus-degraded Eucalyptus sawdust (PE), P. geesteranus-degraded weed tree sawdust (PW) and Ganoderma lucidum-degraded weed tree sawdust (GW), respectively. Characteristics of physico-chemical, enzymatic and microbiological parameters during composting were investigated in terms of temperature, pH, moisture, activities of CMCase, and succession of bacteria and fungus. Results showed that the peak temperature in PEC was 59 °C on 5 days. No ascaris egg was detected in the final composts of PEC, PWC and GWC. The pH of compost in PEC and GWC were about 8.5, which was higher than pH of compost in PWC 7.4. The activities of CMCase in PEC were significantly higher than PWC and GWC during composting. The OM and C/N on 28 days decreased compared to the raw materials. The PCR-DGGE profiles showed significant differences in structure of bacteria and fungus after composting. Four prominent species of bacteria were replaced by uncultured bacterium and the prominent species of fungus were thermophiles and cellulolytic strains on 28 days. Correlation properties were similarly shared by the physico-chemical parameter and bacteria as well as fungus. [ABSTRACT FROM AUTHOR]

Abstract: Starting from polluting waste, such as those produced by the olive oil industry, composting is able to produce stable organic materials that can be suggested as peat surrogate in the preparation of growth media for potted plants. In this work stable and mature olive mill waste compost (OMWC) was produced by using a simplified novel static composting procedure conducted in gas permeable bags. In order to predict its nutritional and suppressive potential, physico-chemical and biological characteristics of OMWC were investigated as well as its performance when used instead of peat in the preparation of growth media for Photinia fraseri cv. “Red Robin” potted plants. The innovative composting technique showed to be fully comparable to conventional methods of aerobic composting and able to convert OMWs into well-humified, stable, mature and rich in nutrients amendment. OMWC was colonized by different fungal species belonging to the genus Aspergillus and Penicillium that showed an appreciable suppressive potential against Sclerotinia sclerotiorum and Phytophthora cactorum. OMWC also resulted suitable for nursery cultivation of P. fraseri, showing the best performance when used at 33 and 66% peat substitution rate. The recycling method proposed represents a virtuous and low cost model for proper and successful management of olive mill waste.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) is a crucial indicator of compost maturity and stability. Different pools of DOM fractions may function distinctly from one another and show unique properties in the transformation of organic matter and microbial activity. In this work, compost DOM was fractionated and the properties of individual DOM fractions including humic acids (HA), fulvic acids (FA) and hydrophilic compounds (Hi) were analyzed. The pools of HA, FA and Hi were studied via elemental analysis, FTIR and UV-Vis spectroscopy, and colloidal properties like particle size and zeta potential were characterized as well. Compared to HA or FA, Hi pool had a higher content of nitrogenous compound, higher saturated degree and more easily oxidized capacity. As composting proceeded, the aromaticity of HA and FA was higher and higher while Hi exhibited only a very slight change. The colloidal analysis indicated that the particle size of DOM subfractions gradually decreased. Hi compounds from matured compost had a good application potential in cations absorption. Taken together, these results provide valuable insights into the evolution and characteristics of DOM fractions during a composting process of dairy manure and Chinese herbal residues. [ABSTRACT FROM AUTHOR]