Calorimetric Techniques

Wadsö, Ingemar

doi:10.1016/b978-0-7236-0909-4.50007-3

Cited by 20 publications

(8 citation statements)

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“…AND PLANT GROWTH Kemp (1996) provides a clear and concise introduction to thermodynamics and enthalpy balances as applied to living systems, while more detailed treatment is provided by Roels (1983). Wadsö (1996) gives a useful introduction to calorimetry, including heat conduction calorimetry. An extensive account of theory, methods and applications of plant calorimetry is given by Criddle & Hansen (1999).…”

Section: Enthalpy Balance Model Of Respirationmentioning

confidence: 99%

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Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation ofEucalyptus globulusseedlings

Macfarlane

Adams

Hansen

2002

Proc. R. Soc. Lond. B

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The enthalpy balance model of growth uses measurements of the rates of heat and CO 2 production to quantify rates of decarboxylation, oxidative phosphorylation and net anabolism. Enthalpy conversion ef ciency (h H ) and the net rate of conservation of enthalpy in reduced biosynthetic products (R S G DH B ) can be calculated from metabolic heat rate (q) and CO 2 rate (R C O 2 ). h H is closely related to carbon conversion ef ciency and the ef ciency of conservation of available electrons in biosynthetic products. R S G DH B and h H can be used, together with biomass composition, to describe the rate and ef ciency of growth of plant tissues. q is directly related to the rate of O 2 consumption and the ratio q:R C O 2 is inversely related to the respiratory quotient.We grew seedlings of Eucalyptus globulus at 16 and 28°C for four to six weeks, then measured q and R C O 2 using isothermal calorimetry. Respiratory rate at a given temperature was increased by a lower growth temperature but h H was unaffected. Enthalpy conversion ef ciency-and, therefore, carbon conversion ef ciency-decreased with increasing temperature from 15 to 35°C. The ratio of oxidative phosphorylation to oxygen consumption (P/O ratio) was inferred in vivo from h H and by assuming a constant ratio of growth to maintenance respiration with changing temperature. The P/O ratio decreased from 2.1 at 10-15°C to less than 0.3 at 35°C, suggesting that decreased ef ciency was not only due to activity of the alternative oxidase pathway. In agreement with predictions from non-equilibrium thermodynamics, growth rate was maximal near 25°C, where the calculated P/O ratio was about half maximum. We propose that less ef cient pathways, such as the alternative oxidase pathway, are necessary to satisfy the condition of conductance matching whilst maintaining a near constant phosphorylation potential. These conditions minimize entropy production and maximize the ef ciency of mitochondrial energy conversions as growing conditions change, while maintaining adequate nite rates of energy processing.

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Section: Enthalpy Balance Model Of Respirationmentioning

confidence: 99%

“…Wadsö (1996) gives a useful introduction to calorimetry, including heat conduction calorimetry. An extensive account of theory, methods and applications of plant calorimetry is given by Criddle & Hansen (1999).…”

Section: Enthalpy Balance Model Of Respirationmentioning

confidence: 99%

Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation ofEucalyptus globulusseedlings

Macfarlane

Adams

Hansen

2002

Proc. R. Soc. Lond. B

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“…De forma a padronizar os valores das calibrações elétricas para celas calorimétricas, reações químicas são também necessárias. O microcalorímetro foi também calibrado utilizando a reação de protonação do tris(hidroximetilaminometano) ou THAM, recomendada para medidas calorimétricas 23,29 . A inoculação do microrganismo (100 µL da suspensão de células de S. cerevisiae) foi sempre feita imediatamente após o descongelamento da ampola num banho a 36 o C por 3 minutos seguida de agitação de 20 segundos.…”

Section: Materiais E Métodosunclassified

“…Beezer 22 e Wadsö 23 contribuíram fundamentalmente no estabelecimento da área conhecida hoje como microcalorimetria biológica.…”

Section: Introductionunclassified

Estudo da fermentação alcoólica de soluções diluídas de diferentes açucares utilizando microcalorimetria de fluxo

Volpe¹

1997

Quím. Nova

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Recebido em 8/4/96; aceito em 18/12/96 STUDY OF THE ALCOHOLIC FERMENTATION OF SUGARS DILUTED SOLUTIONS THROUGH FLOWMICROCALORIMETRY. The present study shows that with liquid nitrogen stored inocula of Saccharomyces cerevisiae, and standardized experimental procedure, flow microcalorimetry can be a valuable tool for monitoring in real time the alcoholic fermentation processes on line. The avaliation of cultural conditions contained different carbon sources for alcohol fermentation (sucrose, glucose, fructose, manose, maltose, galactose, molasses, honey and sugar cane) and their effects on the heat output recording is discussed. Some examples of diauxic growth is given, where the microcalorimeters serves to detect the temporal order of succession of alternating metabolic pathways.Keywords: flow microcalorimetry; heat output; fermentation; Saccharomyces cerevisiae. DIVULGAÇÃO INTRODUÇÃOA liberação de calor é uma propriedade geral do crescimento de microrganismos independentemente da natureza da fonte de carbono, ou se o processo é aeróbico ou anaeróbico. É surpreendente que o primeiro experimento calorimétrico com microrganismos relacionado com fermentação que se tem notícia, foi desenvolvido numa dorna de cervejaria por Dubrunfaut 1 em 1856 e talvez Lavoisier somente tenha malogrado em medir o calor liberado para o meio durante o crescimento de leveduras, em seus intensivos estudos do calor e da fermentação, porque ele estava limitado a 0 o C pelo seu calorímetro de gelo 2 . O experimento de Dubrunfaut poderia ser chamado hoje de "calorimetria dinâmica" e incentivou Rubner 3-6 , no início do sécu-lo, a começar as primeiras medidas calorimétricas verdadeiras, quantificando a produção de calor durante a fermentação e o crescimento das leveduras. Muitas medidas calorimétricas da energia do metabolismo subsequentes ao trabalho de Rubner não foram calorimétricas no sensu strictu porque não mediam diretamente o calor produzido durante o crescimento.A fermentação alcoólica (catabolismo anaeróbico) fornece energia na forma de ATP ou outros compostos de transferência de energia para a biossíntese do material celular e produção do etanol. Estas reações catabólicas acontecem com uma grande diminuição na energia livre, a qual junto com a subsequente hidrólise do ATP durante as reações de biossíntese, transporte e manutenção, resulta na produção de calor. Um balanço energé-tico simplificado para a equação do catabolismo anaeróbico da glicose pela S. cerevisiae, pode ser descrito da seguinte forma: GLICOSE → 2 CO 2 + 2 ETANOL; DG = -175 kJ/mol de glicose O detalhamento desta reação está representada na figura 1, com os respectivos valores de energia livre para cada etapa.Durante os anos 60, Calvet Prat e Skinner 7 deram importante impulso à microcalorimetria estudando a termogenese de sistemas vivos. A importância do calor como uma maneira de monitorar e possivelmente controlar processos fermentativos, é refletida pelo aumento crescente de trabalho publicados nesta área [8][9][10][11][12][13][14][15][16][17][18][19][20] . Nos a...

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“…The measured heat of friction of liquid agitation in the empty ampoule was almost negligible. In contrast, the interaction of milt with buffered AFW and NaCl produced disturbances, which may be caused by heat of friction from the viscosity change of cell suspension (Wadsö , 1987) or heat of protonation or deprotonation of buffer solutions. Enthalpy change caused by Tris buffer is higher than that caused by phosphate buffer (Malen Suurkuusk, pers.…”

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confidence: 99%

A preliminary investigation to compare metabolic heat dissipation by quiescent and activated spermatozoa of landlocked salmon

Penttinen

Hyväurinen

Piironen³

2000

Journal of Fish Biology

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Variation of metabolic heat dissipation between quiescent and active spermatozoa of Salmo salar m. sebago was investigated by direct calorimetry. The technique offers some promise to monitor energy metabolism of teleost sperm. The Fisheries Society of the British IslesThe physiology of fish spermatozoa, especially topics related to motility have received considerable recent attention. As Lahnsteiner & Patzer (1998) summarize, duration of motility, patterns of motility, the mechanisms of initiation and inhibition of motility have all been described well in many fish species. In contrast, only little information is available on the metabolic activity of fish spermatozoa although direct quantification of metabolic costs involved in the quiescent and active phases are important bioenergetic parameters. This deficiency probably reflects the methodological difficulties arising from the requirements of rapid analysis under interchanging test media and metabolic phases.This paper describes an alternative physiological technique, direct calorimetry, to study whether and to what extent metabolic activity of fish spermatozoa is changed during the motility initiation/inhibition. Spermatozoa of landlocked salmon Salmo salar m. sebago Girard were used as a model. The eight mature salmon (50-70 g) were obtained from Saimaa Fisheries and Aquaculture at Enonkoski in early November 1998. The milt samples were collected by hand-stripping and used immediately for calorimetric measurements and determination of spermatocrit by centrifugation (12 000 rpm; 5 min). The spermatocrit was 36-43%, which gives a sperm density of 1·9-2·6 10 10 cells ml 1 as estimated by a spermatocritbased linear regression model (Piironen, 1985).Heat dissipation measurements were performed with a flow-through 3·5 cm 3 stainless steel perfusion assembly of an isothermal microcalorimeter (TAM 2277, Thermometric). The calorimeter was calibrated at 100 W, which allowed the detection of a heat output of 120 W maximum.The milt sample of 75 l (with density around 1·6 10 9 cells) was put into the ampoule, which was then lowered gently into the calorimeter. After an hour of aerobic incubation at 7 C, the heat output of inactive spermatozoa was measurable and was then monitored for 2-3 h. For initiation of the metabolic activity, the milt was diluted with one of the two activation solutions. The first solution consisted of 0·9% (w/v) NaCl buffered to ‡Author to whom correspondence should be addressed.

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Calorimetric Techniques

Cited by 20 publications

References 51 publications

Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation ofEucalyptus globulusseedlings

Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation ofEucalyptus globulusseedlings

Estudo da fermentação alcoólica de soluções diluídas de diferentes açucares utilizando microcalorimetria de fluxo

A preliminary investigation to compare metabolic heat dissipation by quiescent and activated spermatozoa of landlocked salmon

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