Independent mutations in the transcription factor MYB10 cause most of the anthocyanin variation observed in diploid woodland strawberry (Fragaria vesca) and oct

Solid-state fermentation (SSF) is part of the pathway to consolidate waste as a relevant alternative for the valorization of organic waste. The objective of SSF is to produce one or several bioproducts of added value from solid substrates. Solid-state fermentation can use a wide variety of organic waste as substrates thus, it is an excellent candidate in the framework of the circular bioeconomy to change the status of waste from feedstock. The development of SSF was boosted in the previous decade by scientific efforts devoted to the production of hydrolytic enzymes. Nowadays, SSF has expanded to other valuable products: biosurfactants, biopesticides, aromas, pigments, and bio-flocculants, among others. This review explores the conditions to obtain the main emerging SSF products and highlight and discuss the challenges related to the scale-up of these processes and the bioproducts downstream, which hamper their further commercialization.

Solid-state fermentation (SSF) is on the way to become an attractive alternative for the valorisation of a wide range of organic waste. In biological terms, SSF can be defined as the cultivation process in which microorganisms grow on solid materials without the presence of free water. When these solid materials are organic waste and the objective is to produce one or several bioproducts of added value, SSF is a clear opportunity for circular bioeconomy, with a new paradigm “from waste to resource”. The development of SSF started a couple of decades ago, with biomolecules that only could be produced through biological systems, such as enzymes or antibiotics. However, a new generation of SSF bioproducts, which have a “twin” produced by chemical pathways, has emerged in the last years, with the advantages of having lower environmental impacts (for instance, no need of water and less energy requirements) and using waste as substrate. Some of these compounds are highly relevant in the field of chemical engineering: biosurfactants, biopesticides, aromas, bioplastics, pigments and bioflocculants, among others. This review explores the new advances in SSF: from the organic waste used as substrate to the main challenges SSF is facing, that is, mass and heat transfer limitations, bioproducts downstream and scale-up.

Strawberries ( Fragaria sp.) are cherished for their organoleptic properties and nutritional value. However, breeding new cultivars involves the simultaneous selection of many agronomic and fruit quality traits, including fruit firmness and extended postharvest life. The strawberry germplasm collection here studied exhibited extensive phenotypic variation in 26 agronomic and fruit quality traits across three consecutive seasons. Phenotypic correlations and principal component analysis revealed relationships among traits and accessions, emphasizing the impact of plant breeding on fruit weight and firmness to the detriment of sugar or vitamin C content. Genetic diversity analysis on 124 accessions using 44,408 markers denoted a population structure divided into six subpopulations still retaining considerable diversity. Genome‐wide association studies for the 26 traits unveiled 121 significant marker‐trait associations distributed across 95 quantitative trait loci (QTLs). Multiple associations were detected for fruit firmness, a key breeding target, including a prominent locus on chromosome 6A. The candidate gene FaPG1 , controlling fruit softening and postharvest shelf life, was identified within this QTL region. Differential expression of FaPG1 confirmed its role as the primary contributor to natural variation in fruit firmness. A kompetitive allele‐specific PCR assay based on the single nucleotide polymorphism (SNP) AX‐184242253, associated with the 6A QTL, predicts a substantial increase in fruit firmness, validating its utility for marker‐assisted selection. In essence, this comprehensive study provides insights into the phenotypic and genetic landscape of the strawberry collection and lays a robust foundation for propelling the development of superior strawberry cultivars through precision breeding.

This study examined the effects of two different microbial glycolipid biosurfactants on the anaerobic digestion of source-selected biowaste. Sophorolipids and mannosylerythritol lipids were produced through solid-state fermentation using a combination of wheat straw, molasses, and winterization oil cake. The characterization of the biosurfactants was conducted via liquid chromatography-mass spectrometry, which revealed their diverse configurations, highlighting the importance of the purification of biosurfactants produced from waste. When utilized as additives in anaerobic digestion, both sophorolipids and mannosylerythritol lipids demonstrated high biodegradability, facilitating the degradation of recalcitrant matter in the absence of readily biodegradable substrates. Sophorolipids yielded 785-800 mL of methane per gram added, depending on the purification level. Meanwhile, mannosylerythritol lipids produced 948 mL of methane per gram added. Overall, addition of biosurfactants lowered methane production when taking their own production into account, highlighting a key control that many other studies lack. Furthermore, in conjunction with biowaste, sophorolipids augmented the initial concentration of volatile fatty acid by 52%. Sophorolipids showed a high inhibition of the methanogenesis process. A complete microbial analysis of selected samples revealed distinct changes in community composition, with sophorolipids favouring hydrolytic and acidogenic populations, while mannosylerythritol lipids increased methanogenic Archaea. This fact can have important implications in the further use of these additives to improve biowaste AD. In the case of novel biosurfactants such as sophorolipids and mannosylerythritol lipids, which are produced from organic waste, it is evident that there is a lack of studies supporting their effectiveness in anaerobic digestion and their biodegradability in such environments, as well as the real consequences of adding them.