Sustainable Production Methods Research Articles

Novel food materials: Fundamentals and applications in sustainable food systems for food processing and safety

With the increase in global population, environmental hazards, climate change, energy limitations, and a decrease in agricultural land, emerging techniques are critical to raising and enhancing food production and quality. This review aims to draw attention to the latest developments in technology that guarantee the quality and safety of food. It is devoted to highlighting several key materials-based derivatives, extraction methods, chemistry, mechanisms of action, safety considerations, and various other uses. The review discusses the utilization of cutting-edge food materials, including aerogels, C-dots, nanoparticles, nanoemulsions, and conjugates, in several areas of food processing and preservation. These materials offer unique properties that contribute to improving food quality, safety, and shelf life. The review also addresses research challenges and identifies future trends in this field. These challenges may involve optimising synthesis processes, understanding the long-term effects of these materials on human health and the environment, and developing sustainable production methods. By addressing these challenges, researchers can unlock the full potential of advanced food materials. In conclusion, this review underscores the significance of emerging techniques and materials in ensuring food quality and safety. The integration of science and engineering in the development of advanced food materials opens up new possibilities for sustainable food production and preservation. By addressing current challenges and focusing on future trends, researchers can contribute to the advancement of this field and meet growing global food demands.

Use of Chlorella vulgaris and Ulva lactuca as Biostimulant on Lettuce

The important purpose of this work is to evaluate the biostimulant activity of the algae Chlorella vulgaris and Ulva lactuca extracts on the crop plants Lactuca sativa, to compare the effect of these two green algae on plant growth and development as a part of a sustainable plant production method and show that these extracts can be a promissory source for replacing chemical fertilization. The study faces all the phases of plant growth, from the germination of the seeds to the greenhouse plant growth and treatment, matched with the chemical characterization of both the green algae used and the lettuce plants. This work is meant to define a tool to be improved by more experiments and studies in order to suggest a sustainable method that could ensure an adequate use of organic fertilizer. After the identification of the best concentration of the respective extracts of C. vulgaris and U. lactuca, the experiment affirmed that a low concentration (15% C. vulgaris and 25% U. lactuca) of the extracts contributed to the production of plants with a satisfying nutritional profile, while a high concentration (75% U. lactuca) is conducive to lettuce production with some parameters not suitable for human diet and health.

Carbon-negative co-production of methanol and activated carbon from bagasse pyrolysis, physical activation, chemical looping, and methanol synthesis

Methanol is regarded as an important chemical precursor in the chemical industry and has huge potential to replace gasoline and diesel as vehicle fuel. Biomass to methanol is a sustainable and green production method, but its economic and environmental viability is contingent on production technologies and geographic context. This study proposed a carbon-negative methanol production method that integrated four modules of bagasse pyrolysis, physical activation, chemical looping, and methanol synthesis in the context of China. Three scenarios, including co-production of methanol and biochar, co-production of methanol and activated carbon, and co-production of methanol and activated carbon with extra hydrogen, were put forward and simulated in Aspen Plus. An evaluation system was established to quantitatively assess the carbon and energy efficiencies and economic and environmental benefits of the three scenarios. The results suggested that the addition of hydrogen effectively increased the methanol yield in Scenario 3, leading to high carbon and energy efficiencies. Scenarios 1 and 2 exhibited better economic and environmental performance with low payback periods of 6.53 and 5.80 years and low global warming potentials of −1631.18 and −710.28 kg CO2-eq/t methanol. However, Scenario 3 would be economically and environmentally feasible by decreasing hydrogen production costs and implementing green hydrogen production methods in the foreseeable future. This study provides a viable approach for sustainable methanol production in China, thereby aligning with the current imperative of achieving carbon neutrality.

From Nature to Lab: A Review of Secondary Metabolite Biosynthetic Pathways, Environmental Influences, and In Vitro Approaches.

Secondary metabolites are gaining an increasing importance in various industries, such as pharmaceuticals, dyes, and food, as is the need for reliable and efficient methods of procuring these compounds. To develop sustainable and cost-effective approaches, a comprehensive understanding of the biosynthetic pathways and the factors influencing secondary metabolite production is essential. These compounds are a unique type of natural product which recognizes the oxidative damage caused by stresses, thereby activating the defence mechanism in plants. Various methods have been developed to enhance the production of secondary metabolites in plants. The elicitor-induced in vitro culture technique is considered an efficient tool for studying and improving the production of secondary metabolites in plants. In the present review, we have documented various biosynthetic pathways and the role of secondary metabolites under diverse environmental stresses. Furthermore, a practical strategy for obtaining consistent and abundant secondary metabolite production via various elicitation agents used in culturing techniques is also mentioned. By elucidating the intricate interplay of regulatory factors, this review paves the way for future advancements in sustainable and efficient production methods for high-value secondary metabolites.

Potential and limitations of rabbit meat in maintaining food security in Ukraine

The aim of the present review was to assess whether rabbit meat production can help to improve food security in Ukraine and whether it can make a meaningful contribution to the national economy. Rabbit meat is a nutrient-rich and affordable food with a lower environmental impact than red meat from cattle or sheep. Rabbit meat is considered healthy, as it is lower in fat, cholesterol and sodium than other types of meat, and rich in protein. In addition, rabbit meat proteins can serve as a source of bioactive peptides with the angiotensin converting enzyme (ACE) inhibition properties. The health-promoting properties of rabbit meat and role of associated by-products in providing nutritious and safe food for consumers, and in reducing waste in the meat sector, should be promoted. In Ukraine, rabbit meat products are already recommended as part of a healthy diet for children, pregnant women and the elderly, and the market could be broadened by introducing more rabbit-based products for the whole population. Rabbit production in Ukraine is a promising area of economic activity and with a broader market this segment could increase further and become a significant part of the economy. However, the rabbit farming sector in Ukraine needs comprehensive improvement to address existing issues, including the introduction of sustainable production methods in accordance with European animal welfare and meat quality standards.

Bimetallic cobalt-rich Co0.63Ru0.37 nanoalloys encapsulated in carbon nanofibers expediting oxygen evolution reaction under acidic solution

Electrochemical water splitting holds great promise as a sustainable method for oxygen production through energy conversion. However, the scarcity and limited durability of noble metals like Pt, Ru, and Ir, which exhibit excellent electrochemical activity, impede their practical and large-scale application in electrochemical devices. In order to tackle this issue, we prepared bimetallic single-phase Co0.63Ru0.37 nanoalloys encapsulated in carbon nanofibers (Co0.63Ru0.37/CNFs) for highly efficient water oxidation electrocatalysis. This was achieved through a single-step electrospinning process followed by thermal annealing under an inert atmosphere. Co0.63Ru0.37/CNFs demonstrated exceptional electrocatalytic performance for the oxygen evolution reaction (OER), with an overpotential of only 206 mV at 10 mA cm−2 and a Tafel slope of 46.4 mV dec−1, indicating a high level of activity and long-term stability in acidic solutions. Additionally, Co0.63Ru0.37/CNFs exhibited superior OER performance compared to a commercial benchmark catalyst (cIr, 20 wt% metal loading on Vulcan XC-72) in acidic solutions, highlighting their potential as an efficient OER electrocatalyst for acidic water electrolysis. Furthermore, Co0.63Ru0.37/CNFs offer cost-effectiveness due to their primarily carbon composition, with noble Ru accounting for only half of the total metal content.

Moving to conservation agriculture: (1) evidence of rhizome crops performance in existing agroforestry practices of Madhupur Garh, Bangladesh

The continuous practice of mono-cropping by small-scale farmers in Bangladesh has resulted in poor soil quality and declining crop yields. As a result, there is a growing need to explore sustainable production methods that are resource-efficient and environmentally friendly. Conservation agriculture has emerged as a beneficial approach that effectively addresses these challenges by utilizing locally available resources to enhance crop productivity and soil quality. With this in mind, the objective of this study was to assess the impacts of conservation agricultural practices on the growth and yield of ginger and turmeric in the Madhupur Garh of Bangladesh. The study was conducted in the Auronkhola, Gaira, Makontonagar in Madhupur district, using a Randomized Complete Block Design (RCBD) with three replications from July to September 2022. Ginger and turmeric were selected for the trial. The results showed that these spices exhibited significantly higher yields (6090 kg/ha and 11370 kg/ha, respectively) compared to traditionally cultivated vegetables in the farmers' fields. The implementation of conservation agriculture practices contributed to the improved yields. As part of conservation agriculture practices, various factors crucial for crop production, such as soil organic matter content, total nitrogen, phosphorus, potassium levels, and pH, were positively influenced. This was achieved through the use of organic manure, minimal tillage, the retention of permanent crop residues, and crop rotation. Based on the findings, the study concludes that traditional agriculture must transition to conservation agriculture methods in order to achieve increased food production while utilizing fewer resources and minimizing negative environmental impacts. This shift towards conservation agriculture offers a more efficient and sustainable approach to farming.

Algal biohydrogen production: Impact of biodiversity and nanomaterials induction

Fossil fuels are limited in nature and are not environmentally friendly, thus using them to meet the rising energy needs is insufficient. Another major cause of global warming, which is recognized as one of the greatest hazards to the world, is fossil fuels. Finding alternative energy sources that can counteract the drawbacks of fossil fuels is urgently needed. Due to its low environmental impact and a variety of possible sustainable production methods, biohydrogen is one such alternative energy source that has attracted enormous interest and demand. Due to their wide range of environments, rapid growth, and polyphyletic nature, algae-based biological hydrogen production techniques are gaining significant interest. Nevertheless, the main obstacles to the sustainable and commercial application of the algal biohydrogen generation process are low yield, constrained light penetration, low biomass concentration, and expensive downstream processes. Increased attention to algal diversity may help to overcome the limitation of low algal biomass production and yield while enhancing penetration ability. Additionally, the usage of nanomaterials may speed up the process by altering the entire process' response mechanism. Therefore, this review explores algal diversity as one of the strategies of algal biohydrogen production along with elaboration of the impacts of nanomaterials in different pathways of biohydrogen production, namely dark fermentation, photo-fermentation, direct and indirect biophotolysis. Advances in biohydrogen production employing diversified groups of algae with the application of nanomaterials have been extensively summarized with current update mechanisms and existing roadblocks. As a result, the utilization of nanomaterials as a novel and sustainable catalyst has also been thoroughly described for prospective scaling up of algal biohydrogen production.

Development and Optimization of Culture Medium for the Production of Glabridin by Aspergillus eucalypticola: An Endophytic Fungus Isolated from Glycyrrhiza glabra L. (Fabaceae)

Glabridin is a well-known active isoflavone found in the root of licorice (Glycyrrhiza glabra L.) that possess a wide range of biological activity. Plant cells, hairy roots, and fungal endophytes cultures are the most important alternative methods for plant resources conservation and sustainable production of natural compounds, which has received much attention in recent decades. In the present study, an efficient culture condition was optimized for the biomass accumulation and glabridin production from fungal endophyte Aspergillus eucalypticola SBU-11AE isolated from licorice root. Type of culture medium, range of pH, and licorice root extract (as an elicitor) were tested. The results showed that the highest and lowest biomass production was observed on PCB medium (6.43 ± 0.32 g/l) and peptone malt (5.85 + 0.11 g/l), respectively. The medium culture PCB was produced the highest level of glabridin (7.26 ± 0.44 mg/l), while the lowest level (4.47 ± 0.02 mg/l) was obtained from the medium peptone malt. The highest biomass (8.51 ± 0.43 g/l) and glabridin (8.30 ± 0.51 mg/l) production were observed from the PCB medium adjusted with pH = 6, while the lowest value of both traits was obtained from the same medium with pH = 7. The highest production of total glabridin (10.85 ± 0.84 mg/l) was also obtained from the culture medium treated with 100 mg/l of the plant root extract. This information can be interestingly used for the commercialization of glabridin production for further industrial applications.

“University of Central Punjab, Lahore, Pakistan and SDGs Compliance in Energy Conservation in the Post-Pandemic Time Period”

Although by the end of 2021 the major negative impact of COVID-19 had diminished around the world, the pandemic has still not subsided in its real sense. People are being affected and even dying even today, due to COVID-19. To-date (22 August 2022) there were 596 million people effected by the Corona virus (COVID-19) and registered deaths by this disease were 6.45 million globally. By now, a large part of the world population has been inoculated against this disease and even booster doses were also administered to the population at large. In Pakistan till today (22 August 2022) there were 1.57 million cases of the disease and a total of 33,555 deaths.The objective of the study is to compare the energy of University of Central Punjab (UCP) during the pandemic period (April 2020 to June 2021) when UCP was teaching online with data taken after the reopening of the university during the post-pandemic period (June 2021 till July 2022) and relate it to the compliance by UCP in line with SDG framework. Source of the data is the administrative database of University of Central Punjab as well as the internet sources on these issues. Theoretical base would remain the SDG framework and the UI Green Metric World University Rankings framework in regards to this paper.SDG Goal 7 is “Affordable, Reliable and clean energy for all”, with 5 targets. UCP is a SDG’s compliance university and is streamlining its energy usages in such a way that it tends to minimize the usage of fossil fuel and the maximum usage of solar energy for its energy needs so that both cost of energy (electricity) is minimized at the same time the usage of clean renewable energy is increased, thus help protect the environment from pollutants.Due to partial lockdown UCP went into online teaching from April 2020 till June 2021. The university reopened for physical on-campus classes in June 2022. The post pandemic period for UCP is June 2021 to-date (July 2022). UCP data shows that between the period January to March 2020 (before the lockdown due the pandemic), the energy usage of UCP was 694,144 KWH, while in the same period (January to March 2021) when the university went into online teaching the total energy consumption of UCP came down to 518,891.3 KWH or a reduction by 175,253 KWH. The post-pandemic period when the university has again gone into physical on-campus teaching the university energy usage has increased, but due to efficient and sustainable methods of energy usage, consumption and production in place where UCP has three sources of electricity production, (a) the electricity grid, (b) solar panels covering all the constructed areas of the university and (c) on-campus electricity generators run on fossil fuels. UCP has reverse metering agreement with the LESCO grid and therefore not only produces a significant amount of electricity through its Soler panels, but also feeds the grid from its excess production of soler energy, reducing its dependence on the grid. At the same time due to sustainable usages, UCP’s dependence on the generators using fossil fuels has declined. The use of the generators when in the evening and the night the classes are not held, is nil usage, thus saving the environment because of its minimum usage of fossil fuels.

Production of dried Beauveria bassiana conidia in packed-column bioreactor using agro-industrial palm oil residues

Agro-industrial waste byproducts are commonly inexpensive organic nutritional sources for production of filamentous fungi, and selection of an optimal bioreactor is a key factor for attaining satisfactory biomass yield and quality. The insect-pathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) has been extensively mass produced by solid-state fermentation using precooked cereal grains. Here, we propose low-cost palm oil residues as the main substrate using a cylindrical packed-column aerobic bioreactor prototype designed for conidial production of B. bassiana. Fermentation treatments using B. bassiana strain CG1229 assessed the impact of temperature, air flow, substrate moisture content, and ratio between palm fiber (PF) and palm kernel cake (PKC) on conidial yield and desiccation tolerance. Results showed significant enhanced productivity (2 ×1010 conidia g−1 dry matter) and reduced fermentation time (from 168 h to 120 h) by this method compared with the conventional tray bioreactor. Optimal substrate conditions were 60% initial moisture and 30% PF + 70% PKC content, fermentation at 26 °C with aeration rate ≥ 0.2 L min−1. Air drying conidia inside the column yielded > 95% germination. Maximum spore production was achieved in 120 h. Our findings demonstrate the feasibility of using a packed-column bioreactor for mass production of B. bassiana conidia using low-cost agricultural residues, which contributes to a sustainable production method of this biopesticide in Brazil.

Application of an Exhausted Fermentation Broth Obtained from Biohydrogen Production in an Apple Orchard: Assessment of Fruit Quality

About 95% of global hydrogen production is made by fossil fuels using different technologies which are all characterized by high energy consumption and high carbon emissions. Alternatively, more sustainable production methods, such as biological fermentation processes, are under study. Dark fermentation, also called acidogenesis, entails the transformation of a great variety of organic substances into a mixture of organic and inorganic products, as well as gases (H2 and CO2). In this study we tested an exhausted fermentation broth, derived after Clostridium fermentation for H2 production, as a biostimulant via foliar application in an intensive apple orchard. Two different doses were applied upon dilution of the broth in water (100 mL L−1 and 10 mL L−1), evaluating the main fruit quality parameters (fresh weight, fruit diameter, dry matter, firmness, soluble solid content, color lightness, DA index) in addition to macro- and micro-nutrients and heavy metals concentrations. Chemical characterization of the broth showed a high amount of low-MW polypeptides (Trp-Glu-Lys, Ile-Pro-Ile, Phe-Pro-Lys, His-Pro) and organic acids (formic acid, butyric acid, butanedioic acid); moreover, quantitative analyses of inorganic ions showed no heavy metal detection but high concentrations of nitrogen, phosphorus and potassium, compatible with use in agriculture. The fruit quality parameters showed significantly higher mean fruit weight compared to the untreated trees, as well as higher dry matter. No statistical differences were recorded among the treatments for fruit firmness, diameter and yield. Soluble solids content in both treatments were significantly lower than the controls, whereas the DA index mean values were higher in both treatments compared to the controls, indicating a delay in fruit ripening probably due to the high nitrogen broth concentration. Regarding the chemical analyses of fruits, no particular differences were found among the treatments, except for Fe, which showed a significantly higher amount upon treatment with the lower dose. As concerns leaves, no phytotoxic symptoms were detected in both treatments, making the described exhausted broth a candidate for its use as a plant biostimulant. Additional studies are needed to evaluate the ideal application dose, identify further action targets and implement appropriate strategies to concentrate the biostimulant active compounds.

Sustainability analysis of hydrogen production processes

Hydrogen is a versatile energy carrier and storage medium that is expected to have a key role in the energy transition, as it can be employed in a variety of applications. Hydrogen can be produced from different feedstocks and using different processes. Based on the production technology used, hydrogen is conventionally identified by a color. In this work, we compare different hydrogen generation processes: (i) green hydrogen, obtained by electrolysis of water using electricity from floating photovoltaic platforms, (ii) grid hydrogen, also obtained by electrolysis but using grid electricity, (iii) grey hydrogen, produced from natural gas using steam reforming and (iv) blue hydrogen, which is similar to grey hydrogen, but uses hot potassium carbonate as the solvent for carbon capture and storage. The paper considers the production of hydrogen necessary for 2 trips per day of a medium size ferryboat to navigate full electric for 7 h in the Adriatic Sea. Process simulation is applied to solve material and energy balances for each process investigated, as well as for the evaluation of capital and operating costs. Process simulation outcomes are then used to estimate three key performance indicators focused on energetic, economic, and environmental sustainability issues: the energy return on energy invested, the levelized cost of hydrogen, and the life cycle assessment. The energy indicator for grid and green hydrogen has a value of 13.39–14.29, versus a value of 4.59–5.48 for other hydrogen production methods from natural gas. The cost for green hydrogen is slightly higher (8.76) compared to the blue hydrogen (5.50) however green hydrogen has a much lower impact to the environment. Considering the combined results obtained by all the indicators, it is concluded that the most sustainable hydrogen production method is green hydrogen.

"Biosynthesis of psilocybin and its nonnatural derivatives by a promiscuous psilocybin synthesis pathway in Escherichia coli".

Traditional psychedelics are undergoing a transformation from recreational drugs, to promising pharmaceutical drug candidates with the potential to provide an alternative treatment option for individuals struggling with mental illness. Sustainable and economic production methods are thus needed to facilitate enhanced study of these drug candidates to support future clinical efforts. Here, we expand upon current bacterial psilocybin biosynthesis by incorporating the cytochrome P450 monooxygenase, PsiH, to enable the de novo production of psilocybin as well as the biosynthesis of 13 psilocybin derivatives. The substrate promiscuity of the psilocybin biosynthesis pathway was comprehensively probed by using a library of 49 single-substituted indole derivatives, providing biophysical insights to this understudied metabolic pathway and opening the door to the in vivo biological synthesis of a library of previously unstudied pharmaceutical drug candidates.

Nickel-nitride composite: An eco-friendly and efficient alternative to platinum for electrocatalytic hydrogen production

Water electrolysis using the hydrogen evolution reaction (HER) is a promising method for sustainable hydrogen production. Platinum-based catalysts have traditionally been the most efficient HER catalysts, but their scarcity and sluggish water dissociation limit their practical applications. Here we report on a novel superhydrophilic catalyst of nickel supported on nickel molybdenum nitride (Ni/Ni0.8Mo4.2N6) that outperforms platinum-based nanomaterials. Despite the low catalytic activity of Ni or Ni0.8Mo4.2N6 alone, their optimized composite exhibits exceptional HER activity, with respective 500% and 150% increases in the exchange current and turnover frequency compared to commercial Pt/C. Density of states calculations reveal a decrease in electron density of the supported nickel in Ni/Ni0.8Mo4.2N6, leading to a lower free energy of the HER. These findings demonstrate a powerful electron-engineering strategy for designing supported electrocatalysts with outstanding performance for the HER and related processes.

Bioprocess strategies to augment biohydrogen production from algae

Drastic climatic changes and health hazards, in the recent years, due to combustion of fossil fuels has elicited the need to find sustainable and economical fuel alternatives. Hydrogen gas is a versatile energy carrier that can be used for transportation, electricity generation, and industrial processes. It does not produce greenhouse gases or other pollutants when used, making it a promising alternative to fossil fuels. Among the feedstocks used for hydrogen production, algae are found to be a potential source due to their high growth rate, ability to grow in diverse environments, and ability to produce hydrogen via the process of photosynthesis. However, current hydrogen production rates using algae are low, and strategies to improve these rates are needed. This review is aimed to investigate and evaluate different strategies to enhance biohydrogen production using algae. In addition, the prospects of using macro and microalgae as feedstocks have been elucidated. This review also provides brief insights on the current technologies available for algal biohydrogen production and their bottlenecks. The recent advancements, research gaps and future scopes of this research have been highlighted. Overall, the discussion of the various strategies can provide valuable information for the development of cost-effective and sustainable hydrogen production methods.

Use of organic manures in combination with Azotobacter in strawberry: effect on growth, yield and quality attributes

The use of organic manures and biofertilizers as a nutrient source is a sustainable production method to improve crop yield and quality. A pot experiment was conducted during the year 2017–18 and 2018–19 at hi-tech greenhouse of the Department of Horticulture, Choudhary Charan Singh Haryana Agricultural University, Hissar, Haryana (India) with comprised of nine treatments, viz., Sand: FYM (3:1), Sand: FYM (2:1), Sand: Vermicompost (3:1), Sand: Vermicompost (2:1), Sand: FYM (3:1) + Azotobacter, Sand: FYM (2:1) + Azotobacter, Sand: Vermicompost (3:1) + Azotobacter, Sand: Vermicompost (2:1) + Azotobacter and Control (Sand), in a complete randomized design with five replications, over a two-growing seasons. Plants supplied with Sand: Vermicompost (2:1) + Azotobacter inoculation recorded higher plant growth, fruit yield, which was at par with Sand: Vermicompost (3:1) + Azotobacter inoculation than other combination. Maximum TSS, vitamin C and anthocyanin content were observed under the treatment combination of sand: vermicompost (2:1) + Azotobacter inoculation in comparison with other treatments. The results demonstrated that there will be a significant improvement in growth, yield and quality attributes of strawberry, when plats supplied with organic manure in combination of Azotobacter inoculation than without manure and biofertilizer inoculation.

Cross-plane thermal conductivity of h-BN thin films grown by pulsed laser deposition

The distinguished properties of hexagonal boron nitride (h-BN), specifically its atomically smooth surface, large critical electric field, and large electronic bandgap, make it ideal for thin film microelectronics and as an ultrawide bandgap semiconductor. Owing to weak van der Waals interactions between layers, h-BN exhibits a significant degree of anisotropic thermal conductivity. The in-plane thermal conductivity of h-BN has extensively been studied, yet the only measured data of cross-plane thermal conductivity (k⊥) are for exfoliated h-BN films. Exfoliation from bulk crystals is not a sustainable method for scalable production of h-BN due to its low repeatability, low yield, poor control of sample thickness, and limitation to small areas. Thus, it is necessary to investigate the thickness-dependence of k⊥ for thin films grown by a practical growth method, such as pulsed laser deposition (PLD), which enables the production of reliable and large-area h-BN films with a control of film thickness. We grew h-BN using PLD at 750 °C and observed a decreasing trend of k⊥ as thickness increases from 30 to 300 nm, varying from ∼1.5 to ∼0.2 W/(m K). We observed a relatively high k⊥ value for h-BN at a thickness of 30 nm, providing insight into the k⊥ of PLD-grown films suitable for electronics applications.

Comparative life cycle assessment of marine microalgae, Nannochloropsis sp. and fishmeal for sustainable protein ingredients in aquaculture feeds

Fishmeal from small marine pelagic fishes reduces their availability for marine wildlife forage and artisanal fishing catches that support food security in lower income coastal nations. Fishmeal is primarily used in feeds for aquaculture, the world’s fastest-growing food sector. Replacing fishmeal in aquafeeds with more environmentally responsible alternative ingredients can help feed aquaculture transition to more sustainable production methods. Protein from defatted marine microalga, Nannochloropsis sp., produced alongside polyunsaturated fatty acids (PUFAs) for the nutraceutical market lacks a comprehensive open-access analysis of environmental impacts of producing these products from biorefineries. This study compared life cycle impacts (global warming potential, water use, land use, marine eutrophication potential, freshwater eutrophication potential, and biotic resource use) of protein from fishmeal produced in a small pelagic fish biorefinery to protein from defatted Nannochloropsis meal. We conducted an attributional life cycle assessment using primary data provided by Cellana LLC to model biomass cultivation and harvesting at the Kona Demonstration Facility (Hawaii, USA) and literature data to model the downstream processing of biomass into a high-protein fishmeal replacement for the aquafeed market and concentrated PUFAs for the nutraceutical market. Material and energy inputs from a Nannochloropsis biorefinery included 2 harvesting scenarios (wet and dry biomass) and 2 scenarios for oil extraction and processing (i.e., oil fractionation and concentration of PUFAs): solvents or supercritical carbon dioxide. Results for aquafeed protein from defatted Nannochloropsis were that cultivation processes had the largest overall effect for all scenarios; urea and pure liquid carbon dioxide were environmental hot spots; and the processing scenario involving dry biomass followed by oil extraction and oil processing with solvent had significantly lower environmental impacts than protein from fishmeal from a small pelagic fish biorefinery for global warming potential, water use, marine eutrophication potential, freshwater eutrophication potential, and biotic resource use, but not for land use. These results suggest that aquafeed from marine microalgae can be an environmentally sustainable replacement for fishmeal if high-value metabolites are coproduced in a biorefinery.

Assessment of potential renewable energy alternatives for a typical greenhouse aquaponics in Himalayan Region of Nepal

Greenhouse aquaponics (GA) can serve as a sustainable food production method, potentially improving food and nutrition security in resource-constrained and hostile climatic zones such as Nepal's Himalayan region. Energy concerns, however, are one of the major barriers to GA adoption in this region. There is a lack of comprehensive energy demand analysis for GA operations. Therefore, in this study, an energy model for GA based on a quasi-static energy balancing technique was developed to estimate energy demand for the Himalayan region. The study was conducted in 19 districts with varied GA dimensions, and a linear-model was fitted to predict yearly energy consumption. Thereafter, relations to estimate the capacity of PV systems for supplying the required energy were devised. Eventually, this study proposes potential energy management strategies to reduce dependency on a single energy source, reduce energy loss, and enhance resilience to energy concerns. Findings suggest, heating the GA is a major energy concern, accounting up to 85% of the overall energy requirement. Thermal evaluation reveals that conduction and convection losses are the most significant, contributing up to 29.5% of total energy consumption. Moreover, this study testifies the effectiveness of thermal energy storage devices in achieving significant energy savings. The proposed energy management strategies can serve as a decision-making tool for optimizing the design and operation of GA. Furthermore, this research serves as a blueprint for addressing aquaponics related energy challenges worldwide, especially in areas with similar climatic conditions, such as the Hindu Kush Himalaya (HKH) region.