Biodegradation kinetics of 4-fluorocinnamic acid by a consortium of Arthrobacter and Ralstonia strains

Abstract

Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades 4-FBA. A consortium of strains G1 and H1 degraded 4-FCA with Monod kinetics during growth in batch and continuous cultures. Specific growth rates of strain G1 and specific degradation rates of 4-FCA were observed to follow substrate inhibition kinetics, which could be modeled using the kinetic models of Haldane–Andrew and Luong–Levenspiel. The mixed culture showed complete mineralization of 4-FCA with quantitative release of fluoride, both in batch and continuous cultures. Steady-state chemostat cultures that were exposed to shock loadings of substrate responded with rapid degradation and returned to steady-state in 10–15 h, indicating that the mixed culture provided a robust system for continuous 4-FCA degradation.

The biodegradation vs. biotransformation of fluorosubstituted aromatics

“…1). Via dehydrogenation and decarboxylation, 4-fluorocatechol is produced and further degraded by ortho cleavage and formation of 3-fluoromuconic acid (Harper and Blakley 1971b;Engesser et al 1990a;Schlömann et al 1990a;PerezPantoja et al 2009;Hasan et al 2011). The risk of formation of toxic 3-fluorocatechol and non-degradable 2-fluoromuconic acid present in 2-or 3-fluorobenzoate degradation naturally does not play a role in 4-fluorobenzoate degradation.…”

“…strain G1 utilizes 4-fluorocinnamic acid as sole source of carbon and energy. However, only the C 1 and C 2 of the side chain are used for growth and 4-fluorobenzoate is excreted, which can be degraded by other strains along the above-discussed pathway via 4-fluorocatechol (Hasan et al 2011). In strain G1, degradation of 4-fluorocinnamic acid s t a r t s w i t h f o r m a t i o n o f a C o A a d d u c t b y 4 -fluorocinnamoyl-CoA ligase.…”

Complete Genome Sequencing of Protease-Producing Novel Arthrobacter sp. Strain IHBB 11108 Using PacBio Single-Molecule Real-Time Sequencing Technology

“…More than 84 species have been described from alpine, Antarctic, forest, field, and rhizosphere soils; Antarctic lake and deep-sea sediments; South China Sea and Pohang basin waters; and extreme environments, including air in the Russian space laboratory, alpine glacier cryoconite, and an alpine ice cave ( http://www.bacterio.net/arthrobacter.html ). Members of this genus are involved in the biodegradation of the plant alkaloids nicotine ( 4 ), 2,4-dinitrotoluene ( 5 ), and 4-fluorocinnamic acid ( 6 ), and in the production of the enzymes isonitrile hydratase ( 7 ), serine hydroxymethyltransferase ( 8 ), beta-galactosidase ( 9 ), and dehydrogenases ( 10 ). During exploration of microbial communities from sediment and water samples collected from Chandra Tal Lake (32.29°N 77.36°E), an off-white, psychrotrophic isolate showing hydrolysis of skimmed milk was characterized as a novel species based on the highest identity of 97.46% from a 16S rRNA gene sequence comparison with Arthrobacter russicus GTC 863 (T) .…”

An approach to the metabolic degradation of diethylketone (DEK) by Streptococcus equisimilis: Effect of DEK on the growth, biodegradation kinetics and efficiency

“…In this work, for concentrations higher than 3.2 g L −1 the specific growth rate started to decrease, indicating substrate inhibition of growth. According to Hasan et al (2012), this may be due to cell damage or disruption of membrane integrity at higher diethylketone concentrations. The results also show that the "acclimation time", lag phase, is longer for the highest concentrations.…”