Cleaner Fish Research Articles

Bovine Placentome-Derived Extracellular Matrix: A Sustainable 3D Scaffold for Cultivated Meat.

Cultivated meat, an advancement in cellular agriculture, holds promise in addressing environmental, ethical, and health challenges associated with traditional meat production. Utilizing tissue engineering principles, cultivated meat production employs biomaterials and technologies to create cell-based structures by introducing cells into a biocompatible scaffold, mimicking tissue organization. Among the cell sources used for producing muscle-like tissue for cultivated meats, primary adult stem cells like muscle satellite cells exhibit robust capabilities for proliferation and differentiation into myocytes, presenting a promising avenue for cultivated meat production. Evolutionarily optimized for growth in a 3D microenvironment, these cells benefit from the biochemical and biophysical cues provided by the extracellular matrix (ECM), regulating cell organization, interactions, and behavior. While plant protein-based scaffolds have been explored for their utilization for cultivated meat, they lack the biological cues for animal cells unless functionalized. Conversely, a decellularized bovine placental tissue ECM, processed from discarded birth tissue, achieves the biological functionalities of animal tissue ECM without harming animals. In this study, collagen and total ECM were prepared from decellularized bovine placental tissues. The collagen content was determined to be approximately 70% and 40% in isolated collagen and ECM, respectively. The resulting porous scaffolds, crosslinked through a dehydrothermal (DHT) crosslinking method without chemical crosslinking agents, supported the growth of bovine myoblasts. ECM scaffolds exhibited superior compatibility and stability compared to collagen scaffolds. In an attempt to make cultivate meat constructs, bovine myoblasts were cultured in steak-shaped ECM scaffolds for about 50 days. The resulting construct not only resembled muscle tissues but also displayed high cellularity with indications of myogenic differentiation. Furthermore, the meat constructs were cookable and able to sustain the grilling/frying. Our study is the first to utilize a unique bovine placentome-derived ECM scaffold to create a muscle tissue-like meat construct, demonstrating a promising and sustainable option for cultivated meat production.

Embedded three-dimensional printing of thick pea-protein-enriched constructs for large, customized structured cell-based meat production

Recent 3D-printing research showed the potential of using plant-protein-enriched inks to fabricate cultivated meat (CM) via agar-based support baths. However, for fabricating large, customized, structured, thick cellular constructs and further cultivation, improved 3D-printing capabilities and diffusion limit circumvention are warranted. The presented study harnesses advanced printing and thick tissue engineering concepts for such purpose. By improving bath composition and altering printing design and execution, large-scale, marbled, 0.5-cm-thick rib-eye shaped constructs were obtained. The constructs featured stable fibrous architectures comparable to those of structured-meat products. Customized multi-cellular constructs with distinct regions were produced as well. Furthermore, sustainable 1-cm-thick cellular constructs were carefully designed and produced, which successfully maintained cell viability and activity for 3 weeks, through the combined effects of void-incorporation and dynamic culturing. As large, geometrically complex construct fabrication suitable for long-term cellular cultivation was demonstrated, these findings hold great promise for advancing structured CM research.

Canadians' experiences of alternative protein foods and their intentions to alter current dietary patterns

Despite established evidence about the environmental and health benefits of alternative protein foods (APF), considerable knowledge gaps and misconceptions remain toward APF. Drawing on a national survey (1800+ responses), the study explores Canadians' experiences of APF and intentions to alter current dietary patterns focusing on four APF – plant-based alternative proteins (PBAP) – plant-based (PB) milk, PB meat, lab-grown (LG) meat, and other alternative proteins (OAP) – and two animal-based foods (ANBF)– milk and meat. Data were collected based on a proportional stratified sampling method from all regions of Canada and analyzed using econometric models. While PB milk was the most consumed APF, followed by PB meat, LG meat was the least tried among participants. Perceived complexity of APF discouraged individuals from cutting back on ANBF, while increasing the consumption of APF. Perceived relative advantage was positively related to the adoption of APF. Perceived compatibility strongly influenced individuals’ adoption of PB meat and OAP. Likewise, perceived trialability significantly influenced the adoption of PB milk and PB meat. Despite the perception that APF may have high health related risks associated with processing, additives, calorie and sugar content, this did not prevent individuals from consuming PB milk and OAP. However, perceived risks did affect intentions to alter dietary patterns in the next 12 months. Additionally, meat attachment and sustainability orientation significantly predicted current consumption decisions of APF and intentions to alter dietary patterns. Although sustainability orientation motivates dietary changes, it did not always lead to extreme shifts. Finally, several demographic variables (age, gender, and education), dietary preferences (being omnivore), and residential area and region had influence on current consumption decisions and future intentions. In conclusion, by controlling several factors and through a comparative analysis of various protein sources, the study offers insights into the interplay of innovation-adoption characteristics, perceived risks, meat attachment and sustainability orientation in understanding dietary choices and provides some implications for industry stakeholders and policies promoting APF.

Transcriptomic Analysis across Crayfish (Cherax quadricarinatus) Claw Regeneration Reveals Potential Stem Cell Sources for Cultivated Crustacean Meat.

In the face of rising global demand and unsustainable production methods, cultivated crustacean meat (CCM) is proposed as an alternative means to produce delicious lobster, shrimp, and crab products. Cultivated meat requires starting stem cells that may vary in terms of potency and the propensity to proliferate or differentiate into myogenic (muscle-related) tissues. Recognizing that regenerating limbs are a non-lethal source of tissue and may harbor relevant stem cells, we selected those of the crayfish Cherax quadricarinatus as our model. To investigate stem cell activity, we conducted RNA-Seq analysis across six stages of claw regeneration (four pre-molt and two post-molt stages), along with histology and real-time quantitative PCR (qPCR). Our results showed that while genes related to energy production, muscle hypertrophy, and exoskeletal cuticle synthesis dominated the post-molt stages, growth factor receptors (FGFR, EGFR, TGFR, and BMPR) and those related to stem cell proliferation and potency (Cyclins, CDKs, Wnts, C-Myc, Klf4, Sox2, PCNA, and p53) were upregulated before the molt. Pre-molt upregulation in several genes occurred in two growth peaks; Stages 2 and 4. We therefore propose that pre-molt limb regeneration tissues, particularly those in the larger Stage 4, present a prolific and non-lethal source of stem cells for CCM development.

Cell-Based Meat Scaffold Based on a 3D-Printed Starch-Based Gel.

Starch was mixed with a gel to produce a starch-based gel ink, which exhibited favorable printing characteristics. Through the optimization of infill density, 3D-printed scaffolds with 50% infill density and a highly ordered microstructure were successfully fabricated. The addition of calcium carbonate nanoparticles-glucono delta lactone (CaCO3 NPs-GDL) had notable effects on the swelling degree, in vitro digestion, water stability, and pore distribution of the scaffolds. When the amount of CaCO3 NPs in the starch-based gel was 0.075 g, the resulting 3D-printed gel scaffold with a 50% infill density proved to be the most suitable for cultivating cell-based meat. It featured pore sizes ranging from 80 to 120 μm and a compression modulus of 246.76 Pa. After 7 days of proliferation, the C2C12 mouse skeletal myoblasts exhibited an approximately 2.81-fold increase in cell numbers. The fusion index and maturation index of C2C12 cells on the scaffolds were 57.00 ± 0.45% and 34.56 ± 0.56%, respectively. The starch-based gel scaffolds demonstrated excellent water stability and in vitro degradability. Moreover, C2C12 cells exhibited successful proliferation and differentiation on the starch-based scaffolds, ultimately leading to the production of cell-based meat. This study developed a starch-based composite gel scaffold for the manufacture of cell-based meat.

Effect of Chicken Age on Proliferation and Differentiation Abilities of Muscle Stem Cells and Nutritional Characteristics of Cultured Meat Tissue.

This study aimed to investigate effects of chicken age on proliferation and differentiation capacity of muscle satellite cells (MSCs) and to determine total amino acid contents of cultured meat (CM) produced. Chicken MSCs (cMSCs) were isolated from hindlimb muscles of broiler chickens at 5-week-old (5W) and 19-embryonic-day (19ED), respectively. Proliferation abilities (population doubling time and cell counting kit 8) of cMSCs from 19ED were significantly higher than those from 5W (p<0.05). Likewise, both myotube formation area and expression of myosin heavy chain heavy of cMSCs from 19ED were significantly higher than those from 5W (p<0.05). After cMSCs were serially subcultured for long-term cultivation in 2D flasks to produce cultured meat tissue (CMT), total amino acid contents of CMT showed no significant difference between 5W and 19ED chickens (p>0.05). This finding suggests that cMSCs from chicken embryos are more suitable for improving the production efficiency of CM than those derived from young chickens.

Empirical economic analysis shows cost-effective continuous manufacturing of cultivated chicken using animal-free medium.

Cellular agriculture aims to meet the growing demand for animal products. However, current production technologies result in low yields, leading to economic projections that prohibit cultivated meat scalability. Here we use tangential flow filtration for continuous manufacturing of cultivated meat to produce biomass of up to 130 × 106 cells per ml, corresponding to yields of 43% w/v and multiple harvests for over 20 days. Continuous manufacturing was carried out in an animal-component-free culture medium for US$0.63 l-1 that supports the long-term, high density culture of chicken cells. Using this empirical data, we conducted a techno-economic analysis for a theoretical production facility of 50,000 l, showing that the cost of cultivated chicken can drop to within the range of organic chicken at US$6.2 lb-1 by using perfusion technology. Whereas other variables would also affect actual market prices, continuous manufacturing can offer cost reductions for scaling up cultivated meat production.

Life cycle assessment of Beefy-9 and Beefy-R serum-free culture media for cell-cultivated beef production

The sustainable production of cell-cultivated meat requires the use of environmentally friendly nutrients. Culture media, which provides the necessary nutrients for cell proliferation and differentiation is a major contributor to the environmental impacts of cultivated meat production. Fetal bovine serum (FBS) is problematic due to animal sourcing, ethical concerns, and high cost. Beefy-R and Beefy-9 are experimentally validated, serum-free cell culture media designed for bovine myoblast culture. While both formulations include basal media, ascorbic acid, sodium selenite, recombinant proteins, and growth factors, Beefy-9 and Beefy-R contain recombinant albumin and rapeseed protein isolates (RPI) to replace FBS, respectively. While these culture media do not include animal-sourced components, their environmental impacts have not yet been investigated. In this study, life cycle assessment (LCA) was performed to estimate the environmental burdens of Beefy-9 and Beefy-R culture media production and identify hotspots for optimization. Uncertainty was assessed through sensitivity and scenario analyses, as well as Monte Carlo simulation. Our results demonstrate that Beefy-R has significantly lower environmental impacts compared to Beefy-9 in 13 out of 18 evaluated impact categories. For instance, the global warming potential (GWP) of Beefy-R was almost five times lower when compared against that of Beefy-9 production. In Beefy-R, despite the absence of recombinant albumin, recombinant proteins and growth factors were hotspots, accounting for 41 %, 5.9 %, and 12 % of GWP, land use, and water consumption impacts, respectively. This study confirms that RPI can be a more sustainable substitute for recombinant albumin in bovine myoblast serum-free media formulations. Additional research is required to identify low-impact alternatives for other recombinant proteins and growth factors in culture media.

Tolerance of juvenile lumpfish (Cyclopterus Lumpus) to high rearing densities

AbstractLumpfish (Cyclopterus lumpus) are raised as cleaner fish for controlling sea lice. Intensive rearing is complicated by fin nipping that occurs between juvenile conspecifics. Lumpfish density‐dependent interactions are not well understood; therefore, the effects of rearing density for different fish size classes warranted evaluation. Two size classes (2‐ and 13‐g) of juvenile lumpfish were stocked at four different rearing densities (40, 60, 70, and 90 g/L) with growth, survival, and fish aggression assessed over 8 weeks. Mean weight gain and specific growth rates ranged from 170% to 307% and 1.77% to 2.50%, respectively, depending on density treatments, for the 2‐g fish, and from 286% to 471% and 2.42% to 3.10% for the 13‐g fish. Growth was negatively correlated with density, with faster growth linked to lower densities. No mortality occurred in any treatment and significant fish aggression only occurred among the larger lumpfish in the higher rearing densities. Based on these findings, growth of 2‐g lumpfish can be increased if reared at 40 g/L or slowed at 70 g/L without impacting aggression. For grow out of 13‐g fish to ~70 g with minimal aggression, a 40 g/L rearing density is recommended for faster growth and 60 g/L for slower growth.

Optimized Adipogenic Differentiation and Delivery of Bovine Umbilical Cord Stem Cells for Cultivated Meat.

Cultivated meat, also known as cell-based or clean meat, utilizes mesenchymal stem cells to cultivate mature cell types like adipocytes, which are pivotal for imparting the desired taste and texture. The delivery of differentiated cells, crucial in cultivated meat production, is facilitated through extensive exploration of 3D culturing techniques mimicking physiological environments. In this study, we investigated the adipogenic differentiation potential of bovine umbilical cord stem cells (BUSCs), sourced from discarded birth tissue, and assessed the feasibility of delivering differentiated cells for cultivated meat using gelatin methacrylate (GelMA) as a carrier for adipose tissue. Various adipogenic inducers, previously reported to be effective for human mesenchymal stem cells (hMSCs), were evaluated individually or in combination for their efficacy in promoting the adipogenesis of BUSCs. Surprisingly, while the traditional adipogenic inducers, including insulin, dexamethasone, isobutylmethylxantine (IBMX), indomethacin, and rosiglitazone, showed no significant effect on the adipogenic differentiation of BUSCs, efficient differentiation was achieved in the presence of a fatty acid cocktail. Furthermore, we explored methods for the delivery of BUSCs. Differentiated cells were delivered either encapsulated in GelMA hydrogel or populated on the surface of GelMA microparticles (MPs) as the adipose component of cultivated meat. Our findings reveal that after adipogenic induction, the lipid production per cell was comparable when cultured either within hydrogel or on MPs. However, GelMA-MPs supported better cell growth compared to hydrogel encapsulation. Consequently, the overall lipid production is higher when BUSCs are delivered via GelMA-MPs rather than encapsulation. This study not only systematically evaluated the impact of common adipogenic inducers on BUSCs, but also identified GelMA-MPs as a promising carrier for delivering bovine adipocytes for cultivated meat production.

Three-dimensional pore structure of the decellularized parsley scaffold regulates myogenic differentiation for cell cultured meat.

Decellularized plant scaffolds have been used to develop edible scaffolds for cell cultured meat because of their natural structures similar to that of mammalian tissues. However, their diverse three-dimensional (3D) porous structures may lead to differences in myogenic differentiation of skeletal muscle cells. In this study, parsley plant tissues were decellularized and modified by type A gelatin and transglutaminase while retaining, respectively, longitudinal fibrous and transverse honeycomb pore structures. The effects of the structure of the decellularized parsley scaffold on the proliferation and myogenic differentiation of C2C12 cells were investigated and the quality of cell cultured meat was evaluated. The results showed that fibrous pore structure guided cells to be arranged in parallel, whereas honeycomb pore structure connected cells in a circular pattern. After induced differentiation, the fibrous scaffolds were more inclined to form multinucleated myotubes with higher expression of myogenic genes and proteins, and the final cell-based meat contained higher total protein content. Decellularized plant scaffolds with fibrous pore structure were more suitable for myogenic differentiation of C2C12 cells, providing support to the development of edible scaffolds for cultured meat. PRACTICAL APPLICATION: This study investigated the different three-dimensional (3D) pore structure of parsley parenchyma to gain insight into how the 3D pore structure of decellularized plant scaffolds regulates myogenic differentiation, which is expected to address the unstable myogenic differentiation of skeletal muscle cells on decellularized plant scaffolds in cell culture meat production.

Cleaner gobies can solve a biological market task when the correct cue is larger

Animal cognition is deeply influenced by interactions with the environment. A notable example of sophisticated cognition in the animal kingdom is described by the mutualistic relationship between cleaner fish and clients, where decision-making processes play a pivotal role in partner choice and fish survival. In this context, while extensive research has explored the cognition of the cleaner wrasse Labroides dimidiatus, it is important to note that studies on the cognition of other wrasse species and on its Caribbean counterparts, Elacatinus spp., are limited. Therefore, to extend our comprehension of cognition in cleaner fish with different evolutionary backgrounds, it is important to focus our attention on the genus Elacatinus spp. In this study, we used plexiglass plates as surrogates for clients and assessed the ability of cleaner gobies, Elacatinus oceanops, to solve a biological market task where prioritizing an ephemeral food plate over a permanent one would double the food reward. We varied cue-based decision-making using both ecologically relevant cues (plate, size, and color) and non-relevant ones (presentation side). Additionally, we tested their capacity for reversal learning, an indicator of complex cognitive abilities. Notably, cleaner gobies were able to solve the biological markets task when the distinguishing cue was a larger plate size. Given that these gobies tend to prioritize larger predatory clients in nature, our results align with their natural inclination. Consequently, further research, including studies involving wild individuals, is essential to elucidate the cognitive abilities of the studied species and their implications in the ecological context and evolutionary history.

Aligned electrospun starch-pullulan-protein fibers

Electrospun nanofiber mats with potential utility as functionalized scaffolding for cultivated meat were fabricated from octenyl succinic anhydride (OSA) modified starch, pullulan, and either glycomacropeptide (GMP) or whey protein isolate (WPI). A statistical mixture design was used to establish the influence of polymer composition on spinning dope properties including conductivity, surface tension, shear viscosity, and elasticity and relate these properties to spun fiber morphology. Component composition varied – starch 16–24 %, pullulan 4–6 %, protein 0–10 % – while maintaining the overall polymer content at 30 % w/w. The propensity for fiber beading was inversely associated with a timescale for bead formation dependent on the ratio of viscosity to surface tension and directly to a timescale for fiber solidification/drying altered by adjusting relative humidity. Smooth, continuous nanofibers, average diameter of 461–526 nm, were obtained from mixtures that contained less than 4% (w/w) protein, whereas mixtures with greater than 6% (w/w) protein resulted in fibers with beading. Generally, GMP-containing nanofibers exhibited less beading than WPI-containing nanofibers. Aligned fiber mats were produced using a rotating drum collector at different speeds varying from 3600 to 5600 rpm that may serve to template cell growth.

A Glance into the Near Future: Cultivated Meat from Mammalian and Insect Cells

The increasing global population and demand for meat have led to the need to find sustainable and viable alternatives to traditional production methods. One potential solution is cultivated meat (CM), which involves producing meat in vitro from animal stem cells to generate products with nutritional and sensory properties similar to conventional livestock‐derived meat. This article examines current approaches to CM production and investigates how using insect cells could enhance the process. Cell sources are a critical issue in CM production, alongside advances in culture media, bioreactors for scalability, and scaffold development. Insect cells, compared to commonly used mammalian cells, may offer advantages in overcoming technological challenges that hinder cell culture development and expansion. The objective of this review is to emphasize how insects, as a cell source for CM production, could offer a more sustainable option. A crucial aspect for achieving this goal is a comprehensive understanding of the physiology of muscle and fat cells. In this work, the characteristics of insect and mammalian cells are compared, focusing particularly on muscle and fat cell development, regulatory pathways, hormonal regulation, and tissue composition. Insect cells are a promising source for CM, offering a sustainable and environmentally friendly alternative.

Toward an innovation radar for cultivated meat: exploring process technologies for cultivated meat and claims about their social impacts

IntroductionCultivated meat has received growing attention since claims were made that cultivated meat can be produced more ethically and sustainably than the current meat production. However, there are still major challenges in the development of cell lines, scaffolding, growth media, and bioprocess, which need to be overcome to reach industrial production levels. Numerous technological innovations have been proposed to overcome these challenges but they have rarely been evaluated with regard to their social sustainability. Consequently, it remains unclear if and how cultivated meat would contribute towards creating inclusive food systems.MethodsTo bring more clarity, the study identifies different technological solutions that are used or developed for production of cultivated meat and identifies the positive and negative claims about the expected contributions of these technological solutions to social inclusion in food systems, using evidence from the literature review and 11 expert interviews. An innovation radar for cultivated meat is proposed to visualise the variety of technological innovations and the claims about their expected contributions to social sustainability.ResultsThe technologies in the areas cell line development, scaffolding, growth media, and bioprocess are expected to have an impact on inclusion in consumption of cultivated meat. Some cell innovations are expected to raise cognitive barriers due to complex technologies that might be difficult for the consumer to understand. Cultural barriers are expected to be raised by cell innovation entailing genetic engineering and medium innovation using FBS or animal components, which is considered to harm animals. Further, regulatory barriers are expected in the EU if genetic modification is used in the production process, which concerns the areas cells, media, and scaffolding. The innovations for scaffolds are expected to mainly lower cost and cultural barriers since most technologies are already used in the food industry. Bioprocess innovations promise to lower cost barriers, however it must be considered, that most of the collected data for innovations in the bioprocess domain are based on assumptions.DiscussionThe study concludes that at this point in time, the most socially sustainable approach to cultivated meat production is not obvious. Under the current technological state of the art, it is not thinkable that production and consumption of cultivated meat could be socially inclusive. As it remains poorly understood if technologies for cultivated meat production could raise or lower barriers to inclusive consumption and production, further research is needed.

Norwegian consumers’ willingness to try cultured meat

Cultured meat (CM) is likely to reduce environmental footprints and health problems and improve animal welfare, but its success in the market will rely on consumer acceptance. A survey was used to investigate consumer acceptance of CM in Norway. The survey was conducted pre the COVID-19 pandemic and during the pandemic with a total of 4,683 usable responses. A partial proportional odds model was estimated, and identical coefficients were not rejected for the two periods. Social trust, trust in food authorities, and support to green parties were positively associated with the willingness to try CM but there was no association with trust in food retailers. Respondents who emphasized natural components and food safety were less willing, and respondents who emphasized health, novelty, environment, and price were more willing. Young, male, highly educated, urban, non-religious, non-vegetarian supporters of green parties were also more willing to try CM, and marketing activities should target these groups.

Emerging Innovations in Aquaculture: Navigating towards Sustainable Solutions

Aquaculture, as a rapidly expanding sector of global food production, faces increasing scrutiny regarding its environmental impact and sustainability. Emerging technologies are frequently created with the aim of lessening certain negative effects caused by current aquaculture systems. Climate change poses an additional challenge to freshwater aquaculture. The effects of climate change on freshwater aquaculture are more intricate compared to those on land-based agriculture. Recycling nutrients, or reusing nitrogen, using various polyculture systems may be a more viable and efficient option than managing or treating the effluents linked to conventional, intense monoculture method. The Recirculating Aquaculture Systems (RAS), Integrated Multi-Trophic Aquaculture (IMTA), selective breeding, aquaponics, alternative feeds, precision aquaculture, offshore aquaculture, genetic technologies, closed containment systems, and certified sustainable aquaculture. Innovations like probiotics, RNA interference, and cleaner fish are being used to prevent diseases in aquaculture and reduce reliance on antibiotics. Precision aquaculture uses sensors, data analytics and AI to optimize fish health, feeding, and water quality in aquaculture systems. It improves efficiency and sustainability. These innovations collectively represent a paradigm shift towards more environmentally friendly and economically viable aquaculture practices. The aim of this review article is to highlight emerging innovations in aquaculture that are contributing to the development of sustainable solutions for the industry. The article focuses on various cutting-edge technologies and practices that are improving the efficiency, environmental sustainability, and overall quality of aquaculture products. These innovations are making aquaculture more productive, efficient, and sustainable as it continues to grow to meet rising global demand for seafood.

Sea lice management in marine-based salmon farming: Public perceptions and acceptance in England and Scotland

Marine-based salmon farming faces a significant challenge in the management of sea lice infestations, particularly in high-density production areas. Multiple strategies have been employed on salmon farms to prevent and treat sea lice infestations, but they have widely varied in their effectiveness in reducing infestations and their associated impact on the marine environment and fish welfare. Typically, cost and effectiveness are crucial considerations for salmon industries and researchers when determining which practice is optimal for reducing sea lice infestations, but the public's views on sea lice management have not yet been fully assessed. Therefore, an online survey was conducted to examine how the English and Scottish public evaluate different sea lice management practices. Participants were randomly assigned to one of eight conditions: four different types of sea lice management practices (medical treatment, mechanical treatment, cleaner fish treatment, or barrier technology) with two types of information formats (basic information or detailed information). The results showed that participants were more accepting of barrier technology and cleaner fish treatment than medical treatment and mechanical treatment, regardless of whether the presented information was basic or detailed. However, providing detailed information about mechanical treatment and cleaner fish treatment negatively affected the participants' acceptance and perceptions compared to the basic information condition. Specifically, when detailed information was provided, mechanical treatment was evaluated as less natural and less welfare friendly for farmed salmon, and the corresponding salmon products were considered to be less healthy than when basic information was provided. Similarly, when detailed information was provided, cleaner fish treatment was rated as less natural, less environmentally friendly, and less welfare friendly for cleaner fish than when only basic information was provided. This study has implications for salmon industries and policymakers: the public encourages a natural way of managing sea lice that has a minimum negative impact on the environment and farmed salmon, which might clash with the current realities of salmon farming.

Developmental ability of Hanwoo muscle satellite cells under culture conditions mimicking the in vivo environment

Cultivated meat refers to edible meat obtained by proliferating cells without killing livestock in a laboratory. The selection of donor animals is a crucial factor for efficient cell culture production. Hanwoo is a native Korean taurine cattle breed raised as livestock in Korea since before 2000 B.C. Cells isolated from Hanwoo, which has little genetic diversity, are expected to be advantageous in cell culture because of the existence of fewer individual differences. However, cells collected from Hanwoo are in a state where efficient culture conditions have not been established. Therefore, in this study, we investigated the effects of mimicking an in vivo environment on the proliferation and differentiation of Hanwoo muscle satellite cells. The culture conditions consisted of CON (37°C/20% O2), T1 (37°C/2% O2), T2 (39°C/20% O2), and T3 (39°C/2% O2). Cell numbers decreased and expression levels of PAX7 and MYF5 decreased at a temperature of 39°C (p &amp;lt; 0.05). Conversely, 2% oxygen increased the number of cells and expression levels of PAX7 and MYF5 (p &amp;lt; 0.05). A temperature of 39°C inhibited the proliferation of Hanwoo muscle satellite cells by reducing the expression of PAX7 and MYF5 (p &amp;lt; 0.05). Conversely, 2% oxygen promoted the proliferation of Hanwoo muscle satellite cells by enhancing the expression of PAX7 and MYF5 (p &amp;lt; 0.05). During differentiation, a temperature of 39°C improved the myotube area and fusion index (p &amp;lt; 0.05). The RT-qPCR and Western blotting results revealed that a culture temperature of 39°C increased expression levels of the MYH2 gene and DES and MYOG proteins (p &amp;lt; 0.05). Additionally, an interactive condition increased expression levels of MYOD1, DES, and MYOG genes (p &amp;lt; 0.05). These results indicated that a temperature of 39°C promoted the differentiation of Hanwoo muscle satellite cells by increasing DES and MYOG protein expression. Thus, the production of cultivated meat using Hanwoo muscle satellite cells is expected to be efficient under 2% oxygen for proliferation and 39°C for differentiation.

Stakeholders’ justifications in innovation: the case of cell-based meat

Cell-based meat (CBM) is a novel technology that employs the cultivation of animal cells in bioreactors to produce edible meat, representing a breakthrough innovation in the meat production chain. However, innovations are embedded in uncertainty and ambiguity; thus, several stakeholders shape their development and legitimacy. Stakeholders attempt to set their priorities by employing and disseminating justifications when facing novelty situations. This study builds on stakeholder and justification theories to explore the justifications employed by stakeholders and their impacts on innovations such as CBM technology. To this end, interviews with representatives of five stakeholder groups were conducted - startups, NGOs, investors, researchers, and conventional animal-based meat processing firms - and triangulated with secondary data from websites and news. Public Justification Analysis was applied to analyze the data. The results indicate that the analyzed stakeholders converge toward CBM legitimacy and development by sharing similar purposes and values. On the other hand, disputes and justifications contrary to CBM legitimacy are mainly related to traditional values, which can raise obstacles to product development. Hence, by analyzing stakeholders’ justifications, we can understand their behaviors and demonstrate how they shape innovation and a nascent high-tech industry.