This Proceedings volume presents current research at the intersection of sustainable agriculture, food biotechnology, and aquaculture, drawing on contributions from the VI International Scientific and Practical Conference Ecosystems Without Borders 2025, held on October 9, 2025, at Kaliningrad State Technical University (Kaliningrad, Russia). It highlights biotechnological approaches that valorize agricultural and food by‑products, improve feed efficiency, and support environmentally responsible food and feed systems.

The chapters cover a broad range of topics, including enzymatic biocatalysis in food-related chemistry, processing of fish and crustacean by‑products into protein hydrolysates and feed additives, the use of insects and microbial adaptogens in aquaculture feeds, aquaponics systems for plant cultivation, nitrogen fixation stimulants, and innovations in bakery and special‑purpose food formulations. Several contributions focus on rainbow trout nutrition and aquaculture systems, while others address soil quality, lipid‑protein fillers, and extraction technologies from secondary raw materials.

This book is intended for researchers, advanced students, and professionals in agricultural biotechnology, food science, aquaculture, and sustainable bioresource management who seek applied research findings and regionally grounded case studies relevant to sustainable food and feed production.

Olga Babich is Director of the Scientific and Educational Center Industrial Biotechnologies at Immanuel Kant Baltic Federal University (Kaliningrad, Russia) and holds a Doctor of Technical Sciences degree. She has extensive leadership and research experience in industrial and food biotechnology, having previously served as Vice‑Rector for Science and Innovation and Director of major research institutes. Her research focuses on sustainable biotechnologies, biomass and algae valorization, food biotechnology, and the development of innovative technologies for environmental and industrial applications. She has led numerous national and international research projects and grant‑funded initiatives.

Mehdi Nikoo is an Associate Professor at the Artemia and Aquaculture Research Institute, Urmia University (Iran), with an academic affiliation at Jiangnan University (China). He holds a PhD in Aquatic Products Processing and Preserving Engineering from Jiangnan University. His research interests include fish and seafood processing by‑products, protein hydrolysates, and bioactive peptides, with applications in food and aquaculture biotechnology. Dr. Nikoo has authored more than 100 scientific publications and is an active contributor to international research on sustainable aquatic food systems.

Olga Mezenova is Head of the Department of Food Biotechnology at Kaliningrad State Technical University (Russia) and a Doctor of Technical Sciences. She has over 20 years of experience in food and marine biotechnology research and education. Her scientific work focuses on food biotechnology, marine bioresources, and applied biotechnological solutions for the food industry. She has led multiple research and development projects and has extensive experience organizing international scientific conferences in marine and food biotechnology.

Vladimir Volkov is Director of the Centre for Advanced Protein Use Technologies at the Department of Food Biotechnology, Kaliningrad State Technical University (Russia). His research interests focus on advanced protein technologies, food and feed biotechnology, and sustainable bioprocessing. Since 2017, he has led several research and development projects in the biotechnology field and has been actively involved in organizing international scientific conferences. He has broad international academic experience and is a recognized contributor to applied biotechnology research.