Generation of flavors and fragrances through biotransformation and de novo synthesis

Flavors and fragrances are the result of the presence of volatile and non-volatile compounds, appreciated mostly by the sense of smell once they usually have pleasant odors. They are used in perfumes and perfumed products, as well as for the flavoring of foods and beverages. In fact the ability of the microorganisms to produce flavors and fragrances has been described for a long time, but the relationship between the flavor formation and the microbial growth was only recently established. After that, efforts have been put in the analysis and optimization of food fermentations that led to the investigation of microorganisms and their capacity to produce flavors and fragrances, either by de novo synthesis or biotransformation. In this review, we aim to resume the recent achievements in the production of the most relevant flavors by bioconversion/biotransformation or de novo synthesis, its market value, prominent strains used, and their production rates/maximum concentrations.We would like to thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, COMPETE 2020 (POCI-01-0145FEDER-006684), and BiotecNorte operation (NORTE-01-0145FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Functional plasticity in vertebrate scavenger assemblages in the presence of introduced competitors

Introduced species may suppress or enhance ecological functions, or they may have neutral effects in ecosystems where they replace or complement native species. Few studies, however, have explicitly tested for these trajectories, and for the effect these might have for native species. In this study, we experimentally test the trajectory and scale of change in the function of 'carrion removal' at different carrion loads along ocean beaches in Eastern Australia that have different numbers of introduced red foxes (Vulpes vulpes) and several species of native raptors. We hypothesized that the 'positive' effect of foxes on carrion removal would be greatest at high carrion loads, because competition for resources between native and introduced species is lower. Scavenger abundance, fox occurrences, and carrion consumption by these species differed widely between locations and times. Despite distinct spatial differences in the structure of vertebrate scavenger assemblages, total carrion consumption was not significantly different between locations at any carrion load. This lack of variation in functional rates indicates potential functional plasticity in the scavenger assemblage and possible functional accommodation of red foxes. Neutral fox effects on ecological functions or the ecosystem more broadly are, however, very unlikely to extend beyond carrion consumption

L’Agnoletta e la pratica della riscrittura nella novellistica settecentesca

Isoprenoids are the largest class of natural compounds and have extremely diverse chemical and functional properties. They are involved in many different cellular processes, including hormonal regulation, signalling, pest/pathogen defence and redox status. They also provide many of the colours, flavours and aromas found in biology. The diversity of isoprenoids lends them to a wide variety of biotechnological applications, both by exploiting their myriad natural functions and by using them as industrial chemicals/chemical feedstocks. These applications range from fine chemicals (pharmaceuticals, nutraceuticals, antimicrobials) through mid-volume (flavours, fragrances, colourants, fuel additives) and bulk (fuels, synthetic polymers, agricultural chemicals, etc.) products. However, in their natural context, individual isoprenoids are not usually found at sufficient abundance for industrial use. Moreover, extraction and/or purification may be difficult and/or expensive, or production may be highly variable, making industrial production processes challenging or impossible. Artificial synthesis is often not possible due to complexity, expense or other chemical properties/requirements. Consequently, there is a strong movement towards bioengineering of microbes for production of these valuable compounds in controlled fermentation conditions. Here we consider the requirements for developing economically viable isoprenoid production bioprocesses as well as the current state of the art in engineering production in microbes. We also discuss some of the challenges we face in bringing these technologies to the market