Mitigating cognitive deficits with teriflunomide: unraveling PI3K-modulated behavioral outcomes in mice.

BACKGROUND: Alzheimer's disease is a leading neurological disorder that gradually impairs memory and cognitive abilities, ultimately leading to the inability to perform even basic daily tasks. Teriflunomide is known to preserve neuronal activity and protect mitochondria in the brain slices exposed to oxidative stress. The current research was undertaken to investigate the teriflunomide's cognitive rescuing abilities against scopolamine-induced comorbid cognitive impairment and its influence on phosphatidylinositol-3-kinase (PI3K) inhibition-mediated behavior alteration in mice. METHODS: Swiss albino mice were divided into 7 groups; vehicle control, scopolamine, donepezil + scopolamine, teriflunomide (10 mg/kg) + scopolamine; teriflunomide (20 mg/kg) + scopolamine, LY294002 and LY294002 + teriflunomide (20 mg/kg). Mice underwent a nine-day protocol, receiving scopolamine injections (2 mg/kg) for the final three days to induce cognitive impairment. Donepezil, teriflunomide, and LY294002 treatments were given continuously for 9 days. MWM, Y-maze, OFT and rota-rod tests were conducted on days 7 and 9. On the last day, blood samples were collected for serum TNF-α analysis, after which the mice were sacrificed, and brain samples were harvested for oxidative stress analysis. RESULTS: Scopolamine administration for three consecutive days increased the time required to reach the platform in the MWM test, whereas, reduced the percentage of spontaneous alternations in the Y-maze, number of square crossing in OFT and retention time in the rota-rod test. In biochemical analysis, scopolamine downregulated the brain GSH level, whereas it upregulated the brain TBARS and serum TNF-α levels. Teriflunomide treatment effectively mitigated all the behavioral and biochemical alterations induced by scopolamine. Furthermore, LY294002 administration reduced the memory function and GSH level, whereas, uplifted the serum TNF-α levels. Teriflunomide abrogated the memory-impairing, GSH-lowering, and TNF-α-increasing effects of LY294002. CONCLUSION: Our results delineate that the improvement in memory, locomotion, and motor coordination might be attributed to the oxidative and inflammatory stress inhibitory potential of teriflunomide. Moreover, PI3K inhibition-induced memory impairment might be attributed to reduced GSH levels and increased TNF-α levels.

Iron bioleaching and polymers accumulation by an extreme acidophilic bacterium.

In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their economic value. In this context, the development of low cost and eco-friendly approaches, such as bioleaching of metal impurities, is crucial. The acidophilic strain Acidiphilium sp. SJH reduces Fe(III) to Fe(II) by coupling the oxidation of an organic substrate to the reduction of Fe(III) and can therefore be applied in the bioleaching of iron impurities from non-metallic raw materials. In this work, the physiology of Acidiphilium sp. SJH and the reduction of iron impurities from quartz sand and its derivatives have been studied during growth on media supplemented with various carbon sources and under different oxygenation conditions, highlighting that cell physiology and iron reduction are tightly coupled. Although the organism is known to be aerobic, maximum bioleaching performance was obtained by cultures cultivated until the exponential phase of growth under oxygen limitation. Among carbon sources, glucose has been shown to support faster biomass growth, while galactose allowed highest bioleaching. Moreover, Acidiphilium sp. SJH cells can synthesise and accumulate Poly-ß-hydroxybutyrate (PHB) during the process, a polymer with relevant application in biotechnology. In summary, this work gives an insight into the physiology of Acidiphilium sp. SJH, able to use different carbon sources and to synthesise a technologically relevant polymer (PHB), while removing metals from sand without the need to introduce modifications in the process set up.

Polyhydroxybutyrate (PHB) nanoparticles modulate metals toxicity in Hydra viridissima.

The use of bioplastics (e.g., polyhydroxybutyrate) emerged as a solution to help reduce plastic pollution caused by conventional plastics. Nevertheless, bioplastics share many characteristics with their conventional counterparts, such as degradation to nano-sized particles and the ability to sorb environmental pollutants, like metals. This study aimed to assess the potential impacts of the interaction of metals (cadmium - Cd, copper - Cu, and zinc - Zn) with polyhydroxybutyrate nanoplastics (PHB-NPLs; ~200 nm) on the freshwater cnidarian Hydra viridissima in terms of mortality rates, morphological alterations, and feeding behavior. The metal concentrations selected for the combined exposures corresponded to concentrations causing 20 %, 50 %, and 80 % of mortality (LC20, LC50, and LC80, respectively) and the PHB-NPLs concentrations ranged from 0.01 to 1000 µg/L. H. viridissima sensitivity to the metals, based on the LC50's, can be ordered as: Zn < Cd < Cu. Combined exposure to metals and PHB-NPLs yielded distinct outcomes concerning mortality, morphological changes, and feeding behavior, uncovering metal- and dose-specific responses. The interaction between Cd-LCx and PHB-NPLs progressed from no effect at LC20,96h to an ameliorative effect at Cd-LC50,96h. Cu-LCx revealed potential mitigation effects (LC20,96h and LC50,96h) but at Cu-LC80,96h the response shifts to a potentiating effect. For Zn-LCx, response patterns across the combinations with PHB-NPLs were like those induced by the metal alone. PHB-NPLs emerged as a key factor capable of modulating the toxicity of metals. This study highlights the context-dependent interactions between metals and PHB-NPLs in freshwater environments while supporting the need for further investigation of the underlying mechanisms and ecological consequences in forthcoming research.

Formulation of biogenic fluorescent pigmented PHB nanoparticles from Rhodanobacter sp. for drug delivery.

Biogenic nanoparticles (NPs) have emerged as promising therapeutic formulations in effective drug delivery. Despite of various positive attributes, these NPs are often conjugated with various cytotoxic organic fluorophores for bioimaging, thereby reducing its effectiveness as a potential carrier. Herein, we aim to formulate biogenic fluorescent pigmented polyhydroxybutyrate (PHB) NPs from Rhodanobacter sp. strain KT31 (OK001852) for drug delivery. The bacterial strain produced 0.5 g L-1 of polyhydroxyalkanoates (PHAs) from 2.04 g L-1 of dry cell weight (DCW) under optimised conditions via submerged fermentation. Further, structural, thermal, and morphological charactersiation of the extracted PHAs was conducted using advance analytical technologies. IR spectra at 1719.25 cm-1 confirmed presence of C = O functional group PHB. NMR and XRD analysis validated the chemical structure and crystallinity of PHB. TG-DTA revealed Tm (168 °C), Td (292 °C), and Xc (35%) of the PHB. FE-SEM imaging indicated rough surface of the PHB film and the biodegradability was confirmed from open windro composting. WST1 assay showed no significant cell death (> 50%) from 100 to 500 µg/mL, endorsing non-cytotoxic nature of PHB. PHB NPs were uniform, smooth and spherical with size distribution and mean zeta potential 44.73 nm and 0.5 mV. IR and XRD peaks obtained at 1721.75 cm-1 and 48.42 Å denoted C = O and crystalline nature of PHB. Cell proliferation rate of PHB NPs was quite significant at 50 µg/mL, establishing the non-cytotoxic nature of NPs. Further, in vitro efficacy of the PHB NPs needs to be evaluated prior to the biomedical applications.

ATP-free in vitro biotransformation of starch-derived maltodextrin into poly-3-hydroxybutyrate via acetyl-CoA.

In vitro biotransformation (ivBT) facilitated by in vitro synthetic enzymatic biosystems (ivSEBs) has emerged as a highly promising biosynthetic platform. Several ivSEBs have been constructed to produce poly-3-hydroxybutyrate (PHB) via acetyl-coenzyme A (acetyl-CoA). However, some systems are hindered by their reliance on costly ATP, limiting their practicality. This study presents the design of an ATP-free ivSEB for one-pot PHB biosynthesis via acetyl-CoA utilizing starch-derived maltodextrin as the sole substrate. Stoichiometric analysis indicates this ivSEB can self-maintain NADP+/NADPH balance and achieve a theoretical molar yield of 133.3%. Leveraging simple one-pot reactions, our ivSEBs achieved a near-theoretical molar yield of 125.5%, the highest PHB titer (208.3 mM, approximately 17.9 g/L) and the fastest PHB production rate (9.4 mM/h, approximately 0.8 g/L/h) among all the reported ivSEBs to date, and demonstrated easy scalability. This study unveils the promising potential of ivBT for the industrial-scale production of PHB and other acetyl-CoA-derived chemicals from starch.

[Long-term efficacy and safety of divozilimab during 2-year treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]. / Effektivnost' i bezopasnost' dvukhletnei terapii divozilimabom u patsientov s rasseyannym sklerozom v ramkakh randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-4/MIRANTIBUS.

OBJECTIVE: To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg every 24 weeks during 100 weeks for the treatment of patients with multiple sclerosis (MS), including relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) with relapses. MATERIAL AND METHODS: The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS (NCT05385744) included 338 adult patients with MS distributed in a 1:1 ratio into two groups: DIV 500 mg and teriflunomide (TRF) 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks, then entered an additional period from weeks 49 to 100, which included three cycles of therapy. The efficacy was assessed based on the results of brain MRI and registration of data on relapses. RESULTS: 308 subjects completed 5 therapy cycles according to the study protocol. An analysis of the effectiveness of DIV therapy over 2 years showed a persistent suppression of MRI and clinical activity of the disease in comparison with TRF, which was confirmed by all the studied MRI indicators (including CUA; total number of gadolinium-enhancing (GdE) lesions on T1-weighted scans ; number of new or enlarged lesions on T2-weighted scans; lesions volume change on T2-weighted scans; change in the volume of hypointense lesions on T1-weighted scans). The use of DIV was associated with a statistically significant decrease in ARR compared to TRF (p=0.0001). The ARR in the DIV group was 0.057, in the TRF group - 0.164 with 95% confidential interval for the frequency ratio [0.202; 0.593]. The incidence of GdE lesions on T1-weighted scans in the DIV group was significantly lower than in the TRF group. The average number of such lesions was 0.0±0.08 and 1.0±4.46 in the DIV and TRF groups, respectively (p<0.0001). Progression of EDSS was detected in 18 (10.7%) and 36 (21.3%) patients in the DIV and TRF groups, respectively (p=0.0075). The proportion of patients with relapses was 11.2% (n=19) in the DIV group and 23.1% (n=39) in the TRF group (p=0.0039). In the subpopulation of patients with SPMS, no cases of increase in EDSS were detected, and not a single case of exacerbation was recorded over 2 years of using DIV. Also, DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and laboratory abnormalities, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. CONCLUSION: The results of the BCD-132-4/MIRANTIBUS CT indicate a high sustained efficacy and safety of long-term use of DIV in comparison with TRF during 2 years of therapy.

Headache in Multiple Sclerosis: A Narrative Review.

Background: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system characterized by autoimmune-mediated damage to oligodendrocytes and subsequent myelin destruction. Clinical implications: Clinically, the disease presents with many symptoms, often evolving over time. The insidious onset of MS often manifests with non-specific symptoms (prodromal phase), which may precede a clinical diagnosis by several years. Among them, headache is a prominent early indicator, affecting a significant number of MS patients (50-60%). Results: Headache manifests as migraine or tension-type headache with a clear female predilection (female-male ratio 2-3:1). Additionally, some disease-modifying therapies in MS can also induce headache. For instance, teriflunomide, interferons, ponesimod, alemtuzumab and cladribine are associated with an increased incidence of headache. Conclusions: The present review analyzed the literature data on the relationship between headache and MS to provide clinicians with valuable insights for optimized patient management and the therapeutic decision-making process.

Characterization of Ralstonia insidiosa C1 isolated from Alpine regions: Capability in polyhydroxyalkanoates degradation and production.

This study ventures into the exploration of potential poly-3-hydroxybutyrate (PHB) degradation in alpine environments. PHB-degrading bacteria were identified in both campus soil, representing a residential area, and Mt. Kurodake soil, an alpine region in Hokkaido, Japan. Next-generation sequencing analysis indicated that the campus soil exhibited higher microbial diversity, while Ralstonia insidiosa C1, isolated from Mt. Kurodake soil, displayed the highest proficiency in PHB degradation. R. insidiosa C1 efficiently degraded up to 3% (w/v) of PHB and various films composed of other biopolymers at 14 °C. This bacterium synthesized homopolymers using substrates such as 3-hydroxybutyric acid, sugars, and acetic acid, while also produced copolymers using a mixture of fatty acids. The analysis results confirmed that the biopolymer synthesized by strain C1 using glucose was PHB, with physical properties comparable to commercial products. The unique capabilities of R. insidiosa C1, encompassing both the production and degradation of bioplastics, highlight its potential to establish a novel material circulation model.

Association of oral disease-modifying agents and their adherence trajectories with annual relapses in multiple sclerosis.

BACKGROUND: Real-world effectiveness can vary across oral disease-modifying agents (DMAs) and their adherence trajectories in patients with multiple sclerosis (MS). However, previous studies have not considered longitudinal adherence patterns while evaluating oral DMAs. OBJECTIVES: This study aimed to evaluate the association of oral DMAs and their adherence trajectories with annualized relapse rate (ARR) in patients with MS. METHODS: This retrospective observational cohort study based on the 2015-2019 MarketScan Commercial Claims and Encounters Database involved continuous enrolled adults (18-64 years) with ≥1 MS diagnosis (ICD-9/10-CM:340/G35) and ≥ 1 oral DMA prescription. Patients were grouped into incident fingolimod (FIN), teriflunomide (TER), and dimethyl fumarate (DMF) users based on the index DMA with a one-year washout period. Annual DMA adherence trajectories based on the monthly Proportion of Days Covered (PDC) one year after treatment initiation were identified using Group-Based Trajectory Modeling (GBTM). The validated claims-based ARR was evaluated during the one-year follow-up period using generalized boosted model-based inverse probability treatment weights with negative binomial regression model. RESULTS: The study cohort consisted of 994 MS patients who initiated with FIN (23.0%), TER (22.3%), and DMF (54.7%) during the study period. GBTM grouped eligible patients into three adherence trajectories: complete adherers (59.2%), slow decliners (23.8%), and rapid decliners (17.0%). The proportion of complete adherers varied across the oral DMAs (FIN: 67.1%, TER: 55.4%, and DMF: 57.4%). The negative binomial regression modeling revealed that, while there was no difference in ARR across the three DMAs, rapid decliners (adjusted incidence rate ratio[aIRR]: 1.6, 95% CI: 1.1-2.4) had a higher rate of relapses compared to completely adherent patients. The type of oral DMAs did not moderate the relationship between ARR and the adherence trajectory groups. CONCLUSIONS: Adherence trajectories classified as rapid decliners were associated with a higher ARR than complete adherers after adjusting for their type of oral DMAs. Longitudinal medication adherence patterns are critical in reducing relapse rates in MS.

Impact of the environmental parameters on single cell protein production and composition by Cupriavidus necator.

Due to the rapid increase in the world's population, many developing countries are facing malnutrition problems, including famine and food insecurity. Particularly, the deficiency of protein sources becomes a serious problem for human and animal nutrition. In this context, Single Cell Proteins, could be exploited as an alternative source of unconventional proteins. The aim of the study was to investigate SCP production and composition by Cupriavidus necator under various environmental conditions, temperature and pH values. A mono-factorial approach was implemented using batch bioreactor cultures under well-controlled conditions. Results were compared in terms of bacterial growth and SCP composition (proteins, nucleic acids, amino acids and elemental formula). Complementary analyses were performed by flow cytometry to study cell morphology, membrane permeability and the presence of Poly(3-hydroxybutyrate) (PHB) production. Our data confirmed the ability of C. necator to produce high amount of proteins (69 %DW at 30 °C and pH7). The results showed that temperature and pH independently impact SCP production and composition. This impact was particularly observed at the highest temperature (40 °C) and also the lowest pH value (pH5) providing lower growth rates, cell elongation, changes in granularity and lower amounts of proteins (down to 44 %DW at pH5) and nucleic acids. These low percentages were related to the production of PHB production (up to 44 %DW at 40 °C) which is the first report of a PHB accumulation in C. necator under nutrient unlimited conditions.

Enantiomer-Specific Cardiovascular Effects of the Ketone Body 3-Hydroxybutyrate.

BACKGROUND: The ketone body 3-hydroxybutyrate (3-OHB) increases cardiac output (CO) by 35% to 40% in healthy people and people with heart failure. The mechanisms underlying the effects of 3-OHB on myocardial contractility and loading conditions as well as the cardiovascular effects of its enantiomeric forms, D-3-OHB and L-3-OHB, remain undetermined. METHODS AND RESULTS: Three groups of 8 pigs each underwent a randomized, crossover study. The groups received 3-hour infusions of either D/L-3-OHB (racemic mixture), 100% L-3-OHB, 100% D-3-OHB, versus an isovolumic control. The animals were monitored with pulmonary artery catheter, left ventricle pressure-volume catheter, and arterial and coronary sinus blood samples. Myocardial biopsies were evaluated with high-resolution respirometry, coronary arteries with isometric myography, and myocardial kinetics with D-[11C]3-OHB and L-[11C]3-OHB positron emission tomography. All three 3-OHB infusions increased 3-OHB levels (P<0.001). D/L-3-OHB and L-3-OHB increased CO by 2.7 L/min (P<0.003). D-3-OHB increased CO nonsignificantly (P=0.2). Circulating 3-OHB levels correlated with CO for both enantiomers (P<0.001). The CO increase was mediated through arterial elastance (afterload) reduction, whereas contractility and preload were unchanged. Ex vivo, D- and L-3-OHB dilated coronary arteries equally. The mitochondrial respiratory capacity remained unaffected. The myocardial 3-OHB extraction increased only during the D- and D/L-3-OHB infusions. D-[11C]3-OHB showed rapid cardiac uptake and metabolism, whereas L-[11C]3-OHB demonstrated much slower pharmacokinetics. CONCLUSIONS: 3-OHB increased CO by reducing afterload. L-3-OHB exerted a stronger hemodynamic response than D-3-OHB due to higher circulating 3-OHB levels. There was a dissocitation between the myocardial metabolism and hemodynamic effects of the enantiomers, highlighting L-3-OHB as a potent cardiovascular agent with strong hemodynamic effects.

Inorganic polyphosphate and ion transport across biological membranes.

Inorganic polyphosphate (polyP) is widely recognized for playing important roles and processes involved in energy and phosphate storage, regulation of gene expression, and calcium signaling. The less well-known role of polyP is as a direct mediator of ion transport across biological membranes. Here, we will briefly summarize current knowledge of the molecular mechanisms of how polyP can be involved in membrane ion transport. We discuss three types of mechanisms that might involve polyP: (1) formation of non-protein channel complex that includes calcium, polyP, and polyhydroxybutyrate (PHB); (2) modulation of the channel activity of PHBlated protein channels; and (3) direct effects of polyP on the function of the voltage-gated ion channels in the process that do not involve PHB.

Real-world experience of teriflunomide in relapsing multiple sclerosis: paramagnetic rim lesions may play a role.

Objectives: The aims of this study were to report the effectiveness and safety of teriflunomide in Chinese patients with relapsing-remitting multiple sclerosis (RRMS) and to explore the association of paramagnetic rim lesion (PRL) burden with patient outcome in the context of teriflunomide treatment and the impact of teriflunomide on PRL burden. Methods: This is a prospective observational study. A total of 100 RRMS patients treated with teriflunomide ≥3 months were included in analyzing drug persistence and safety. Among them, 96 patients treated ≥6 months were included in assessing drug effectiveness in aspects of no evidence of disease activity (NEDA) 3. The number and total volume of PRL were calculated in 76 patients with baseline susceptibility-weighted imaging (SWI), and their association with NEDA3 failure during teriflunomide treatment was investigated. Results: Over a treatment period of 19.7 (3.1-51.7) months, teriflunomide reduced annualized relapse rate (ARR) from 1.1 ± 0.8 to 0.3 ± 0.5, and Expanded Disability Status Scale (EDSS) scores remained stable. At month 24, the NEDA3% and drug persistence rate were 43.8% and 65.1%, respectively. In patients with a baseline SWI, 81.6% had at least 1 PRL, and 42.1% had ≥4 PRLs. The total volume of PRL per patient was 0.3 (0.0-11.5) mL, accounting for 2.3% (0.0%-49.0%) of the total T2 lesion volume. Baseline PRL number ≥ 4 (OR = 4.24, p = 0.009), younger onset age (OR = 0.94, p = 0.039), and frequent relapses in initial 2 years of disease (OR = 13.40, p = 0.026) were associated with NEDA3 failure. The PRL number and volume were not reduced (p = 0.343 and 0.051) after teriflunomide treatment for more than 24 months. No new safety concerns were identified in this study. Conclusion: Teriflunomide is effective in reducing ARR in Chinese patients with RRMS. Patients with less PRL burden, less frequent relapses, and relatively older age are likely to benefit more from teriflunomide, indicating that PRL might be a valuable measurement to inform clinical treatment decision.

Catalytic Synthesis of (S)-CHBE by Directional Coupling and Immobilization of Carbonyl Reductase and Glucose Dehydrogenase.

Ethyl (S)-4-chloro-3-hydroxybutyrate ((S)-CHBE) is an important chiral intermediate in the synthesis of the cholesterol-lowering drug atorvastatin. Studying the use of SpyTag/SpyCatcher and SnoopTag/SnoopCatcher systems for the asymmetric reduction reaction and directed coupling coenzyme regeneration is practical for efficiently synthesizing (S)-CHBE. In this study, Spy and Snoop systems were used to construct a double-enzyme directed fixation system of carbonyl reductase (BsCR) and glucose dehydrogenase (BsGDH) for converting 4-chloroacetoacetate (COBE) to (S)-CHBE and achieving coenzyme regeneration. We discussed the enzymatic properties of the immobilized enzyme and the optimal catalytic conditions and reusability of the double-enzyme immobilization system. Compared to the free enzyme, the immobilized enzyme showed an improved optimal pH and temperature, maintaining higher relative activity across a wider range. The double-enzyme immobilization system was applied to catalyze the asymmetric reduction reaction of COBE, and the yield of (S)-CHBE reached 60.1% at 30 °C and pH 8.0. In addition, the double-enzyme immobilization system possessed better operational stability than the free enzyme, and maintained about 50% of the initial yield after six cycles. In summary, we show a simple and effective strategy for self-assembling SpyCatcher/SnoopCatcher and SpyTag/SnoopTag fusion proteins, which inspires building more cascade systems at the interface. It provides a new method for facilitating the rapid construction of in vitro immobilized multi-enzyme complexes from crude cell lysate.

Metabolic modeling of Halomonas campaniensis improves polyhydroxybutyrate production under nitrogen limitation.

Poly-hydroxybutyrate (PHB) is an environmentally friendly alternative for conventional fossil fuel-based plastics that is produced by various microorganisms. Large-scale PHB production is challenging due to the comparatively higher biomanufacturing costs. A PHB overproducer is the haloalkaliphilic bacterium Halomonas campaniensis, which has low nutritional requirements and can grow in cultures with high salt concentrations, rendering it resistant to contamination. Despite its virtues, the metabolic capabilities of H. campaniensis as well as the limitations hindering higher PHB production remain poorly studied. To address this limitation, we present HaloGEM, the first high-quality genome-scale metabolic network reconstruction, which encompasses 888 genes, 1528 reactions (1257 gene-associated), and 1274 metabolites. HaloGEM not only displays excellent agreement with previous growth data and experiments from this study, but it also revealed nitrogen as a limiting nutrient when growing aerobically under high salt concentrations using glucose as carbon source. Among different nitrogen source mixtures for optimal growth, HaloGEM predicted glutamate and arginine as a promising mixture producing increases of 54.2% and 153.4% in the biomass yield and PHB titer, respectively. Furthermore, the model was used to predict genetic interventions for increasing PHB yield, which were consistent with the rationale of previously reported strategies. Overall, the presented reconstruction advances our understanding of the metabolic capabilities of H. campaniensis for rationally engineering this next-generation industrial biotechnology platform. KEY POINTS: A comprehensive genome-scale metabolic reconstruction of H. campaniensis was developed. Experiments and simulations predict N limitation in minimal media under aerobiosis. In silico media design increased experimental biomass yield and PHB titer.

In vitro degradation and antibacterial activity of bacterial cellulose deposited flax fabric reinforced with polylactic acid and polyhydroxybutyrate.

The objective of this study was to prepare biocomposites through the solution casting method followed by compression moulding in which bacterial cellulose (BC) deposited flax fabric (FF) produced through fermentation is coated with minimal amount of polylactic acid (PLA) and polyhydroxybutyrate (PHB). Biocomposites incorporated with 60 % of PLA or PHB (% w/w) show enhanced tensile strength. Cross-sectional morphology showed good superficial interaction of these biopolymers with fibres of FF thereby filling up the gaps present between the fibres. The tensile strength of biocomposites at 60 % PLA and 60 % PHB improved from 37.97 MPa (i.e., BC deposited FF produced in presence of honey) to 67.17 MPa and 56.26 MPa, respectively. Further, 0.25 % of nalidixic acid (NA) (% w/w) and 6 % of oleic acid (OA) (% w/w) incorporation into the biocomposites imparted prolonged antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The in vitro cytotoxicity of biocomposites was determined using L929 mouse fibroblast cells. The 3-(4,5-cime- thylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cytotoxicity tests showed that the PHB derived biocomposites along with antibacterial compounds in it were non-toxic. In vitro degradation of biocomposites was measured for up to 8 weeks in the mimicked physiological environment that showed a gradual rate of degradation over the period.

Polyhydroxyalkanoate recovery overview: properties, characterizations, and extraction strategies.

Due to their excellent properties, polyhydroxyalkanoates are gaining increasing recognition in the biodegradable polymer market. These biogenic polyesters are characterized by high biodegradability in multiple environments, overcoming the limitation of composting plants only and their versatility in production. The most consolidated techniques in the literature or the reference legislation for the physical, chemical and mechanical characterisation of the final product are reported since its usability on the market is still linked to its quality, including the biodegradability certificate. This versatility makes polyhydroxyalkanoates a promising prospect with the potential to replace fossil-based thermoplastics sustainably. This review analyses and compares the physical, chemical and mechanical properties of poly-ß-hydroxybutyrate and poly-ß-hydroxybutyrate-co-ß-hydroxyvalerate, indicating their current limitations and strengths. In particular, the copolymer is characterised by better performance in terms of crystallinity, hardness and workability. However, the knowledge in this area is still in its infancy, and the selling prices are too high (9-18 $ kg-1). An analysis of the main extraction techniques, established and in development, is also included. Solvent extraction is currently the most widely used method due to its efficiency and final product quality. In this context, the extraction phase of the biopolymer production process remains a major challenge due to its high costs and the need to use non-halogenated toxic solvents to improve the production of good-quality bioplastics. The review also discusses all fundamental parameters for optimising the process, such as solubility and temperature.

Life Cycle of Functional All-Green Biocompatible Fibrous Materials Based on Biodegradable Polyhydroxybutyrate and Hemin: Synthesis, Service Life, and the End-of-Life via Biodegradation.

This article addresses the entire life cycle of the all-green fibrous materials based on poly(3-hydroxybutyrate) (PHB) containing a natural biocompatible additive Hemin (Hmi): from preparation, service life, and the end of life upon in-soil biodegradation. Fibrous PHB/Hmi materials with a highly developed surface and interconnected porosity were prepared by electrospinning (ES) from Hmi-containing feed solutions. Structural organization of the PHB/Hmi materials (porosity, uniform structure, diameter of fibers, surface area, distribution of Hmi within the PHB matrix, phase composition, etc.) is shown to be governed by the ES conditions: the presence of even minor amounts of Hmi in the PHB/Hmi (below 5 wt %) serves as a powerful tool for the control over their structure, performance, and biodegradation. Service characteristics of the PHB/Hmi materials (wettability, prolonged release of Hmi, antibacterial activity, breathability, and mechanical properties) were studied by different physicochemical methods (scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, contact angle measurements, antibacterial tests, etc.). The effect of the structural organization of the PHB/Hmi materials on their in-soil biodegradation at the end of life was analyzed, and key factors providing efficient biodegradation of the PHB/Hmi materials at all stages (from adaptation to mineralization) are highlighted (high surface area and porosity, thin fibers, release of Hmi, etc.). The proposed approach allows for target-oriented preparation and structural design of the functional PHB/Hmi nonwovens when their structural supramolecular organization with a highly developed surface area controls both their service properties as efficient antibacterial materials and in-soil biodegradation upon the end of life.

The production, recovery, and valorization of polyhydroxybutyrate (PHB) based on circular bioeconomy.

As an energy-storage substance of microorganisms, polyhydroxybutyrate (PHB) is a promising alternative to petrochemical polymers. Under appropriate fermentation conditions, PHB-producing strains with metabolic diversity can efficiently synthesize PHB using various carbon sources. Carbon-rich wastes may serve as alternatives to pure sugar substrates to reduce the cost of PHB production. Genetic engineering strategies can further improve the efficiency of substrate assimilation and PHB synthesis. In the downstream link, PHB recycling strategies based on green chemistry concepts can replace PHB extraction using chlorinated solvents to enhance the economics of PHB production and reduce the potential risks of environmental pollution and health damage. To avoid carbon loss caused by biodegradation in the traditional sense, various strategies have been developed to degrade PHB waste into monomers. These monomers can serve as platform chemicals to synthesize other functional compounds or as substrates for PHB reproduction. The sustainable potential and cycling value of PHB are thus reflected. This review summarized the recent progress of strains, substrates, and fermentation approaches for microbial PHB production. Analyses of available strategies for sustainable PHB recycling were also included. Furthermore, it discussed feasible pathways for PHB waste valorization. These contents may provide insights for constructing PHB-based comprehensive biorefinery systems.