Co-production of polysaccharides, ginsenosides and succinic acid from Panax ginseng residue: A typical industrial herbal waste

Comprehensive reutilization of Glycyrrhiza uralensis residue by extrusion-biological pretreatment for coproduction of flavonoids, cellulase, and ethanol

A continuous chemical-free green approach was investigated for the comprehensive reutilization of all components in herbal extraction residues (HERs), taking Glycyrrhiza uralensis residue (GUR) as an example. The GUR structural changes induced by mechanical extrusion which improve the specific surface area and enzyme accessibility of GUR. With 3 % pretreated GUR loading of high-tolerance Penicillium oxalicum G2. The reducing sugar yield of 11.45 g/L was achieved, along with an 81.06 % in situ enzymatic hydrolysis. Finally, 8.23 g/L bioethanol (0.40 g/g total sugar) was produced from GUR hydrolysates after 24 h fermentation of Pichia stipitis G32. The amount of functional medicinal ingredients extracted from GUR after hydrolysis (39.63 mg/g) was 37.69 % greater than that of un-pretreated GUR. In total, 1.49 g flavonoids, 294.36 U cellulase, and 14.13 g ethanol could be produced from 100 g GUR using this process, illustrating that this green and efficient process has the potential for industrial production.

Fe(III)/peroxymonosulfate oxidation system for the degradation of rhein, a toxic component abundance in rhubarb residue

Rhubarb is widely used in health care, but causing a great amount of rhein-containing herbal residue. Rhein with several toxicities might pollute environment, damage ecology and even hazard human health if left untreated. In this study, the degradation effects of bisulfite- (BS) and peroxymonosulfate- (PMS) based oxidation systems on rhein in rhubarb residue were compared and investigated. The effects of BS and PMS with two valence states of ferric ion (Fe) on the degradation of rhein in rhubarb residue were optimized for the selection of optimal oxidation system. The influences of reaction temperature, reaction time and initial pH on the removal of rhein under the optimal oxidation system were evaluated. The chemical profiles of rhubarb residue with and without oxidation process were compared by UPLC-QTOF-MS/MS, and the degradation effects were investigated by PLS-DA and S plot/OPLS-DA analysis. The results manifested that PMS showed relative higher efficiency than BS on the degradation of rhein. Moreover, Fe(III) promoted the degradation effect of PMS, demonstrated that Fe(III)/PMS is the optimal oxidation system to degrade rhein in rhubarb residue. Further studies indicated that the degradation of rhein by the Fe(III)/PMS oxidation system was accelerated with the prolong of reaction time and the elevation of reaction temperature, and also affected by the initial pH. More importantly, Fe(III)/PMS oxidation system could degrade rhein in rhubarb residue completely under the optimal conditions. In conclusion, Fe(III)/PMS oxidation system is a feasible method to treat rhein in rhubarb residue.

Production of cost-competitive bioethanol and value-added co-products from distillers' grains: Techno-economic evaluation and environmental impact analysis

Here, Baijiu distillers' grains (BDGs) were employed in biorefinery development to generate value-added co-products and bioethanol. Through ethyl acetate extraction at a 1:6 solid-liquid ratio for 10 h, significant results were achieved, including 100 % lactic acid and 92 % phenolics recovery. The remaining BDGs also achieved 99 % glucan recovery and 81 % glucan-to-glucose conversion. Simultaneous saccharification and fermentation of remaining BDGs at 30 % loading resulted in 78.5 g bioethanol/L with a yield of 94 %. The minimum selling price of bioethanol varies from $0.149-$0.836/kg, contingent on the co-product market prices. The biorefinery processing of one ton of BDGs caused a 60 % reduction in greenhouse gas emissions compared to that of the traditional production of 88 kg corn-lactic acid, 70 kg antioxidant phenolics, 234 kg soybean protein, and 225 kg corn-bioethanol, along with emissions from BDG landfilling. The biorefinery demonstrated a synergistic model of cost-effective bioethanol production and low-carbon emission BDGs treatment.

Advances in succinic acid production: the enhancement of CO2 fixation for the carbon sequestration benefits

Succinic acid (SA), one of the 12 top platform chemicals produced from biomass, is a precursor of various high value-added derivatives. Specially, 1 mol CO2 is assimilated in 1 mol SA biosynthetic route under anaerobic conditions, which helps to achieve carbon reduction goals. In this review, methods for enhanced CO2 fixation in SA production and utilization of waste biomass for SA production are reviewed. Bioelectrochemical and bioreactor coupling systems constructed with off-gas reutilization to capture CO2 more efficiently were highlighted. In addition, the techno-economic analysis and carbon sequestration benefits for the synthesis of bio-based SA from CO2 and waste biomass are analyzed. Finally, a droplet microfluidics-based high-throughput screening technique applied to the future bioproduction of SA is proposed as a promising approach.

Highly-efficient lipid production from hydrolysate of Radix paeoniae alba residue by oleaginous yeast Cutaneotrichosporon oleaginosum

Valorization of herbal extraction residues (HERs) into value-added products is pivotal for the sustainability of Chinese medicine industry. Here, seven different enzymatic hydrolysates of dilute acid pretreated HERs were evaluated for lipid production by Cutaneotrichosporon oleaginosum. Among them, the highest sugar yield via hydrolysis and the maximum lipid production were obtained from Radix paeoniae alba residue (RPAR). More interestingly, high proportion of sugar polymers was disintegrated into fermentable sugars during the pretreatment step, allowing a cheap non-enzymatic route for producing sugars from RPAR. A repeated dilute acid pretreatment gained a high sugar concentration of 241.6 g/L through reusing the pretreatment liquor (PL) for four times. Biomass, lipid concentration, and lipid content achieved 49.5 g/L, 35.7 g/L and 72.2 %, respectively, using fed-batch culture of PL. The biodiesel parameters indicated lipids produced from HERs were suitable for biodiesel production. This study offers a cost-effective way to upgrade the HERs waste into micro-biodiesel.

The Effects of Radix isatidis Raw Material on Egg Quality, Serum Biochemistry, Gut Morphology and Gut Flora

China produces more than 30 million tons of drug residues every year. Therefore, innovative solutions are needed to mitigate environmental damage. Certain plant compounds boost hens' health and performance. Radix isatidis is promising for layer production. This study elucidates the multidimensional impact of Radix isatidis residual material (RIHR) on laying hens, focusing on the egg quality, intestinal health and the microbial landscape. A total of 288 55-week-old Peking powder laying hens with similar laying rates and body weights were randomly divided into four groups, with eight replicates per group and nine hens per replicate. The groups were divided into a control group, an RIHR low-dose group, a medium-dose group and a high-dose group according to a single-factor, completely randomized design. For the three RIHR treatment groups, the added amounts were 5 kg/t, 10 kg/t and 15 kg/t, respectively. Liquid chromatography- mass spectrometry (LC-MS), molecular docking, fluorescence quantitative PCR and other methods were used. The results showed that three main anti-inflammatory and antiviral compounds were identified in RIHR-indirubin (0.21 μg/g), deoxyvasicinone (0.18 μg/g) and epigoitrin (0.39 μg/g). RIHR significantly increased the eggshell thickness, Haugh unit and protein height (p < 0.05). It also had significant antioxidant and anti-inflammatory effects on ilea and ceca (p < 0.05). The microbial analysis demonstrated that RIHR supplementation led to a significant reduction in foregut Lactobacillus levels (p < 0.05). In the hindgut, a significant increase in pathogenic bacteria was observed (p < 0.05). The study concludes that RIHR's anti-inflammatory compounds may directly act on the intestinal tract to modulate inflammation, highlighting its potential for targeted interventions in poultry health and nutrition.

Efficient decolorization of oligosaccharides in ginseng (Panax ginseng) residue using ultrasound-assisted macroporous resin

An efficient decolorization method for ginseng residue oligosaccharides (GROs) using ultrasound-assisted D392 macroporous resin was developed. The decolorization effects and color differences of activated carbon adsorption, hydrogen peroxide oxidation, and resin adsorption were evaluated. The optimal conditions of the three decolorization methods for static, dynamic, ultrasound-assisted resin adsorption were compared. The results showed that ultrasound-assisted decolorization had the best decolorization effect of greatly decreasing the decolorization time to 80 min. Color difference analysis revealed the process of pigment removal during GRO decolorization. The UV-visible full-wavelength scan showed that most pigments were removed after decolorization. The characterizations by the Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that the chemical structure and crystallinity of the GROs did not change upon decolorization. In addition, the molecular weight distribution did not change significantly. This research contributes to further exploration of the structures and functions of GROs.

Recycling utilization of Chinese medicine herbal residues resources: systematic evaluation on industrializable treatment modes

Traditional Chinese medicine (TCM) is an indispensable part of the world health and medical system and plays an important role in treatment, prevention, and health care. These TCM produce a large amount of Chinese medicine herbal residues (CHMRs) during the application process, most of which are the residues after the decoction or extraction of botanical medicines. These CMHRs contain a large number of unused components, which can be used in medical, breeding, planting, materials, and other industries. Considering the practical application requirements, this paper mainly introduces the low-cost treatment methods of CHMRs, including the extraction of active ingredients, cultivation of edible fungi, and manufacture of feed. These methods not only have low upfront investment, but also have some income in the future. Furthermore, other methods are briefly introduced. In conclusion, this paper can provide a reference for people who need to deal with CMHRs and contribute to the sustainable development of TCM.

Techno-economic analysis and life cycle assessment of poly (butylene succinate) production using food waste

In this present study, the production of poly (butylene succinate) (PBS) from food waste was investigated and critical factors were evaluated. The economic feasibility of the process was investigated, as well as the minimum selling price (MSP) of PBS and sensitivity analysis of economic factors based on critical input parameters. 1,4-butanediol price and solvent usage in PBS purification significantly impacted economics during the process. In this process, the MSP of PBS was 3.5 $/kg. The Monte Carlo simulation technique was used to determine the uncertainty in the MSP of PBS. The plant's return on investment (ROI), payback period, internal rate of return (IRR), and net present value (NPV) were 15.79 %, 6.33 years, 16.48 %, and 58,879,000 USD, respectively. The environmental impact factors were evaluated. The results showed the GHG emission from the process was 5.19 kg CO₂-eq/kg of PBS which is low than conventional PBS production.

A Novel Strategy for Screening Active Components in Cistanche tubulosa Based on Spectrum-Effect Relationship Analysis and Network Pharmacology

Cistanche tubulosa (Schenk) R. Wight is a valuable herbal medicine in China. The study aimed to explore the potential mechanisms of C. tubulosa on antioxidant activity using spectrum-effect relationship and network pharmacology and the possibilities of utilizing herbal dregs. In this work, different extracts of C. tubulosa, including herbal materials, water extracts, and herbal residues, were evaluated using high-performance liquid chromatography (HPLC) technology. In addition, the antioxidant activities were estimated in vitro, including 2, 2-diphenyl-1-picrylhydrazyl; superoxide anion; and hydroxyl radical scavenging assays. The spectrum-effect relationships between the HPLC fingerprints and the biological capabilities were analyzed via partial least squares regression, bivariate correlation analysis, and redundancy analysis. Furthermore, network pharmacology was used to predict potential mechanisms of C. tubulosa in the treatment of antioxidant-related diseases. According to the results, eleven common peaks were shared by different extracts. Geniposidic acid, echinacoside, verbascoside, tubuloside A, and isoacteoside were quantified and compared among different forms of C. tubulosa. The spectrum-effect relationship study indicated that peak A ₆ might be the most decisive component among the three forms. Based on network pharmacology, there were 159 target genes shared by active components and antioxidant-related diseases. Targets related to antioxidant activity and relevant pathways were discussed. Our results provide a theoretical basis for recycling the herbal residues and the potential mechanisms of C. tubulosa in the treatment of antioxidant-related diseases.

Effects of down-regulation of ackA expression by CRISPR-dCpf1 on succinic acid production in Actinobacillus succinogenes

Succinic acid (SA), a key intermediate in the cellular tricarboxylic acid cycle (TCA), is a 4-carbon dicarboxylic acid of great industrial value. Actinobacillus succinogenes can ferment various carbon sources and accumulate relatively high concentrations of SA, but few reliable genetic engineering tools exist for A. succinogenes and this has hindered strain improvement to increase SA production for industrial application. Two different repressors, endonuclease-deactivated Cas9 (dCas9) from Streptococcus pyogenes and Cpf1 (dCpf1) from Francisella tularensis, were applied to construct a CRISPRi system in A. succinogenes. Codon-optimized Cas9 and native Cpf1 were successfully expressed in A. succinogenes, and the corresponding sgRNA and crRNA expression elements, promoted by the fumarate reductase promoter, frd, were introduced into the CRISPRi plasmid. The highest repression of the ackA gene (encoding acetate kinase) and thereby acetic acid production (~ eightfold) was achieved by the dCpf1-based CRISPRi system, in which the mutation site, E1006A acted at the start of the coding region of ackA, the gene which regulates acetic acid biosynthesis. Compared with the ackA gene knockout mutant, cell growth was moderately improved and SA production increased by 6.3%. Further, the SA titer and productivity in a 3 L fermenter reached 57.06 g/L and 1.87 g/L/h, and there was less acetic acid production. A dCpf1-based CRISPRi-mediated gene repression system was successfully established for the first time, providing a simple and effective tool for studying functional genomics in A. succinogenes and optimizing SA production.

Reclamation of ginseng residues using two-stage fermentation and evaluation of their beneficial effects as dietary feed supplements for piglets

Environmental pollution caused by herbal residues, such as ginseng residue (GR), and the huge waste of medicinal ingredients in such residues hinder the development of the pharmaceutical industry. Few studies focused on the biotransformation of GRs and the practical utilization of their bioproducts. In this study, we developed a two-stage fermentation method to optimize GR bioconversion and used the fermented products as dietary supplements for piglets. The tested GR contained abundant lignocelluloses, protein, sugar, and amino acids. Approximately 43.10% of the total lignocelluloses were degraded into sugars by Inonotus obliquus in stage 1 of fermentation. Meanwhile, the sugar content increased by 36.20%, which became the feed for Bacillus subtilis and Saccharomyces cerevisiae in stage 2 of fermentation. These two strains boosted the production of bacterial proteins and other metabolites, including peptides, organic acids, and amino acids. At the end of fermentation, the contents of bioactive compounds significantly increased by 3.18%-21.79%. The dietary supplementation of fermented GR significantly improved the growth performance (6.47%-7.98%), intestinal microbiota, immune function, and healthy status and reduced the diarrhea incidence and noxious gas emission of the piglets. This study provides evidence-based results for the development and deployment of a circular economy between ginseng and livestock industries.

Highly efficient glucose production from raw non-pretreated Chinese medicinal herbal residues via the synergism of cellulase and amylolytic enzymes

Available literature on Chinese medicinal herbal residues (CMHRs) bioconversion highlights pretreatment prior to saccharification with cellulase without considering the presence of starch constituent. Herein, four commonly found CMHRs were tested for starch content, and it was found they all contained starch with content ranging from 4.74% to 16.78%. Hydrolysis of raw CMHRs with combined cellulase and amylolytic enzymes yielded increments of 16.85% to 26.51% in 48-h glucan conversion compared to cellulase alone. Further study showed 48-h glucan conversion of raw CMHRs outperformed that pretreated by water-ethanol successive extraction, ultrasound and acid, but underperformed alkali-pretreated CMHRs. Although increasing 48-h glucan conversion in the range of 7.40% to 24.10% compared to raw CMHRs, alkaline pretreatment demonstrated low glucose recovery and incurred additional cost, making it unfavorable. Saccharification of the four raw CMHRs with combined enzymes seems like a preferred option considering the elimination of high-cost pretreatment step.

Sustainable Food Systems: The Case of Functional Compounds towards the Development of Clean Label Food Products

The addition of natural components with functional properties in novel food formulations confers one of the main challenges that the modern food industry is called to face. New EU directives and the global turn to circular economy models are also pressing the agro-industrial sector to adopt cradle-to-cradle approaches for their by-products and waste streams. This review aims to present the concept of “sustainable functional compounds”, emphasizing on some main bioactive compounds that could be recovered or biotechnologically produced from renewable resources. Herein, and in view of their efficient and “greener” production and extraction, emerging technologies, together with their possible advantages or drawbacks, are presented and discussed. Μodern examples of novel, clean label food products that are composed of sustainable functional compounds are summarized. Finally, some action plans towards the establishment of sustainable food systems are suggested.