Application of dielectric spectroscopy to unravel the physiological state of microorganisms: current state, prospects and limits.

Microbial physiology is an essential characteristic to be considered in the research and industrial use of microorganisms. Conventionally, the study of microbial physiology has been limited to carrying out qualitative and quantitative analysis of the role of individual components in global cell behaviour at a specific time and under certain growth conditions. In this framework, groups of observable cell physiological variables that remain over time define the physiological states. Recently, with advances in omics techniques, it has been possible to demonstrate that microbial physiology is a dynamic process and that, even with low variations in environmental culture conditions, physiological changes in the cell are provoked. However, the changes cannot be detected at a macroscopic level, and it is not possible to observe these changes in real time. As an alternative to solve this inconvenience, dielectric spectroscopy has been used as a complementary technique to monitor on-line cell physiology variations to avoid long waiting times during measurements. In this review, we discuss the state-of-the-art application of dielectric spectroscopy to unravel the physiological state of microorganisms, its current state, prospects and limitations during fermentation processes. Key points • Summary of the state of the art of several issues of dielectric spectroscopy. • Discussion of correlation among dielectric properties and cell physiological states. • View of the potential use of dielectric spectroscopy in monitoring bioprocesses.

Dielectric property measurements as a method to determine the physiological state of Kluyveromyces marxianus and Saccharomyces cerevisiae stressed with furan aldehydes.

Cell physiology parameters are essential aspects of biological processes; however, they are difficult to determine on-line. Dielectric spectroscopy allows the on-line estimation of viable cells and can provide important information about cell physiology during culture. In this study, we investigated the dielectric property variations in Kluyveromyces marxianus SLP1 and Saccharomyces cerevisiae ERD yeasts stressed by 5-hydroxymethyl-2-furaldehyde and 2-furaldehyde during aerobic growth. The dielectric properties of cell permittivity, specific membrane capacitance (Cm), and intracellular conductivity (σIn) were considerably affected by furan aldehydes in the same way that the cell population, viability, cell size, substrate consumption, organic acid production, and respiratory parameters were. The yeasts stressed with furan aldehydes exhibited three physiological states (φ): adaptation, replicating, and nonreplicating states. During the adaptation state, there were small and stable signs of permittivity, Cm, and σIn; additionally, no cell growth was observed. During the replicating state, cell growth was restored, and the cell viability increased; in addition, the permittivity and σIn increased rapidly and reached their maximum values, while the Cm decreased. In the nonreplicating state, the permittivity and σIn were stable, and Cm decreased to its minimum value. Our results demonstrated that knowing dielectric properties allowed us to obtain information about the physiological state of the cells under control and stressed conditions. Since the permittivity, Cm, and σIn are directly associated with the physiological state of the yeast, these results should contribute to a better understanding of the stress response of yeasts and open the possibility to on-line monitor and control the physiological state of the cell in the near future.

Manejo perioperatorio de una mujer portadora del gen de la adrenoleucodistrofia ligada al X para artroscopia de hombro / Perioperative management of a female diagnosed with heterozygous X-linked adrenoleukodystrophy scheduled for shoulder arthroscopy

La adrenoleucodistrofia ligada al cromosoma X (ALD-X) pertenece al grupo de enfermedades raras debidas a errores congénitos del metabolismo. Clínicamente, presenta diferentes manifestaciones que el anestesiólogo debe tener en cuenta durante el perioperatorio (disfunción respiratoria, hipotonía, insuficiencia suprarrenal o hepática, reflujo gastroesofágico, osteopenia, crisis epilépticas). Se presenta el caso de una mujer de 42 años portadora del gen que fue sometida a anestesia general combinada para artroscopia de hombro. Se hizo bloqueo ecoguiado del plexo braquial a nivel interescalénico, inducción anestésica con tiopental y fentanilo, y mantenimiento con sevofluorano. El procedimiento transcurrió sin incidencias, la evolución postoperatoria fue favorable y la paciente fue dada de alta a domicilio

X-linked adrenoleukodystrophy (X-ALD) belongs to a family of rare diseases due to inborn errors of metabolism. It has a wide spectrum of clinical manifestations that anaesthesiologists should recognise during the perioperative period (respiratory centre dysfunction, hypotonia, adrenal or hepatic failure, gastroesophageal reflux disease, osteopenia, seizures).The case is presented of a 42-year-old X-linked adrenoleukodystrophy female carrier, who underwent combined general and an ultrasound-guided interscalene brachial plexus block anaesthesia for shoulder arthroscopy. Induction was performed with thiopentone and fentanyl, and sevoflurane was used as inhaled maintenance agent. No events were recorded during the procedure. Her post-operative recovery was satisfactory and she was later discharged home

Perioperative management of a female diagnosed with heterozygous X-linked adrenoleukodystrophy scheduled for shoulder arthroscopy. / Manejo perioperatorio de una mujer portadora del gen de la adrenoleucodistrofia ligada al X para artroscopia de hombro.

X-linked adrenoleukodystrophy (X-ALD) belongs to a family of rare diseases due to inborn errors of metabolism. It has a wide spectrum of clinical manifestations that anaesthesiologists should recognise during the perioperative period (respiratory centre dysfunction, hypotonia, adrenal or hepatic failure, gastroesophageal reflux disease, osteopenia, seizures).The case is presented of a 42-year-old X-linked adrenoleukodystrophy female carrier, who underwent combined general and an ultrasound-guided interscalene brachial plexus block anaesthesia for shoulder arthroscopy. Induction was performed with thiopentone and fentanyl, and sevoflurane was used as inhaled maintenance agent. No events were recorded during the procedure. Her post-operative recovery was satisfactory and she was later discharged home.

Performance evaluation of Pichia kluyveri, Kluyveromyces marxianus and Saccharomyces cerevisiae in industrial tequila fermentation.

Traditionally, industrial tequila production has used spontaneous fermentation or Saccharomyces cerevisiae yeast strains. Despite the potential of non-Saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. Therefore, in this work, Agave tequilana juice was fermented at an industrial level using two non-Saccharomyces yeasts (Pichia kluyveri and Kluyveromyces marxianus) with fermentation efficiency higher than 85 %. Pichia kluyveri (GRO3) was more efficient for alcohol and ethyl lactate production than S. cerevisiae (AR5), while Kluyveromyces marxianus (GRO6) produced more isobutanol and ethyl-acetate than S. cerevisiae (AR5). The level of volatile compounds at the end of fermentation was compared with the tequila standard regulation. All volatile compounds were within the allowed range except for methanol, which was higher for S. cerevisiae (AR5) and K. marxianus (GRO6). The variations in methanol may have been caused by the Agave tequilana used for the tests, since this compound is not synthesized by these yeasts.

Derrame pericárdico neoplásico infectado por Salmonella enteritidis / Pericardial overflow infected by Salmonell enteritidis

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