Self-assembling peptide nanofibers and nanoceramics in a model of alveolar bone repair: Insights from in vivo experiments and clinical trial

Introduction

Tooth extraction initiates a cascade of homeostatic and structural modifications within the periodontal tissues, culminating in alveolar ridge resorption. To prevent ridge resorption following extraction and facilitate successful placement of an implant-supported prosthesis, alveolar ridge preservation was performed.

Methods

In this study, the biocompatibility of a nanocomposite consisting of self-assembling peptide nanofibers (organic phase) and tri-calcium phosphate-nano hydroxyapatite (mineral phase), was evaluated in rabbits. Subsequently, the nanocomposite was grafted onto a model of alveolar bone repair in patients.

Results

The in vivo findings revealed no significant differences in the irritation ranking score and average thickness of the reaction zone between the nanocomposite and control groups. Furthermore, there were no significant differences in the appearance of necrosis, granulation tissue, fibroplasia, neovascularization, and hemorrhage as well as in the number of neutrophils, mast cells, lymphocytes, macrophages, and giant cells between the two groups. The defect area was completely filled with newly formed bone trabeculae and cavities containing bone marrow, indicating angiogenesis, while remnants of the scaffold were observed in the deeper region of the defects, adjacent to the bone marrow, considered osteoinductive. The clinical trial findings (TRN: IR.IUMS.REC.1401.355) demonstrated robust bone regeneration after 3.5 months of socket preservation, whereas the bone in the control group experienced atrophy. The nanocomposite facilitated soft tissue healing without any signs of infection or other periodontal malfunction.

Conclusion

The application of nanotechnology has enhanced the bio-functionality of alloplastic materials, positioning this nanocomposite a promising alternative to autografts and allografts in alveolar bone repair.

Deciphering the Catalytic Proficiency and Mechanism of the N-Acetylglucosamine Deacetylase From Pantoea dispersa

Glucosamine (GlcN) is a widely utilized amino monosaccharide. It is traditionally synthesized from N-acetylglucosamine (GlcNAc) via chemical processes that pose environmental threats. In pursuit of a greener alternative, our investigation explored biocatalysis with a Pantoea dispersa derived deacetylase (Pd-nagA), showcasing its efficacy as a catalyst in GlcN production. As a result, this work provides a comprehensive characterization of Pd-nagA, scrutinizes its enzymatic behavior, and delves into the deacetylation mechanism in detail. Heterologous expression methods were utilized for the production and isolation of Pd-nagA, followed by a kinetic evaluation highlighting its enzymatic activity. The complex interactions between the enzyme and its substrate were investigated by integrating classical molecular dynamics, quantum mechanics/molecular mechanics simulations, funnel metadynamics, and on-the-fly probability enhanced sampling techniques, thereby elucidating the precise deacetylation pathway. Rigorous computational analysis results demonstrated that Pd-nagA exhibited promising specificity and efficiency for GlcNAc with a high turnover rate. The catalytic residues central to the reaction were identified, and the underlying quantum reaction mechanism was detailed. Our findings suggest an approach to GlcN production using eco-friendly biocatalysis, positioning Pd-nagA at the forefront of industrial application not only because of its remarkable catalytic capabilities but also due to its potential for enzyme optimization.

Photoproduction of Aviation Fuel β-Caryophyllene From the Eukaryotic Green Microalga Chlamydomonas reinhardtii

β-caryophyllene is a plant-derived sesquiterpene and is regarded as a promising ingredient for aviation fuels. Microalgae can convert CO2 into energy-rich bioproducts through photosynthesis, making them potential platforms for the sustainable production of sesquiterpenes. However, heterologous sesquiterpene engineering in microalgae is still in its infancy, and β-caryophyllene production in eukaryotic photosynthetic microorganisms has not been reported. In this study, we succeeded in producing β-caryophyllene in the model eukaryotic microalga Chlamydomonas reinhardtii by heterologously expressing a β-caryophyllene synthase (QHS). Furthermore, overexpressing the key enzyme of the 2-C-methyl-D-erythritol 4-phosphate pathway in the QHS-expressing strain (QHS-DXS-HDR-18) resulted in a 17-fold higher β-caryophyllene production compared to the single expression of QHS (QHS-28). Additionally, when isopentenyl diphosphate isomerase (CrIDI) was overexpressed, the β-caryophyllene production was up to 480.6 μg/L in QHS-DXS-HDR-CrIDI-16 and increased by 1.8-fold compared to the parental strain QHS-DXS-HDR-18. Under photoautotrophic and photomixotrophic conditions in photobioreactors, the β-caryophyllene production in QHS-DXS-HDR-CrIDI-16 reached 854.7 and 1016.8 μg/L, respectively. Noticeably, all the β-caryophyllene-producing strains generated in this study did not exhibit adverse effects on cell growth and photosynthesis activity compared to the untransformed strain. This study demonstrates the first successful attempt to produce β-caryophyllene in the eukaryotic microalga C. reinhardtii and develops a novel strategy for increasing sesquiterpene production in eukaryotic photosynthetic microorganisms.

Chemical constituents from the endophytic fungus Aspergillus sp. S3 of Hibiscus tiliaceus

A new sterol, aspersterol E (1), a newly discovered alkaloid, asperginine A (2), and five known compounds (3-7) were obtained from the endophytic fungus Aspergillus sp. S3 of Hibiscus tiliaceus Linn. The compounds were extracted from their fermentation products using silica gel, ODS C18, and semi-preparative HPLC. The structure of each compound was determined through spectroscopic analysis. All the obtained compounds (1-7) were evaluated for their cytotoxic activity against the mouse pre-gastric cancer cell line MFC by using the MTT assay. The IC50 values of compounds 1, 2, 3, and 5 were found to be 153.43 μM, 61.25 μM, 73.19 μM, and 181.69 μM respectively.

Endophytes as bioenhancers of plant growth: An overview

The need for food production rises with the era of expanding population. As a result, there is more indirect demand for chemical pesticides and fertilizers. Serious environmental concerns result from the continuous and careless usage of chemicals. Additionally, they could make the land infertile. One of the finest substitutes for chemicals is to use microorganisms, particularly endophytes. Endophytes uses both direct and indirect mechanisms to encourage plant growth by increased mineral availability, resilience to biotic and abiotic stresses, synthesis of significant phytohormones. This review is focused on exploring the plant growth promoting effect of endophytes and its potential implications in the crop production.

Asphaltenes biodegradation from heavy crude oils by the yeast Yarrowia lipolytica

Heavy crude oil reserves are characterized by their high viscosity and density, largely due to significant quantities of asphaltenes. The removal of asphaltene precipitates from oil industry installations is crucial, as they can contaminate catalysts and obstruct pipelines. Therefore, this study aimed to bio-transform heavy oil asphaltenes into smaller molecules using the yeast Yarrowia lipolytica, known for its ability to efficiently degrade hydrophobic substrates. For this purpose, asphaltenes were extracted from crude oil samples, and yeast growth was assessed in a mineral medium containing 2, 5, or 10 g L-1 of asphaltenes. After 168 h of incubation, liquid-liquid extraction was conducted on samples from the Yarrowia lipolytica growth medium using chloroform. The extracted fractions were then quantified by gas chromatography. The results indicated that the yeast could utilize the asphaltenes as a carbon source for growth, though there was a delay in growth compared to the control (glucose as the carbon source), with a maximum biomass concentration of 2.26 g L-1 achieved at 144 h. From the experimental design, it was determined that a higher concentration of aromatic compounds was achieved under the conditions of 115 rpm, 2 g L-1 of asphaltenes, and 0.5 g L-1 of cell inoculum. Conversely, to obtain a higher concentration of saturated compounds, the optimal conditions were 160 rpm, 5 g L-1 of asphaltenes, and 1.0 g L-1 of cell inoculum. Molecular docking results indicated that asphaltenes have a high affinity for cytochrome P450, laccase, and Lip2, with interactions observed with their catalytic triads, suggesting a significant role for these enzymes in asphaltene bioconversion.

Laccase based per- and polyfluoroalkyl substances degradation: Status and future perspectives

Per- and polyfluoroalkyl substances (PFAS) with stable carbon-fluorine bonds are used in a wide range of industrial and commercial applications. Due to their extreme environmental persistence, PFAS have the potential to bioaccumulate, cause adverse effects, and present challenges regarding remediation. Recently, microbial and enzymatic reactions for sustainable degradation of PFAS have gained attention from researchers, although biological decomposition of PFAS remains challenging. Surprisingly, laccases, the multi-copper oxidases produced by various organisms, showed potential for PFAS degradation. Mediators play key roles in initiating laccase induced PFAS degradation and defluorination reactions. The laccase-catalyzed PFAS degradation reactions are relatively slower than normal biocatalytic reactions and the low activity of native laccases constrains their capacity to complete defluorination. With their low redox potential and narrow substrate scope, an innovative remediation strategy must be taken to accelerate this reaction. In this review we have summarized the status, challenges, and future perspectives of enzymatic PFAS degradation. The knowledge of laccase-based defluorination and the molecular basis of the reaction mechanisms overviewed in this study could inform future applications of laccases for sustainable PFAS remediation.

Myceliophthora thermophila as promising fungal cell factories for industrial bioproduction: From rational design to industrial applications

Myceliophthora thermophila stands out as a prominent fungal cell factory, garnering growing interest due to its distinctive traits advantageous. Currently, M. thermophila has been developed as an efficient cell factory, producing a variety of products from various raw materials. In this review, we firstly discuss the potential advantages of M. thermophila as a platform for metabolic engineering and industrial applications, with special emphasis on its physiological characteristics, the development of genetic modification techniques and tools, gene expression and regulation strategies. Then, the latest progress in industrial application of M. thermophila as microbial cell factory was systematically summarized, including biochemical synthesis platform, enzyme expression platform, antibody protein and vaccine production platform, bio-organic fertilizer production platform, and efficient enzyme element library. Finally, the current challenges of M. thermophila as a cell factory and its corresponding strategies are proposed, aiming to achieve green biomanufacturing of multiple products with higher efficiency.

Selenium nanoparticles improved biochemical and physiological properties and antioxidant systems of savoury under drought stress

To investigate the effectiveness of selenium (Se) and Se nanoparticles (Se-NPs) in improving biochemical and physiological characteristics of savoury in drought stress conditions, a factorial experiment based on the completely randomised design with three replications was used. Results demonstrate that Se-NPs considerably enhanced several biochemical parameters, such as relative water content (RWC), antioxidant enzymes activity, and total soluble protein in drought and normal conditions. At the stress level from 100 to 40% of field capacity, a gradual decrease in chlorophyll and CARs contents was observed and under stress and normal conditions, the application of Se-NPs (10 mg L-1) led to an increase in the content of pigments. Total soluble protein, total phenolic and flavonoid contents showed significant increases in plants treated with Se-NPs under drought stress. Generally, the use of Se-NPs in drought stress conditions can be effective in improving the growth, biochemical, and physiological characteristics of savoury.

Comprehensive Biotechnological Strategies for Podophyllotoxin Production from Plant and Microbial Sources

Podophyllotoxin is derived from plant sources and exhibits strong anticancer activity. However, limited natural availability and environmental impacts from traditional extraction methods drive the search for alternative production approaches. This review explores diverse strategies for sustainable podophyllotoxin synthesis, including biosynthesis, semi-synthesis, and biotransformation. Biosynthetic methods involve metabolic pathway engineering in plant or microbial cells, enabling increased yields by manipulating precursor availability and gene expression. Semi-synthetic approaches modify podophyllotoxin precursors or intermediates to enhance therapeutic effects, with derivatives like etoposide and teniposide showing clinical efficacy. Biotransformation, utilising organisms such as endophytic fungi or human hepatic enzymes, enables the transformation of substrates like deoxypodophyllotoxin into podophyllotoxin or its derivatives, yielding compounds with reduced environmental impact and improved purity. The anticancer efficacy of podophyllotoxin and its derivatives stems from multiple mechanisms. These compounds disrupt cell mitosis by inhibiting microtubule assembly, impairing nucleoside transport, and blocking topoisomerase II activity, leading to DNA cleavage and cancer cell apoptosis. Podophyllotoxin and its derivatives also exhibit anti-angiogenesis and anti-metastatic effects through signalling pathway modulation. Notably, derivatives like deoxypodophyllotoxin utilise advanced delivery systems, enhancing targeted efficacy and reducing side effects. Given the varied mechanisms and growing therapeutic applications, optimising biotransformation and delivery techniques remains essential for advancing podophyllotoxin-based therapies. This comprehensive review underscores the compound's potential as a robust anticancer agent and the need for continued research to maximise its production and clinical effectiveness.

Enhancing biobutanol production by optimizing acetone-butanol-ethanol fermentation from sorghum grains through strategic immobilization of amylolytic enzymes

Tannin-containing sorghum grains, suitable for acetone-butanol-ethanol (ABE) production by Clostridium acetobutylicum, have required pretreatment to eliminate tannins inhibiting the strain's amylolytic activity. This study investigates biobutanol production enhancement by immobilizing enzymes on polydopamine-functionalized polyethersulfone (PES) membranes with magnetic nanoparticles for Separated Hydrolysis and Fermentation (SHF) and Simultaneous Saccharification and Fermentation (SSF) processes. After multi-stage hot water treatment, TG3 sorghum (from the third stage) was used, where the enzyme-immobilized PES membrane produced 4.75 g/L of ABE (3.24 g/L butanol) under SSF, 0.85 g/L under SHF, and 1.1 g/L under simple fermentation. For TG6 (from the sixth stage), 3.23, 1.29, and 1.25 g/L of ABE was produced under SSF, SHF, and simple fermentation, respectively. This enhanced performance is due to the reduced enzyme inhibition. Reusability experiments showed that the membrane retained 30 % of initial activity after three cycles. These findings suggest that enzyme-immobilized membranes can intensify ABE production and enable integrated cell recovery.

Advances and new horizons in metabolic engineering of heterotrophic bacteria and cyanobacteria for enhanced lactic acid production

Bacteria species such as E.Coli, Lactobacilli, and pediococci play an important role as starter strains in fermentation food or polysaccharides into lactic acid. These bacteria were metabolically engineered using multiple proven genome editing methods to enhance relevant phenotypes. The efficacy of these procedures varies depending on the editing tool used and researchers' ability to pick suitable recombinants, which significantly increased genome engineering throughput. Cyanobacteria produce oxygenic photosynthesis and play an important role in carbon dioxide fixing. The fixed carbon dioxide is then retained as polysaccharides in cells and metabolised into various low carbon molecules such as lactate, succinate, and ethanol. Lactate is used as a building ingredient in various bioplastics, food additives, and medicines. This review covers the recent advances in lactic acid production through metabolic and genetic engineering in bacteria and cyanobacteria.

Designing synthetic microbial communities with the capacity to upcycle fermentation byproducts to increase production yields

Microbial cell factories, which convert feedstocks into a product of value, have the potential to help transition toward a bio-based economy with more sustainable ways to produce food, fuels, chemicals, and materials. One common challenge found in most bioconversions is the co-production, together with the product of interest, of undesirable byproducts or overflow metabolites. Here, we designed a strategy based on synthetic microbial communities to address this issue and increase overall production yields. To achieve our goal, we created a Yarrowia lipolytica co-culture comprising a wild-type (WT) strain that consumes glucose to make biomass and citric acid (CA), and an 'upcycler' strain, which consumes the CA produced by the WT strain. The co-culture produced up to two times more β-carotene compared with the WT monoculture using either minimal medium or hydrolysate. The proposed strategy has the potential to be applied to other bioprocesses and organisms.

Effect of CHO cell line constructed with CMAH gene-directed integration on the recombinant protein expression

Chinese hamster ovary (CHO) cells are the most widely used platform for recombinant therapeutic protein (RTP) production. Traditionally, the development of CHO cell lines has mainly depended on random integration of transgenes into the genome, which is not conducive to stable long-term expression. Cytidine monophosphate N-acetylneuraminic acid hydroxylase (CMAH) is expressed in CHO cells and produces N-hydroxyacetylneuraminic acid, which may cause a human immune response. However, the effects of transgene integration at the CMAH site on RTP expression in CHO cells remain unclear. In this study, we selected CMAH gene, which is lacking in humans, as the target site to construct recombinant CHO cell line using the CRISPR/Cas9 technique. Erythropoietin (EPO) and EGFP integration at the CMAH site resulted in more stable expression levels and lower heterogeneity than random integration. In addition, the proportion of N-glycosylation levels in the EPO glycoside of CMAH integration site also changed. In conclusion, CMAH site integration improved the stability of RTP expression in CHO cells.

Protein engineering of an oxidative cleavage-free pathway for crocetin-dialdehyde production in Escherichia coli

The growing depletion of petroleum resources and the increasing demand for sustainable alternatives have spurred advancements in microorganism-based biofactories. Among high-value compounds, carotenoids are widely sought after in pharmaceuticals, cosmetics, and nutrition, making them prime candidates for microbial production. In this study, we engineered an efficient biosynthetic pathway in Escherichia coli for the production of the C20-carotenoid crocetin-dialdehyde. By bypassing traditional oxidative cleavage reactions mediated by carotenoid cleavage dioxygenases (CCDs), our approach reduces the enzymatic complexity of the pathway. Using the crystal structure of a CrtMLIKE enzyme identified in this study, we developed a mutant enzyme capable of condensing two C10-geranyl pyrophosphate molecules to form C20-phytoene. This intermediate was then desaturated and oxidized by CrtN and CrtP to produce crocetin-dialdehyde, achieving a yield of 1.13 mg/L. By reducing enzyme requirements from six to three and eliminating the need for CCDs, this pathway alleviates metabolic stress on the host and enhances the scalability of production for industrial applications. Overall, our research presents a streamlined and innovative approach to carotenoid biosynthesis, advancing sustainable production methods for short-chain carotenoids.

Decoding the difference of four species of Cordyceps based on polysaccharides and immunomodulation activity

Nucleosides and polysaccharides are the main bioactive ingredients of Cordyceps genus. Nucleosides shows significant differences in different Cordyceps species. However, the differences of polysaccharides have not been decoded. Here, the structure characters of polysaccharides including molecular weight (Mw) distribution, compositional monosaccharides and glycosidic linkage types were compared in C. sinensis (CS), C. militaris (CM), silkworm-hosted C. militaris (SCM) and Cordyceps fermented products (CSF). Compositional monosaccharides including mannose, glucose and galactose, and 1,4-Glcp glycosidic linkage were found abundant in Cordyceps species. Chemometric analysis showed that Cordyceps exhibit significant differences in structural information especially glycosidic linkage types. Besides, polysaccharides in CS and CSF-4 had obviously strong capacity of stimulating phagocytic, NO production and cytokines secretion. Gray relational analysis and Pearson correlation analysis were performed to further investigate the relationship between key polysaccharide structure and immunomodulatory activities. The results indicated that polysaccharides with relatively large number of 1, 4-Glcp and Mw in range of 7.16 × 106 Da-7.99 × 107 Da and 1.43 × 104 D-6.94 × 105 Da probably contributed to its immunomodulatory activities. The chemical and biological evaluation of natural and various cultured cordyceps in this study is useful for understanding and regulating the quality of cultured Cordyceps.

Molecular mechanisms of cold stress response in cotton: Transcriptional reprogramming and genetic strategies for tolerance

Cold stress has a huge impact on the growth and development of cotton, presenting a significant challenge to its productivity. Comprehending the complex molecular mechanisms that control the reaction to CS is necessary for developing tactics to improve cold tolerance in cotton. This review paper explores how cotton responds to cold stress by regulating gene expression, focusing on both activating and repressing specific genes. We investigate the essential roles that transcription factors and regulatory elements have in responding to cold stress and controlling gene expression to counteract the negative impacts of low temperatures. Through a comprehensive examination of new publications, we clarify the intricacies of transcriptional reprogramming induced by cold stress, emphasizing the connections between different regulatory elements and signaling pathways. Additionally, we investigate the consecutive effects of cold stress on cotton yield, highlighting the physiological and developmental disturbances resulting from extended periods of low temperatures. The knowledge obtained from this assessment allows for a more profound comprehension of the molecular mechanisms that regulate cold stress responses, suggesting potential paths for future research to enhance cold tolerance in cotton by utilizing targeted genetic modifications and biotechnological interventions.

Stress response proteins within biofilm matrixome protect the cell membrane against heavy metals-induced oxidative damage in a marine bacterium Bacillus stercoris GST-03

Biofilm formation is a key adaptive response of marine bacteria towards stress conditions. The protective mechanisms of biofilm matrixome proteins against heavy metals (Pb and Cd) induced oxidative damage in the marine bacterium Bacillus stercoris GST-03 was investigated. Exposure to heavy metals resulted in significant changes in cell morphology, biofilm formation, and matrixome composition. Biofilm-encased cells showed lower oxidative damage. Biofilm matrixome protein exhibited major conformational changes, with 100 % α-helix turned to 62.33 % and 69.64 % of random coil under Pb and Cd stress, respectively. Fluorescence quenching kinetics revealed slow interactions between biofilm matrixome proteins and heavy metals (Kq values < 2.0 × 1010). Thermodynamic analysis showed negative ∆G (-16.02 kJ/mol for Pb and -17.45 kJ/mol for Cd) and binding dissociation constant (KD) (1530 ± 157 μM for Pb and 875 ± 97.4 μM for Cd), indicating a stronger binding affinity of biofilm matrixome to heavy metals. Pb stress led to overproduction of detoxification proteins (YnaI, KhtS, Bacillopeptidase F), competence and sporulation proteins (RapF, CSSF, XkdP), while Cd exposure leads to overproduction of proteins involved in protein misfolding repair (YlxX, cysteine-tRNA ligase, YacP), DNA repair (YfkN), and redox balance (cysteine synthase, YdiK). The findings highlight the resilience of B. stercoris GST-03 to heavy metal stress in biofilm mode.

Preparation and anti-inflammation activity of λ-carrageenan oligosaccharides degraded by a novel λ-carrageenase Car3193

To date, less attention has been paid to λ-carrageenases and their enzymatic hydrolysates than to κ- and ι-carrageenases and their hydrolysates. In this study, a Gram-negative strain Polaribacter sp. NJDZ03 was isolated from the surface of an Antarctic macroalga, Desmarestia sp., and a novel λ-carrageenase gene car3193 was isolated from it. The car3193 gene was 2832 bp long, and encoded an enzyme consisting of 943 amino acids. Although Car3193 had the typical PQQ structure at the N-terminal, its predicted active sites, Arg93 and Asn361, differed from those of other reported λ-carrageenases. The optimum temperature and pH of recombinant Car3193 towards λ-carrageenan were 50 °C and 7.0, respectively. The degradation products of λ-carrageenan produced by Car3193 were λ-neocarrabiose-, λ-neocarratetraose-, and λ-neocarraoctose-saccharides. Two products of enzymatic hydrolysis, λ-COs-1 (degree of polymerization 2; DP2) and λ-COS-2 (DP8), showed excellent anti-inflammatory activity towards lipopolysaccharide-induced RAW264.7 macrophages. Treatment with λ-COs-1 (DP2) and λ-COS-2 (DP8) significantly inhibited the secretion of the pro-inflammatory factors TNF-α, IL-6, IL-1β, and NO by RAW264.7 macrophages, and stimulated the secretion of the anti-inflammatory factors TGF-β1 and IL-10. The anti-inflammatory activity of λ-COs-1 was stronger than that of λ-COS-2, and λ-COs-1 had a dose-dependent bioactive effect, whereas λ-COS-2 did not. Further analyses showed that these carrageenan oligomers stimulated an anti-inflammatory response by inhibiting the NF-κB signaling pathway. Car3193 has potential applications in industry because of its high activity and strong stability, and its ability to generate bioactive products.

Emergence of ADM-mediated bioconjugate to enhance longevity and catalytic efficiency of urease

The versatile nature of the urease enzyme makes it a valuable asset in biological and industrial contexts. The creation of bioconjugates using enzyme-polymer combinations has extended the shelf life and stability of urease. A triblock copolymer, PAM-co-PDPA-co-PMAA@urease (ADM@urease), was synthesized using acrylamide (AM), 2,5-dioxopyrrolidin-1-ylacrylate (DPA), methacrylic acid (MAA), and urease via the RAFT-Grafting-To polymerization method. This polymeric interface stabilizes the enzyme and enhances substrate binding and product release, significantly boosting enzymatic efficiency. To enhance pH's influence on urease activity, three ADM grades were developed by adjusting pH-responsive MAA levels, confirmed by GPC analysis. ADM micellized at acidic pH values of 6.47 or lower, with a critical micelle concentration (CMC) of at least 0.125 mg/mL. Kinetic evaluations using Berthelot reagents at various pH levels and temperatures compared free enzyme and urease encapsulated in ADM@urease. The Michaelis-Menten constant (Km) values, derived from the Lineweaver-Burk plot, were similar for both forms. The ADM@urease demonstrated optimal stability and catalytic efficacy with a Km value of 1.18 and Vmax of 1.92 at pH 4. By improving the stability, efficiency, and performance of urease, this encapsulation technology offers potential for sustainable, eco-friendly industrial applications and advancements in biotechnology.

An effective cell-penetrating peptide-based loading method to extracellular vesicles and enhancement in cellular delivery of drugs

Extracellular vesicles (EVs) have been demonstrated to own the advantages in evading phagocytosis, crossing biological barriers, and possessing excellent biocompatibility and intrinsic stability. Based on these characteristics, EVs have been used as effective therapeutic carriers for drug delivery, but the low drug loading capacity greatly limits further applications. Herein, we developed a drug loading method based on cell-penetrating peptide (CPP) to enhance the encapsulation of therapeutic reagents in EVs, and EVs-based drug delivery system achieved higher killing efficacy to tumor cells. Urinary EVs and chemotherapy reagent doxorubicin (DOX) were used as model. It is easy to conjugate CPP with DOX (CPP-DOX) through the linker N-succinimidyl 3-maleimidopropionate (SMP). CPP-DOX was incubated with EVs under a mild condition, promoting the encapsulation of DOX into EV cavities. CPP-DOX-EVs showed strong anticancer ability since EVs delivery facilitated the uptake by cancer cells. EVs loading of CPP-DOX exhibited higher drug loading efficiency at 37.18%, presenting about 2.5 times increase in efficiency over EVs loading of DOX through passive incubation. Easy operation and controllable condition further reinforce the advantages compared with other loading methods. CPP-based drug loading method provides an effective strategy for EVs-based drug delivery system.

Microfluidic systems and ultrasonics for emulsion-based biopolymers: A comprehensive review of techniques, challenges, and future directions

Over the past decade, the advancement of microfluidic technology associated with ultrasonics had received a considerate impact across the field, especially in biomedical and polymer synthesis applications. Nevertheless, there are much hindrance remained unsolved, to achieve simple processing, high scalability and high yield biopolymer products that stabilize during the process. In this review, we discuss the underlying physics for both microfluidic and ultrasonic integration in the synthesis of emulsion-based biopolymer and application. The current progress was outlined, focus on its related applications. We also summarized the current strengths and weakness of the microfluidic-ultrasonic integrated technology, aiming to contribute into SDG 12 for responsible consumption and production.

Oregano polyphenols reduce human insulin amyloid aggregation

Human insulin may undergo fibrillization under specific conditions, impairing its function and promoting its accumulation in amyloid deposits. Oregano (Origanum vulgare L.) leaves are rich in biologically active compounds such as polyphenols. Thus, we investigated their ability to inhibit insulin amyloid aggregation. The oregano aqueous extract phytochemical analysis (LC-MS/MS-DAD) revealed the presence of four major compounds: lithospermic acid (LA), rosmarinic acid (RA), oreganol A (OA), and luteolin-7-O-diglucuronide (L7dG), respectively. Compounds and their mixtures were subsequently screened for anti-amyloid activity and evaluated against oregano lyophilizate (LYO) utilizing ThT assay, AFM and ATR-FTIR analyses. LYO inhibited insulin fibrillization more effectively than its main constituent RA, prolonging the lag phase approximately two-fold. L7dG has been the most effective of the tested individual compounds, prolonging the lag phase by roughly 20 %, followed by LA, whereas OA was ineffective. Subsequently, we measured the anti-amyloid activity of two kinds of equimolar mixtures: either containing individually active compounds or analogous mixtures to which inactive OA was added. Surprisingly, LA:OA mixture proved to be the most effective. However, adding L7dG to the OA mixtures led to activity loss. The interactions of oregano polyphenols with the amyloidogenic regions of insulin were elucidated using molecular docking, explaining observed changes in their anti-amyloid activity. We conclude that when investigating the anti-amyloid activity of samples of natural origin and determining the activity of the extracts and their individual main components, it is necessary to consider their mutual interactions, which can significantly affect the final effect of the analyzed mixture.

Macaw palm is a harbor of new non-grass species of dark septate endophytes belonging to the genus Pseudophialophora (Magnaporthaceae)

Macaw palm (Acrocomia aculeata) is an oleaginous crop native to Brazil with significant economic and environmental value. It has been explored commercially in Brazil within sustainable management. The microbiota associated with macaw palm is still little known and there is no report about their root's fungal endophytes. Recently, the community of dark septate endophytes (DSE) from macaw palm began to be investigated, and new taxa were found. The present study aimed to describe two new Pseudophialophora species associated with macaw palm roots. The isolation method performed was the dilution-to-extinction cultivation. ITS, RPB1, tef1-α, LSU, and SSU regions were amplified and sequenced for phylogenetic analyses. The isolates formed two phylogenetically independent lineages and we proposed the new species P. chlamydospora and P. endophytica. For the first time, new taxa of DSE fungi were described from macaw palm.

Control efficacy of Bt-Cry1Ab maize (event DBN9936) against Ostrinia furnacalis (Guenée) in Sichuan Province, China

BACKGROUND

The Asian corn borer (ACB), Ostrinia furnacalis (Guenée), is a major pest restricting maize production in Asia. The Chinese government has approved the commercial planting of Bt-Cry1Ab maize (event DBN9936), but its control potential against the ACB in southern regions remains unclear. This study evaluated the sensitivity of ACB to Cry1Ab protein expressed in Bt-Cry1Ab maize and determined the control efficacy of Bt-Cry1Ab maize against the ACB in Sichuan Province, a major maize-producing region in southern China, based on pilot planting in the field, and larval feeding bioassays in the field and laboratory.

RESULT

The Cry1Ab protein contents in different tissues of Bt-Cry1Ab maize ranged from 31.20-88.27 μg g-1. The range of median lethal concentrations (LC50) and median growth inhibitory concentration (GIC50) values of Cry1Ab protein expressed in Bt-Cry1Ab maize against ACB larvae were 0.036-0.109 μg mL-1 and 0.002-0.018 μg mL-1, respectively. The first and fourth instar ACB larvae were unable survive feeding on different tissues of Bt-Cry1Ab maize plants. Field experiments conducted from 2023 to 2024 indicated that the number of ACB larvae per 100 plants, plant damage rate, leaf damage rate, male ear damage rate, female ear damage rate, and stalk damage rate in the Bt-Cry1Ab maize fields were reduced by 95.36% ± 2.17%, 83.98% ± 1.73%, 89.45% ± 1.50%, 100.00% ± 0.00%, 69.79% ± 4.88% and 100.00% ± 0.00%, respectively, compared to conventional maize fields.

CONCLUSION

The ACB population in Sichuan Province, China is sensitive to Cry1Ab expressed in Bt-Cry1Ab maize (event DBN993). Planting Bt-Cry1Ab maize efficiently reduces the population of ACB larvae and the percentage of damaged maize plants, and has great application potential in the integrated pest management of the ACB in Sichuan Province, China. © 2024 Society of Chemical Industry.

RNAi-based transgenic maize to control double-spotted leaf beetle (Monolepta hieroglyphica)

BACKGROUND

The double-spotted leaf beetle (DLB), Monolepta hieroglyphica, is becoming a significant corn pest in China. It mainly attacks corn silk and developing kernels during the adult stage and is causing significant corn yield loss in north-eastern China. The damage caused by DLB is expected to worsen as pesticide usage is likely to decrease along with the upcoming commercial planting of transgenic lepidopteran-resistant maize in China. Therefore, it is highly desirable to develop transgenic corn for DLB resistance.

RESULTS

Three target genes, MhSsj1, MhSnf7 and MhSec23A were cloned from DLB by their sequence similarity to their corresponding homologous genes known for their effectiveness as RNA interference (RNAi) targets in western corn rootworm (WCR, Diabrotica virgifera virgifera). Injection of the double-stranded RNAs (dsRNAs) of MhSsj1, MhSnf7 and MhSec23A to DLB adults was highly effective to suppress the messenger RNAs (mRNAs) of these genes and resulted in high mortality. Furthermore, a synergistic effect was observed among the dsRNAs of these three target genes. Transgenic maize plants simultaneously transcribing dsRNAs of any two of the three target genes were found to be highly resistant to DLB adults, showcasing the potential of utilizing RNAi-based strategy for transgenic DLB control.

CONCLUSION

MhSsj1, MhSnf7 and MhSec23A are effective RNAi target genes and transgenic corn based on suppression of these genes by RNAi are effective for controlling adult DLB. © 2024 Society of Chemical Industry.

Lignocellulosic materials valorization in second generation biorefineries: an opportunity to produce fungal biopigments

Second generation biorefineries play an important role in the production of renewable energy and fuels, utilizing forest and agro-industrial residues and by-products as raw materials. The integration of novel bioproducts, such as: xylitol, β-carotene, xylooligosaccharides, and biopigments into the biorefinery's portfolio can offer economic benefits in the valorization of lignocellulosic materials, particularly cellulosic and hemicellulosic fractions. Fungal biopigments, known for their additional antioxidant and antimicrobial properties, are appealing to consumers and can have applications in various industrial sectors, including food and pharmaceuticals. The use of lignocellulosic materials as carbon and nutrient sources for the growth medium helps to reduce production costs, increasing the competitiveness of fungal biopigments in the market. In addition, the implementation of biopigment production in biorefineries allows the utilization of underutilized fractions, such as hemicellulose, for value-added bioproducts. This study deals with the potential of fungal biopigments production in second generation biorefineries in order to diversify the produced biomolecules together with energy generation. A comprehensive and critical review of the recent literature on this topic has been conducted, covering the major possible raw materials, general aspects of second generation biorefineries, the fungal biopigments and their potential for incorporation into biorefineries.

Dual-domain superoxide dismutase: In silico prediction directed combinatorial mutation for enhanced robustness and catalytic efficiency

The robustness and catalytic activity of superoxide dismutase (SOD) are still the main factors limiting their application in industrial fields. This study aims to further improve the properties of a natural thermophilic iron/manganese dual-domain SOD (Fe/Mn-SODA fused with N-terminal polypeptide) from Geobacillus thermodenitrificans NG80-2 (GtSOD) by modifying its each domain using in-depth in silico prediction analysis as well as protein engineering. First, computational analysis of the N-terminal domain and GtSODA domain was respectively performed by using homologous sequence alignment and virtual mutagenesis. Seven proposed mutation sites favoring increased robustness were screened out for single-point mutants (SPMs) construction. Enzymatic characterization of these SPMs identified the most favorable mutation sites E107 and S265 located in two different domains. Subsequently, the dual-domain site combinatorial mutant (DDSCM) E107L/S265K showed significant superposition effects and additional improvement in catalytic efficiency, with a Kcat/Km value of 145.45 %, 33.66 %, and 60.33 % higher than the wild type (WT), the SPMs E107L and S265K, respectively. Molecular dynamics simulations, structural and surface charge analysis revealed the possible mechanism by which combinatorial mutations improve the robustness and catalytic activity of GtSOD. Furthermore, DDSCM showed more significant resistance to ultraviolet B and various stress than WT, indicating its highly competitive industrial application prospects.

Exploration of the Out-of-Phase Phenomenon in Shake Flasks by CFD Calculations of Volumetric Power Input, kLa Value and Shear Rate at Elevated Viscosity

Culture broth with secreted macromolecules and culture broth of filamentous fungi showing disperse growth exhibit elevated viscosity, usually with shear-thinning flow behavior. High viscosity, however, poses a serious challenge in the production and research of these compounds and organisms. It commonly causes insufficient mixing and oxygen transfer in large- and small-scale bioreactors. Computational Fluid dynamics (CFD) has been proven to be a valuable tool for the computation of important bioprocess parameters. The published literature for small-scale shaken bioreactors, especially shake flasks, however, almost exclusively focuses on water-like viscosity. In this paper, a previously published CFD model for 250 mL shake flasks was used to simulate experiments at high viscosities of up to 100 mPa·s. Compared to experimental data, the CFD model accurately predicted the liquid distribution and computed the volumetric power input with a deviation of less than 7% and the kLa value within a factor of two, compared to the kLa correlation from Henzler and Schedel. Furthermore, a novel approach to compute the shear rate was tested. Lastly, new insights into the out-of-phase phenomenon were gained. The presented data confirms the usefulness of the already established critical phase numbers of 0.91 and 1.26, while underlying the fundamentally smooth transition from in-phase to out-of-phase operating conditions.

Genome-wide association study of rice (Oryza sativa L.) inflorescence architecture

Rice yield strongly depends on panicle size and architecture but the genetics underlying these traits and their coordination with environmental cues through various signaling pathways have remained elusive. A genome-wide association study (GWAS) was performed to pinpoint the underlying genetic determinants for rice panicle architecture by analyzing 20 panicle-related traits using a data set consisting of 44,100 SNPs. We defined QTL windows around significant SNPs by the rate of LD decay for each chromosome and used these windows to identify putative candidate genes associated with the trait. Using a publicly available RNA-seq data set we performed analyses to identify the differentially expressed genes between stem and panicle with putative functions in panicle architecture. In total, 52 significant SNPs were identified, corresponding to 41 unique QTLs across the 12 rice chromosomes, with the most signals appearing on chromosome 1 (nine associated SNPs), and seven significant SNPs for each of chromosomes 8 and 12. Some novel genes such as Ankyrin, Duf, Kinesin and Brassinosteroid insensitive were found to be associated with panicle size. A haplotype analysis showed that genetic variation in haplotypes qMIL2 and qNSBBH21 were related to two traits, MIL, the greatest distance between two nodes on the rachis, and NSBBH, the number of primary branches in the bottom half of a panicle, respectively. Analysis of epistatic interactions revealed a marker affecting clustered traits. Several QTLs were identified on different chromosomes for the first time which may explain the phenotypic diversity of rice panicle architecture we observe in our collection of accessions. The identified candidate genes and haplotypes could be used in marker-assisted selection to improve rice yield through gene pyramiding.

TaERFL1a enhances drought resilience through DHAR-mediated ASA-GSH biosynthesis in wheat

Wheat is one of the important cereal crops around the world, but it often suffers from abiotic stresses, which threaten food security. Thus, it is critical to identify the genes that determine drought tolerance in wheat. AP2/ERFs are known to regulate drought stress in various crops. In this study, TaERFL1a-overexpressing wheat transgenic lines (TaERFL1a-OEs) were used to determine drought resilience mechanism. After 12 d without watering, the growth phenotype of TaERFL1a-OEs was better than that of the wild type (WT), whose activities of superoxide dismutase and catalase, and contents of ascorbate acid (ASA) and glutathione (GSH) were significantly increased, while malondialdehyde content was significantly decreased. Transcriptome analysis revealed that 28,520 genes were differentially expressed between TaERFL1a-OEs and WT under drought condition. Further analysis found that these DEGs were involved in multiple stress-response processes, especially in the ASA-GSH pathway. qPCR revealed that the expression levels of GPX, DHAR, and MDHAR, which are suggested to be participated in ASA-GSH biosynthesis, were significantly up-regulated in TaERFL1a-OEs under drought stress, especially the DHAR gene. Moreover, dual-luciferase and luciferase complementation imaging revealed that TaERFL1a was more promoted DHAR transcription to a greater extent than other genes. Furthermore, yeast one-hybrid, electrophoretic mobility shift assay, and chromatin immunoprecipitation combined with qPCR revealed that TaERFL1a regulates DHAR expression by binding to the cis-element ERF in DHAR promoter and promotes the transcription of later in vivo and in vitro. Overall, our results provided molecular regulatory evidence for TaERFL1a in wheat drought stress and suggested candidate genes for improving drought-tolerant wheat breeding.

Repressor MrERF4 and Activator MrERF34 Synergistically Regulate High Flavonol Accumulation Under UV-B Irradiation in Morella rubra Leaves

Flavonols are important plant photoprotectants to defence UV-B irradiation, however, the underlying transcriptional regulatory mechanism of rapid flavonol accumulation in response to UV-B remains unknown. In this study, content of flavonols was significantly induced from 0.11 to 3.80 mg/g fresh weight by UV-B irradiation in leaves of Morella rubra seedlings. MrERF34 was identified as an activator that can regulate the expression of MrFLS2, and promoted flavonol biosynthesis with activator MrMYB12 under UV-B treatment. Transient overexpression of MrERF34 resulted in higher flavonol accumulation, while virus-induced gene silencing of MrERF34 reduced the content of flavonols in bayberry leaves. We further demonstrated that a repressor MrERF4 inhibited the expression of MrERF34 and MrMYB12 as well as MrFLS2 via ERF-associated-amphiphilic repression motif. Exposure to UV-B reduced the promoter activity and transcription of MrERF4, which weakened the inhibitory effect of MrERF4 on MrERF34, MrMYB12, and MrFLS2, leading to a tremendous accumulation of flavonols. Such inhibitory roles of MrERF4 in regulation of flavonol biosynthesis were further validated by transient overexpression in leaves of Nicotiana benthamiana and M. rubra. These findings enrich the synergistical regulatory mechanisms between repressor and activators in flavonol biosynthesis, and provide new insights into photoprotectants biosynthesis to mitigate UV-B stress in plants.

Structures and properties of α-amylase and glucoamylase immobilized by ZIF-8 via one-pot preparation

The immobilization of α-amylase and glucoamylase using a metal-organic framework (enzyme@ZIF-8) was prepared in situ through a one-pot method. The morphology, crystal structure, and molecular characteristics of the free enzyme and enzyme@ZIF-8 were characterized. The enzyme@ZIF-8 exhibited the rhombic dodecahedron morphology, with a decrease in particle size. Successful immobilization of α-amylase and glucoamylase within ZIF-8 was confirmed, with 30-40 % loading rate. The immobilization process did not significantly alter the crystal structure of ZIF-8. The changes in secondary structure of enzyme after immobilization resulted in modification of catalytic activity of enzyme. The melting enthalpy of enzyme @ZIF-8 increased with the increase of enzyme content. The melting peak temperature of the enzyme immobilized by ZIF-8 increased. The activity of free and immobilized enzymes was influenced by the different time, pH and temperature. At pH 5-8 and temperature 60-80 °C, the activity of the immobilized enzyme was significantly greater than that of the free enzyme. The repeatability of enzyme@ZIF-8 was 61.52 % after three cycles. The kinetic parameters of Michaelis-Menten model for enzymatic reaction were determined by fitting the initial rate of reactions and initial substrate concentration data. The Michaelis-Menten constant (KM) values of immobilized enzyme were lower than that of free enzyme, indicating the greater affinity between the enzyme and the substrate.

Microbial exopolysaccharides: Classification, biosynthetic pathway, industrial extraction and commercial production to unveil its bioprospection: A comprehensive review

Polysaccharides, found universally in all living-species, exhibit diverse biochemical structures and play crucial roles in microorganisms, animals, and plants to defend against pathogens, environmental stress and climate-changing. Microbial exopolysaccharides are essential for cell adhesion and stress resilience and using them has notable advantages over synthetic polysaccharides. Exopolysaccharides have versatile structures and physicochemical properties, used in food systems, therapeutics, cosmetics, agriculture, and polymer industries. Immense economic and infrastructural constraints hinder its widespread commercial use, necessitating a deeper understanding of metabolic-pathways amidst changing environmental climate that influences the biomass composition of EPS-producing wild-microbes. Green and sustainable extraction of EPS from microbes followed by commercial product development has still not been exploited comprehensively. Yield of EPS production vary from 0.1 to 3 g/g of cell weight, influenced by fermentation conditions. Economic barriers, including substrate and processing costs, limit commercial viability. Key biosynthetic pathways involve glycosyltransferases enzymes, whose regulatory network gaps and substrate specificity remain areas for optimization. Addressing these could enhance yields and lower production costs. Review illustrates various microbial-exopolysaccharides, influencing factors of production, and offer valuable insights on the bioplastic, biofuel, agri-bioproduct, and biomedicine. But their bioprospecting potential is yet to be exhaustively explored, along with their pros and cons nor documented comprehensively in scientific literature.

Is it possible to shape the microalgal biomass composition with operational parameters for target compound accumulation?

Microalgae, as photosynthetic microorganisms, offer a sustainable source of proteins, lipids, carbohydrates, pigments, vitamins, and antioxidants. Leveraging their advantages, such as fast growth, CO2 fixation, cultivation without arable land, and wastewater utilisation, microalgae can produce a diverse range of compounds. The extracted products find applications in bioenergy, animal feed, pharmaceuticals, nutraceuticals, cosmetics, and food industries. The selection of microalgal species is crucial, and their biochemical composition varies during growth phases influenced by environmental factors like light, salinity, temperature, and nutrients. Manipulating growth conditions shapes biomass composition, optimising the production of target compounds. This review synthesises research from 2019 onwards, focusing on stress induction and two-stage cultivation in microalgal strategies. This review takes a broader approach, addressing the effects of various operating conditions on a range of biochemical compounds. It explores the impact of operational parameters (light, nutrient availability, salinity, temperature) on biomass composition, elucidating microalgal mechanisms. Challenges include species-specific responses, maintaining stable conditions, and scale-up complexities. A two-stage approach balances biomass productivity and compound yield. Overcoming challenges involves improving upstream and downstream processes, developing sophisticated monitoring systems, and conducting further modelling work. Future efforts should concentrate on strain engineering and refined monitoring, facilitating real-time adjustments for optimal compound accumulation. Moreover, conducting large-scale experiments is essential to evaluate the feasibility and sustainability of the process through techno-economic analysis and life cycle assessments.

Insights into the low-temperature adaptation of an enzyme as studied through ancestral sequence reconstruction

For billions of years, enzymes have evolved in response to the changing environments in which their host organisms lived. Various lines of evidence suggest the earliest primitive organisms inhabited high-temperature environments and possessed enzymes adapted to such conditions. Consequently, extant mesophilic and psychrophilic enzymes are believed to have adapted to lower temperatures during the evolutionary process. Herein, we analyzed this low-temperature adaptation using ancestral sequence reconstruction. Previously, we generated the phylogenetic tree of 3-isopropylmalate dehydrogenases (IPMDHs) and reconstructed the sequence of the last bacterial common ancestor. The corresponding ancestral enzyme displayed high thermostability and catalytic activity at elevated temperatures but moderate activity at low temperatures (Furukawa et al., Sci. Rep., 2020;10:15493). Here, to identify amino acid residues that are responsible for the low-temperature adaptation, we reconstructed and characterized all 11 evolutionary intermediates that sequentially connect the last bacterial common ancestor with extant mesophilic IPMDH from Escherichia coli. A remarkable change in catalytic properties, from those suited for high reaction temperatures to those adapted for low temperatures, occurred between two consecutive evolutionary intermediates. Using a combination of sequence comparisons between ancestral proteins and site-directed mutagenesis analyses, three key amino acid substitutions were identified that enhance low-temperature catalytic activity. Intriguingly, amino acid substitutions that had the most significant impact on activity at low temperatures displayed no discernable effect on thermostability. However, these substitutions markedly reduced the activation energy for catalysis, thereby improving low-temperature activity. The results were further investigated by molecular dynamics simulations of the predicted structures of the ancestral enzymes. Our findings exemplify how ancestral sequence reconstruction can identify residues crucial for adaptation to low temperatures.

The key molecular mechanisms of antagonism induced by combined exposure to erythromycin and roxithromycin in Chlorella pyrenoidosa

Emerging pollutants such as antibiotics have raised great concern in recent years, but the complex coexistence of multiple antibiotics in the environment poses a new challenge in the accurate assessment of the toxicity of antibiotics to aquatic organisms such as microalgae. In this study, the mechanism of action of a combination of erythromycin (ERY) and roxithromycin (ROX) on Chlorella pyrenoidosa was illustrated based on the physiological-biochemical response and transcriptomic analysis. The results revealed an inhibitory effect on the biomass of C. pyrenoidosa at 14 d in all treatment groups, whereas an antagonistic effect was observed in the coexposure groups. The photosystem was the main target despite the existence of multiple compensatory mechanisms, such as expanding the antenna size and initiating alternative electron carriers. The intercept of electrons on the donor side of PSI limited the production of energy, whereas the adjustment of the content and ratio of pigments strengthened microalgal adaptation. Enzymes and genes related to the degradation of exogenous compounds, including cytochrome P450 (P450), glutathione S-transferase (GST) and ABC transporters, mediated the detoxification of antibiotics. The upregulated expression of related genes induced by coexposure increased resistance and explained the antagonistic effects. The shift in energy allocation by increasing the proportion of lipids met the urgent requirements of microalgal physiological activities. This study reemphasizes the modes of interactions between multiple antibiotics and provides new insights into the mechanisms of antagonism induced by combinations of antibiotics.

Efficiency and process development for microbial biomass production using oxic bioelectrosynthesis

Autotrophic microbial electrosynthesis (MES) processes are mainly based on organisms that rely on carbon dioxide (CO2) as an electron acceptor and typically have low biomass yields. However, there are few data on the process and efficiencies of oxic MES (OMES). In this study, we used the knallgas bacterium Kyrpidia spormannii to investigate biomass formation and energy efficiency of cathode-dependent growth. The study revealed that the process can be carried out with the same electron efficiency as conventional gas fermentation, but overcomes disadvantages, such as the use of explosive gas mixtures. When accounting only for the electron input via electrical energy, a solar energy demand of 67.89 kWh kg-1 dry biomass was determined. While anaerobic MES is ideally suited to produce methane, short-chain alcohols, and carboxylic acids, its aerobic counterpart could extend this important range of applications to not only protein for use in the food and feed sector, but also further complex products.

Soil Cadmium Pollution Decreases Phosphorus-Mineralizing Microbial Diversity and Reduces Phosphorus Availability

Cadmium (Cd) has become a major environmental concern, adversely affecting soil quality and crop productivity. Cd pollution disrupts soil nutrient cycling, particularly phosphorus (P), which is crucial for plant growth. In this study, we conducted a meta-analysis to assess the impact of Cd on soil phosphorus availability, followed by pot experiments using maize (Zea mays) to investigate the effects of varying Cd concentrations (0, 0.5, 1.0, 2.5, and 5.0 mg/kg) on phosphorus uptake, soil phosphorus fractions, and microbial diversity. The results revealed that when soil Cd concentrations exceeded 1.0 mg/kg, maize growth and phosphorus uptake were significantly inhibited (P < 0.05), with a 25.3-64.9% reduction in yield. Cd pollution decreased soil available phosphorus and altered its chemical forms, as indicated by a decrease in soluble P fractions (H2O-Pi, NaHCO3-Pi) and an increase in insoluble P fractions (NaOH-Pi, HCl-Pi). Total organic and inorganic phosphorus increased by 5.6-29.4% and 5.8-23.5%, respectively, while active phosphorus decreased by 19.3-58.6%, and steady-state phosphorus increased by 5.2-26.0%. The activities of alkaline phosphatase (AKP) and acid phosphatase (ACP) were significantly reduced under higher Cd concentrations (P < 0.05). Microbial biomass carbon (MBC) decreased significantly, while phosphorus transformation-related genes (phoD, phnK, ppx, pqqC) were reduced by up to 82.4%. In summary, Cd pollution significantly alters maize rhizosphere microbial communities, reduces the abundance of phosphorus transformation-related microorganisms and functional genes, and disputes phosphorus mineralization. These changes reduced soil active phosphorus content, ultimately decreasing phosphorus availability for maize. This study emphasizes the need for further research on Cd-induced phosphorus transformation mechanisms and microbial responses, and suggests developing soil management strategies to mitigate the adverse effects of Cd on phosphorus availability.

Kraft lignin biobleaching by a dye-decolorizing peroxidase from the Antarctic Pseudomonas sp. AU10 strain

Pseudomonas sp. AU10 is an Antarctic psychrotolerant bacterium that produces a dye-decolorizing peroxidase (DyP-AU10). The recombinant enzyme (rDyP-AU10) is a heme-peroxidase that decolors dyes and modifies kraft lignin. In this work, we report the best activity parameters for lignin modification (at 45 °C and pH 4) and show that the enzyme increases the number of aldehydes, ketones, and phenolic compounds. The analyses of the HPLC profile of samples also support that rDyP-AU10 induces the chemical change of kraft lignin. The enzyme also acts as a biobleaching agent on cellulose pulps, as shown by the reduction in kappa number. We also included experiments with a commercial laccase from Trametes versicolor and performed experiments using single enzymes and, in combination. The results show that rDyP-AU10 and the commercial laccase do not have a synergic activity as a modifying system, on cellulose pulp as substrates. However, results suggest that rDyP-AU10 holds potential as a member of the portfolio of lignin-modifying enzymes.

Phenylpropanoids for the control of fungal diseases of postharvest fruit

In recent years, there has been a growing interest in developing greener and safer substances for the control of postharvest fungal diseases of fruit. Secondary metabolic pathways play an important role in plant defense responses, and the phenylpropanoid metabolic pathway is one of the most important secondary metabolic pathways in plant defense. More and more studies have shown that exogenous phenylpropanoids treatments can inhibit postharvest fungal diseases. On the one hand, these biologically active phenylpropanoids are fungistatic and can act directly on the fungal cells infesting the postharvest fruit to inhibit spore germination and mycelial growth. On the other hand, phenylpropanoids treatment can improve plant resistance. In this review, we summarize recent achievements in the mechanisms and applications of phenylpropanoids, including cinnamic acid, p-coumaric acid and esters, caffeic acid, ferulic acid, and chlorogenic acid, in the inhibition of fungal pathogens and the reduction of postharvest losses. In addition, we propose further research hotspots and development directions based on combining nanomaterials and biotechnology.

Directional anchoring of polymer-lysozyme nanohybrids for adhesive capture and enhanced removal of Alicyclobacillus acidoterrestris in fruit juices

The acidophilic and heat-resistant traits of Alicyclobacillus acidoterrestris (A. acidoterrestris) present a formidable challenge to fruit juices production safety. To address the limitations of conventional thermal sterilization, a novel bacterial capture device MPDEL has been developed. This innovative device utilizes dopamine-coated magnetic nanoparticles that are covalently linked with lysozyme, enabling efficient and rapid capture of A. acidoterrestris in acidic juices, followed by facile magnetic-controlled separation for subsequent removal. Lysozyme not only recognizes and directional anchors the bacterial surface, but facilitates the adhesion of polydopamine to the bacterial surface. Benefiting from the abundant binding sites and rapid adsorption kinetics, this un-thermal treatment completely removes 104 CFU/mL of A. acidoterrestris from the juice within a span of 20 min. The MPDEL exhibits high capture performance, negligible cytotoxicity and no discernable impact on juice quality, offering a novel option for the removal of A. acidoterrestris from fruit juices.

Optimization of co-valorisation techniques for dairy and paper pulp wastewater in the cultivation of Chlorococcum sp. with a focus on mixture design, microwave-assisted pretreatment, and bioethanol production

This study optimized biomass and lipid accumulation using mixed dairy and paper-pulp wastewater for the cultivation of Chlorococcum sp. The obtained microalgal biomass was thereafter subjected to microwave-assisted pretreatment for optimal fermentable sugar release. Microwave power (100-700 W), pretreatment time (1-7 min), and acid-liquid ratio (1-5 %) were the input parameters for the pretreatment optimization study. The wastewater mixture ratios (25:75, 50:50, 100:0) of dairy and paper-pulp wastewater (DWW and PWW respectively) were achieved using simplex lattice mixture design to obtain high biomass and lipid accumulation in Chlorococcum sp cultivation. The model recommended a mixture of 64.69 % DWW and 35.31 % PWW for optimal biomass concentration, and a ratio of 34.21 % DWW and 65.79 % PWW for maximum lipid accumulation, predicting biomass concentration of 1.17 g/L and lipid accumulation of 0.39 g/g. Experimental validation resulted in biomass concentration and lipid accumulation 0.94 g/L and 0.39 g/g, respectively. Moreover, the experimental confirmation of the predicted fermentable sugar (11.14 g/L) yielded 15.67 g/L with pretreatment set points of 2.52 % HCl for 4.06 min at 700 W. Additionally, the prospect of the optimized pretreated microalgal biomass for bioethanol production (7.85 g/L) was achieved. Findings from this study could facilitate the implementation of DWW and PWW wastewaters utilization that could significantly lower the use of scarce potable water in keeping with portable water, energy, and environmental sustainability nexus towards the realisation of a circular bioeconomy.

The hypoglycemic effect of mulberry (Morus atropurpurea) fruit lacking fructose and glucose by regulation of the gut microbiota

Mulberries are known to be rich in hypoglycemic active substances such as anthocyanins and dietary fiber, which primarily aid in regulating gut microbiota. However, their high sugar content, such as fructose, hinders their application in hypoglycemic functional foods. This research utilized microbial fermentation technology to remove the fructose and glucose in mulberries (FM), subsequently evaluating their hypoglycemic properties and balancing gut microbiota. Results indicated that administering varying doses of FM to type 2 diabetic mice for five weeks notably decreased blood sugar and insulin levels, improved dyslipidemia and insulin resistance, enhanced antioxidant capacity, repaired organ damage, and regulated hypoglycemic activity by influencing mRNA expression of key signaling factors in the PI3K/Akt and AMPK pathways. Analysis of the intestinal microbiota composition revealed that FM can modulate specific bacterial populations, increasing beneficial bacteria like Lactobacillus, Bifidobacterium and Akkermansia while inhibiting harmful bacteria like Escherichia-Shigella and Helicobacter. This restoration of the intestinal microecological balance helped regulate host sugar metabolism homeostasis and affect the secretion of short chain fatty acid (SCFA) synthase in the gut microbiota to increase the production of SCFAs. These findings offer significant support for the potential use of FM in the treatment of diabetes.

Automated Laser-Assisted Single-Cell Sorting for Cell Functional and RNA Sequencing

Accurate and efficient sorting of single target cells is crucial for downstream single-cell analysis, such as RNA sequencing, to uncover cellular heterogeneity and functional characteristics. However, conventional single-cell sorting techniques, such as manual micromanipulation or fluorescence-activated cell sorting, do not match current demands and are limited by low throughput, low sorting efficiency and precision, or limited cell viability. Here, we report an automated, highly efficient single-cell sorter, integrating laser-induced forward transfer (LIFT) with a high-throughput picoliter micropore array. The micropore array was surface-functionalized to manipulate liquid surface tension, facilitating the formation of single-cell picoliter droplets in the micropores to realize automated and highly efficient (>80%) single-cell isolation. Using an in-house built microscopic system, rare target cells were identified and automatically retrieved by LIFT with precise sorting efficiency (about 100%) for downstream single-cell analysis while maintaining high cell viability (about 80%). As a case demonstration, we demonstrated the accurate sorting of rare transfected PC-9 cells and post-transfection cell culture, minimizing cell loss and the risk of contamination. Furthermore, we performed single-cell RNA sequencing and showed that high-quality single-cell transcriptome information was efficiently and reliably obtained during cell sorting, preventing additional costs due to low sorting accuracy. The single-cell sorter will become invaluable for single-cell analysis, laying the foundation for multiomics analysis and precision medicine research.

From the lab to the field and closer to the market: Production of the biopolymer cyanophycin in plants

A range of studies has investigated the production of biopolymers in plants but a comprehensive assessment of feasibility and environmental safety and consumer acceptance is lacking. This review delivers such an assessment. It describes the establishment of the production in tobacco and potato, the analysis of lead events in the greenhouse and in the field, the establishment and upscaling of effective isolation processes and storage conditions, taking the cyanobacterial storage peptide cyanophycin (CGP) as an example. The paper lists several industrial and medical applications of CGP and its building blocks Arg-Asp-dipeptides. This production is especially interesting because the CGP content can exceed 10% of the dry weight (dw) in the greenhouse and still deliver 4 gram per plant in the field. Furthermore, risk assessment of CGP production in potatoes in vitro, in vivo, in the greenhouse, and in the field showed no relevant differences concerning environment or consumer safety compared with the near isogenic control. A consumer choice analysis in four European countries showed a preference for biodegradable CGP in food-wrapping materials over conventional plastic wrapping. Although data on economic feasibility is lacking, CGP as a renewable, biodegradable and CO2-neutrally produced compound, is preferable over fossil fuels in many applications.

Investigating the production and synergistic antibacterial activity of bacteriocin-like substance from Brevibacillus laterosporus SA-14 (TISTR 2453) for enhanced wound healing

The rise in antimicrobial-resistant (AMR) bacteria, especially Methicillin-resistant Staphylococcus aureus (MRSA), is a global health concern. Bacteriocins are promising antibiotic alternatives. This study aimed to enhance the production of bacteriocin-like substances (BLS) from Brevibacillus laterosporus SA-14 (TISTR 2453) by optimizing nutrients, evaluating antibacterial activity, assessing synergy with vancomycin, and testing the cytotoxicity and wound healing effects on human keratinocytes. The results showed that when the SA-14 strain was cultured in half-formula Luria-Bertani broth (LB/2) with added carbon sources (glucose, sucrose, and lactose), all cultures reached the late log phase at 24 h, and antibacterial activity was exhibited against various MRSA strains after 48 h, except for the LB/2 supplemented with glucose, likely due to carbon catabolite repression. However, the addition of nitrogen sources, including skim milk, peptone, and beef extract resulted in high antibacterial activity at 48 h, with skim milk being the most effective for BLS production. The BLS was precipitated with 80 % ammonium sulfate, achieving a 38.09 % yield and a protein concentration of 6.97 ± 1.12 mg/mL. The SDS-PAGE analysis revealed five bands of proteins with molecular weights of 25-250 kDa. The minimum inhibitory concentration of BLS ranged from 0.44 to 0.87 mg/mL, with an minimum bactericidal concentration) of 0.87 mg/mL for all MRSA strains. A synergistic effect with vancomycin was observed at 0.22 mg/mL BLS and 1 μg/mL vancomycin, with an fractional inhibitory concentration index of 1.00, indicating an additive effect. At a concentration of 0.22 mg/mL, BLS was non-cytotoxic to HaCaT cells and promoted complete wound healing after 48 h. Therefore, BLS produced by the SA-14 strain is suitable for controlling AMR, especially MRSA, and has the potential for application in wound dressings in the future.

Magnesium ions enhance biogenic amine degradation by Pichia kudriavzevii MZ5: Insights from transcriptomics and novel recombinant enzyme expression

The modification of enzymes by Mg2+ may enhance their functional properties. In this study, we investigated the role of Mg2+ in the degradation of biogenic amines (BAs) using yeast enzymes. Research has found that adding 0.2 g/L Mg2+ significantly enhances the degradation efficiency of Pichia kudriavzevii MZ5 towards BAs, increasing the degradation rates of histamine and tyramine by 6.6 times and 5.4 times, respectively. Through transcriptome analysis and NCBI database screening, the gene 0PichiaG024360, homologous to the known laccase gene 18-L-14 and specific to P. kudriavzevii, was identified and shown to have 2.8 times higher expression in Mg2+-treated yeast. Kyoto Encyclopedia of Genes and Genomes analysis indicated that Mg2+ activates energy and amino acid metabolism pathways, thereby enhancing BA degradation. The PichiaZGC2436 enzyme encoded by the 0PichiaG024360 gene was expressed in Escherichia coli BL-21(DE3) and showed stability at pH 4.5-6 and 25-37 °C, optimal pH at 4.5 and optimal temperature at 37 °C. This enzyme degraded several BAs, achieving a 93 % total amine degradation rate within 48 h, including 54.1 % histamine degradation and 100 % tryptamine, phenylethylamine, cadaverine, spermidine, and spermine degradation. These findings suggest a new strategy for enhancing yeast-mediated BA degradation using Mg2+ to improve the quality and safety of fermented foods.

Improvement of torularhodin production by Rhodotorula glutinis through the stimulation of physicochemical stress and application of the bioproduct as an additive in the food industry

Carotenoids are pigments responsible for the red-orange colorations in valuable food products, and they can be produced via biotechnological means through microorganisms. Beyond their role as natural colorants, some carotenoids offer significant health benefits due to their antioxidant properties, making them valuable nutritional additives in the food industry. However, obtaining these compounds from natural sources with high quantity and purity poses challenges which reduces its market share when produced through a biotechnological route. This study proposes utilizing nutritional and physical stress to enhance carotenoid production, specifically torularhodin, using the yeast Rhodotorula glutinis CCT-2186. A Design of Experiments approach identified malt extract as the most suitable nitrogen source for maximizing carotenoid production. Furthermore, introducing a surfactant (Tween 80) in the culture medium, and extending the cultivation time to 96 h, led to an increase in torularhodin production, reaching a notable 2.097 mg/mL (377,68% more when compared to the initial condition) under the best condition [(%w/v): dextrose (1), KH2PO4 (0.052), MgSO4.7H2O (0.052) and NH4NO3 (0.4), malt extract with a pH of 5.0/ 96 h/30 °C]. Lastly, to demonstrate the viability of utilizing the carotenoid extract as a food colorant, it was applied in edible gelatin. These findings highlight the critical role of nutritional, physical, and mechanical stresses in optimizing torularhodin production, particularly the conversion of γ-carotene to torularhodin by R. glutinis.

Enhancing denitrifying anaerobic methane oxidation for nitrogen removal with low-temperature biochar

Denitrifying Anaerobic Methane Oxidation (DAMO), which utilizes methane for denitrification, offers an efficacious approach for nitrogen removal in wastewater and greenhouse gas mitigation. However, slow microbial growth and low methane mass transfer efficiency limit its practical application. This study demonstrates that straw biochar, particularly when pyrolyzed at 300 °C, enhances DAMO's nitrogen removal performance. Specifically, biochar from cotton (CB300) and maize (MB300) stalks at 300 °C increased the nitrate removal rate by 2.6 and 2.4 times, respectively, compared to the control. Correlation analysis revealed a positive link between nitrate removal rates and oxygen-containing functional groups in biochar, which may facilitate electron transfer. Long-term DAMO reactor operation confirmed significant enhancements in nitrogen removal with 300 °C biochars. CB300 and MB300 biochars increased key functional genes (mcrA and pmoA) and enriched DAMO archaea (ANME-2D). These findings suggest that low-temperature biochar is a cost-effective and sustainable approach to enhance the nitrogen removal performance of DAMO.