Environmental Impacts of Experimental Production of Lactic Acid for Bioplastics from Ulva spp

Cradle-to-gate life cycle assessment of Spirulina bioplastic produced via plasticization with glycerol

Bioplastics have been used as alternatives to conventional petroleum-based plastics to lessen the burdens on marine and terrestrial environments due to their non-biodegradability and toxicity. However, recent studies have shown that not all bioplastics may be environmentally friendly. Microalgae, such as Spirulina that do not require arable land, have been identified as a potential bioplastic source. In this study, cradle-to-gate life cycle assessment (LCA) was carried out in openLCA program using the Agribalyse database, to evaluate the environmental impacts of Spirulina bioplastic, formed from plasticization of Spirulina powder with glycerol. Two processes were created for the inventories of (i) Spirulina powder and (ii) Spirulina bioplastic, where the output of the former served as an input for the latter. The extruded bioplastic sheets were food-grade and could be used as edible packaging materials. The bioplastic was also compared to conventional plastics and it was found that the energy consumption was 3.83 ± 0.26 MJ/kg-bioplastic, which was 12% and 22% higher than that of LDPE and PVC plastic films, respectively. The impacts on the environment showed that the chemical growth medium (Zarrouk medium) and electricity were the main contributors in most of the categories. Compared to the PVC and LDPE films, the Spirulina bioplastic's impacts on the aquatic ecosystems were 2-3 times higher. The global warming potential of the Spirulina bioplastic was 1.99 ± 0.014 kg CO2 eq, which was 23% and 47% lower than that of LDPE and PVC films, respectively. Sensitivity analysis was carried out by changing the electricity source and using alternative growth media. Except for the case of switching to solar energy, the results for other cases did not differ significantly from the base case scenario. Future studies were suggested to identify different greener alternatives to the growth medium as well as different energy mixes for more environmentally benign solutions.

Algal-based bioplastics: global trends in applied research, technologies, and commercialization

The excessive global demand for plastic materials has resulted in severe plastic waste pollution. Conventional plastics derived from non-renewable fossil fuels are non-biodegradable, leading to significant environmental problems. Algal-based bioplastics represent a more viable, renewable, and sustainable alternative to conventional plastics. They have identical properties and characteristics as conventional plastics while being naturally biodegradable. The potential of the algal biomass value chain has already been well-established by researchers. Here, we review the novel insights on research, technology, and commercialization trends of algal-based bioplastics, encompassing macroalgae and green microalgae/cyanobacteria. Data showed that within the last decade, there has been substantial interest in utilizing microalgae for biopolymer production, with more focus on using cyanobacterial species compared to green algae. Moreover, most of the research conducted has largely focused on the production of PHA or its co-polymers. Since 2011, there have been a total of 55 patents published related to algal-based bioplastics production. To date, ~ 81 entities worldwide (commercial and private businesses) produce bioplastics from algae. Overall results of this study emphasized that even with the economic and social challenges, algae possess a substantial potential for the sustainable development of bioplastics while also addressing the UN's SDGs.

Feasibility of bioplastic production using micro- and macroalgae- A review

Plastic disposal and their degraded products in the environment are global concern due to its adverse effects and persistence in nature. To overcome plastic pollution and its impacts on environment, a sustainable bioplastic production using renewable feedstock's, such as algae, are envisioned. In this review, the production of polymer precursors such as polylactic acid, polyhydroxybutyrates, polyhydroxyalkanoates, agar, carrageenan and alginate from microalgae and macroalgae through direct conversion and fermentation routes are summarized and discussed. The direct conversion of algal biopolymers without any bioprocess (whole algal biomass used emphasizing zero waste discharge concept) favours economic feasibility. Whereas indirect method uses conversion of algal polymers to monomers after pretreatment followed by bioplastic precursor production by fermentation are emphasized. This review paper also outlines the current state of technological developments in the field of algae-based bioplastic, both in industry and in research, and highlights the creation of novel solutions for green bioplastic production employing algal polymers. Finally, the cost economics of the bioplastic production using algal biopolymers are clearly mentioned with future directions of next level bioplastic production. In this review study, the cost estimation was given at laboratory level bioplastic production using casting methods. Further development of bioplastics at pilot scale level may give clear economic feasibility of production at industry. Here, in this review, we emphasized the overview of algal biopolymers for different bioplastic product development and its economic value and also current industries involved in bioplastic production.

Comprehensive assessment of biorefinery potential for biofuels production from macroalgal biomass: Towards a sustainable circular bioeconomy and greener future

Marine macroalgae have attracted significant interest as a viable resource for biofuel and value-added chemical production due to their abundant availability, low production costs, and high carbohydrate and lipid content. The growing awareness of socio-economic factors worldwide has led to a greater consideration of marine macroalgae as a sustainable source for biofuel production and the generation of valuable products. The integration of biorefinery techniques into biofuel production processes holds immense potential for fostering the development of a circular bioeconomy on a broad scale. Extensive research was focused on the technoeconomic and environmental impact analysis of biofuel production from macroalgal biomass. The integrated biorefinery processes offers valuable pathways for the practical implementation of macroalgae in diverse conversion technologies. These studies provided crucial insights into the large-scale industrial production of biofuels and associated by-products. This review explores the utilization of marine macroalgal biomass for the production of biofuels and biochemicals. It examines the application of assessment tools for evaluating the sustainability of biorefinery processes, including process integration and optimization, life cycle assessment, techno-economic analysis, socio-economic analysis, and multi-criteria decision analysis. The review also discusses the limitations, bottlenecks, challenges, and future perspectives associated with utilizing macroalgal biomass for the production of biofuels and value-added chemicals.

Composite materials for innovative urban farming of alternative food sources (macroalgae and crickets)

Facing an inexorable growth of the human population along with substantial environmental changes, the assurance of food security is a major challenge of the present century. To ensure responsible food consumption and production (SDG 12), new approaches in the food system are required. Thus, environmentally controlled, sustainable production of alternative food sources are of key interest for both urban agriculture and food research. To face the current challenge of integrating food production systems within existing structures, multidisciplinary discourses are required. Here, we bring together novel technologies and indoor farming techniques with the aim of supporting the development of sustainable food production systems. For this purpose, we investigated the feasibility of 10 composite materials for their innovative use as structural support in macroalgal cultivation (settlement substrates) and cricket rearing (housing). Considering material resistance, rigidity, and direct material-organism interactions, the bio-based composite polylactic acid (PLA) was identified as a suitable material for joint farming. For macroalgae cultivation, PLA sustained the corrosive cultivation conditions and provided a suitable substrate without affecting the macroalgal physiology or nutritional composition (carotenoids and chlorophylls). For cricket rearing, PLA provided a suitable and recyclable shelter, which was quickly accepted by the animals without any observed harm. In contrast, other common composite components like phenolic resin or aramid were found to be unsuitable due to being harmful for the cultivated organisms or instable toward the applied sterilization procedure. This multidisciplinary study not only provides profound insights in the developing field of urban indoor food production from a new perspective, but also bridges material science and farming approaches to develop new sustainable and resilient food production systems.

Macroalgal biomass as a potential resource for lactic acid fermentation

Lactic acid is an essential platform chemical with various applications in the chemicals, food, pharmaceutical, and cosmetic industries. Currently, the demand for lactic acid is driven by the role of lactic acid as the starting material for the production of bioplastic polylactide. Microbial fermentation for lactic acid production is favored due to the production of enantiomerically pure lactic acid required for polylactide synthesis, as opposed to the racemic mixture obtained via chemical synthesis. The utilization of first-generation feedstock for commercial lactic acid production is challenged by feedstock costs and sustainability issues. Macroalgae are photosynthetic benthic aquatic plants that contribute tremendously towards carbon capture with subsequent carbon-rich biomass production. Macroalgae are commercially cultivated to extract hydrocolloids, and recent studies have focused on applying biomass as a fermentation feedstock. This review provides comprehensive information on the design and development of sustainable and cost-effective, algae-based lactic acid production. The central carbon regulation in lactic acid bacteria and the metabolism of seaweed-derived sugars are described. An exhaustive compilation of lactic acid fermentation of macroalgae hydrolysates revealed that lactic acid bacteria can effectively ferment the mixture of sugars present in the hydrolysate with comparable yields. The environmental impacts and economic prospects of macroalgal lactic acid are analyzed. Valorization of the vast amounts of spent macroalgal biomass residue post hydrocolloid extraction in a biorefinery is a viable strategy for cost-effective lactic acid production.

A Retrospective Review of Global Commercial Seaweed Production-Current Challenges, Biosecurity and Mitigation Measures and Prospects

Commercial seaweed cultivation has undergone drastic changes to keep up with the increasing demand in terms of the quantity and quality of the algal biomass needed to meet the requirements of constant innovation in industrial applications. Diseases caused by both biotic and abiotic factors have been identified as contributing to the economic loss of precious biomass. Biosecurity risk will eventually affect seaweed production as a whole and could cripple the seaweed industry. The current review sheds light on the biosecurity measures that address issues in the seaweed industry pushing towards increasing the quantity and quality of algal biomass, research on algal diseases, and tackling existing challenges as well as discussions on future directions of seaweed research. The review is presented to provide a clear understanding of the latest biosecurity developments from several segments in the seaweed research, especially from upstream cultivation encompassing the farming stages from seeding, harvesting, drying, and packing, which may lead to better management of this precious natural resource, conserving ecological balance while thriving on the economic momentum that seaweed can potentially provide in the future. Recommended breeding strategies and seedling stock selection are discussed that aim to address the importance of sustainable seaweed farming and facilitate informed decision-making. Sustainable seaweed cultivation also holds the key to reducing our carbon footprint, thereby fighting the existential crisis of climate change plaguing our generation.

Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films.