Substrate inhibition kinetics of phenol degradation by Pseudomonas fluorescence from steady state and wash-out data

Abstract

ABSTRACT:The present study investigated the phenol utilization kinetics of a pure culture of an indigenousPseudomonas fluorescence under steady state and non-steady state (washout) conditions. Steady states of a continuous culture with an inhibitory substrate was used to estimate kinetic parameters under substrate limitation (chemo stat operation) Pure cultures of an indigenous Pseudomonas fluorescence were grown in continuous culture on phenol as the sole source of carbon and energy at dilution rates of 0.010 -0.20/h. Using different dilution rates, several steady states were investigated and the specific phenol consumption rates were calculated. In addition, phenol degradation was investigated by increasing the dilution rate above the critical dilution rate (washout cultivation). The results showed that the specific phenol consumption rate increased with increased dilution rate at steady state and phenol degradation by Pseudomonas fluorescence can be described by simple substrate inhibition kinetics under substrate limitation but cannot be described by simple substrate inhibition kinetics under washout cultivation. Fitting of the steady state data from continuous cultivation to various inhibition models resulted in the best fit for Haldane, Yano and Koga (2), Aiba and Teissier kinetic inhibition models. The r smax value of 0.229 mg/mg/h obtained from the inhibition model equations was comparable to the experimentally calculated r smax value of 0.246 mg/mg/h obtained under washout cultivation. Therefore, the biokinetic constants evaluated using these models showed good tolerance and growth of the indigenous organism.

Biodegradation of Cypermethrin by a newly isolated actinomycetes HU-S-01 from wastewater sludge

“…Microbial biodegradation of environmental pollutants is a field of growing importance because of its enormous potential for environmental clean up (Schmid et al, 2001;Dua et al, 2002;Pazos et al, 2003;Ugoji, 2008 and. It is a practical and applicable solution for detoxifying phenols, diesel fuel, azo dyes, anionic surfactants and pesticide in a range of varying conditions whether in fruits, vegetables, river or soil (Grant et al, 2002;Hosseini et al, 2007;Agarry and Solomon, 2008;Babel and Opiso, 2007;Agarry et al,2009;Kebria et al, 2009;Dhanasekaran et al, 2009;Ghasemi et al, 2010). Many efforts have been undertaken to isolate bacteria, capable of biodegradation of synthetic pyrethroid insecticides and a lot of pyrethroid-degrading microorganisms have been isolated from soil and polluted water (Sakata et al,1992;Maloeny et al, 1993;Halden et al,1999;Nirmali et al, 2005;Jilani and Khan, 2006;Tallur et al, 2008;Arulazhagan et al, 2010;Murugesan et al, 2010).…”

Kinetics of growth and caffeine demethylase production of Pseudomonas sp. in bioreactor

“…In another report on phenol degradation using mixed culture of Pseudomonas aeruginosa and Pseudomonas fluorescence, kinetics data were fitted well by Haldane, Yano Fig. 4 Luedeking-Piret model fit between specific production rate, q p (U g CDW -1 h -1 ), and specific growth rate, l (h -1 ) and Koga, and Aiba and Teissier models [2]. Haldane model also fitted well for substrate inhibition kinetics for Rhodococcus sp.…”

Understanding the simultaneous biodegradation of thiocyanate and salicylic acid by Paracoccus thiocyanatus and Pseudomonas putida

“…So, the biological reactors in these studies were frequently considered as ''black boxes'' difficult to predict and control (Herrero and Stuckey). Others woks use model pollutants or synthetic wastewaters and pure cultures (Agarry et al 2009;Agarry and Solomon 2008;Arutchelvan et al 2005;Combarros et al 2014Combarros et al , 2015Juang and Tsai 2006;Kim and Katayama 2000;Kwon et al 2002). The aim of these studies is usually to define the capacity of the bacterium to degrade a specific compound, the biodegradation pathway and the effect of the culture conditions on the bacterial activity.…”

“…Pure cultures usually show lower resistance to stress conditions than mixed ones, amplifying the response of the system to perturbations. The removal of phenol or cyanide compounds in biological wastewaters processes using pure cultures of Pseudomonas, Klebsiella, Ralstonia, Thibacillus or Paracoccus has been analyzed (Agarry et al 2009;Agarry and Solomon 2008;Combarros et al 2014Combarros et al , 2015Juang and Tsai 2006;Kim and Katayama 2000;Kwon et al 2002). The main limitation of these studies is that they provide too simple scenarios, which usually do not reflect the complexity of the interactions.…”