Modelling the kinetics of hexavalent molybdenum (Mo6+) reduction by the Serratia sp. strain MIE2 in batch culture

Abstract

In the present work, the kinetics of hexavalent molybdenum reduction by the Serratia sp. strain MIE2 were investigated using several kinetic models, such as Monod, Haldane, Teissier, Aiba, Yano, Han and Levenspiel and Luong. The statistical analysis showed that the best model was Teissier, which had the lowest RMSE and AICc values, the highest adjusted R 2 values, and an F test and with a bias factor and an accuracy factor nearest to unity (1.0). The calculated value for the Teissier constants, such as p max , K s and K i , was 0.506 lmol Mo-blue h -1 , 6.53 mM and 29.41 mM, respectively. The effect of heavy metals showed that hexavalent molybdenum reduction by the strain MIE2 was inhibited by silver, mercury and copper with a total inhibition of 96, 97, and 45 %, respectively, at a concentration of 1 ppm. Otherwise, the Mo-reducing enzyme was inhibited by mercury and zinc with an inhibition of 88 and 65 %, respectively. Most of the respiratory inhibitors did not inhibit the Mo-reducing enzyme activity, indicating that the respiratory system in this bacterium is not the site of the hexavalent molybdenum reduction. The results obtained from this study could be useful for estimating the relationship between molybdenum-blue production and the molybdate concentration, which may be important during the up scaling of the molybdenum bioremediation process.

Microbiological Reduction of Molybdenum to Molybdenum Blue as a Sustainable Remediation Tool for Molybdenum: A Comprehensive Review

“…The inhibition by cyanide of Mo reduction in E. cloacae 48 indicates that the location occurred downstream from cytochrome [72]. However, all of the respiratory inhibitors tested on the recently isolated Mo-reducing bacteria showed no inhibition of the Mo-reducing enzyme [66][67][68]93,94,96,101,102,129]. The use of cyanide has only recently been discovered to increase the pH of the reaction mixture because it transforms the reaction mixture into a highly alkaline solution.…”

Inhibition Kinetics Study of Molybdenum Reduction by Pantoea sp. strain HMY-P4

“…Molybdenum reduction kinetic was carried out according a previous method [12]. Batch experiment (100 mL) was carried out in 250 mL conical flask but the initial molybdate concentration was varied from 0 to 100 mM.…”

“…In Bacillus sp A.rzi and Serratia sp. MIE2, mathematical modelling performed on hexavalent molybdenum reduction to Mo-blue suggest that the best models were the Luong and Teissier models, respectively [11,12]. The Luong and Teissier models, despite the widely recorded Haldane model allow for the determination of crucial substrate concentration, which can fully inhibit the rate of bacterial processes [13,14].…”

Modelling the Inhibition Kinetics of Molybdenum Reduction by the Molybdate-reducing Enterobacter cloacae

“…The rate of the reduction of molybdenum to Mo-blue Molybdenum was carried out according a previous method [14]. Batch experiment (100 mL) was carried out in 250 mL conical flask but the initial molybdate concentration was varied from 0 to 100 mM.…”

“…The only few reports are in Bacillus sp A.rzi and Serratia sp. MIE2, where mathematical modelling performed on the hexavalent molybdenum reduction to Mo-blue suggest that the best models were the Luong and Teissier models, respectively [13,14]. The Luong and Teissier models, despite the widely recorded Haldane model allow for the determination of crucial substrate concentration, which can fully inhibit the rate of bacterial processes [15,16].…”