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Polyhydroxyalkanoates (PHA) is a carbon neutral material that contributes to reducing greenhouse gas emissions due to manufactured from biomass and easily degraded by the enzymatic effects of microorganisms in the natural environment. However, PHA exhibits poorer mechanical properties and processability compared with petroleum‐based plastics. This study used cellulose nanofiber (CNF) to improve limit of PHA. Moreover, CNF was silylated to reduce polarity difference with PHA and enhance the dispersibility of nanocellulose at PHA. At a result, the silylation process was successfully performed by Si‐CH3 stretching peaks in Fourier transform infrared spectroscopy spectra and hydrophobicity of TEOS‐MTES‐CNF (TECNF) was confirmed by observed water contact angle (147°). In addition, nanostructure of TECNF was maintained during silylation and drying process through field emission scanning electron microscopy. Moreover, the PHA/TECNF composite showed enhanced processability, and tensile strength was increase almost 37% (0.52 MPa) compared with PHA. Oxygen transmission rates (300 cc/m2۰day) and single lap shear strength (225 kPa) were determined to be at least equivalent or superior to those of commercial packaging materials. Therefore, TECNF could be considered as a reinforcing agent, nucleating agent, and plasticizer in PHA. Also, this composite has possibilities to using as environmentally friendly packaging materials. [ABSTRACT FROM AUTHOR]

To construct a novel nano-carrier with dual ligands to achieve superior anti-tumour efficacy and lower toxic side effects. Liposomes were prepared by thin film hydration method. Ultraviolet, high performance liquid chromatography, nano-size analyser, ultrafiltration centrifugation, dialysis, transmission electron microscope, flow cytometry, Cell Counting Kit-8, confocal laser scanning microscopy, transwell, and tumorsphere assay were used to study the characterisations, cytotoxicity, and in vitro targeting of dg-Bcan targeting peptide (BTP-7)/pHA-temozolomide (TMZ)/tetra(4-carboxyphenyl)porphyrin (TCPP)-Lip. BTP-7/pHA-TMZ/TCPP-Lip was a spheroid with a mean diameters of 143 ± 3.214 nm, a polydispersity index of 0.203 ± 0.025 and a surface charge of −22.8 ± 0.425 mV. The drug loadings (TMZ and TCPP) are 7.40 ± 0.23% and 2.05 ± 0.03% (mg/mg); and the encapsulation efficiencies are 81.43 ± 0.51% and 84.28 ± 1.64% (mg/mg). The results showed that BTP-7/pHA-TMZ/TCPP-Lip presented enhanced targeting and cytotoxicity. BTP-7/pHA-TMZ/TCPP-Lip can specifically target the tumour cells to achieve efficient drug delivery, and improve the anti-tumour efficacy and reduces the systemic toxicity. [ABSTRACT FROM AUTHOR]

The industrial production of polyhydroxyalkanoates (PHAs) faces several limitations that hinder their competitiveness against traditional plastics, mainly due to high production costs and complex recovery processes. Innovations in microbial biotechnology offer promising solutions to overcome these challenges. The modification of the biosynthetic pathways is one of the main tactics; allowing for direct carbon flux toward PHA formation, increasing polymer accumulation and improving polymer properties. Additionally, techniques have been implemented to expand the range of renewable substrates used in PHA production. These feedstocks are inexpensive and plentiful but require costly and energy-intensive pretreatment. By removing the need for pretreatment and enabling the direct use of these raw materials, microbial biotechnology aims to reduce production costs. Furthermore, improving downstream processes to facilitate the separation of biomass from culture broth and the recovery of PHAs is critical. Genetic modifications that alter cell morphology and allow PHA secretion directly into the culture medium simplify the extraction and purification process, significantly reducing operating costs. These advances in microbial biotechnology not only enhance the efficient and sustainable production of PHAs, but also position these biopolymers as a viable and competitive alternative to petroleum-based plastics, contributing to a circular economy and reducing the dependence on fossil resources. [ABSTRACT FROM AUTHOR]

Abstract Background Parry-Romberg syndrome (PRS) is a rare progressive degenerative disorder of unknown etiology. Here we report a rare case of PRS combined with lens subluxation in Eye and ENT hospital of Fudan University, Shanghai. To our knowledge, it is the first reported case of PRS combined with lens subluxation that has been managed surgically with phacoemulsification and CTR placement and IOL implantation in Shanghai. Case presentation A 60-year-old woman was referred for “right visual blur for 2 years” and had persistent right facial paralysis of unknown etiology since the age 12. She had right facial muscle atrophy and paralysis. Eye examination also showed the right eyelid pseudoptosis, enophthalmos, age-related cataract combined with lens subluxation existed in the right eye. The patient was diagnosed as age-related cataract and lens subluxation in the right eye and progressive hemifacial atrophy (Parry-Romberg syndrome). We conducted a combined phacoemulsification, IOL and CTR implantation and pupilloplasty surgery for the patient under general anesthesia and the postoperative UCVA was 20/30 and remained for 1 year’s follow up. Conclusions Here we reported a rare case of PHA combined with lens subluxation in China. After appropriate eye surgery, the patient achieved satisfying vision result in the right eye.

Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) is a polymer obtained by bacterial fermentation that emerges as an alternative to polymers of petrochemical origin. The complex crystallization kinetics that occurs over 15 days after melting, known as ageing, limits its industrial application. During the aging process, there is a change of the degree of crystallinity, which has an effect on the chemical structure of the material. Additionally, changes in the mechanical properties, colorimetry, and dimensional shrinkage are observed. Different material properties are observed depending on the cooling conditions employed. For the ageing process, two different conditions are considered: ageing at room temperature and annealing at high temperature (60 °C). [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) are intracellular biopolymers that microorganisms use for energy and carbon storage. They are mechanically similar to petrochemical plastics when chemically extracted, but are completely biodegradable. While they have potential as a replacement for petrochemical plastics, their high production cost using traditional carbon sources remains a significant challenge. One potential solution is to modify heterotrophic PHA-producing strains to utilize alternative carbon sources. An alternative approach is to utilize methylotrophic or autotrophic strains. This article provides an overview of bacterial strains employed for PHA production, with a particular focus on those exhibiting the highest PHA content in dry cell mass. The strains are organized according to their carbon source utilization, encompassing autotrophy (utilizing CO2, CO) and methylotrophy (utilizing reduced single-carbon substrates) to heterotrophy (utilizing more traditional and alternative substrates). [ABSTRACT FROM AUTHOR]

Nowadays, the world is facing a general problem of resource overconsumption and waste overproduction: to address these two issues, the United Nations delivered the 12th Sustainable Development Goal (SDG), which has the objective of ensuring sustainable consumption and production patterns. Currently, polymers are present in every aspect of our lives and have the disadvantage of mostly coming from fossil sources and causing pollution when disposed of the wrong way. Agriculture plays a key role in the overall world environmental issues, being responsible for the creation of between 13 and 21% of global greenhouse gas (GHG) emissions. Moreover, it represents a continuously growing field, producing large amounts of waste. These residues can cause serious environmental concerns and high costs when disposed. However, agri-food waste (AFW) is a natural source of natural biopolymers, such as lignin, cellulose, pectin, and starch, but can also be used as a substrate to produce other non-toxic and biodegradable biopolymers, such as chitosan, polyhydroxyalkanoates (PHAs), and polylactic acid (PLA) through microbial fermentation. These polymers find applications in agricultural practices such as mulching films, soil stabilizers, hydrogels, nanocarriers, and coating for seeds, fruits, and vegetables. The employment of AFW in the production of non-toxic, sustainable, and biodegradable biopolymers for their agricultural utilization is an example of a virtuous circular economy approach that could help agriculture to be more sustainable. [ABSTRACT FROM AUTHOR]

Background: Parry-Romberg syndrome (PRS) is a rare progressive degenerative disorder of unknown etiology. Here we report a rare case of PRS combined with lens subluxation in Eye and ENT hospital of Fudan University, Shanghai. To our knowledge, it is the first reported case of PRS combined with lens subluxation that has been managed surgically with phacoemulsification and CTR placement and IOL implantation in Shanghai. Case presentation: A 60-year-old woman was referred for "right visual blur for 2 years" and had persistent right facial paralysis of unknown etiology since the age 12. She had right facial muscle atrophy and paralysis. Eye examination also showed the right eyelid pseudoptosis, enophthalmos, age-related cataract combined with lens subluxation existed in the right eye. The patient was diagnosed as age-related cataract and lens subluxation in the right eye and progressive hemifacial atrophy (Parry-Romberg syndrome). We conducted a combined phacoemulsification, IOL and CTR implantation and pupilloplasty surgery for the patient under general anesthesia and the postoperative UCVA was 20/30 and remained for 1 year's follow up. Conclusions: Here we reported a rare case of PHA combined with lens subluxation in China. After appropriate eye surgery, the patient achieved satisfying vision result in the right eye. [ABSTRACT FROM AUTHOR]

The use of residual streams as feedstock for the production of polyhydroxyalkanoates (PHAs) is growing steadily, as it allows the valorization of waste and nutrients otherwise disposed of and the potential production of a biodegradable bioplastic. To date, the environmental and economic costs associated with this process limit its scale-up, which is why it is important to identify possible solutions and optimize the costliest steps. With this in mind, a laboratory-scale sequenced batch reactor (SBR, 5 L) was constructed to allow the selection of a mixed microbial culture able to convert volatile fatty acids (VFAs) into PHA. The reactor is fed with synthetic water containing VFAs, ammonium, phosphate, and micronutrients, typical compounds of fermented streams of certain wastes, such as cheese whey, food waste, or wastewater sludge. The biomass selected and produced by this first reactor is sent to an accumulation reactor, which is fed with a solution rich in VFAs, allowing the accumulation of PHAs. The role of aeration and its impacts on the main process parameters were analyzed. Three scenarios corresponding to different aeration rates were analyzed: 0.08, 0.16, and 0.32 vvm. The SBR was operated at an organic load rate of 600 mgCOD L−1d−1, under a dynamic feeding regime (feast–famine) and a short hydraulic retention time (HRT; 1 day). The results obtained showed that a value of 0.32 enabled better selection and better settling of the sludge. Furthermore, a potential correlation between aeration rate and VFA and NH4+ consumption rates was identified. The resulting biomass was able to accumulate up to 0.15 ± 0.02 g PHAgVSS−1. [ABSTRACT FROM AUTHOR]

Hydroxalkanoate polymers, or polyhydroxyalkanoates (PHAs) are a diverse group of prokaryotic carbon and energy storage reserves. Since, PHAs have many of the same material characteristics as traditional plastics, they have been the subject of much interest as biodegradable alternatives to traditional fossil fuel based plastic polymers. Lately, much attention has been focused on establishing methods for the cost-effective manufacturing of PHAs. The isolation, qualitative and quantitative analysis and chemical characterisation of polyhydroxyalkanoates (PHAs) play a crucial role in the establishment of any kind of procedure. Various methodologies are required to initially identify potent microorganisms capable of synthesising polyhydroxyalkanoates (PHA), subsequently to ascertain unique building units of PHA polymer and last, to comprehend the structural and conformational chemistry of PHA at the intramolecular scale. This work aims to consolidate the existing methodologies for the identification, quantitative measurement and characterization of polyhydroxyalkanoates (PHAs), while also examining their respective merits and drawbacks. [ABSTRACT FROM AUTHOR]

Physiological and metabolic behavior of photoheterotrophic mixed cultures (PHMCs), monocultures of Rhodopseudomonas palustris , Clostridium pasteurianum and Syntrophomonas wolfei and a designed microbial consortium (DMC), consisting of these microorganisms that emulates natural consortia were studied. Growing and photoheterotrophic nongrowing conditions to simulate the use of dark fermentative effluents were used. Under growing conditions, C. pasteurianum showed higher bioH 2 production (8.5 mmol) and molar bioH 2 yield (21 mmoLH 2 /gCOD), while R. palustris did not produce this gas. Under nongrowing conditions, DMC reached the highest bioH 2 production (10 mmol) and bioH 2 yield (78.6 mmoLH 2 /gCOD) together with Poly-hydroxy-alkanoates (PHA), followed for PHMC-C2 (7.5; 59.6) and the monocultures. Higher bioH 2 and PHA production of the PHMC and the DMC suggest that these conditions promote the use of nonconventional energy pathways, and interactions among microbial populations that allow for the survival and sustain bioH 2 production. This study forms the basis for more in-depth studies of the metabolic behavior of photosynthetic natural and designed cultures. [Display omitted] • Metabolic behavior of natural and designed photoheterotrophic cultures was evaluated. • Nongrowing conditions promote the highest bioH 2 production in microbial consortia. • Microbial interactions allow for the survival and sustain bioH 2 production. • BioH 2 and PHA production are involved in the metabolic energy conservation. • Feasibility of design a microbial community for high bioH 2 production was demonstrated. [ABSTRACT FROM AUTHOR]

The aim of this review is to provide a comprehensive understanding by surveying patent documents and scientific articles on current progress in obtaining biopolymers from microalgae grown in wastewater. Raising critical points, current market panorama, trends and perspectives for the implementation of the integrated microalgae biorefinery. The searches for articles and patents were carried out using the terms microalgae, algae, polyhydroxyalkanoate, polymer, and biopolymer. About 57 patents and 27 articles directly related to the topic were found. The USA is the country with the highest number of patents (32), followed by the Republic of Korea (12). Companies are the biggest depositors (50%). Currently, the focus of research is centered on increasing the efficiency of treatments, aiming at large-scale production. Scientific articles show that little has been researched on the extraction of biopolymers from microalgae grown in wastewater. The ability of microalgae to act in the bioremediation of effluents stands out, as well as in the production of bioproducts of industrial interest. However, there is a gap regarding the economic feasibility of implementing current methods to obtain biopolymers, due to the high cost of production (2 × current methods). In addition, more research must be carried out, seeking to evaluate the techno-economic scenario (focused currently on PHB) and bioprospecting new strains to implement the integrated biorefinery concept. These are strategies that could increase the profitability of this sector, and enabling the use of microalgae to obtain biopolymers from effluents is considered a key factor to promote an industrial shift. [ABSTRACT FROM AUTHOR]

Ectoine, a crucial osmoprotectant for salt adaptation in halophiles, has gained growing interest in cosmetics and medical industries. However, its production remains challenged by stringent fermentation process in model microorganisms and low production level in its native producers. Here, we systematically engineered the native ectoine producer Halomonas bluephagenesis for ectoine production by overexpressing ectABC operon, increasing precursors availability, enhancing product transport system and optimizing its growth medium. The final engineered H. bluephagenesis produced 85 g/L ectoine in 52 h under open unsterile incubation in a 7 L bioreactor in the absence of plasmid, antibiotic or inducer. Furthermore, it was successfully demonstrated the feasibility of decoupling salt concentration with ectoine synthesis and co-production with bioplastic P(3HB- co -4HB) by the engineered H. bluephagenesis. The unsterile fermentation process and significantly increased ectoine titer indicate that H. bluephagenesis as the chassis of Next-Generation Industrial Biotechnology (NGIB), is promising for the biomanufacturing of not only intracellular bioplastic PHA but also small molecular compound such as ectoine. • Ectoine hyperproduction was achieved by systematically engineering a native producer Halomonas bluephagenesis. • 85 g/L ectoine was produced in a 7 L non-sterile fed-batch fermentation without plasmid, antibiotic, or inducer. • Dependence of ectoine synthesis and NaCl concentration was removed in the H. bluephagenesis. • Bioplastic P(3HB- co -4HB) and ectoine was co-produced by engineered H. bluephagenesis. [ABSTRACT FROM AUTHOR]

A general guide how to implement process safety management (PSM) is missing in the literature. This article provides general procedure to implement PSM which any industry in underdeveloped, developing and developed countries can adopt to start PSM implementation. PSM implementation can be initiated through the proposed framework consisting of four steps: (1) PSM introduction, (2) Assigning departmental wise PSM duties, (3) Trainings and (4) Audits and improvements. Trainings include process hazard analysis (PHA) using Integrated What‐If/HAZOP analysis, quantitative risk assessments using ALOHA or equivalent software, PSM forms developments and other trainings. In a case study, ammonia release is estimated and quantified using ALOHA. Nine various forms for PSM are required to be developed for industry implementing PSM. Various trainings should be arranged including specific learning outcomes and few examples are discussed in this article. An audit scheme is proposed for any new industry implementing PSM. PSM elements implementation sequence is discussed. New established industries can adopt this procedure to implement PSM following suggested forms and sequences, which can help engineers in understanding PSM implementation. This PSM implementation proposed framework is being implemented in the fertilizer industry and caustic industry. [ABSTRACT FROM AUTHOR]

Abstract Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) is a polymer obtained by bacterial fermentation that emerges as an alternative to polymers of petrochemical origin. The complex crystallization kinetics that occurs over 15 days after melting, known as ageing, limits its industrial application. During the aging process, there is a change of the degree of crystallinity, which has an effect on the chemical structure of the material. Additionally, changes in the mechanical properties, colorimetry, and dimensional shrinkage are observed. Different material properties are observed depending on the cooling conditions employed. For the ageing process, two different conditions are considered: ageing at room temperature and annealing at high temperature (60 °C).

The use of stable isotope-labeled polymers in in situ biodegradation tests provides detailed information on the degradation process. As isotope-labeled raw chemicals are generally expensive, it is desirable to prepare polymer samples with high production yields and high isotope-labeling ratios. The biodegradable plastic poly[(R)-3-hydroxybutyrate)] (P(3HB)) is produced by microorganisms. In this study, to produce carbon 13 (13C)-labeled P(3HB) from [U-13C6]D-glucose (13C-glucose), the culture conditions needed for high production yields and high 13C-labeling ratios were investigated using Ralstonia eutropha NCIMB 11599 and recombinant Escherichia coli JM109. We found that over 10 g/L of P(3HB) could be obtained when these microorganisms were cultured in Luria-Bertani (LB3) medium containing 3 g/L NaCl and 40 g/L 13C-glucose, while 1.4–4.7 g/L of P(3HB) was obtained when a mineral salt (MS) medium containing 20 g/L 13C-glucose was used. The 13C-labeling ratio of P(3HB) was determined by 1H nuclear magnetic resonance and gas chromatography-mass spectrometry (GC-MS), and both analytical methods yielded nearly identical results. High 13C-labeling ratios (97.6 atom% by GC-MS) were observed in the MS medium, whereas low 13C-labeling ratios (88.8–94.4 atom% by GC-MS) were observed in the LB3 medium. Isotope effects were observed for the P(3HB) content in cells cultured in the LB3 medium and the polydispersity of P(3HB).

The industrial production of polyhydroxyalkanoates (PHAs) faces several limitations that hinder their competitiveness against traditional plastics, mainly due to high production costs and complex recovery processes. Innovations in microbial biotechnology offer promising solutions to overcome these challenges. The modification of the biosynthetic pathways is one of the main tactics; allowing for direct carbon flux toward PHA formation, increasing polymer accumulation and improving polymer properties. Additionally, techniques have been implemented to expand the range of renewable substrates used in PHA production. These feedstocks are inexpensive and plentiful but require costly and energy-intensive pretreatment. By removing the need for pretreatment and enabling the direct use of these raw materials, microbial biotechnology aims to reduce production costs. Furthermore, improving downstream processes to facilitate the separation of biomass from culture broth and the recovery of PHAs is critical. Genetic modifications that alter cell morphology and allow PHA secretion directly into the culture medium simplify the extraction and purification process, significantly reducing operating costs. These advances in microbial biotechnology not only enhance the efficient and sustainable production of PHAs, but also position these biopolymers as a viable and competitive alternative to petroleum-based plastics, contributing to a circular economy and reducing the dependence on fossil resources.

Recently, the FDA-approved iron oxide nanoparticle, ferumoxytol, has been found to enhance the efficacy of pharmacological ascorbate (AscH−) in treating glioblastoma, as AscH− reduces the Fe3+ sites in the nanoparticle core. Given the iron oxidation state specificity of T2* relaxation mapping, this study aims to investigate the ability of T2* relaxation to monitor the reduction of ferumoxytol by AscH− with respect to its in vitro therapeutic enhancement. This study employed an in vitro glioblastoma MRI model system to investigate the chemical interaction of ferumoxytol with T2* mapping. Lipofectamine was utilized to facilitate ferumoxytol internalization and assess intracellular versus extracellular chemistry. In vitro T2* mapping successfully detected an AscH−-mediated reduction of ferumoxytol (25.6 ms versus 2.8 ms for FMX alone). The T2* relaxation technique identified the release of Fe2+ from ferumoxytol by AscH− in glioblastoma cells. However, the high iron content of ferumoxytol limited T2* ability to differentiate between the external and internal reduction of ferumoxytol by AscH− (ΔT2* = +839% for external FMX and +1112% for internal FMX reduction). Notably, the internalization of ferumoxytol significantly enhances its ability to promote AscH− toxicity (dose enhancement ratio for extracellular FMX = 1.16 versus 1.54 for intracellular FMX). These data provide valuable insights into the MR-based nanotheranostic application of ferumoxytol and AscH− therapy for glioblastoma management. Future developmental efforts, such as FMX surface modifications, may be warranted to enhance this approach further. [ABSTRACT FROM AUTHOR]

5-Aminovaleric acid (5-AVA), 5-hydroxyvalerate (5HV), copolymer P(3HB- co -5HV) of 3 -hydroxybutyrate (3HB) and 5HV were produced from L-lysine as a substrate by recombinant Halomonas bluephagenesis constructed based on codon optimization, deletions of competitive pathway and L-lysine export protein, and three copies of davBA genes encoding L-lysine monooxygenase (DavB) and 5-aminovaleramide amidohydrolase (DavA) inserted into its genome to form H. bluephagenesis YF117Δ gabT 1+2 , which produced 16.4 g L−1 and 67.4 g L−1 5-AVA in flask cultures and in 7 L bioreactor, respectively. It was able to de novo synthesize 5-AVA from glucose by L-lysine-overproducing H. bluephagenesis TD226. Corn steep liquor was used instead of yeast extract for cost reduction during the 5-AVA production. Using promoter engineering based on P porin mutant library for downstream genes, H. bluephagenesis YF117 harboring pSEVA341-P porin 42 - yqhD EC produced 6 g L−1 5HV in shake flask growth , while H. bluephagenesis YF117 harboring pSEVA341-P porin 42 - yqhD EC -P porin 278 - phaC RE -abfT synthesized 42 wt% P(3HB- co -4.8 mol% 5HV) under the same condition. Thus, H. bluephagenesis was successfully engineered to produce 5-AVA and 5HV in supernatant and intracellular P(3HB- co -5HV) utilizing L-lysine as the substrate. [Display omitted] • 5-Aminovaleric acid (5-AVA), 5-hydroxyvalerate (5HV), and P(3HB- co -5HV) were produced by Halomonas bluephagenesis. • The engineered strain YF117Δ gabT 1+2 , produced 16.4and 67.4 g L−1 5-AVA in flask cultures and in 7 L bioreactor, respectively. • It was able to de novo synthesize around 600 mg L−1 5-AVA from glucose by L-lysine- overproducing H. bluephagenesis TD226. • H. bluephagenesis YF117 harboring pSEVA341-P porin 42 - yqhD EC produced 6 g L−1 5HV in shake flasks. • YF117 harboring pSEVA341-P porin 42 - yqhD EC -P porin 278 - phaC RE - abfT synthesized 42 wt% P(3HB- co -4.8 mol% 5HV). [ABSTRACT FROM AUTHOR]

A large number of non-degradable materials have severely damaged the ecological environment. Now, people are increasingly pursuing the use of environmentally friendly materials to replace traditional chemical materials. Polyhydroxyalkonates (PHAs) are receiving increasing attention because of the unique biodegradability and biocompatibility they offer. However, the applications of PHAs are still limited due to high production costs and insufficient study. This project examines the optimal electrospinning parameters for the production of PHA-based fibrous membranes for air filtration. A common biodegradable polyester, Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), was electrospun into a nanofibrous membrane with a well-controlled surface microstructure. In order to produce smooth, bead-free fibers with micron-scale diameters, the effect of the process parameters (applied electric field, solution flow rate, inner diameter of hollow needle, and polymer concentration) on the electrospun fiber microstructure was optimized. The well-defined fibrous structure was optimized at an applied electric field of 20 kV, flow rate of 0.5 mL/h, solution concentration of 12 wt.%, and needle inner diameter of 0.21 mm. The morphology of the electrospun PHBV fibrous membrane was observed by scanning electron microscopy (SEM). Fourier transform infrared (FTIR) and Raman spectroscopy were used to explore the chemical signatures and phases of the electrospun PHBV nanofiber. The ball burst strength (BBS) was measured to assess the mechanical strength of the membrane. The small pore size of the nanofiber membranes ensured they had good application prospects in the field of air filtration. The particle filtration efficiency (PFE) of the optimized electrospun PHBV fibrous membrane was above 98% at standard atmospheric pressure. [ABSTRACT FROM AUTHOR]

The study was carried out to evaluate the efficacy of conventional broth vaccine and biofilm Haemorrhagic Septicaemia (H.S.) vaccine in cattle by using passive hemagglutination assay (PHA), monoclonal antibody enzyme-linked immunosorbent assay (ELISA), Avidin Biotin-ELISA and passive mouse protection test (PMPT) tests. Conventional broth and biofilm vaccines were prepared using P52 vaccine strain by incorporating adjuvant alum and bentonite clay, respectively. Two groups of cattle consisting twelve animals in each group were immunized separately with conventional broth and biofilm vaccines. The immune response of cattle against two vaccines were assayed by PHA and ELISA using crude capsular and outer membrane protein (OMP) antigen extracted from Pasteurella multocida organism grown under biofilm mode condition, to quantify the levels of antibody at monthly intervals up to six months post vaccination. In general in all the tests, biofilm vaccine showed not only high antibody titres but also prolonged protective immune response up to 24 weeks of observation period in the present study compared to 16 weeks in case of conventional broth vaccine. There was a significant difference observed in antibody titres between PHA and the ELISA tests, indicating ELISA tests are more sensitive to detecting antibody titre in serum than PHA test. Among two ELISA tests, there was a significant difference seen between monoclonal antibody ELISA kit and ABELISA titres indicating that AB-ELISA was more sensitive. [ABSTRACT FROM AUTHOR]

One of the most recent innovations to promote a circular economy during wastewater treatment is the production of biopolymers. It has recently been demonstrated that it is possible to integrate the production of biopolymers in the form of polyhydroxyalkanoates (PHA) with nitrogen removal via nitrite during the treatment of sludge reject water. In the present study, simulation of a new process for bioresource recovery was conducted by an appropriate modification of the Activated Sludge Model 3. The process consists of the integrated nitrogen removal via nitrite from sludge reject water and the selection of PHA-storing biomass by inducing a feast and famine regime under aerobic and anoxic conditions. According to the results, it is anticipated that simulation data matched very satisfactorily with the experimental data and confirmed the main experimental observation, showing that during the famine period the PHA depletion was almost complete due to the availability of nitrite as the electron acceptor. Simulation results indicate that the selection of the volumetric organic loading rate and of the relative duration of the aerobic feast/anoxic famine duration is critical in order to allow for the effective denitritation of the internally stored PHA during the famine phase. [ABSTRACT FROM AUTHOR]

The rising global demand for animal-based food has an increasingly detrimental ecological impact, exacerbated by significant food waste (approximately one-third of all food). This research aimed to analyze the possibility of changing the usually balanced feed with sustainable alternatives that remain as a by-product of the production of farms, grain processing, and breweries, thus promoting the sustainability of agriculture. The mealworm larvae were reared on different substrates: (1) agar-agar gels, wheat bran, and brewer's yeast, (2) carrots, wheat bran, and brewer's yeast, (3) sprouted potatoes, wheat bran, and brewer's yeast, and (4) carrots, brewers' spent grain and brewer's yeast. For analysis, the frozen larvae were lyophilized and tested for chemical safety in three accredited laboratories. The results have shown that all tested samples had lower levels of pesticides than the detection limit. In scientific literature, we didn't find studies on polycyclic aromatic hydrocarbons (PAH). In our study, we found PAH in the substrate and these toxins, as our study shows, can also enter the larvae, but no significant accumulation was observed (sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene was 0.0007 mg/kg). Furthermore, the total content of PAH, benzo(a)pyrene and histamine did not exceed recommended levels. We have noticed that the highest concentration of heavy metals (e.g., chromium—1.45 ± 0.02) was found in the sample with the brewer's by-products. While numerous studies utilize plant-derived by-products, the accumulation of glycoalkaloids has not been explored. Among the all glycoalkaloids (tomatidin, tomatine, α-solanine, α-chaconine and solanidin), amounts of α-solanine and α-chaconine were the highest, detected in the sample with sprouted potatoes (175.12 ± 0.21 and 139.32 ± 0.32 mg/kg, respectively). The amount of total putrescine, tyramine, spermine, and spermidine in mealworm larvae was statistically higher compared to the amount detected in the substrate, and histamine level-on the contrary, was statistically significantly lower compared to the amount detected in the substrate. Considering the amount of toxic substances found in the substrate from the by-products, we can assume that mealworms did not accumulate high levels of toxins, which would violate regulations. [ABSTRACT FROM AUTHOR]

This review presents a comprehensive update of the biopolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), emphasizing its production, properties, and applications. The overall biosynthesis pathway of PHBV is explored in detail, highlighting recent advances in production techniques. The inherent physicochemical properties of PHBV, along with its degradation behavior, are discussed in detail. This review also explores various blends and composites of PHBV, demonstrating their potential for a range of applications. Finally, the versatility of PHBV-based materials in multiple sectors is examined, emphasizing their increasing importance in the field of biodegradable polymers. [ABSTRACT FROM AUTHOR]

During the execution of a change using Management of Change (MOC), the risk to the facility is increased because things are in flux until the change is completed and documented and personnel trained. During this time P&IDs, SOPs, and other procedures are being developed or changed. Construction or tie‐ins in preparation, or as part of the change, are going on. Thus, during the change until it is complete, the potential for error, and therefore the risk, is increased. This potential for error emanates from the use of not‐yet implemented P&IDs, the use of unapproved or old procedures, and unintended connections and flows from or to piping that contains hazardous materials. Additional risk results from an incorrect workflow where the appropriate individuals were not included in the review or the necessary approvals are bypassed. Another possible risk is unknowingly impacting an existing safeguard by changing related equipment. Thus, the MOC process needs to be carefully managed, not only for an individual MOC but the aggregate of all the MOCs that are being worked on at the same time. The elements for minimizing the risk of a change are described, and a tool to monitor the MOC process, which includes automatic metrics, is illustrated. [ABSTRACT FROM AUTHOR]

Summary: Plant‐based co‐production of polyhydroxyalkanoates (PHAs) and seed oil has the potential to create a viable domestic source of feedstocks for renewable fuels and plastics. PHAs, a class of biodegradable polyesters, can replace conventional plastics in many applications while providing full degradation in all biologically active environments. Here we report the production of the PHA poly[(R)‐3‐hydroxybutyrate] (PHB) in the seed cytosol of the emerging bioenergy crop Camelina sativa engineered with a bacterial PHB biosynthetic pathway. Two approaches were used: cytosolic localization of all three enzymes of the PHB pathway in the seed, or localization of the first two enzymes of the pathway in the cytosol and anchoring of the third enzyme required for polymerization to the cytosolic face of the endoplasmic reticulum (ER). The ER‐targeted approach was found to provide more stable polymer production with PHB levels up to 10.2% of the mature seed weight achieved in seeds with good viability. These results mark a significant step forward towards engineering lines for commercial use. Plant‐based PHA production would enable a direct link between low‐cost large‐scale agricultural production of biodegradable polymers and seed oil with the global plastics and renewable fuels markets. [ABSTRACT FROM AUTHOR]

In this study, bacterial strains isolated from olive oil mill wastewater assigned to Bacillus (n = 4) and Klebsiella (n = 1) genera, were evaluated for their ability to accumulate intracellular PHA granules using Sudan Black staining. A maximum PHA production of 0.14 g/L (i.e., 30.2% wt./wt. in dry biomass) was observed in Bacillus amyloliquefaciens strain OM81 after 72 h of incubation in the presence of 2% glucose (synthetic medium). To reduce bioplastic production costs and recover a polluting product, olive mill wastewater was tested as a carbon source. In this context, the maximum growth (1.45 g/L) was observed in the presence of 50% olive mill wastewater. After extracting the biopolymers with chloroform, quantitative and qualitative analyses were conducted using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). FTIR showed an absorption band at 1730 cm−1 assigned to the elongation of the PHB carbonyl groups. This approach offers a dual benefit of reducing pollution and bioplastic production costs. The Bacillus amyloliquefaciens strain OM81 showed promising results for PHAs production, making it a potential candidate for further investigation. [ABSTRACT FROM AUTHOR]

The use of stable isotope-labeled polymers in in situ biodegradation tests provides detailed information on the degradation process. As isotope-labeled raw chemicals are generally expensive, it is desirable to prepare polymer samples with high production yields and high isotope-labeling ratios. The biodegradable plastic poly[(R)-3-hydroxybutyrate)] (P(3HB)) is produced by microorganisms. In this study, to produce carbon 13 (13C)-labeled P(3HB) from [U-13C6]D-glucose (13C-glucose), the culture conditions needed for high production yields and high 13C-labeling ratios were investigated using Ralstonia eutropha NCIMB 11599 and recombinant Escherichia coli JM109. We found that over 10 g/L of P(3HB) could be obtained when these microorganisms were cultured in Luria-Bertani (LB3) medium containing 3 g/L NaCl and 40 g/L 13C-glucose, while 1.4–4.7 g/L of P(3HB) was obtained when a mineral salt (MS) medium containing 20 g/L 13C-glucose was used. The 13C-labeling ratio of P(3HB) was determined by 1H nuclear magnetic resonance and gas chromatography-mass spectrometry (GC-MS), and both analytical methods yielded nearly identical results. High 13C-labeling ratios (97.6 atom% by GC-MS) were observed in the MS medium, whereas low 13C-labeling ratios (88.8–94.4 atom% by GC-MS) were observed in the LB3 medium. Isotope effects were observed for the P(3HB) content in cells cultured in the LB3 medium and the polydispersity of P(3HB). [ABSTRACT FROM AUTHOR]

The mechanical behavior of polymer materials is heavily influenced by a phenomenon known as crazing. Crazing is a precursor to damage and leads to the formation of cracks as it grows in both thickness and tip size. The current research employs an in situ SEM method to investigate the initiation and progression of crazing in all-biopolymeric blends based on Polyhydroxyalkanoates (PHAs). To this end, two chemically different grades of PHA, namely poly(hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV), were melt-blended with polybutyrate adipate terephthalate (PBAT). The obtained morphologies of blends, the droplet/fibrillar matrix, were highly influenced by the plasticity of the matrices as well as the content of the minor phase. Increasing the concentration of PBAT from 15 to 30 wt.% resulted in the brittle to ductile transition. It changed the mechanism of plastic deformation from single craze-cracking to homogeneous and heterogeneous intensified crazing for PHB and PHBHV matrices, respectively. Homogeneous tensile crazes formed perpendicularly to the draw direction at the initial stages of deformation, transformed into shear crazes characterized by oblique edge propagation for the PHBHV/PBAT blend. Such angled crazes suggested that the displacement might be caused by shear localized deformation. The crazes' strength and the time to failure increased with the minor phase fibers. These fibers, aligned with the tensile direction and spanning the width of the crazes, were in the order of a few micrometers in diameter depending on the concentration. The network of fibrillar PBAT provided additional integrity for larger plastic deformation values. This study elucidates the mechanism of crazing in PHA blends and provides strategies for controlling it. [ABSTRACT FROM AUTHOR]

The Chevron Refining organization has completed a multi‐year effort to create process hazard analysis (PHA) templates and checklists to improve the consistency and quality of PHAs. The goal of this study is to provide an overview of the content, development process, and lessons learned. The lessons learned included the following. Members of PHA teams and SMEs have differing experiences and perspectives on the risk of loss of containment, necessitating a standardized method for developing consequences and modifiers. Typical PHA teams (e.g., facilitator, process and/or design engineer, and operator) will have differing levels of engineering and operating experience, making a thorough understanding of the various types of equipment and processes in a typical refining unit impractical. PHA teams cannot realistically bring in SMEs on an as needed basis to aid with the analysis. Concerns that templated solutions might cause PHA teams to lose their creativity and focus only on the templates, and that templates might omit or incorrectly assess a hazard, have been outweighed by the benefits of the templates. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) are intracellular biopolymers that microorganisms use for energy and carbon storage. They are mechanically similar to petrochemical plastics when chemically extracted, but are completely biodegradable. While they have potential as a replacement for petrochemical plastics, their high production cost using traditional carbon sources remains a significant challenge. One potential solution is to modify heterotrophic PHA-producing strains to utilize alternative carbon sources. An alternative approach is to utilize methylotrophic or autotrophic strains. This article provides an overview of bacterial strains employed for PHA production, with a particular focus on those exhibiting the highest PHA content in dry cell mass. The strains are organized according to their carbon source utilization, encompassing autotrophy (utilizing CO2, CO) and methylotrophy (utilizing reduced single-carbon substrates) to heterotrophy (utilizing more traditional and alternative substrates).

Abstract Aerobic hydrogen-oxidizing ‘Knallgas’ bacteria are promising candidates for microbial cell factories due to their ability to use hydrogen and carbon dioxide as the sole energy and carbon sources, respectively. These bacteria can convert atmospheric CO2 to chemicals which could help to mitigate climate change by replacing fossil fuel-based chemicals. A known method to enhance the product yield is to disrupt competing metabolic pathways in the host organism. One such pathway in many ‘Knallgas’ bacteria is polyhydroxybutyrate (PHB) biosynthesis. In this study, the PHB biosynthesis genes of a non-model ‘Knallgas’ bacterium Xanthobacter sp. SoF1 were identified. Consequently, the phaA, phaB and phaC genes were individually deleted and the resulting knockouts were evaluated for their ability to produce PHB in autotrophic shake flask and small-scale bioreactor cultivations. The results demonstrate that PHB production was inactivated in the phaC1 knockout strain, which advances the development of Xanthobacter sp. SoF1 as a production host. Graphical Abstract

Extremophilic microorganisms such as those that thrive in high-salt and high-alkaline environments are promising candidates for the recovery of useful biomaterials including polyhydroxyalkanoates (PHAs). PHAs are ideal alternatives to synthetic plastics because they are biodegradable, biocompatible, and environmentally friendly. This work was aimed at conducting a bioprospection of bacteria isolated from hypersaline-alkaliphilic lakes in Kenya for the potential production of PHAs. In the present study, 218 isolates were screened by Sudan Black B and Nile Red A staining. Of these isolates, 31 were positive for PHA production and were characterized using morphological, biochemical, and molecular methods. Through 16S rRNA sequencing, we found that the isolates belonged to the genera Arthrobacter spp., Bacillus spp., Exiguobacterium spp., Halomonas spp., Paracoccus spp., and Rhodobaca spp. Preliminary experiments revealed that Bacillus sp. JSM-1684023 isolated from Lake Magadi had the highest PHA accumulation ability, with an initial biomass-to-PHA conversion rate of 19.14% on a 2% glucose substrate. Under optimized fermentation conditions, MO22 had a maximum PHA concentration of 0.516 g/L from 1.99 g/L of cell dry weight and 25.9% PHA conversion, equivalent to a PHA yield of 0.02 g/g of biomass. The optimal PHA production media had an initial pH of 9.0, temperature of 35 °C, salinity of 3%, and an incubation period of 48 h with 2.5% sucrose and 0.1% peptone as carbon and nitrogen sources, respectively. This study suggests that bacteria isolated from hypersaline and alkaliphilic tropical lakes are promising candidates for the production of polyhydroxyalkanoates.

The crystallisation process of polyhydroxyalkanoates (PHA) polymers plays a key role on final properties of manufactured parts due to most PHA are highly sensitive to physical aging which leads to embrittlement. The secondary crystallisation associated with the aging process can be partially controlled by the cooling process during manufacturing or, even, by heat treatments such as annealing. A critical parameter in additive manufacturing is the difficulty to achieve good adhesion of the material to the printing bed. The bed temperature plays a key role on PHBH crystallisation, which leads to shrinkage having a negative effect on polymer-to-bed adhesion. In this work, a study of the effect of different processing parameters such as the printing temperature, the bed temperature, the cooling conditions, as well as raster direction on the final properties of PHBH 3D-printed parts is carried out.

The synthesis of PHA was first investigated using WFOs obtained from smoked-sprat heads, substandard fresh sprats, and fresh mackerel heads and backbones. All the WFOs ensured the growth of the wild-type strain Cupriavidus necator B-10646 and the synthesis of PHA, regardless of the degree of lipid saturation (from 0.52 to 0.65) and the set and ratio of fatty acids (FA), which was represented by acids with chain lengths from C14 to C24. The bacterial biomass concentration and PHA synthesis were comparable (4.1–4.6 g/L and about 70%) when using WFO obtained from smoked-sprat heads and fresh mackerel, and it was twice as high as the bacterial biomass concentration from the fresh sprat waste. This depended on the type of WFO, the bacteria synthesized P(3HB) homopolymer or P(3HB-co-3HV-co-3HHx) copolymer, which had a lower degree of crystallinity (Cx 71%) and a lower molecular weight (Mn 134 kDa) compared to the P(3HB) (Mn 175–209 kDa and Cx 74–78%) at comparable temperatures (Tmelt and Tdegr of 158–168 °C and 261–284 °C, respectively). The new types of WFO, studied for the first time, are suitable as a carbon substrates for PHA synthesis. The WFOs obtained in the production of canned Baltic sprat and Baltic mackerel can be considered a promising and renewable substrate for PHA biosynthesis. [ABSTRACT FROM AUTHOR]

In the present scenario, rising environmental concerns of non-biodegradable plastic pollution and depletion of petroleum based raw materials lead to the development of biopolymers. The biodegradability of biopolymers gives them a specific advantage for the environmental concerns. Polyhydroxyalkanoates (PHAs) are a type of biopolymers which are synthesized by microorganisms. Although there are different substrates available in pure forms which are currently used in the production of PHA, 40% of production cost depends on the expensive substrate which is a major disadvantage and make it far from many applications. The use of an inexpensive carbon source which is high in organic matter content such as waste streams of process industries can make this process viable and diminish PHA production cost. This study explores the current research initiatives on various agricultural and industrial waste feedstocks, formulations and processing conditions for producing PHA in a way that is both inexpensive and beneficial to the environment. The creation of fermentation conditions and metabolic engineering techniques for promoting microbial growth and PHA synthesis were also discussed in the review. [ABSTRACT FROM AUTHOR]

Bioremediation techniques are increasingly popular in addressing soil pollution. Despite this, using earthworms as first actors or adjuvants in decontamination is an open and little-discussed field. This paper focuses on vermiremediation effectiveness alone or combined with other bioremediation methods, such as phytoremediation and bioaugmentation. Literature was collected following the PRISMA criteria, setting the search with the following keywords: "(vermiremediation) AND (bioremediation OR phytoremediation OR plant*) AND (bioaugmentation OR bacteria)". The investigation was performed on Google Scholar, Science Direct, SciFinder and Web of Science databases. The article data were collected, compared, elaborated, graphically summarised and discussed to assess if the earthworms' activities play a critical role in tackling several soil pollutions. Furthermore, the review aimed to identify the most promising techniques in the function of the xenobiotic examined: organic, inorganic or both. Any gaps and criticism were highlighted to facilitate future research in this study area. [ABSTRACT FROM AUTHOR]

Aerobic hydrogen-oxidizing 'Knallgas' bacteria are promising candidates for microbial cell factories due to their ability to use hydrogen and carbon dioxide as the sole energy and carbon sources, respectively. These bacteria can convert atmospheric CO2 to chemicals which could help to mitigate climate change by replacing fossil fuel-based chemicals. A known method to enhance the product yield is to disrupt competing metabolic pathways in the host organism. One such pathway in many 'Knallgas' bacteria is polyhydroxybutyrate (PHB) biosynthesis. In this study, the PHB biosynthesis genes of a non-model 'Knallgas' bacterium Xanthobacter sp. SoF1 were identified. Consequently, the phaA, phaB and phaC genes were individually deleted and the resulting knockouts were evaluated for their ability to produce PHB in autotrophic shake flask and small-scale bioreactor cultivations. The results demonstrate that PHB production was inactivated in the phaC1 knockout strain, which advances the development of Xanthobacter sp. SoF1 as a production host. Key points: phaA, phaB and phaC knockouts of Xanthobacter sp. SoF1 were constructed. PHB content of the knockouts grown in continuous gas fermentation was determined. PHB-deficient phaC1 knockout strain had higher protein content than the wild type. [ABSTRACT FROM AUTHOR]

In open environment applications, fibers are increasingly being used that are expected to biodegrade in the soil after their desired service life. Biodegradable polymer fibers are a versatile alternative to natural fibers. In this study, the degradation behavior of fibers made from polylactic acid (PLA) and a polyhydroxy alkanoate (PHA) blend with PLA, as well as a bicomponent fiber (BICO) made from polybutylene succinate (PBS) and PLA, was investigated. The fibers were stored in topsoil at 23 °C for 12 weeks. In addition, fibers were stored in compost at 58 °C for 4 weeks to investigate the degradation behavior in an industrial composting plant. Reference materials were also stored without substrate under the same temperatures and humidity conditions. Samples were taken regularly, and mechanical testing, scanning electron microscopy (SEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and infrared spectroscopy (IR) were used to study the degradation of the fibers. After 12 weeks in soil at ambient temperatures, the PLA and BICO fibers showed no degradation. The PHA fibers showed cracks in SEM, a decrease in molecular weight, and changes in the IR spectrum. No evidence of biological influence (bacteria or fungi) was found. Under industrial composting conditions, all fibers showed a decrease in strength and molecular weight. For the BICO and the PHA fibers, the SEM images show significant changes. Especially in the PHA fibers, fungal mycelia can be seen. The studies provide a better insight into the processes involved in the degradation behavior under different environmental conditions. [ABSTRACT FROM AUTHOR]

Producing polyhydroxyalkanoate (PHA) from lignin through biological conversion has great further potential, but is held by its high heterogeneous characteristic toxicity of the depolymerized products, and low bioconversion of the depolymerized products. In this study, a Fenton-like reaction, which is inspired by fungal decay strategy, was reported to cleave Kraft lignin linkages and produce low toxic mono-aromatic and low molecular organic compounds for microbial conversion. The treatment improved the bioconversion of lignin to PHA by 141.7% compared to Kraft lignin. The bond cleavage of Kraft lignin was characterized by Py-GC/MS and 2D NMR. Seven major depolymerized products were chosen to test their toxicity effect on bacterial fermentation. Furthermore, 920.4 mg of PHA was obtained from 1-L black liquor after Fenton-like reaction treatment. This is a novel attempt mimicking fungal decay strategy coupled with the microbial conversion of lignin into high-value PHA with a sustainable future. [ABSTRACT FROM AUTHOR]

The present study explains the growth pattern and polyhydroxyalkanoate (PHA) production capacity of Bacillus sp. CYR1 as it uses various fatty acids as carbon sources. Various combinations of fatty acids were used for the growth of strain CYR1. Among them, strain CYR1 showed good growth with the combination of two fatty acids (acetic acid and butyric acid) and the combination of three fatty acids (acetic acid, propionic acid, and caproic acid). Apart from the growth pattern, PHA production was also evaluated. PHA production was in coordination with the growth pattern. Bacteria incubated with the combination of acetic acid–butyric acid produced 0.158 g/L, and acetic acid–propionic acid–caproic acid produced 0.241 g/L of PHA. It is essential to reduce the substrate cost for PHA production by replacing expensive carbon sources with wastewater. The organic compounds in domestic and industrial wastewater contain various fatty acids. By studying different combinations of fatty acids, we gained new insights into utilizing wastewater containing various fatty acids as substrates for PHA production. [ABSTRACT FROM AUTHOR]