Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better health and well-being, new biomedicines, natural cosmeceuticals, environmental conservation, and sustainable energy sources. These societal needs stimulated the interest of researchers on the diverse and underexplored marine environments as promising and sustainable sources of biomolecules and biomass, and they are addressed by the emerging field of marine (blue) biotechnology. Blue biotechnology provides opportunities for a wide range of initiatives of commercial interest for the pharmaceutical, biomedical, cosmetic, nutraceutical, food, feed, agricultural, and related industries. This article synthesizes the essence, opportunities, responsibilities, and challenges encountered in marine biotechnology and outlines the attainment and valorization of directly derived or bio-inspired products from marine organisms. First, the concept of bioeconomy is introduced. Then, the diversity of marine bioresources including an overview of the most prominent marine organisms and their potential for biotechnological uses are described. This is followed by introducing methodologies for exploration of these resources and the main use case scenarios in energy, food and feed, agronomy, bioremediation and climate change, cosmeceuticals, bio-inspired materials, healthcare, and well-being sectors. The key aspects in the fields of legislation and funding are provided, with the emphasis on the importance of communication and stakeholder engagement at all levels of biotechnology development. Finally, vital overarching concepts, such as the quadruple helix and Responsible Research and Innovation principle are highlighted as important to follow within the marine biotechnology field. The authors of this review are collaborating under the European Commission-funded Cooperation in Science and Technology (COST) Action Ocean4Biotech – European transdisciplinary networking platform for marine biotechnology and focus the study on the European state of affairs.

Over the last 2 decades, several coronaviruses (CoVs) have crossed the species barrier into humans, causing highly prevalent and severe respiratory diseases, often with fatal outcomes. CoVs are a large group of enveloped, single-stranded, positive-sense RNA viruses, which encode large replicase polyproteins that are processed by viral peptidases to generate the nonstructural proteins (Nsps) that mediate viral RNA synthesis. Papain-like peptidases (PLPs) and chymotrypsin-like cysteine 3C-like peptidase are essential for coronaviral replication and represent attractive antiviral drug targets. Furthermore, CoVs utilize the activation of their envelope spike glycoproteins by host cell peptidases to gain entry into cells. CoVs have evolved multiple strategies for spike protein activation, including the utilization of lysosomal cysteine cathepsins. In this review, viral and host peptidases involved in CoV cell entry and replication are discussed in depth, with an emphasis on papain-like cysteine cathepsins. Furthermore, important findings on cysteine peptidase inhibitors with regard to virus attenuation are highlighted as well as the potential of such inhibitors for future treatment strategies for CoV-related diseases.