New efficient meta-fermentation process for lactic acid production from municipal solid waste.

BACKGROUND: The global market for lactic acid is witnessing growth on the back of increasing applications of lactic acid for manufacturing polylactic acid. Indeed, the lactic acid market is expected to reach 9.8 billion US dollars by 2025. The new concept of meta-fermentation has been proposed in recent years as an alternative to fermentation with pure cultures, due to multiple advantages such as lower susceptibility to contamination, no need for sterilization of culture media or lower raw material costs. However, there are still challenges to overcome to increase the conversion efficiency, decrease formation of by-products and facilitate fermentation control. In this context, the purpose of the study was to develop a robust meta-fermentation process to efficiently produce lactic acid from the OFMSW, stable at pre-industrial scale (1500 L). To maximize lactic acid production, operating conditions (pH, HRT) were modified, and a novel bioaugmentation strategy was tested. RESULTS: A LAB-rich inoculum was generated with LAB isolated from the digestate and grown in the laboratory with MRS medium. After feeding this inoculum to the digester (bioaugmentation), lactic acid accumulation up to 41.5 gO2/L was achieved under optimal operating conditions. This corresponds to more than 70% of the filtered COD measured in the digestate. The amount of lactic acid produced was higher than the volatile fatty acids under all feeding strategies applied. CONCLUSIONS: The operating conditions that enhanced the production of lactic acid from mixed cultures were 55ºC, 2 days HRT and pH 4.8-5.7, with pH-control once a day. The bioaugmentation strategy improved the results obtained in the prototype without applying reinoculation. Lactic acid was the main product along with other carboxylic acids. Further improvements are needed to increase purity as well as lactic acid concentration to reach economic feasibility of the whole process (digestion of OFMSW and downstream).

[Medical Care of people living with HIV in the Instituto Mexicano del Seguro Social]. / Atención a personas que viven con el VIH en el IMSS.

Infection by the human immunodeficiency virus (HIV) is apublic health problem worldwide, however, the incidence has remained relatively stable. In Mexico, around 10,000 new cases are reported each year. The Instituto Mexicano del Seguro Social (IMSS) has been a pioneer in the care of people living with HIV (PLWHA), gradually incorporating the different antiretroviral drugs (ARV). The first ARV used at the institutional level was zidovudine, in the 1990s, and later other agents were incorporated, such as protease inhibitors, drugs from the group of non-nucleoside analogs, and integrase inhibitors. In 2020, the migration to ARV schemes coformulated in a single tablet based on integrase inhibitors, which constitute a highly effective option and timely supply of drugs has been achieved in 99% of the population. In the aspect of prevention, the IMSS has also been a pioneer by being the first institution to implement HIV pre-exposure prophylaxis in 2021 at the national level and since 2022 universal post-exposure prophylaxis is available. The IMSS continues to be at the forefront incorporating the use of different management tools and instruments for the benefit of the population living with HIV. This document summarizes the history of HIV in the IMSS from the beginning of the epidemic to the present time.

La infección por el virus de la inmunodeficiencia humana (VIH) es un problema de salud pública a nivel mundial, sin embargo, la incidencia ha permanecido relativamente estable. En México se informa de alrededor de 10,000 casos nuevos al año. El Instituto Mexicano del Seguro Social (IMSS) ha sido pionero en la atención a las personas que viven con el VIH (PVV), incorporando paulatinamente los diferentes medicamentos antirretrovirales (ARV). El primer ARV utilizado a nivel institucional fue la zidovudina, en la década de los noventa, y posteriormente fueron incorporados otros agentes como los inhibidores de la proteasa, los medicamentos del grupo de los análogos no nucleósidos y los inhibidores de la integrasa. En el año 2020 ocurrió la migración a esquemas de ARV coformulados en una sola tableta a base de inhibidores de la integrasa, que constituyen una opción de alta eficacia y se ha logrado el surtimiento oportuno de los fármacos en el 99% de la población. En el aspecto de la prevención, el IMSS también ha sido pionero al ser la primera institución en implementar la profilaxis preexposición de VIH en el año 2021 a nivel nacional y desde el año 2022 se dispone de la profilaxis postexposición universal. El IMSS continúa a la vanguardia incorporando el uso de diferentes herramientas e instrumentos de gestión para beneficio de la población que vive con el VIH. En el presente documento se sintetiza la historia del VIH en el IMSS desde los inicios de la epidemia hasta el momento actual.