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Abstract Background Ashbya gossypii is a filamentous fungus widely utilized for industrial riboflavin production and has a great potential as a microbial chassis for synthesizing other valuable metabolites such as folates, biolipids, and limonene. Engineered strains of A. gossypii can effectively use various waste streams, including xylose-rich feedstocks. Notably, A. gossypii has been identified as a proficient biocatalyst for producing limonene from xylose-rich sources. This study aims to investigate the capability of engineered A. gossypii strains to produce various plant monoterpenes using agro-industrial waste as carbon sources. Results We overexpressed heterologous terpene synthases to produce acyclic, monocyclic, and bicyclic monoterpenes in two genetic backgrounds of A. gossypii. These backgrounds included an NPP synthase orthogonal pathway and a mutant erg20 F95W allele with reduced FPP synthase activity. Our findings demonstrate that A. gossypii can synthesize linalool, limonene, pinene, and sabinene, with terpene synthases showing differential substrate selectivity for NPP or GPP precursors. Additionally, co-overexpression of endogenous HMG1 and ERG12 with heterologous NPP synthase and terpene synthases significantly increased sabinene yields from xylose-containing media. Using mixed formulations of corn-cob lignocellulosic hydrolysates and either sugarcane or beet molasses, we achieved limonene and sabinene productions of 383 mg/L and 684.5 mg/L, respectively, the latter representing a significant improvement compared to other organisms in flask culture mode. Conclusions Engineered A. gossypii strains serve as a suitable platform for assessing plant terpene synthase functionality and substrate selectivity in vivo, which are crucial to understand monoterpene bioproduction. The NPP synthase pathway markedly enhances limonene and sabinene production in A. gossypii, achieving levels comparable to those of other industrial microbial producers. Furthermore, these engineered strains offer a novel approach for producing monoterpenes through the valorization of agro-industrial wastes.

The pathogenesis of frontal fibrosing alopecia has been linked to specific genetic variants. CYP1B1 codes for a component of the cytochrome p450 machinery that is involved in the metabolism of xenobiotic oestrogens. The study of the prevalence of polymorphisms in this gene may help to understand their role in the development of frontal fibrosing alopecia. The aim of this study is to describe the frequency of genetic variations in the alleles HLA-B*07:02 and CYP1B1 in patients with frontal fibrosing alopecia. A cross-sectional study was designed to evaluate blood samples from patients with frontal fibrosing alopecia who attended the Dermatology Department at University Hospital Ramón y Cajal (Madrid, Spain), in search of the polymorphisms rs9258883 and rs1800440 in the alleles HLA-B*07:02 and CYP1B1, respectively. A total of 223 patients were included in the study. Among the 83.8% of patients who carried the rs9258883 polymorphism in HLA-B*07:02, 58.7% were heterozygous for this variant and it was not present in 14.8% of the cases. The majority of patients with frontal fibrosing alopecia lacked the protective rs1800440 polymorphism in CYP1B1 (75.2%). This suggests a relevant role of this variant in development of frontal fibrosing alopecia. The genetic approach to this condition might influence patient prognosis and therapy options.

Abstract Background Limonene is a cyclic monoterpene that has applications in the food, cosmetic, and pharmaceutical industries. The industrial production of limonene and its derivatives through plant extraction presents important drawbacks such as seasonal and climate issues, feedstock limitations, low efficiency and environmental concerns. Consequently, the implementation of efficient and eco-friendly bioprocesses for the production of limonene and other terpenes constitutes an attractive goal for microbial biotechnology. In this context, novel biocatalysts with the ability to produce limonene from alternative carbon sources will help to meet the industrial demands of limonene. Results Engineered strains of the industrial fungus Ashbya gossypii have been developed to produce limonene from xylose. The limonene synthase (LS) from Citrus limon was initially overexpressed together with the native HMG1 gene (coding for HMG-CoA reductase) to establish a limonene-producing platform from a xylose-utilizing A. gossypii strain. In addition, several strategies were designed to increase the production of limonene. Hence, the effect of mutant alleles of ERG20 (erg20 F95W and erg20 F126W ) were evaluated together with a synthetic orthogonal pathway using a heterologous neryl diphosphate synthase. The lethality of the A. gossypii double mutant erg20 F95W−F126W highlights the indispensability of farnesyl diphosphate for the synthesis of essential sterols. In addition, the utilization of the orthogonal pathway, bypassing the Erg20 activity through neryl diphosphate, triggered a substantial increase in limonene titer (33.6 mg/L), without critically altering the fitness of the engineered strain. Finally, the overexpression of the native ERG12 gene further enhanced limonene production, which reached 336.4 mg/L after 96 h in flask cultures using xylose as the carbon source. Conclusions The microbial production of limonene can be carried out using engineered strains of A. gossypii from xylose-based carbon sources. The utilization of a synthetic orthogonal pathway together with the overexpression of ERG12 is a highly beneficial strategy for the production of limonene in A. gossypii. The strains presented in this work constitute a proof of principle for the production of limonene and other terpenes from agro-industrial wastes such as xylose-rich hydrolysates in A. gossypii.

Gangliosides are glycolipids occurring in higher animals, with a sphingoid core in the form of ceramide, bound to a glycan moiety including several units of sialic acid. Gangliosides are involved in important (patho)-physiological processes as components of cell membranes in humans, which has led to intensive study and interest in production strategies. Their structural variability depends on the combination of a sphingoid base, a fatty acyl chain, and an attached oligosaccharide. The combinatorial diversity differs and grows exponentially in synthetic biology approaches, e.g., use of microbial cell factories. A specific analytical platform accounting for this complexity is not available to date. However, quantification of the intermediates of the whole biosynthetic route is needed to boost projects on biotechnological ganglioside production. In this study, a fast high-throughput quantitative LC-MS/MS methodology was developed to cover analysis of gangliosides, with a wider structural perspective adapted to fungal organisms. This work was achieved using metabolically engineered strains that further allowed to test detection in biological complex matrixes. Ganglioside backbones—hitherto uncharacterized—with the five most common fungal sphingoid bases and both simple and hydroxylated fatty acids were subjected to characterization. The addition of glycans to the polar head was also successfully monitored with up to 4 units—corresponding to GD3 which bears two sialic acid units and furthermore represents the common precursor for the whole ganglio-series. This platform represents an improved methodology to study the biochemical diversity associated to gangliosides for natural and metabolically engineered biosynthetic pathways.

The essay indicates the main antecedents for the organization of the health system in Chile that is presently in force, with transformations following the country's coup d'état 50 years ago. It describes the recent debate over, and resistance to, the transformation and strengthening of the public system, with regard to controlling the health industry in the post-dictatorship, from the point of view of the sectors of economic power as well as the important viewpoint of the population, which in the face of a discouraged public health sector, seems to overlook the collective meaning of health care and the role of a state guarantor and protector of minimum social rights. [ABSTRACT FROM AUTHOR]

El artículo aborda el trabajo remunerado en la vejez como fenómeno complejo, para enriquecer la discusión de la Terapia Ocupacional y los estudios sobre la ocupación acerca del tema. Se detiene en la relevancia del trabajo como ocupación y reflexiona sobre las desigualdades que se construyen en torno al trabajo de las personas mayores. Al proponer un diálogo interdisciplinario con la perspectiva del curso de la vida, destaca la relación entre las trayectorias laborales y los contextos históricos en los que estas se insertan. El texto resalta la importancia del tema para la Terapia Ocupacional, la necesidad de comprender el trabajo en la vejez y de cuestionar la mirada individualizadora que tienden a usar los estudios disciplinares sobre el asunto. Esto implica dinamizar las teorías clásicas de la Terapia Ocupacional, de manera que trasciendan los enfoques clínicos centrados en la prevención y el tratamiento de las enfermedades de las personas mayores, y se interroguen por los sistemas políticos, económicos y sociales en los que se enmarca el trabajo de esta población.