Noninvasive measurement of dissolved oxygen in shake flasks

Tolosa, Leah; Kostov, Yordan; Harms, Peter D.; Rao, Govind

doi:10.1002/bit.10409

Cited by 95 publications

(75 citation statements)

References 17 publications

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“…Los cultivos agitados en frascos Erlenmeyer presentan limitaciones en la transferencia de oxígeno (Gupta & Rao 2003, Tolosa et al 2002, esto provocaría un metabolismo respirofermentativo mixto en Hansenula anomala RIVE 7-1-5 con la consecuente variabilidad en la producción de productos de la fermentación. Los factores que influyen en la transferencia de oxígeno incluyen la relación volumen del frasco Erlenmeyer/volumen del medio de cultivo, diametro del cuello del frasco e inclusive el tipo y las características del tapón (Nikakhtari & Hill 2006).…”

Section: Resultados Y Discusiónunclassified

Estudio de la actividad fermentativa de Hansenula anomala y producción de compuestos químicos de importancia sensorial

et al. 2012

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ResumenSe ha estudiado la actividad fermentativa de Hansenula anomala RIVE 7-1-5 con el objetivo de evaluar la producción de compuestos químicos de importancia sensorial. Los resultados mostraron que fermenta bien monosacáridos y también sucrosa y maltosa. Su actividad fermentativa es inhibida a concentraciones de 100,0mg/L de metabisulfito de sodio en el medio. Además, es capaz de producir 5,81±0,1 % v/v de etanol. La agitación del medio de cultivo incrementa la producción de alcoholes superiores (679,2 mg/L) y etil acetato (206,0±8,0 mg/L), por el contrario disminuye la producción de ácido acético (196,0±7,0 mg/L). La producción de glicerol fue similiar tanto en cultivo estático (sin agitación) como agitado. Durante el cultivo batch en biorreactor a condiciones aireadas la tasa de crecimiento (µ) alcanzó el valor de 0,13 h -1 y se observó la producción de ácido acético hasta 4,2±0,3 g/L. La concentración de oxígeno en el medio afecta su metabolismo, así cantidades insuficientes de oxígeno provocaría un metabolismo respirofermentativo con la producción de etanol, alcoholes superiores, ésteres y ácido acético. El control de la aireación al medio de fermentación es una herramienta útil para controlar el balance entre la actividad respiratoria y fermentativa y así la síntesis de compuestos de importancia sensorial en la producción de bebidas fermentadas no tradicionales. Palabras clave:Hansenula anomala, fermentación alcohólica, alcoholes superiores, etil acetato, cultivo por lote. AbstractThe fermentative behaviour of Hansenula anomala RIVE 7-1-5 was studied in order to evaluate the production of chemical compounds of sensory importance. The results demonstrated that the strain ferments very well monosaccharides and also sucrose and maltose. Its fermentative activity was inhibited at concentrations of 100 mg/L of sodium metabisulphite in the medium. Furthermore, it was able to produce 5,81±0,1% (v/v) of ethanol. Agitation of the culture medium increases the production of higher alcohols (679,2 mg/L) and ethyl acetate (206,0±8,0 mg/L), but on the contrary affects the production of acetic acid (196,0±7,0mg/L). Glycerol production was similar in static (without agitation) and shaken cultivation. During batch cultivation carried out in biorreactor under aerated conditions the growth rate (µ) reached value of 0,13 h -1 and, it was also observed production of acetic acid at levels of 4,2±0,3 g/L. The oxygen concentration in the medium affects its metabolism, thus insufficient amounts of oxygen would provoke a respirofermentative metabolism with production of ethanol, higher alcohols, esters and acetic acid. The control of aeration during fermentation is a useful tool to control the balance between the respiratory and fermentative activity and thus; synthesis of compounds of sensory importance in the production of non-traditional fermented beverages.

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Section: Resultados Y Discusiónunclassified

Estudio de la actividad fermentativa de Hansenula anomala y producción de compuestos químicos de importancia sensorial

et al. 2012

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“…Even when cultures are vigorously shaken, yeast rapidly deplete the growth medium of O 2 and cultures become increasingly anaerobic over time (30). Anaerobically grown yeast are auxotrophic for ergosterol (31); therefore, prolonged culturing may result in decreased sterol biosynthesis.…”

Section: Izh1 Izh2 Izh3mentioning

confidence: 99%

Metalloregulation of yeast membrane steroid receptor homologs

Lyons

Villa

Regalla

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

113

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Zinc is an essential micronutrient that can also be toxic. An intricate mechanism exists in yeast that maintains cellular zinc within an optimal range. The centerpiece of this mechanism is the Zap1p protein, a transcription factor that senses zinc deficiency and responds by up-regulating genes involved in zinc metabolism. A microarray screen for novel Zap1p target genes suggested a role in zinc homeostasis for four homologous yeast genes. The expression of two of these genes, YDR492w and YOL002c, suggested direct regulation by Zap1p, whereas the expression of YOL002c and a third homologous gene, YOL101c, was induced by high zinc. YDR492w and YOL002c are confirmed to be direct Zap1p target genes. The induction of YOL002c and YOL101c by toxic metal ion exposure is shown to be mediated by the Mga2p hypoxia sensor. Furthermore, YOL101c is induced by deletion of the Aft1p ironresponsive transcription factor. These three genes, along with a fourth yeast homolog, YLR023c, have phenotypic effects on zinc tolerance and Zap1p activity. Because of their metalloregulation, zinc-related phenotypes, and highly conserved motifs containing potential metal-binding residues, this family has been renamed the IZH gene family (Implicated in Zinc Homeostasis). Furthermore, these genes are regulated by exogenous fatty acids, suggesting a dual role in lipid metabolism. The IZH genes encode membrane proteins that belong to a ubiquitous protein family that includes hemolysin III and vertebrate membrane steroid receptors. We propose that the IZH genes affect zinc homeostasis either directly or indirectly by altering sterol metabolism.

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“…Optical detection of oxygen partial pressure (pO 2 ) is based on quenching of emission of a fluorescent metal-ligand complex as described previously (Szmacinski and Lakowicz, 1994;Tolosa, et al, 2002). Briefly, the excited state of the luminescent dye (i.e.…”

Section: Oxygen Measurementsmentioning

confidence: 99%

Miniature and Low-cost Wireless Sensor Platform for Environmental Monitoring

Kostov¹,

Rao²,

Ghosh³

2007

Self Cite

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Standard Form 298 (Rev. 8/98) REPORT DOCUMENTATION PAGEPrescribed by ANSI Std. Z39.18 Form Approved OMB No. 0704-0188The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to the Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. A sensor platform with DO, pH, and turbidity sensors was developed. It was equipped with pH and oxygen sensitive fluorescent foils. The foils were attached outside of the waterproof case and read through optical window. They had also antibiofouling protection, which allowed them to operate for extended period of time. A microcontroller switched the channels and collected the reading of O2, pH, and turbidity every 15 minutes, than transmitted it through wires interface to a base station. The platform operates from 4 AA size alkaline batteries. The transmitter has a range of approximately 1 kilometer, depending on the terrain, with transmission rate of 10 kbps The sensor platform is miniature in size (3"x3"x3" sensing head, electronics and battery pack) and low-cost (~ $450/unit). The main aim of the SEED project was to provide proof-of-concept of a miniature wireless sensor platform for water quality monitoring. This project successfully developed a small (3"x3"x3") and low-cost sensor node that accommodates three optical sensing devices and transmits the collected data through wireless communication to a base station. The platform was equipped and tested with optical sensors for three common water quality parameters: dissolved oxygen, pH, and turbidity. The platform is amenable to future expansion to include additional sensing elements that are under development at UMBC and elsewhere for the detection of specific contaminants such as CO , heavy metals, PAHs, and toxic gases. The project team is actively seeking partners to advance the technology to commercialization. PLEASE DO NOT RETURN YOUR

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Noninvasive measurement of dissolved oxygen in shake flasks

Cited by 95 publications

References 17 publications

Estudio de la actividad fermentativa de Hansenula anomala y producción de compuestos químicos de importancia sensorial

Estudio de la actividad fermentativa de Hansenula anomala y producción de compuestos químicos de importancia sensorial

Metalloregulation of yeast membrane steroid receptor homologs

Miniature and Low-cost Wireless Sensor Platform for Environmental Monitoring

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