Genetic heterogeneity of engineered Escherichia coli Nissle 1917 strains during scale-up simulation.

Advanced microbiome therapeutics have emerged as a powerful approach for the treatment of numerous diseases. While the genetic instability of genetically engineered microorganisms is a well-known challenge in the scale-up of biomanufacturing processes, it has not yet been investigated for advanced microbiome therapeutics. Here, the evolution of engineered Escherichia coli Nissle 1917 strains producing Interleukin 2 and Aldafermin were investigated in two strain backgrounds with and without the three error-prone DNA polymerases polB, dinB, and umuDC, which contribute to the mutation rate of the host strain. Whole genome short-read sequencing revealed the genetic instability of the pMUT-based production plasmid after serial passaging for approximately 150 generations using an automated platform for high-throughput microbial evolution in five independent lineages for six distinct strains. While a reduction of the number of mutations of 12%-43% could be observed after the deletion of the error-prone DNA polymerases, the interruption of production-relevant genes could not be prevented, highlighting the need for additional strategies to improve the stability of advanced microbiome therapeutics.

Bioprocess development for cord blood mesenchymal stromal cells on microcarriers in Vertical-Wheel bioreactors.

Equine mesenchymal stromal cells (MSCs) have been found to be beneficial for the treatment of many ailments, including orthopedic injuries, due to their superior differentiation potential and immunomodulating properties. Cell therapies require large cell numbers, which are not efficiently generated using conventional static expansion methods. Expansion of equine cord blood-derived MSCs (eCB-MSCs) in bioreactors, using microcarriers as an attachment surface, has the potential to generate large numbers of cells with increased reproducibility and homogeneity compared with static T-flask expansion. This study investigated the development of an expansion process using Vertical-Wheel (VW) bioreactors, a single-use bioreactor technology that incorporates a wheel instead of an impeller. Initially, microcarriers were screened at small scale to assess eCB-MSC attachment and growth and then in bioreactors to assess cell expansion and harvesting. The effect of different donors, serial passaging, and batch versus fed batch were all examined in 0.1 L VW bioreactors. The use of VW bioreactors with an appropriate microcarrier was shown to be able to produce cell densities of up to 1E6 cells/mL, while maintaining cell phenotype and functionality, thus demonstrating great potential for the use of these bioreactors to produce large cell numbers for cell therapies.

Modeling large-scale bioreactors with diffusion equations. Part I: Predicting axial dispersion coefficient and mixing times.

Bioreactor scale-up is complicated by dynamic interactions between mixing, reaction, mass transfer, and biological phenomena, the effects of which are usually predicted with simple correlations or case-specific simulations. This two-part study investigated whether axial diffusion equations could be used to calculate mixing times and to model and characterize large-scale stirred bioreactors in a general and predictive manner without fitting the dispersion coefficient. In this first part, a resistances-in-series model analogous to basic heat transfer theory was developed to estimate the dispersion coefficient such that only available hydrodynamic numbers and literature data were needed in calculations. For model validation, over 800 previously published experimentally determined mixing times were predicted with the transient axial diffusion equation. The collected data covered reactor sizes up to 160 m3 , single- and multi-impeller configurations with diverse impeller types, aerated and non-aerated operation in turbulent and transition flow regimes, and various mixing time quantification methods. The model performed excellently for typical multi-impeller configurations as long as flooding conditions were avoided. Mixing times for single-impeller and few nonstandard bioreactors were not predicted equally well. The transient diffusion equation together with the developed transfer resistance analogy proved to be a convenient and predictive model of mixing in typical large-scale bioreactors.

Modeling large-scale bioreactors with diffusion equations. Part II: Characterizing substrate, oxygen, temperature, carbon dioxide, and pH profiles.

Large-scale fermentation processes involve complex dynamic interactions between mixing, reaction, mass transfer, and the suspended biomass. Empirical correlations or case-specific computational simulations are usually used to predict and estimate the performance of large-scale bioreactors based on data acquired at bench scale. In this two-part-study, one-dimensional axial diffusion equations were studied as a general and predictive model of large-scale bioreactors. This second part focused on typical fed-batch operations where substrate gradients are known to occur, and characterized the profiles of substrate, pH, oxygen, carbon dioxide, and temperature. The physically grounded steady-state axial diffusion equations with first- and zeroth-order kinetics yielded analytical solutions to the relevant variables. The results were compared with large-scale Escherichia coli and Saccharomyces cerevisiae experiments and simulations from the literature, and good agreement was found in substrate profiles. The analytical profiles obtained for dissolved oxygen, temperature, pH, and CO 2 ${\text{CO}}_{2}$ were also consistent with the available data. Distribution functions for the substrate were defined, and efficiency factors for biomass growth and oxygen uptake rate were derived. In conclusion, this study demonstrated that axial diffusion equations can be used to model the effects of mixing and reaction on the relevant variables of typical large-scale fed-batch fermentations.

A streamlined, automated workflow to screen and triage large numbers of baculoviruses for protein expression.

The baculovirus expression system is a powerful and widely used method to generate large quantities of recombinant protein. However, challenges exist in workflows utilizing either liquid baculovirus stocks or the Titerless Infected-Cells Preservation and Scale-Up (TIPS) method, including the time and effort to generate baculoviruses, screen for protein expression and store large numbers of baculovirus stocks. To mitigate these challenges, we have developed a streamlined, hybrid workflow which utilizes high titer liquid virus stocks for rapid plate-based protein expression screening, followed by a TIPS-based scale-up for larger protein production efforts. Additionally, we have automated each step in this screening workflow using a custom robotic system. With these process improvements, we have significantly reduced the time, effort and resources required to manage large baculovirus generation and expression screening campaigns.

Systems approaches to scaling up: a systematic review and narrative synthesis of evidence for physical activity and other behavioural non-communicable disease risk factors.

BACKGROUND: Non-communicable diseases (NCDs) are the leading causes of death worldwide. Systems approaches have potential for creating sustainable outcomes at scale but have rarely been used to support scale up in physical activity/nutrition promotion or NCD prevention more generally. This review aimed to: (i) synthesise evidence on the use of systems approaches in scaling up interventions targeting four behavioural risk factors for NCDs; and (ii) to explore how systems approaches have been conceptualised and used in intervention implementation and scale up. METHOD: Seven electronic databases were searched for studies published 2016-2021. Eligible studies targeted at least one of four NCD behavioural risk factors (physical inactivity, tobacco use, alcohol consumption, diet), or described evaluation of an intervention planned for or scaled up. Studies were categorised as having a (i) high, (ii) moderate, or (iii) no use of a systems approach. A narrative synthesis of how systems approaches had been operationalised in scale up, following PRISMA guidelines. RESULTS: Twenty-one intervention studies were included. Only 19% (n = 4) of interventions explicitly used systems thinking to inform intervention design, implementation and scale up (targeting all four risk factors n = 2, diet n = 1, tobacco use n = 1). Five studies ('high use') planned and implemented scale up with an explicit focus on relations between system elements and used system changes to drive impact at scale. Seven studies ('moderate use') considered systems elements impacting scale-up processes or outcomes but did not require achieving system-level changes from the outset. Nine studies ('no use') were designed to work at multiple levels among multiple agencies in an intervention setting, but the complexity of the system and relations between system elements was not articulated. We synthesised reported barriers and facilitators to scaling up, and how studies within each group conceptualised and used systems approaches, and methods, frameworks and principles for scaling up. CONCLUSION: In physical activity research, and NCD prevention more broadly, the use of systems approaches in scale up remains in its infancy. For researchers, practitioners and policymakers wishing to adopt systems approaches to intervention implementation at scale, guidance is needed on how to communicate and operationalise systems approaches in research and in practice. TRIAL REGISTRATION: PROSPERO (CRD42021287265).

Itaconate Production from Crude Substrates with U. maydis: Scale-up of an Industrially Relevant Bioprocess.

BACKGROUND: Industrial by-products accrue in most agricultural or food-related production processes, but additional value chains have already been established for many of them. Crude glycerol has a 60% lower market value than commercial glucose, as large quantities are produced in the biodiesel industry, but its valorisation is still underutilized. Due to its high carbon content and the natural ability of many microorganisms to metabolise it, microbial upcycling is a suitable option for this waste product. RESULTS: In this work, the use of crude glycerol for the production of the value-added compound itaconate is demonstrated using the smut fungus Ustilago maydis. Starting with a highly engineered strain, itaconate production from an industrial glycerol waste stream was quickly established on a small scale, and the resulting yields were already competitive with processes using commercial sugars. Adaptive laboratory evolution resulted in an evolved strain with a 72% increased growth rate on glycerol. In the subsequent development and optimisation of a fed-batch process on a 1.5-2 L scale, the use of molasses, a side stream of sugar beet processing, eliminated the need for other expensive media components such as nitrogen or vitamins for biomass growth. The optimised process was scaled up to 150 L, achieving an overall titre of 72 g L- 1, a yield of 0.34 g g- 1, and a productivity of 0.54 g L- 1 h- 1. CONCLUSIONS: Pilot-scale itaconate production from the complementary waste streams molasses and glycerol has been successfully established. In addition to achieving competitive performance indicators, the proposed dual feedstock strategy offers lower process costs and carbon footprint for the production of bio-based itaconate.

Set-up of a pharmaceutical cell bank of Magnetospirillum gryphiswaldense MSR1 magnetotactic bacteria producing highly pure magnetosomes.

We report the successful fabrication of a pharmaceutical cellular bank (PCB) containing magnetotactic bacteria (MTB), which belong to the Magnetospirillum gryphiswaldense MSR1 species. To produce such PCB, we amplified MTB in a minimal growth medium essentially devoid of other heavy metals than iron and of CMR (Carcinogenic, mutagenic and reprotoxic) products. The PCB enabled to acclimate MTB to such minimal growth conditions and then to produce highly pure magnetosomes composed of more than 99.9% of iron. The qualification of the bank as a PCB relies first on a preserved identity of the MTB compared with the original strain, second on genetic bacterial stability observed over 100 generations or under cryo-preservation for 16 months, third on a high level of purity highlighted by an absence of contaminating microorganisms in the PCB. Furthermore, the PCB was prepared under high-cell load conditions (9.108 cells/mL), allowing large-scale bacterial amplification and magnetosome production. In the future, the PCB could therefore be considered for commercial as well as research orientated applications in nanomedicine. We describe for the first-time conditions for setting-up an effective pharmaceutical cellular bank preserving over time the ability of certain specific cells, i.e. Magnetospirillum gryphiswaldense MSR1 MTB, to produce nano-minerals, i.e. magnetosomes, within a pharmaceutical setting.

How long does it take to scale-up obesity prevention interventions?

OBJECTIVE: The scale-up of evidence-based interventions is necessary to reverse high rates of obesity. However, scale-up doesn't occur frequently nor in a timely manner. While it has been estimated that takes 14-17 years for research translation to occur, the time taken to scale-up prevention interventions is largely unknown. This study examined the time taken to scale-up obesity prevention interventions across four scale-up pathways. METHODS: A sample of obesity prevention interventions that had been scaled-up or implemented at scale were found using a structured search strategy. Included interventions were mapped against four scale-up pathways and timeframes associated with each stage of the scale-up pathway were identified to determine the time taken to scale-up. RESULTS: Of the 90 interventions found that were scaled-up to at least a city-wide level, less than half reported a comprehensive research pathway to scale-up and a third did not report any evidence of efficacy or effectiveness prior to scale-up. The time taken to scale-up ranged from 0 to 5 years depending on the pathway taken. Those following a comprehensive pathway took approximately 5 years to scale-up, while interventions that had only one evidence generating step took between 1 and 1.5 years to scale-up. For the remaining interventions, scale-up occurred immediately post-development without evidence generation. CONCLUSIONS: Our findings indicate that the scale-up of obesity prevention interventions can occur more quickly than previous estimates of 14-17 years. Our findings support previous research that scale-up of interventions occurs through a variety of pathways and often scale-up occurs in absence of prior evidence of effectiveness.

Continuous chiral separation process for high-speed countercurrent chromatography established and scaled up: A case of Voriconazole enantioseparation.

An efficient method for the continuous separation of Voriconazole enantiomers was developed using sulfobutyl ether-ß-cyclodextrin (SBE-ß-CD) as a chiral selector in high-speed countercurrent chromatography (HSCCC) with different types. The separation was performed using a two-phase solvent system consisting of n-hexane/ethyl acetate/100 mmol/L phosphate buffer solution (pH = 3.0, containing 50 mmol/L SBE-ß-CD) (1.5:0.5:2, v/v/v). A fast and predictable scale-up process was achieved using an analytical DE HSCCC instrument. The optimized parameters were subsequently applied to a preparative Tauto HSCCC instrument, resulting in consistent separation time and enantiomeric purity, with throughput boosted by a remarkable 11-fold. Preparative HSCCC successfully separated 506 mg of the racemate, delivering enantiomers exceeding 99% purity as confirmed by high-performance liquid chromatography analysis. This investigation presents an effective methodology for forecasting the HSCCC scale-up process and attaining continuous separation of chiral drugs.

Size estimation of key populations and 'bridge populations' based on the network scale-up method in Ukraine.

INTRODUCTION: Correct estimation of the size of key and bridge populations is crucial for an efficient HIV/AIDS response in resource-limited settings, enabling efficient program planning and resource allocation. The hidden nature of these groups poses challenges to traditional methods, leading to the adoption of innovative approaches like the network scale-up method (NSUM). In this article we present the results of a NSUM study conducted in 2020 in Ukraine, focusing on four key populations and three bridge populations, highlighting challenges and contributions to development of the method. METHODS: From July to September 2020, we conducted a nationally representative survey in Ukraine via computer-assisted telephone interviews, and applied the known population method and summation method to estimate social networks sizes. Results were weighted based on individual sampling probability and adjusted for social respect and visibility factors to address potential limitations. RESULTS: Our study achieved a 20% response rate with 10,000 completed interviews. The social network size, using the known population method, was 213 people, and 125 using the summation method. Adjusting for the social respect and visibility, estimated key populations sizes were 295,857 [248,714-343,001] people who inject drugs, 152,267 [109,960-194,573] men who have sex with men, 78,385 [57,146-99,619] sex workers, and 9,963 [7,352-12,571] transgender people, detailed by age and gender. Bridge populations were estimated at 62,162 [50,445-73,879] sexual partners of people who inject drugs, 284,348 [233,113-335,583] clients of sex workers, and 13,697 [7,370-20,026] female partners of men who have sex with men. CONCLUSIONS: NSUM proves reliable for estimating key populations size with appropriate corrections. It shows promise for further use in Ukraine, considering limited geographic coverage of the integrated bio-behavioral studies to use multiplier-based methods. However, the validity concerns persist for estimating bridge populations size, emphasizing the need for further method refinement and addressing implementation issues, particularly those related to data collection.

Community Control of Hypertension and Diabetes (CoCo-HD) program in the Indian states of Kerala and Tamil Nadu: a study protocol for a type 3 hybrid trial.

INTRODUCTION: India grapples with a formidable health challenge, with an estimated 315 million adults afflicted with hypertension and 100 million living with diabetes mellitus. Alarming statistics reveal rates for poor treatment and control of hypertension and diabetes. In response to these pressing needs, the Community Control of Hypertension and Diabetes (CoCo-HD) program aims to implement structured lifestyle interventions at scale in the southern Indian states of Kerala and Tamil Nadu. AIMS: This research is designed to evaluate the implementation outcomes of peer support programs and community mobilisation strategies in overcoming barriers and maximising enablers for effective diabetes and hypertension prevention and control. Furthermore, it will identify contextual factors that influence intervention scalability and it will also evaluate the program's value and return on investment through economic evaluation. METHODS: The CoCo-HD program is underpinned by a longstanding collaborative effort, engaging stakeholders to co-design comprehensive solutions that will be scalable in the two states. This entails equipping community health workers with tailored training and fostering community engagement, with a primary focus on leveraging peer supportat scale in these communities. The evaluation will undertake a hybrid type III trial in, Kerala and Tamil Nadu states, guided by the Institute for Health Improvement framework. The evaluation framework is underpinned by the application of three frameworks, RE-AIM, Normalisation Process Theory, and the Consolidated Framework for Implementation Research. Evaluation metrics include clinical outcomes: diabetes and hypertension control rates, as well as behavioural, physical, and biochemical measurements and treatment adherence. DISCUSSION: The anticipated outcomes of this study hold immense promise, offering important learnings into effective scaling up of lifestyle interventions for hypertension and diabetes control in low- and middle-income countries (LMICs). By identifying effective implementation strategies and contextual determinants, this research has the potential to lead to important changes in healthcare delivery systems. CONCLUSIONS: The project will provide valuable evidence for the scaling-up of structured lifestyle interventions within the healthcare systems of Kerala and Tamil Nadu, thus facilitating their future adaptation to diverse settings in India and other LMICs.

Scale up of the learning circles: a participatory action approach to support local food systems in four diverse First Nations school communities within Canada.

BACKGROUND: Addressing Indigenous food security and food sovereignty calls for community-driven strategies to improve access to and availability of traditional and local food. Participatory approaches that integrate Indigenous leadership have supported successful program implementation. Learning Circles: Local Healthy Food to School is a participatory program that convenes a range of stakeholders including food producers, educators and Knowledge Keepers to plan, implement and monitor local food system action. Pilot work (2014-2015) in Haida Gwaii, British Columbia (BC), showed promising results of the Learning Circles (LC) approach in enhancing local and traditional food access, knowledge and skills among youth and adolescents. The objective of the current evaluation was therefore to examine the process of scaling-up the LC vertically within the Haida Nation; and horizontally across three diverse First Nations contexts: Gitxsan Nation, Hazelton /Upper Skeena, BC; Ministikwan Lake Cree Nation, Saskatchewan; and Black River First Nation, Manitoba between 2016 and 2019. METHODS: An implementation science framework, Foster-Fishman and Watson's (2012) ABLe Change Framework, was used to understand the LC as a participatory approach to facilitate community capacity building to strengthen local food systems. Interviews (n = 52), meeting summaries (n = 44) and tracking sheets (n = 39) were thematically analyzed. RESULTS: The LC facilitated a collaborative process to: (1) build on strengths and explore ways to increase readiness and capacity to reclaim traditional and local food systems; (2) strengthen connections to land, traditional knowledge and ways of life; (3) foster community-level action and multi-sector partnerships; (4) drive actions towards decolonization through revitalization of traditional foods; (5) improve availability of and appreciation for local healthy and traditional foods in school communities; and (6) promote holistic wellness through steps towards food sovereignty and food security. Scale-up within Haida Gwaii supported a growing, robust local and traditional food system and enhanced Haida leadership. The approach worked well in other First Nations contexts, though baseline capacity and the presence of champions were enabling factors. CONCLUSIONS: Findings highlight LC as a participatory approach to build capacity and support iterative planning-to-action in community food systems. Identified strengths and challenges support opportunities to expand, adopt and modify the LC approach in other Indigenous communities with diverse food systems.

Unlocking growth potential in Halomonas bluephagenesis for enhanced PHA production with sulfate ions.

The mutant strain Halomonas bluephagenesis (TDH4A1B5P) was found to produce PHA under low-salt, non-sterile conditions, but the yield was low. To improve the yield, different nitrogen sources were tested. It was discovered that urea was the most effective nitrogen source for promoting growth during the stable stage, while ammonium sulfate was used during the logarithmic stage. The growth time of H. bluephagenesis (TDH4A1B5P) and its PHA content were significantly prolonged by the presence of sulfate ions. After 64 hr in a 5-L bioreactor supplemented with sulfate ions, the dry cell weight (DCW) of H. bluephagenesis weighed 132 g/L and had a PHA content of 82%. To promote the growth and PHA accumulation of H. bluephagenesis (TDH4A1B5P), a feeding regimen supplemented with nitrogen sources and sulfate ions with ammonium sodium sulfate was established in this study. The DCW was 124 g/L, and the PHA content accounted for 82.3% (w/w) of the DCW, resulting in a PHA yield of 101 g/L in a 30-L bioreactor using the optimized culture strategy. In conclusion, stimulating H. bluephagenesis (TDH4A1B5P) to produce PHA is a feasible and suitable strategy for all H. bluephagenesis.

Understanding the integration of artificial intelligence in healthcare organisations and systems through the NASSS framework: a qualitative study in a leading Canadian academic centre.

BACKGROUND: Artificial intelligence (AI) technologies are expected to "revolutionise" healthcare. However, despite their promises, their integration within healthcare organisations and systems remains limited. The objective of this study is to explore and understand the systemic challenges and implications of their integration in a leading Canadian academic hospital. METHODS: Semi-structured interviews were conducted with 29 stakeholders concerned by the integration of a large set of AI technologies within the organisation (e.g., managers, clinicians, researchers, patients, technology providers). Data were collected and analysed using the Non-Adoption, Abandonment, Scale-up, Spread, Sustainability (NASSS) framework. RESULTS: Among enabling factors and conditions, our findings highlight: a supportive organisational culture and leadership leading to a coherent organisational innovation narrative; mutual trust and transparent communication between senior management and frontline teams; the presence of champions, translators, and boundary spanners for AI able to build bridges and trust; and the capacity to attract technical and clinical talents and expertise. Constraints and barriers include: contrasting definitions of the value of AI technologies and ways to measure such value; lack of real-life and context-based evidence; varying patients' digital and health literacy capacities; misalignments between organisational dynamics, clinical and administrative processes, infrastructures, and AI technologies; lack of funding mechanisms covering the implementation, adaptation, and expertise required; challenges arising from practice change, new expertise development, and professional identities; lack of official professional, reimbursement, and insurance guidelines; lack of pre- and post-market approval legal and governance frameworks; diversity of the business and financing models for AI technologies; and misalignments between investors' priorities and the needs and expectations of healthcare organisations and systems. CONCLUSION: Thanks to the multidimensional NASSS framework, this study provides original insights and a detailed learning base for analysing AI technologies in healthcare from a thorough socio-technical perspective. Our findings highlight the importance of considering the complexity characterising healthcare organisations and systems in current efforts to introduce AI technologies within clinical routines. This study adds to the existing literature and can inform decision-making towards a judicious, responsible, and sustainable integration of these technologies in healthcare organisations and systems.

Costs and scale-up costs of community-based Oral HIV Self-Testing for female sex workers and men who have sex with men in Jakarta and Bali, Indonesia.

BACKGROUND: The proportion of individuals who know their HIV status in Indonesia (66% in 2021) still remains far below the first 95% of UNAIDS 2030 target and were much lower in certain Key Populations (KPs) particularly Female Sex Workers (FSW) and Male having Sex with Male (MSM). Indonesia has implemented Oral HIV Self-testing (oral HIVST) through Community-based screening (HIV CBS) in addition to other testing modalities aimed at hard-to-reach KPs, but the implementation cost is still not analysed. This study provides the cost and scale up cost estimation of HIV CBS in Jakarta and Bali, Indonesia. METHODS: We estimated the societal cost of HIV CBS that was implemented through NGOs. The HIV CBS's total and unit cost were estimated from HIV CBS outcome, health care system cost and client costs. Cost data were presented by input, KPs and areas. Health care system cost inputs were categorized into capital and recurrent cost both in start-up and implementation phases. Client costs were categorized as direct medical, direct non-medical cost and indirect costs. Sensitivity and scenario analyses for scale up were performed. RESULTS: In total, 5350 and 1401 oral HIVST test kits were distributed for HIV CBS in Jakarta and Bali, respectively. Average total client cost for HIV CBS Self testing process ranged from US$1.9 to US$12.2 for 1 day and US$2.02 to US$33.61 for 2 days process. Average total client cost for HIV CBS confirmation test ranged from US$2.83 to US$18.01. From Societal Perspective, the cost per HIVST kit distributed were US$98.59 and US$40.37 for FSW and MSM in Jakarta andUS$35.26 and US$43.31 for FSW and MSM in Bali. CONCLUSIONS: CBS using oral HIVST approach varied widely along with characteristics of HIV CBS volume and cost. HIV CBS was most costly among FSW in Jakarta, attributed to the low HIV CBS volume, high personnel salary cost and client cost. Future approaches to minimize cost and/or maximize testing coverage could include unpaid community led distribution to reach end-users, integrating HIVST into routine clinical services via direct or secondary distribution and using social media network.

Outdoor biohydrogen production by thermotolerant Rhodopseudomonas pentothenatexigens KKU-SN1/1 in a cluster of ten bioreactors system.

In tropical regions, the viability of outdoor photo-fermentative biohydrogen production faces challenges arising from elevated temperatures and varying light intensity. This research aimed to explore how high temperatures and outdoor environments impact both biohydrogen production and the growth of purple non-sulfur bacteria. Our findings revealed the potential of Rhodopseudomonas spp. as a robust outdoor hydrogen-producing bacteria, demonstrating its capacity to thrive and generate biohydrogen even at 40 °C and under fluctuating outdoor conditions. Rhodopseudomonas harwoodiae NM3/1-2 produced the highest cumulative biohydrogen of 223 mL/L under anaerobic light conditions at 40 °C, while Rhodopseudomonas harwoodiae 2M had the highest dry cell weight of 2.93 g/L. However, R. harwoodiae NM3/1-2 demonstrated the highest dry cell weight of 3.99 g/L and Rhodopseudomonas pentothenatexigens KKU-SN1/1 exhibited the highest cumulative biohydrogen production of 400 mL/L when grown outdoors. In addition, the outdoor enhancement of biohydrogen production was achieved through the utilization of a cluster of ten bioreactors system. The outcomes demonstrated a notable improvement in biohydrogen production efficiency, marked by the highest daily biohydrogen production of 493 mL/L d by R. pentothenatexigens KKU-SN1/1. Significantly, the highest biohydrogen production rate was noted to be 17 times greater than that observed in conventional batch production methods. This study is the first to utilize R. pentothenatexigens and R. harwoodiae for sustained biohydrogen production at high temperatures and in outdoor conditions over an extended operational period. The successful utilization of a clustered system of ten bioreactors demonstrates potential to scale-up for industrial biohydrogen production.

Multi-year in situ hydrogeochemical monitoring of hard rock lithium mine tailings in a large-scale experimental pile.

Spodumene, a lithian mineral found in granitic pegmatites, is a major source of lithium. In situ, multi-year and large-scale (>10s of tons) predictive hydrogeochemical studies can be of great value for informing mine waste rock and tailings management, not least because the material is exposed to the actual climate where it is meant to be stored. However, such studies are rare given their cost and size, and previous ones have focused mainly on sulfide-bearing materials. An experimental field cell filled with spodumene beneficiation tailings was built at the Whabouchi lithium mine site in northern Québec (Canada) and monitored during four consecutive years. In parallel, column laboratory kinetic testing on the same material was conducted for water quality parameters to compare the effect of testing scales on the geochemical behavior. Geochemical results and release rates were overall similar between laboratory and field, and consistent with previously published laboratory results for materials from the same site. The leachates were neutral to slightly alkaline, with ions from feldspars (Ca > Na > K) and residual spodumene (Li) being notable solutes. Concentrations for most solutes surveyed remained higher in the field after four years than in columns at the end of the experiment. One major difference between laboratory and field was a brief (less than 2 years) increase in iron concentrations from the field cell, resulting in Fe-oxyhydroxides precipitation, that was not observed in laboratory. The source of this iron is arguably residual ferrosilicon (used for dense medium separation) and this difference is attributed to the different testing conditions and configurations in the laboratory versus in situ. Field hydrogeological results highlight strong seasonal patterns and the rapid response of this sand-like, sulfide-poor material to ambient temperature changes and wetting-drying events. The tailings both wet and drain rapidly and easily given their water retention curve and the range of matrix suctions recorded during frost-free months. Net infiltration through the tailings was estimated to represent 55% of total precipitation in summer (June-October) 2021. This study provides a comprehensive assessment of the environmental behavior of hard rock lithium mine tailings under real, sub-arctic climatic conditions and outlines similarities and differences between laboratory- and field-generated geochemical results.

Catalytic methane decomposition on CNT-supported Fe-catalysts.

Methane, either as natural gas or as a resource obtained from various bioprocesses (e.g., digestion, landfill) can be converted to carbon and hydrogen according to. CH4(g)→C(s)+2H2(g)ΔH298K=74.8kJ/mol. Previous research has stressed the growing importance of substituting the high-temperature Steam Methane Reforming (SMR) by a moderate temperature Catalytic Methane Decomposition (CMD). The carbon formed is moreover of nanotube nature, in high industrial demand. To avoid the use of an inert support for the active catalyst species, e.g., Al2O3 for Fe, leading to a progressive contamination of the catalyst by support debris and coking of the catalyst, the present research investigates the use of carbon nanotubes (CNTs) as Fe-support. Average CH4 conversions of 75-85% are obtained at 700 °C for a continuous operation of 40 h. The produced CNT from the methane conversion can be continuously removed from the catalyst bed by carry-over due to its bulk density difference (∼120 kg/m3) with the catalyst itself (∼1500 kg/m3). CNT properties are fully specified. No thermal regeneration of the catalyst is required. A tentative process layout and economic analysis demonstrate the scalability of the process and the very competitive production costs of H2 and CNT.

Statistical optimization and sequential scale-up of α-galactosidase production by Actinoplanes utahensis B1 from shake flask to pilot scale.

α-Galactosidase (α-GAL) is a class of hydrolase that releases galactose from galacto-oligosaccharides and synthetic substrates such as pNPG. In this study, the production of α-GAL by Actinoplanes utahensis B1 in submerged fermentation was enhanced by using statistical methods. The effects of temperature, pH, and inoculum percentage on enzyme secretion were optimized using BBD of RSM. The optimized process was scaled up from the shake flask to the laboratory scale (5 L) and to pilot scale (30 L) using KLa based scale-up strategy. By using BBD, a maximum yield of 62.5 U/mL was obtained at a temperature of 28 °C, a pH of 6.9, and an inoculum of 6.4%. Scale-up was performed successfully and achieved a yield of 74.4 U/mL and 76.8 U/mL in laboratory scale and pilot scale fermenters. The TOST was performed to validate the scale-up strategy and the results showed a confidence level of 95% for both scales indicating the perfect execution of scale-up procedure. Through the implementation of BBD and scale-up strategy, the overall enzyme yield has been significantly increased to 76%. This is the first article to explore the scale-up of α-GAL from the A. utahensis B1 strain and provide valuable insights for industrial applications.