Techno-Economic and Life Cycle Assessment of Wastewater Management from Potato Starch Production: Present Status and Alternative Biotreatments

Sustainable media feedstocks for cellular agriculture

The global food system is shifting towards cellular agriculture, a second domestication marked by cultivating microorganisms and tissues for sustainable food production. This involves tissue engineering, precision fermentation, and microbial biomass fermentation to establish food value chains independent of traditional agriculture. However, these techniques rely on growth media sourced from agricultural, chemical (fossil fuels), and mining supply chains, raising concerns about land use competition, emissions, and resource depletion. Fermentable sugars, nitrogen, and phosphates are key ingredients derived from starch crops, energy-intensive fossil fuel based processes, and finite phosphorus resources, respectively. This review explores sustainable alternatives to reduce land use and emissions associated with cellular agriculture media ingredients. Sustainable alternatives to first generation sugars (lignocellulosic substrates, sidestreams, and gaseous feedstocks), sustainable nitrogen sources (sidestreams, green ammonia, biological nitrogen fixation), and efficient use of phosphates are reviewed. Especially cellulosic sugars, gaseous chemoautotrophic feedstocks, green ammonia, and phosphate recycling are the most promising technologies but economic constraints hinder large-scale adoption, necessitating more efficient processes and cost reduction. Collaborative efforts are vital for a biotechnological future grounded in sustainable feedstocks, mitigating competition with agricultural land and emissions.

A chemical window into the impact of RNAi silencing of the StNAC103 gene in potato tuber periderms: Soluble metabolites, suberized cell walls, and antibacterial defense

The growth and survival of terrestrial plants require control of their interactions with the environment, e.g., to defend against desiccation and microbial invasion. For major food crops, the protection conferred by the outer skins (periderm in potato) is essential to cultivation, storage, and marketing of the edible tubers and fruits. Potatoes are particularly vulnerable to bacterial infections due to their high content of water and susceptibility to mechanical wounding. Recently, both specific and conserved gene silencing (StNAC103-RNAi and StNAC103-RNAi-c, respectively) were found to increase the load of wax and aliphatic suberin depolymerization products in tuber periderm, implicating this NAC gene as a repressor of the wax and suberin biosynthetic pathways. However, an important gap in our understanding of StNAC103 silencing concerns the metabolites produced in periderm cells as antimicrobial defense agents and potential building blocks of the deposited suberin biopolymer. In the current work, we have expanded prior studies on StNAC103 silenced lines by conducting comprehensive parallel analyses to profile changes in chemical constituents and antibacterial activity. Compositional analysis of the intact suberized cell walls using solid-state ¹³C NMR (ssNMR) showed that NAC silencing produced an increase in the long-chain aliphatic groups deposited within the periderm cell walls. LC-MS of polar extracts revealed up-regulation of glycoalkaloids in both StNAC103-RNAi and StNAC103-RNAi-c native periderms but down-regulation of a phenolic amine in StNAC103-RNAi-c and a phenolic acid in StNAC103-RNAi native periderms. The nonpolar soluble metabolites identified using GC-MS included notably abundant long-chain alkane metabolites in both silenced samples. By coordinating the differentially accumulated soluble metabolites and the suberin depolymerization products with the ssNMR-based profiles for the periderm polymers, it was possible to obtain a holistic view of the chemical changes that result from StNAC103 gene silencing. Correspondingly, the chemical composition trends served as a backdrop to interpret trends in the chemical barrier defense function of native tuber periderms, which was found to be more robust for the nonpolar extracts.

Microbial Resources, Fermentation and Reduction of Negative Externalities in Food Systems: Patterns toward Sustainability and Resilience

One of the main targets of sustainable development is the reduction of environmental, social, and economic negative externalities associated with the production of foods and beverages. Those externalities occur at different stages of food chains, from the farm to the fork, with deleterious impacts to different extents. Increasing evidence testifies to the potential of microbial-based solutions and fermentative processes as mitigating strategies to reduce negative externalities in food systems. In several cases, innovative solutions might find in situ applications from the farm to the fork, including advances in food matrices by means of tailored fermentative processes. This viewpoint recalls the attention on microbial biotechnologies as a field of bioeconomy and of ‘green’ innovations to improve sustainability and resilience of agri-food systems alleviating environmental, economic, and social undesired externalities. We argue that food scientists could systematically consider the potential of microbes as ‘mitigating agents’ in all research and development activities dealing with fermentation and microbial-based biotechnologies in the agri-food sector. This aims to conciliate process and product innovations with a development respectful of future generations’ needs and with the aptitude of the systems to overcome global challenges.

Use of Organic Wastes and Industrial By-Products to Produce Filamentous Fungi with Potential as Aqua-Feed Ingredients

Organic-rich waste and industrial by-product streams, generated in enormous amounts on a daily basis, contain substantial amounts of nutrients that are worthy of recovery. Biological conversion of organic-waste streams using filamentous fungi is a promising approach to convert nutrients into value-added bioproducts, such as fungal biomass. High-protein fungal biomass contains different kinds and levels of amino acids, fatty acids, immunostimulants, antioxidants, pigments, etc., which make it a potential choice for application in animal feed supplementation. Considering the challenges long faced by the aquaculture industry in fishmeal production due to the increasing prices and environmental concerns, the aquaculture industry is forced to provide alternative protein-rich sources to replace conventional fishmeal. In this review, the possibilities of utilization of filamentous fungi biomass cultivated on organic-rich waste streams, as an alternative nutrient source in fish feed, were thoroughly reviewed.