Oxygen mass transfer studies on batch cultivation of P. aeruginosa in a biocalorimeter

Abstract

Abbreviations: DO: dissolved oxygen OTR: oxygen transfer rate OUR: oxygen uptake rateIn the present work volumetric mass transfer coefficient (k L a) was investigated during batch cultivations of Pseudomonas aeruginosa on a nutrient media. The effects of process variables (viz. impeller speed, oxygen flow and geometry of impeller) on the volumetric mass transfer coefficient of oxygen, k L a, in a biocalorimeter (Bio-RC1) was investigated and reported in this research work. The experimental data have been analyzed employing MATLAB to obtain the influences of the process parameters on k L a. An attempt was made to correlate volumetric mass transfer coefficient with metabolic heat production rate at optimized process conditions. The correlation reported in this work would be useful to control and scale up of bioprocesses.

Gas–liquid mass transfer studies for biomass support materials in a bioreactor

“…The power input per unit volume and superficial gas velocity are major correlation coefficients for k L a . Equations of the following type are frequently found for the correlation of k L a in the literature 5, 6, 14–18 where P is the mechanical agitation power in gas liquid dispersion (W); V is liquid volume (m 3 ); Vs is superficial gas velocity (m s −1 ); C is a constant; and a and b are exponents.…”

“…Oxygen mass transfer can be described and analyzed by means of the mass transfer coefficient k L a , which is the most important parameter involved in the design and operation of mixing–sparging equipment for bioreactors. The k L a values are affected by many factors including geometrical and operational characteristics of the vessels, agitation, air flow rate, media composition, liquid properties, concentration and microorganism morphology, and biocatalyst properties 3–6…”

Impact of aeration and agitation on metabolic heat and protease secretion of Aspergillus tamarii in a real-time biological reaction calorimeter

“…filamentous fungal broth) and for water (Nienow et al 1983). Thus, to determine the power number in BioRTCal, a previously worked out strategy was adopted (Sivaprakasam et al 2008); N P for the pitched blade turbine was approximately 1.25 (Houcine et al 2000). To characterize mixing for the agitation and aeration conditions, Reynolds number (N Re ) was employed.…”

“…Calorimetry also plays an important role in quantitative engineering and in bioreactor control (Surianarayanan et al 2012). In some of the reported studies, the metabolic heat production has been correlated to microbial growth, oxygen uptake and product formation (Sivaprakasam et al 2008). Improvements in sensitivity of bench scale calorimeters have made it possible to undertake real-time monitoring of several bioprocesses (Marison et al 1998).…”

Inhibition of shrimp pathogenic vibrios by extracellular compounds from a proteolytic bacterium Pseudomonas sp. W3

“…Pseudomonads are attractive bacteria for testing as sources of new bioactive compounds including antibiotics, bacteriocins, biosurfactants and bacteriolytic enzymes (Vijayan et al 2006;Kumar et al 2008;Sivaprakasam et al 2008). They are widely distributed in soil and aquatic habitats including shrimp ponds (Sakami et al 2008).…”