Trametes versicolor Laccase-Based Magnetic Inorganic-Protein Hybrid Nanobiocatalyst for Efficient Decolorization of Dyes in the Presence of Inhibitors

In the present investigation, an ecofriendly magnetic inorganic-protein hybrid system-based enzyme immobilization was developed using partially purified laccase from Trametes versicolor (TvLac), Fe3O4 nanoparticles, and manganese (Mn), and was successfully applied for synthetic dye decolorization in the presence of enzyme inhibitors. After the partial purification of crude TvLac, the specific enzyme activity reached 212 U∙mg total protein-1. The synthesized Fe3O4/Mn3(PO4)2-laccase (Fe3O4/Mn-TvLac) and Mn3(PO4)2-laccase (Mn-TvLac) nanoflowers (NFs) exhibited encapsulation yields of 85.5% and 90.3%, respectively, with relative activities of 245% and 260%, respectively, compared with those of free TvLac. One-pot synthesized Fe3O4/Mn-TvLac exhibited significant improvements in catalytic properties and stability compared to those of the free enzyme. Fe3O4/Mn-TvLac retained a significantly higher residual activity of 96.8% over that of Mn-TvLac (47.1%) after 10 reuse cycles. The NFs showed potential for the efficient decolorization of synthetic dyes in the presence of enzyme inhibitors. For up to five reuse cycles, Fe3O4/Mn-TvLac retained a decolorization potential of 81.1% and 86.3% for Coomassie Brilliant Blue R-250 and xylene cyanol, respectively. The synthesized Fe3O4/Mn-TvLac showed a lower acute toxicity towards Vibrio fischeri than pure Fe3O4 nanoparticles did. This is the first report of the one-pot synthesis of biofriendly magnetic protein-inorganic hybrids using partially purified TvLac and Mn.

Attenuation of Las/Rhl quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa PAO1 by Artocarpesin

The emergence of multidrug resistance and increased pathogenicity in microorganisms is conferred by the presence of highly synchronized cell density dependent signalling pathway known as quorum sensing (QS). The QS hierarchy is accountable for the secretion of virulence phenotypes, biofilm formation and drug resistance. Hence, targeting the QS phenomenon could be a promising strategy to counteract the bacterial virulence and drug resistance. In the present study, artocarpesin (ACN), a 6-prenylated flavone was investigated for its capability to quench the synthesis of QS regulated virulence factors. From the results, ACN showed significant inhibition of secreted virulence phenotypes such as pyocyanin (80%), rhamnolipid (79%), protease (69%), elastase (84%), alginate (88%) and biofilm formation (88%) in opportunistic pathogen, Pseudomonas aeruginosa PAO1. Further, microscopic observation of biofilm confirmed a significant reduction in biofilm matrix when P. aeruginosa PAO1 was supplemented with ACN at its sub-MIC concentration. Quantitative gene expression studies showed the promising aspects of ACN in down regulation of several QS regulatory genes associated with production of virulence phenotypes. Upon treatment with sub-MIC of ACN, the bacterial colonization in the gut of Caenorhabditis elegans was potentially reduced and the survival rate was greatly improved. The promising QS inhibition activities were further validated through in silico studies, which put an insight into the mechanism of QS inhibition. Thus, ACN could be considered as possible drug candidate targeting chronic microbial infections.

Sequential Co-Immobilization of Enzymes on Magnetic Nanoparticles for Efficient l-Xylulose Production

Multi-enzymatic strategies have shown improvement in bioconversion during cofactor regeneration. In this study, purified l-arabinitol 4-dehydrogenase (LAD) and nicotinamide adenine dinucleotide oxidase (Nox) were immobilized via individual, mixed, and sequential co-immobilization approaches on magnetic nanoparticles, and were evaluated to enhance the conversion of l-arabinitol to l-xylulose. Initially, the immobilization of LAD or Nox on the nanoparticles resulted in a maximum immobilization yield and relative activity of 91.4% and 98.8%, respectively. The immobilized enzymes showed better pH and temperature profiles than the corresponding free enzymes. Furthermore, co-immobilization of these enzymes via mixed and sequential methods resulted in high loadings of 114 and 122 mg/g of support, respectively. Sequential co-immobilization of these enzymes proved more beneficial for higher conversion than mixed co-immobilization because of better retaining Nox residual activity. Sequentially co-immobilized enzymes showed a high relative conversion yield with broader pH, temperature, and storage stability profiles than the controls, along with high reusability. To the best of our knowledge, this is the first report on the mixed or sequential co-immobilization of LAD and Nox on magnetic nanoparticles for l-xylulose production. This finding suggests that selecting a sequential co-immobilization strategy is more beneficial than using individual or mixed co-immobilized enzymes on magnetic nanoparticles for enhancing conversion applications.

Manipulating Microbial Cell Morphology for the Sustainable Production of Biopolymers

The total rate of plastic production is anticipated to surpass 1.1 billion tons per year by 2050. Plastic waste is non-biodegradable and accumulates in natural ecosystems. In 2020, the total amount of plastic waste was estimated to be 367 million metric tons, leading to unmanageable waste disposal and environmental pollution issues. Plastics are produced from petroleum and natural gases. Given the limited fossil fuel reserves and the need to circumvent pollution problems, the focus has shifted to biodegradable biopolymers, such as polyhydroxyalkanoates (PHAs), polylactic acid, and polycaprolactone. PHAs are gaining importance because diverse bacteria can produce them as intracellular inclusion bodies using biowastes as feed. A critical component in PHA production is the downstream processing procedures of recovery and purification. In this review, different bioengineering approaches targeted at modifying the cell morphology and synchronizing cell lysis with the biosynthetic cycle are presented for product separation and extraction. Complementing genetic engineering strategies with conventional downstream processes, these approaches are expected to produce PHA sustainably.

Denovo production of resveratrol by engineered Saccharomyces cerevisiae W303-1a using pretreated Gracilaria corticata extracts

OBJECTIVE

Assembly and construction of resveratrol production pathway in Saccharomyces cerevisiae for denovo production of resveratrol using seaweed extract as fermentation medium.

RESULTS

Genes involved in the production of resveratrol from tyrosine pathway, tyrosine ammonia lyase (FTAL) gene from Flavobacterium johnsoniae (FjTAL), the 4-coumarate:CoA ligase gene from Arabidopsis thaliana (4CL1) and the stilbene synthase gene from Vitis vinifera (VvSTS) were introduced into low copy, high copy and integrative vector and transformed into S. cerevisiae W303-1a. The resulting strains W303-1a/pARS-res5, W303-1a/2µ-res1 and W303-1a/IntUra-res9 produced a level of 2.39 ± 0.01, 3.33 ± 0.03 and 8.34 ± 0.03 mg resveratrol l-1 respectively. CRISPR mediated integration at the δ locus resulted in 17.13 ± 1.1 mg resveratrol l-1. Gracilaria corticata extract was tested as a substrate for the growth of transformant to produce resveratrol. The strain produced a comparable level, 13.6 ± 0.54 mg resveratrol l-1 when grown in seaweed extract medium.

CONCLUSIONS

The strain W303-1a/IntδC-res1 utilized Gracillaria hydrolysate and produced 13.6 ± 0.54 mg resveratrol l-1 and further investigations are being carried out focusing on pathway engineering and optimization of process parameters to enhance resveratrol yield.

Bacterial biofilm inhibitors: An overview

Bacteria that cause infectious diseases adopt biofilms as one of their most prevalent lifestyles. Biofilms enable bacteria to tolerate environmental stress and evade antibacterial agents. This bacterial defense mechanism has rendered the use of antibiotics ineffective for the treatment of infectious diseases. However, many highly drug-resistant microbes have rapidly emerged owing to such treatments. Different signaling mechanisms regulate bacterial biofilm formation, including cyclic dinucleotide (c-di-GMP), small non-coding RNAs, and quorum sensing (QS). A cell density-dependent phenomenon, QS is associated with c-di-GMP (a global messenger), which regulates gene expression related to adhesion, extracellular matrix production, the transition from the planktonic to biofilm stage, stability, pathogenicity, virulence, and acquisition of nutrients. The article aims to provide information on inhibiting biofilm formation and disintegrating mature/preformed biofilms. This treatment enables antimicrobials to target the free-living/exposed bacterial cells at lower concentrations than those needed to treat bacteria within the biofilm. Therefore, a complementary action of antibiofilm and antimicrobial agents can be a robust strategic approach to dealing with infectious diseases. Taken together, these molecules have broad implications for human health.

Coriolus versicolor laccase-based inorganic protein hybrid synthesis for application in biomass saccharification to enhance biological production of hydrogen and ethanol

In this study, a bio-friendly inorganic protein hybrid-based enzyme immobilization system using partially purified Coriolus versicolor laccase (CvLac) was successfully applied to biomass hydrolysis for the enhancement of sugar production aimed at generating biofuels. After four days of incubation, the maximum CvLac production was achieved at 140 U/mg of total protein in the presence of inducers such as copper and wheat bran after four days of incubation. Crude CvLac immobilized through inorganic protein hybrids such as nanoflowers (NFs) using zinc as Zn3(PO4)2/CvLac hybrid NFs (Zn/CvLac-NFs) showed a maximum encapsulation yield of 93.4% and a relative activity of 265% compared to free laccase. The synthesized Zn/CvLac-NFs exhibited significantly improved activity profiles and stability compared to free enzymes. Furthermore, Zn/CvLac-NFs retained a significantly high residual activity of 96.2% after ten reuse cycles. The saccharification of poplar biomass improved ∼2-fold in the presence of Zn/CvLac-NFs, with an 8-fold reduction in total phenolics compared to the control. The Zn/CvLac-NFs treated biomass hydrolysate showed high biological hydrogen (H2) production and ethanol conversion efficiency of up to 2.68 mol/mol of hexose and 79.0% compared to the control values of 1.27 mol of H2/mol of hexose and 58.4%, respectively. The CvLac hybrid NFs are the first time reported for biomass hydrolysis, and a significant enhancement in the production of hydrogen and ethanol was reported. The synthesis of such NFs based on crude forms of diverse enzymes can potentially be extended to a broad range of biotechnological applications.

Encapsulation of Methanotrophs within a Polymeric Matrix Containing Copper- and Iron-Based Nanoparticles to Enhance Methanol Production from a Simulated Biogas

The production of renewable energy or biochemicals is gaining more attention to minimize the emissions of greenhouse gases such as methane (CH4) and carbon dioxide for sustainable development. In the present study, the influence of copper (Cu)- and iron (Fe)-based nanoparticles (NPs), such as Cu, Fe3O4, and CuFe2O4, was evaluated during the growth of methanotrophs for inoculum preparation and on the development of a polymeric-matrix-based encapsulation system to enhance methanol production from simulated biogas (CH4 and CO2). The use of simulated biogas feed and the presence of NP-derived inoculums produce a remarkable enhancement in methanol production up to 149% and 167% for Methyloferula stellata and Methylocystis bryophila free-cells-based bioconversion, respectively, compared with the use of pure CH4 as a control feed during the growth stage. Furthermore, these methanotrophs encapsulated within a polymeric matrix and NPs-based systems exhibited high methanol production of up to 156%, with a maximum methanol accumulation of 12.8 mmol/L over free cells. Furthermore, after encapsulation, the methanotrophs improved the stability of residual methanol production and retained up to 62.5-fold higher production potential than free cells under repeated batch reusability of 10 cycles. In the presence of CH4 vectors, methanol production by M. bryophila improved up to 16.4 mmol/L and retained 20% higher recycling stability for methanol production in paraffin oil. These findings suggest that Cu and Fe NPs can be beneficially employed with a polymeric matrix to encapsulate methanotrophs and improve methanol production.

Fracture Liaison Service and Its Role in Secondary Fracture Prevention in Malaysia: A Scoping Review

Introduction

Fragility fractures, which occur after a low-trauma injury, increases with advancing age. Such fracture doubles the life-time risk of sustaining another fracture. This risk is highest in the immediate 18 months after the index fracture. However, most patients do not receive the appropriate risk assessment and intervention to reduce this risk. A coordinated model of care termed Fracture Liaison Service (FLS) has been reported to address this treatment gap.

Materials and methods

This scoping review aims to explore the potential role and delivery of FLS services in Malaysia. Scientific and non-scientific sources relevant to FLS were identified from electronic bibliographic databases, specialist journals and relevant websites. Findings were categorised into themes and presented narratively.

Results

FLS services remain concentrated in the Klang Valley. Even within FLS services, many do not have extensive coverage to risk assess all fracture patients. These services are multidisciplinary in nature where there are links between different departments, such as orthopaedics, osteoporosis expertise, bone densitometry, rehabilitation, falls services and primary care. FLS was able to increase the number of people undergoing fracture risk assessment and treatment. The importance of FLS was highlighted by local experts and stakeholders. Its implementation and delivery are supported by a number of national guidelines.

Conclusion

FLS is central to our national efforts to reduce the impending fragility fracture crisis in the coming years. Continued effort is needed to increase coverage within FLS services and across the country. Training, awareness of the problem, research, and policy change will support this endeavour.

Exploiting Polyhydroxyalkanoates for Biomedical Applications

Polyhydroxyalkanoates (PHA) are biodegradable plastic. Numerous bacteria produce PHAs under environmental stress conditions, such as excess carbon-rich organic matter and limitations of other nutritional elements such as potassium, magnesium, oxygen, phosphorus, and nitrogen. In addition to having physicochemical properties similar to fossil-fuel-based plastics, PHAs have unique features that make them ideal for medical devices, such as easy sterilization without damaging the material itself and easy dissolution following use. PHAs can replace traditional plastic materials used in the biomedical sector. PHAs can be used in a variety of biomedical applications, including medical devices, implants, drug delivery devices, wound dressings, artificial ligaments and tendons, and bone grafts. Unlike plastics, PHAs are not manufactured from petroleum products or fossil fuels and are, therefore, environment-friendly. In this review, a recent overview of applications of PHAs with special emphasis on biomedical sectors, including drug delivery, wound healing, tissue engineering, and biocontrols, are discussed.

Bacterial cell immobilized packed bed reactor for the elimination of dissolved organics from biologically treated post-tanning wastewater and its microbial community profile

In conventional, the biologically treated tannery wastewaters are rich in dissolved organics and the application of reverse osmosis (RO) to biologically treated tannery wastewater was challenged with fouling and failure of RO membrane due to existence of lingering dissolved organic compounds. In present investigation the bacterial cell immobilized packed bed reactor (CIPBR) was operated to remove the dissolved organic compounds in biologically treated post-tanning wastewater to avoid membrane fouling in RO. The efficient microbial syndicate to eliminate dissolved organics in post-tanning wastewater was isolated and immobilized on to the carbon silica matrix (CSM) in the range of 2.98 ± 0.2 × 10⁷ cells gm^-1 of CSM and the same was used as a carrier matrix in the packed bed reactor. The CIPBR established the COD_tot, COD_dis and BOD removal efficiency by 61 ± 4%, 57 ± 4% and 87 ± 3% respectively with COD_tot, COD_dis and BOD remained in the treated wastewater as 236 ± 21 mg/L, 228 ± 21 mg/L, and 12 ± 3 mg/L under continuous operation. The removal of dissolved organic compounds from the post-tanning wastewater was confirmed using UV-Visible and FT-IR spectroscopic studies. Among the total microbial community, the phylum Proteobacteria played most abundant role with 48.47% of relative abundance for the removal of dissolved organics in biologically treated post-tanning wastewater. The significance of the study is to replace the tertiary treatment unit operation in the conventional ETP/CETP to remove dissolved organics in wastewater.

Integration of biogas derived from dark fermentation and anaerobic digestion of biowaste to enhance methanol production by methanotrophs

Biowaste-derived sugars or greenhouse gases, such as methane (CH₄) and carbon dioxide (CO₂), can be used to generate eco-friendly biofuels, such as hydrogen (H₂) or methanol. In the present study, enzyme-based rice straw (RS) hydrolysate was used to produce dark-fermentative (DF) biogas (H₂ and CO₂), which was subsequently integrated with biogas (CH₄ and CO₂) derived from anaerobic digestion (AD) to generate methanol via methanotrophs. First, DF of RS hydrolysate yielded 2.82 mol of H₂/mol of hexose. Second, the integration of biogas derived from DF and AD in the presence of CH₄ vectors yielded 13.8 mmol/L of methanol via methanotrophs. Moreover, under the repeated batch mode, 64.6 mmol/L of methanol was produced. This is the first report on the integration of biogas derived from AD and DF of biowaste to produce biomethanol. These findings may facilitate the development of a sustainable biowaste-based circular economy for producing biofuels.

Laccase Immobilization on Copper-Magnetic Nanoparticles for Efficient Bisphenol Degradation

Laccase activity is influenced by copper (Cu) as an inducer. In this study, laccase was immobilized on Cu and Cu-magnetic (Cu/Fe₂O₄) nanoparticles (NPs) to improve enzyme stability and potential applications. The Cu/Fe₂O₄ NPs functionally activated by 3-aminopropyltriethoxysilane and glutaraldehyde exhibited an immobilization yield and relative activity (RA) of 93.1 and 140%, respectively. Under optimized conditions, Cu/Fe₂O₄ NPs showed high loading of laccase up to 285 mg/g of support and maximum RA of 140% at a pH 5.0 after 24 h of incubation (4°C). Immobilized laccase, as Cu/Fe₂O₄-laccase, had a higher optimum pH (4.0) and temperature (45°C) than those of a free enzyme. The pH and temperature profiles were significantly improved through immobilization. Cu/Fe₂O₄-laccase exhibited 25-fold higher thermal stability at 65°C and retained residual activity of 91.8% after 10 cycles of reuse. The degradation of bisphenols was 3.9-fold higher with Cu/Fe₂O₄-laccase than that with the free enzyme. To the best of our knowledge, Rhus vernicifera laccase immobilization on Cu or Cu/Fe₂O₄ NPs has not yet been reported. This investigation revealed that laccase immobilization on Cu/Fe₂O₄ NPs is desirable for efficient enzyme loading and high relative activity, with remarkable bisphenol A degradation potential.

Prospecting Microbial Genomes for Biomolecules and Their Applications

Bioactive molecules of microbial origin are finding increasing biotechnological applications. Their sources range from the terrestrial, marine, and endophytic to the human microbiome. These biomolecules have unique chemical structures and related groups, which enable them to improve the efficiency of the bioprocesses. This review focuses on the applications of biomolecules in bioremediation, agriculture, food, pharmaceutical industries, and human health.

Plastic Eating Enzymes: A Step Towards Sustainability

The large-scale usage of petro-chemical-based plastics has proved to be a significant source of environmental pollution due to their non-biodegradable nature. Microbes-based enzymes such as esterases, cutinases, and lipases have shown the ability to degrade synthetic plastic. However, the degradation of plastics by enzymes is primarily limited by the unavailability of a robust enzymatic system, i.e., low activity and stability towards plastic degradation. Recently, the machine learning strategy involved structure-based and deep neural networks show desirable potential to generate functional, active stable, and tolerant polyethylene terephthalate (PET) degrading enzyme (FAST-PETase). FAST-PETase showed the highest PET hydrolytic activity among known enzymes or their variants and degraded broad ranges of plastics. The development of a closed-loop circular economy-based system of plastic degradation to monomers by FAST-PETase followed by the re-polymerization of monomers into clean plastics can be a more sustainable approach. As an alternative to synthetic plastics, diverse microbes can produce polyhydroxyalkanoates, and their degradation by microbes has been well-established. This article discusses recent updates in the enzymatic degradation of plastics for sustainable development.

Deep-sea sediment metagenome from Bay of Bengal reveals distinct microbial diversity and functional significance

Bay of Bengal (BoB) has immense significance with respect to ecological diversity and natural resources. Studies on microbial profiling and their functional significance at sediment level of BoB remain poorly represented. Herein, we describe the microbial diversity and metabolic potentials of BOB deep-sea sediment samples by subjecting the metagenomes to Nanopore sequencing. Taxonomic diversity ascertained at various levels revealed that bacteria belonging to phylum Proteobacteria predominantly represented in sediment samples NIOT_S7 and NIOT_S9. A comparative study with 16S datasets from similar ecological sites revealed depth as a crucial factor in determining taxonomic diversity. KEGG annotation indicated that bacterial communities possess sequence reads corresponding to carbon dioxide fixation, sulfur, nitrogen metabolism, but at varying levels. Additionally, gene sequences related to bioremediation of dyes, plastics, hydrocarbon, antibiotic resistance, secondary metabolite synthesis and metal resistance from both the samples as studied indicate BoB to represent a highly diverse environmental niche for further exploration.

Synthetic design of methanotroph co-cultures and their immobilization within polymers containing magnetic nanoparticles to enhance methanol production from wheat straw-based biogas

In this study, various methanotroph co-cultures were designed to enhance methanol production from biogas produced through the anaerobic digestion of wheat straw (WS). Furthermore, whole-cell immobilization was performed using magnetic nanoparticle (MNP)-loaded polymers to develop an efficient bioprocess. The anaerobic digestion of WS by cattle dung yielded 219 L/kg of total solids reduced. Methanol produced was 5.08 and 6.39 mmol/L by pure- and co-cultures from biogas, respectively. The optimization of process parameters enhanced methanol production to 6.82 mmol/L by co-culturing Mithylosinus sporium and Methylocella tundrae. The immobilized co-culture within the MNP-doped polymers exhibited much higher cumulative methanol of up to 70.74 mmol/L than the production of 22.34 mmol/L by free cells after ten cycles of reuse. This study suggests that MNP-doped polymer-based immobilization of methanotrophs is a unique approach for producing renewable fuels from biomass-derived biogas, a greenhouse gas.

Characterization of a xylitol dehydrogenase from Aspergillus flavus and its application in l-xylulose production

An NAD⁺-dependent xylitol dehydrogenase from A. flavus (AfXDH) was cloned and successfully expressed in Escherichia coli. AfXDH gene sequence revealed an open reading frame of 1,110 bp, encoding a polypeptide of 369 amino acids with a calculated molecular mass of 38,893 Da. Among various polyols, sorbitol and xylitol were preferred substrates of AfXDH with K_m values of 16.2 and 16.9 mM, respectively. AfXDH showed the highest activity in Tris-glycine-NaOH buffer (pH 9.5) at 50°C; it required Zn²⁺ or Mn²⁺ for enzyme activity. The half-life at 40°C and half denaturation temperature (T_1/2) was 200 min and 45°C, respectively. Bioinformatic analyses along with biochemical properties confirmed that AfXDH belonged to the medium-chain dehydrogenase/reductase family. AfXDH exhibits higher thermostability and k_cat values than those of other XDHs. The feasibility of using AfXDH in l-xylulose production was demonstrated. AfXDH, when coupled with Streptococcus pyogenes NADH oxidase, efficiently converted xylitol to l-xylulose with 97% yield, suggesting its usefulness for the industrial l-xylulose production from xylitol.

Mild Alkaline Pretreatment of Rice Straw as a Feedstock in Microbial Fuel Cells for Generation of Bioelectricity

The dependency on non-renewable fossil fuels as an energy source has drastically increased global temperatures. Their continuous use poses a great threat to the existing energy reserves. Therefore, the energy sector has taken a turn toward developing eco-friendly, sustainable energy generation by using sustainable lignocellulosic wastes, such as rice straw (RS). For lignocellulosic waste to be utilized as an efficient energy source, it needs to be broken down into less complex forms by pretreatment processes, such as alkaline pretreatment using NaOH. Varied NaOH concentrations (0.5%,1.0%,1.5%,2%) for alkaline pretreatment of RS were used for the holocellulose generation. Amongst the four NaOH concentrations tested, RS-1.5% exhibited higher holocellulose generation of 80.1%, whereas 0.5%, 1 5 and 2% pointed 71.9%, 73.8%, and 78.5% holocellulose generation, respectively. Further, microbial fuel cells (MFCs) were tested for voltage generation by utilizing holocellulose generated from untreated (RS-0%) and mildly alkaline pretreated RS (RS-1.5%) as a feedstock. The MFC voltage and maximum power generation using RS-0% were 194 mV and 167 mW/m2, respectively. With RS-1.5%, the voltage and maximum power generation were 556 mV and 583 mW/m2, respectively. The power density of RS-1.5% was three-fold higher than that of RS-0%. The increase in MFC power generation suggests that alkaline pretreatment plays a crucial role in enhancing the overall performance.

Recent developments in antimicrobial growth promoters in chicken health: Opportunities and challenges

With a continuously increasing human population is an increasing global demand for food. People in countries with a higher socioeconomic status tend to switch their preferences from grains to meat and high-value foods. Their preference for chicken as a source of protein has grown by 70% over the last three decades. Many studies have shown the role of feed in regulating the animal gut microbiome and its impact on host health. The microbiome absorbs nutrients, digests foods, induces a mucosal immune response, maintains homeostasis, and regulates bioactive metabolites. These metabolic activities are influenced by the microbiota and diet. An imbalance in microbiota affects host physiology and progressively causes disorders and diseases. With the use of antibiotics, a shift from dysbiosis with a higher density of pathogens to homeostasis can occur. However, the progressive use of higher doses of antibiotics proved harmful and resulted in the emergence of multidrug-resistant microbes. As a result, the use of antibiotics as feed additives has been banned. Researchers, regulatory authorities, and managers in the poultry industry have assessed the challenges associated with these restrictions. Research has sought to identify alternatives to antibiotic growth promoters for poultry that do not have any adverse effects. Modulating the host intestinal microbiome by regulating dietary factors is much easier than manipulating host genetics. Research efforts have led to the identification of feed additives, including bacteriocins, immunostimulants, organic acids, phytogenics, prebiotics, probiotics, phytoncides, and bacteriophages. In contrast to focusing on one or more of these alternative bioadditives, an improved feed conversion ratio with enhanced poultry products is possible by employing a combination of feed additives. This article may be helpful in future research towards developing a sustainable poultry industry through the use of the proposed alternatives.

Recovery from Cranial Nerve Symptoms after Flow Diversion without Coiling for Unruptured Very Large and Giant ICA Aneurysms

BACKGROUND AND PURPOSE

Cranial nerve symptoms, including visual impairment and ophthalmoplegia, are one of the most common presentations of very large and giant (≥15 mm) ICA aneurysms. In this study, we evaluated the treatment outcomes of flow diversion and conventional coiling in terms of recovery from cranial nerve symptoms and postoperative complications.

MATERIALS AND METHODS

Seventy-nine patients with unruptured ICA aneurysms of >15 mm who were treated with flow diversion or conventional coiling between December 2009 and December 2020 were retrospectively evaluated. We compared the radiologic and clinical outcomes, including recovery from cranial nerve symptoms, between the 2 groups.

RESULTS

Twenty-eight of 49 patients (57.1%) treated with flow diversion and 10 of 30 patients (33.3%) treated with conventional coiling initially presented with cranial nerve symptoms (P = .068). In the clinical follow-up, the symptom recovery rate was significantly higher in those treated with flow diversion (15 [50%] versus 3 [25%] with conventional coiling, P = .046). Multivariate logistic regression analysis demonstrated that flow diversion was significantly associated with symptom recovery (OR, 7.425; 95% CI, 1.091-50.546; P = .040). The overall postoperative complication rate was similar (flow diversion, 10 [20.4%]; conventional coiling, 6 [20.0%], P = .965), though fatal hemorrhagic complications occurred only in patients with intradurally located aneurysms treated with flow diversion (4 [8.2%] versus 0 [0.0%] with coiling, P = .108).

CONCLUSIONS

Flow diversion without coiling for very large and giant ICA aneurysms yielded a higher rate of recovery from cranial nerve symptoms, but it may be related to an increased hemorrhagic complication rate, especially for intradurally located aneurysms.

Recent Strategies for the Immobilization of Therapeutic Enzymes

Therapeutic enzymes play important roles in modern medicine due to their high affinity and specificity. However, it is very expensive to use them in clinical medicine because of their low stability and bioavailability. To improve the stability and effectiveness of therapeutic enzymes, immobilization techniques have been employed to enhance the applications of therapeutic enzymes in the past few years. Reported immobilization techniques include entrapment, adsorption, and covalent attachment. In addition, protein engineering is often used to improve enzyme properties; however, all methods present certain advantages and limitations. For carrier-bound immobilization, the delivery and release of the immobilized enzyme depend on the properties of the carrier and enzyme. In this review, we summarize the advantages and challenges of the current strategies developed to deliver therapeutic enzymes and provide a future perspective on the immobilization technologies used for therapeutic enzyme delivery.

Green Synthesis of Silver-Decorated Magnetic Particles for Efficient and Reusable Antimicrobial Activity

Metal and metal hybrid nanostructures have shown tremendous application in the biomedical and catalytic fields because of their plasmonic and catalytic properties. Here, a green and clean method was employed for the synthesis of silver nanoparticle (Ag NP)-SiO₂-Fe₂O₃ hybrid microstructures, and biomolecules from green tea extracts were used for constructing the hybrid structures. The SiO₂-Fe₂O₃ structures were synthesized using an ethanolic green tea leaf extract to form Bio-SiO₂-Fe₂O₃ (BSiO₂-Fe₂O₃) structures. Biochemical studies demonstrated the presence of green tea biomolecules in the BSiO₂ layer. Reduction of the silver ions was performed by a BSiO₂ layer to form Ag NPs of 5–10 nm in diameter in and on the BSiO₂-Fe₂O₃ microstructure. The reduction process was observed within 600 s, which is faster than that reported elsewhere. The antimicrobial activity of the Ag-BSiO₂-Fe₂O₃ hybrid structure was demonstrated against Staphylococcus aureus and Escherichia coli, and the nanostructures were further visualized using confocal laser scanning microscopy (CLSM). The magnetic properties of the Ag-BSiO₂-Fe₂O₃ hybrid structure were used for studying reusable antimicrobial activity. Thus, in this study, we provide a novel green route for the construction of a biomolecule-entrapped SiO₂-Fe₂O₃ structure and their use for the ultra-fast formation of Ag NPs to form antimicrobial active multifunctional hybrid structures.

The Emerging Biotherapeutic Agent: Akkermansia

The human gastrointestinal tract (GIT) is a well-recognized hub of microbial activities. The microbiota harboring the mucus layer of the GIT act as a defense against noxious substances, and pathogens including Clostridium difficile, Enterococcus faecium, Escherichia coli, Salmonella Typhimurium. Toxins, pathogens, and antibiotics perturb the commensal floral composition within the GIT. Imbalanced gut microbiota leads to dysbiosis, manifested as diseases ranging from obesity, diabetes, and cancer to reduced lifespan. Among the bacteria present in the gut microbiome, the most beneficial are those representing Firmicutes and Bacteroidetes. Recent studies have revealed the emergence of a novel biotherapeutic agent, Akkermansia, which is instrumental in regaining eubiosis and conferring various health benefits.

Biomolecules Production from Greenhouse Gases by Methanotrophs

Harmful effects on living organisms and the environment are on the rise due to a significant increase in greenhouse gas (GHG) emissions through human activities. Therefore, various research initiatives have been carried out in several directions in relation to the utilization of GHGs via physicochemical or biological routes. An environmentally friendly approach to reduce the burden of significant emissions and their harmful effects is the bioconversion of GHGs, including methane (CH4) and carbon dioxide (CO2), into value-added products. Methanotrophs have enormous potential for the efficient biotransformation of CH4 to various bioactive molecules, including biofuels, polyhydroxyalkanoates, and fatty acids. This review highlights the recent developments in methanotroph-based systems for methanol production from GHGs and proposes future perspectives to improve process sustainability via biorefinery approaches.

Immunoglobulin D Multiple Myeloma with a “Hidden” Lambda Light Chain

Introduction/Objective

In rare cases, the conventional immunofixation gel electrophoresis technique fails to detect the light chain of an M-protein. We report a case of immunoglobulin (Ig) D multiple myeloma with a hidden lambda (λ) light chain.

Methods/Case Report

Capillary electrophoresis (CE) (Sebia CAPILLARYS 2) was used to detect and quantify M- proteins in serum specimens. Immunosubtraction (IS) on the CAPILLARYS 2 systems was used to identify the classes of M-proteins. Conventional gel immunofixation electrophoresis (IFE) was performed, using monospecific antisera for IgD, IgE, kappa (κ) or λ in the Sebia HYDRASYS system, and IgG, IgA, IgM, κ or λ in the Helena SPIFE3000 system. Beta-mercaptoethanol (BME) with Fluidil were used as reduction agents.

Results (if a Case Study enter NA)

Results of serum CE showed two abnormal peaks in beta 2 and gamma regions, suspected to be positive for M-proteins. IS results showed subtraction for λ light chain only in both peaks, suggesting two monoclonal λ light chains. In contrary, no monoclonal λ light chain was detected in gamma region by IFE (Sebia). Epitope masking in the folded monoclonal protein was suspected to cause the “hidden λ light chain” and was further investigated by two laboratory approaches. IFE performed on the Helena SPIFE3000 system found two λ bands in beta 2 and gamma regions, which was consistent with the results from IS. The treatment of BME with Fluidil helped unmasking the hidden epitope and revealed the λ band in gamma region on IFE (Sebia).

Conclusion

The medical laboratories should be aware of the described scenario. The failure to detect light chains of certain intact M-proteins is most likely due to the structurally inaccessibility of light chains. It is recommended that treatment with reduction agents or use of an alternative methodology or IS might be helpful for investigating suspected heavy chain only cases, due to the limitation of conventional methodology.

The Variations of Insulin-like Growth Factor 1 Measured between Siemens Immulite, DiaSorin Liaison and IDS iSYS

Introduction/Objective

Insulin-like Growth Factor 1 (IGF-1) is a biomarker for the evaluation of growth hormone activity in the hypothalamic-pituitary axis. The current most common methodology for IGF-1 measurement is automated immunometric assays. In this study, we compared the IGF-1 on Siemens Immulite 2000, DiaSorin Liaison XL and IDS iSYS.

Methods/Case Report

Residual 30-110 serum specimens were randomly selected from routine hospital orders. IGF- 1 was measured on these three platforms and compared with Passing-Bablok regression. Bias was evaluated using the Bland-Altman method.

Results (if a Case Study enter NA)

Weighted Deming regression analysis showed approximately 80% and 56% positive bias on IDS iSYS and DiaSorin Liaison, compared with Siemens Immulite (iSYS=1.81*Immulite-117.65, r=0.91; Liaison=1.56*Immulite-4.58, r=0.98). There was approximately 8% positive bias on Liaison, compared with iSYS (Liaison=1.08*iSYS+0.56, r=0.99). The Passing-Bablok regression analysis revealed approximately 67% and 54% positive bias (iSYS=1.67*Immulite-75, r=0.91; Liaison=1.54*Immulite-3.44, r=0.91). Approximately 8% positive bias on Liaison was observed, compared with iSYS (Liaison=1.08*iSYS+5.65, r=0.99). The Bland-Altman plot showed the agreement between iSYS and Immulite IGF-1 was on average 129.6±123.3 ng/mL, 98.6±148.8 ng/mL between Liaison and Immulite and 37.0±46.5 ng/mL between Liaison and iSYS.

Conclusion

Immunoassays rely on the specificity of antibodies. There are wide variations between different immunoassay platforms for IGF-1 measurement. The standardization of IGF-1 assay is lack. It would be a challenge for clinicians to monitor IGF-1 or treat the patients with pituitary disorders, when switching to another platform. The potential impact of the variations in IGF-1 measurement between different immunoassay platforms should be aware.

Biotin and Zn2+ Increase Xylitol Production by Candida tropicalis

In this study, the medium requirements to increase the production of xylitol by using Candida tropicalis (CT) have been investigated. The technique of single addition or omission of medium components was applied to determine the nutritional requirements. The addition of amino acids such as Asp, Glu, Gln, Asn, Thr, and Gly had no significant effect on CT growth. However, in the absence of other metal ions, there was a higher concentration of cell growth and xylitol production when only Zn2+ was present in the medium. The analysis of various vitamins unveiled that biotin and thiamine were the only vitamins required for the growth of CT. Surprisingly, when only biotin was present in the medium as a vitamin, there was less growth of CT than when the medium was complete, but the amount of xylitol released was significantly higher. Overall, this study will increase the xylitol production using the single omission or addtion technique.

Development of the Asia Pacific Consortium on Osteoporosis (APCO) Framework: clinical standards of care for the screening, diagnosis, and management of osteoporosis in the Asia-Pacific region

Guidelines for doctors managing osteoporosis in the Asia-Pacific region vary widely. We compared 18 guidelines for similarities and differences in five key areas. We then used a structured consensus process to develop clinical standards of care for the diagnosis and management of osteoporosis and for improving the quality of care.

PURPOSE

Minimum clinical standards for assessment and management of osteoporosis are needed in the Asia-Pacific (AP) region to inform clinical practice guidelines (CPGs) and to improve osteoporosis care. We present the framework of these clinical standards and describe its development.

METHODS

We conducted a structured comparative analysis of existing CPGs in the AP region using a "5IQ" model (identification, investigation, information, intervention, integration, and quality). One-hundred data elements were extracted from each guideline. We then employed a four-round Delphi consensus process to structure the framework, identify key components of guidance, and develop clinical care standards.

RESULTS

Eighteen guidelines were included. The 5IQ analysis demonstrated marked heterogeneity, notably in guidance on risk factors, the use of biochemical markers, self-care information for patients, indications for osteoporosis treatment, use of fracture risk assessment tools, and protocols for monitoring treatment. There was minimal guidance on long-term management plans or on strategies and systems for clinical quality improvement. Twenty-nine APCO members participated in the Delphi process, resulting in consensus on 16 clinical standards, with levels of attainment defined for those on identification and investigation of fragility fractures, vertebral fracture assessment, and inclusion of quality metrics in guidelines.

CONCLUSION

The 5IQ analysis confirmed previous anecdotal observations of marked heterogeneity of osteoporosis clinical guidelines in the AP region. The Framework provides practical, clear, and feasible recommendations for osteoporosis care and can be adapted for use in other such vastly diverse regions. Implementation of the standards is expected to significantly lessen the global burden of osteoporosis.

Site-directed lysine modification of xylanase for oriented immobilization onto silicon dioxide nanoparticles

Enhanced covalent immobilization of xylanase from Chaetomium globosum (XylCg) onto SiO₂ nanoparticles was achieved by the modification of surface residues. The mutation of surface residues to lysine by site-directed mutagenesis increased the immobilization efficiency (IE) and immobilization yield (IY). The immobilized mutant XylCg (N172K-H173K-S176K-K133A-K148A) exhibited an IY of 99.5% and IE of 135%, which were 1.8- and 4.3-fold higher than immobilized wildtype (WT). Regarding the catalytic properties, the k_cat and k_cat/K_m values were 1850 s^-1 and 2030 mL mg^-1 s^-1 for the immobilized mutant, and 331 s^-1 and 404 mL mg^-1 s^-1 for the immobilized WT, respectively. Additionally, the immobilized mutant exhibited four times higher thermal stability than the immobilized WT at 60 °C. These results suggest that surface-mutated lysine residues confer good stability and orientation on the support matrix, thus improving the overall performance of xylanase.

Correction to: Biomethanol Production from Methane by Immobilized Co-cultures of Methanotrophs

[This corrects the article DOI: 10.1007/s12088-020-00883-6.].

Regulation of Plant Mineral Nutrition by Signal Molecules

Microbes operate their metabolic activities at a unicellular level. However, it has been revealed that a few metabolic activities only prove beneficial to microbes if operated at high cell densities. These cell density-dependent activities termed quorum sensing (QS) operate through specific chemical signals. In Gram-negative bacteria, the most widely reported QS signals are acylhomoserine lactones. In contrast, a novel QS-like system has been elucidated, regulating communication between microbes and plants through strigolactones. These systems regulate bioprocesses, which affect the health of plants, animals, and human beings. This mini-review presents recent developments in the QS and QS-like signal molecules in promoting plant health.

Polyhydroxyalkanoates: Trends and advances toward biotechnological applications

Plastics are an integral part of most of the daily requirements. Indiscriminate usage and disposal have led to the accumulation of massive quantities of waste. Their non-biodegradable nature makes it increasingly difficult to manage and dispose them. To counter this impending disaster, biodegradable polymers, especially polyhydroxy-alkanoates (PHAs), have been envisaged as potential alternatives. Owing to their unique physicochemical characteristics, PHAs are gaining importance for versatile applications in the agricultural and medical sectors. Applications in the medical sector are more promising because of their commercial viability and sustainability. Despite such potential, their production and commercialization are significant challenges. The major limitations are their poor mechanical strength, production in small quantities, costly feed, and lack of facilities for industrial production. This article provides an overview of the contemporary progress in the field, to attract researchers and stakeholders to further exploit these renewable resources to produce biodegradable plastics on a commercial scale.

Integrating anaerobic digestion of potato peels to methanol production by methanotrophs immobilized on banana leaves

In the present study, potato peels were subjected to anaerobic digestion (AD) to produce biogas (methane [CH₄] and carbon dioxide), which was subsequently used as a substrate for methanol production by methanotrophs. AD resulted in high yields of up to 170 L CH₄/kg total solids (TS) from 250 mL substrate (2% TS, w/v). Under optimized conditions, maximum methanol production of 4.97 and 3.36 mmol/L from raw biogas was observed in Methylocella tundrae and Methyloferula stellata, respectively. Immobilization of methanotrophs on banana leaves showed loading of up to 156 mg dry cell mass/g support. M. tundrae immobilized on banana leaves retained 31.6-fold higher methanol production stability, compared to non-immobilized cells. To the best of our knowledge, this is the first study on immobilization of methanotrophs on banana leaves for producing methanol from potato peels AD-derived biogas. Such integrative approaches may be improved through process up-scaling to achieve sustainable development.

Transcriptome and translatome of CO2 fixing acetogens under heterotrophic and autotrophic conditions

Acetogens are anaerobic bacteria that utilise gaseous feedstocks such as carbon monoxide (CO) and carbon dioxide (CO2) to synthesise biomass and various metabolites via the energetically efficient Wood-Ljungdahl pathway. Because of this pathway, acetogens have been considered as a novel platform to produce biochemicals from gaseous feedstocks, potentially replacing the conventional thermochemical processes. Despite their advantages, a lack of systematic understanding of the transcriptional and translational regulation in acetogens during autotrophic growth limits the rational strain design to produce the desired products. To overcome this problem, we presented RNA sequencing and ribosome profiling data of four acetogens cultivated under heterotrophic and autotrophic conditions, providing data on genome-scale transcriptional and translational responses of acetogens during CO2 fixation. These data facilitate the discovery of regulatory elements embedded in their genomes, which could be utilised to engineer strains to achieve better growth and productivity. We anticipate that these data will expand our understanding of the processes of CO2 fixation and will help in the designing of strains for the desired biochemical production.

Diet, Gut Microbiota and COVID-19

Worldwide, millions of individuals have been affected by the prevailing SARS-CoV-2. Therefore, a robust immune system remains indispensable, as an immunocompromised host status has proven to be fatal. In the absence of any specific antiviral drug/vaccine, COVID-19 related drug repurposing along with various other non-pharmacological measures coupled with lockdown have been employed to combat this infection. In this context, a plant based rich fiber diet, which happens to be consumed by a majority of the Indian population, appears to be advantageous, as it replenishes the host gut microbiota with beneficial microbes thereby leading to a symbiotic association conferring various health benefits to the host including enhanced immunity. Further, implementation of the lockdown which has proven to be a good non-pharmacological measure, seems to have resulted in consumption of home cooked healthy diet, thereby enriching the beneficial microflora in the gut, which might have resulted in better prognosis of COVID-19 patients in India in comparison to that observed in the western countries.

Blindness increases the risk for hip fracture and vertebral fracture but not the risk for distal radius fracture: a longitudinal follow-up study using a national sample cohort

The risks for hip fracture and vertebral fracture, but not the risk for distal radius fracture, were significantly higher in the blindness group than in the control group with a maximum 12-year follow-up.

PURPOSE

To evaluate the influence of visual impairment on the risk for osteoporotic fractures at common sites: hip, thoracic/lumbar vertebra, and distal radius.

METHODS

This longitudinal follow-up study used a database of a national sample cohort from 2002 to 2013 provided by the Korean National Health Insurance Service. Of a total of 1,125,691 subjects, 3918 patients with visual impairment and age ≥ 50 years were enrolled in a 1:4 ratio; 15,672 control participants were matched for age, sex, income, and region of residence. Stratified Cox proportional-hazards models were used to evaluate the crude and adjusted (for steroid medication, rheumatoid arthritis, depression, osteoporosis, diabetes mellitus, and stroke history) hazard ratios (HRs) for each fracture site. Fracture diagnoses were based on the ICD-10 codes: hip fracture (S720, S721, S722), vertebral fracture (S220, S320), and distal radius fracture (S525).

RESULTS

The HRs for hip and vertebral fracture were significantly higher in the blindness group (adjusted HR = 2.46, p < 0.001 for hip fracture; adjusted HR = 1.42, p = 0.020 for thoracic/lumbar vertebral fracture) than in the matched control group. However, the HR for distal radius fracture was not higher in the blindness group. The HRs for all three fracture sites were not significantly higher in the non-blindness visual impairment group after adjustment.

CONCLUSION

The risks for hip fracture and vertebral fracture were significantly higher in the blindness group. However, the risk for distal radius fracture was not related to visual impairment including blindness.

Rhus vernicifera Laccase Immobilization on Magnetic Nanoparticles to Improve Stability and Its Potential Application in Bisphenol A Degradation

In the present study, Rhus vernicifera laccase (RvLac) was immobilized through covalent methods on the magnetic nanoparticles. Fe₂O₃ and Fe₃O₄ nanoparticles activated by 3-aminopropyltriethoxysilane followed with glutaraldehyde showed maximum immobilization yields and relative activity up to 81.4 and 84.3% at optimum incubation and pH of 18 h and 5.8, respectively. The maximum RvLac loading of 156 mg/g of support was recorded on Fe₂O₃ nanoparticles. A higher optimum pH and temperature of 4.0 and 45 °C were noted for immobilized enzyme compared to values of 3.5 and 40 °C for free form, respectively. Immobilized RvLac exhibited better relative activity profiles at various pH and temperature ranges. The immobilized enzyme showed up to 16-fold improvement in the thermal stability, when incubated at 60 °C, and retained up to 82.9% of residual activity after ten cycles of reuses. Immobilized RvLac exhibited up to 1.9-fold higher bisphenol A degradation efficiency potential over free enzyme. Previous reports have demonstrated the immobilization of RvLac on non-magnetic supports. This study has demonstrated that immobilization of RvLac on magnetic nanoparticles is very efficient especially for achieving high loading, better pH and temperature profiles, and thermal- and solvents-stability, high reusability, and higher degradation of bisphenol A.

Conversion of biogas to methanol by methanotrophs immobilized on chemically modified chitosan

In this study, chitosan modified with glutaraldehyde (GLA), 3-aminopropyltriethoxysilane (APTES), polyethyleneimine, and APTES followed by GLA (APTES-GLA) as a support material was used to improve methanol production from biogas. Among these support materials, chitosan-APTES-GLA showed the highest increase in immobilization yield and relative efficiency of Methylomicrobium album up to 56.4% and 97.7%, respectively. Maximum cell loading of 236 mg dry cell mass per g-support was observed for M. album., which is 7.7-fold higher than that of chitosan. The immobilized M. album maintained a 23.9-fold higher methanol production compared to free cells after 8 cycles of reuse; it also produced 6.92 mmol·L^-1 methanol from biogas that originated from anaerobic digestion of rice straw, thereby validating its industrial application. This is the first report on the immobilization of methanotrophs on chemically modified chitosans to improve cell loading and relative efficiency, and its potential applications in the conversion of greenhouse gases to methanol.

The Current and Future Challenges of Hip Fracture Management in Malaysia

By 2050, it is predicted that six million hip fractures will occur each year of which the majority will happen in Asia. Malaysia is not spared from this predicted rise and its rate of increase will be one of the highest in this region. Much of this is driven by our unprecedented growth in the number of older people. Characteristics of individuals with hip fractures in Malaysia mirror what has been reported in other countries. They will be older multimorbid people who were already at risk of falls and fractures. Outcomes were poor with at least a quarter do not survive beyond 12 months and in those that do survive have limitation in their mobility and activities of daily living. Reviewing how these fractures are managed and incorporating new models of care, such as orthogeriatric care, could address these poor outcomes. Experts have warned of the devastating impact of hip fracture in Malaysia and that prompt action is urgently required. Despite that, there remains no national agenda to highlight the need to improve musculoskeletal health in the country.

Deploying Biomolecules as Anti-COVID-19 Agents

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) known as COVID-19 has emerged as a major threat to human existence. COVID-19 seems to have undergone adaptive evolution through an intermediate host, most likely bats. The flu leads to severe pneumonia that causes respiratory and multi-organ failure. The absence of any known treatment procedures, drugs, or vaccines has created panic around the World. The need is to develop rapid testing kits, drugs and vaccines. However, these proposals are time-consuming processes. At present social distancing along with previously known traditional medicines can act as quick and short-term alternatives for treating this viral flu.

3D Printed Bioresponsive Devices with Selective Permeability Inspired by Eggshell Membrane for Effective Biochemical Conversion

Eggshell membrane has selective permeability that enables gas or liquid molecules to pass through while effectively preventing migration of microbial species. Herein, inspired by the architecture of the eggshell membrane, we employ three-dimensional (3D) printing techniques to realize bioresponsive devices with excellent selective permeability for effective biochemical conversion. The fabricated devices show 3D conductive carbon nanofiber membranes in which precultured microbial cells are controllably deployed. The resulting outcome provides excellent selective permeability between chemical and biological species, which enables acquisition of target responses generated by biological species confined within the device upon input signals. In addition, electrically conductive carbon nanofiber networks provide a platform for real-time monitoring of metabolism of microbial cells in the device. The suggested platform represents an effort to broaden microbial applications by constructing biologically programmed devices for desired responses enabled by designated deployment of engineered cells in a securely confined manner within enclosed membranes using 3D printing methods.

CO2 -Reductive, Copper Oxide-Based Photobiocathode for Z-Scheme Semi-Artificial Leaf Structure

Green plants convert sunlight into high-energy chemicals by coupling solar-driven water oxidation in the Z-scheme and CO₂ fixation in the Calvin cycle. In this study, formate dehydrogenase from Clostridium ljungdahlii (ClFDH) is interfaced with a TiO₂ -coated CuFeO₂ and CuO mixed (ClFDH-TiO₂ |CFO) electrode. In this biohybrid photocathode, the TiO₂ layer enhances the photoelectrochemical (PEC) stability of the labile CFO photocathode and facilitates the transfer of photoexcited electrons from the CFO to ClFDH. Furthermore, inspired by the natural photosynthetic scheme, the photobiocathode is combined with a water-oxidizing, FeOOH-coated BiVO₄ (FeOOH|BiVO₄ ) photoanode to assemble a wireless Z-scheme biocatalytic PEC device as a semi-artificial leaf. The leaf-like structure effects a bias-free biocatalytic CO₂ -to-formate conversion under visible light. Its rate of formate production is 2.45 times faster than that without ClFDH. This work is the first example of a wireless solar-driven semi-biological PEC system for CO₂ reduction that uses water as an electron feedstock.