Protection of bacteria against toxicity of phenol by immobilization in calcium alginate

Keweloh, Heribert; Heipieper, Hermann J.; Rehm, Hans‐Jürgen

doi:10.1007/bf00257609

Cited by 151 publications

(104 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The increased substrate removal with Ca-alginate cells compared to free cells has been reported by many scientists (Keweloh et al 1989;Rhee et al 1996;Manohar et al 2001). In the present study, the immobilised cells possessed a higher degradation capacity at the initial endosulfan concentration of 350 μg/L than free cells, even though the cell contents in both free cells and immobilised cells were similar.…”

Section: Comparison Between the Efficiency Of Free And Immobilised Cellssupporting

confidence: 59%

Biodegradation of Endosulfan by Pseudomonas fluorescens

et al. 2015

View full text Add to dashboard Cite

The endosulfan-degrading bacterial strain Pseudomonas fluorescens was isolated, and degradation of endosulfan by freely suspended and calcium-alginate entrapped bacterial cells were investigated in batch as well as in packed bed column studies. Freely suspended Pseudomonas fluorescens cells with biomass maximum OD/OD 0 value of 1.68 at 610 nm could degrade endosulfan with an initial concentration of 350.24±0.83 μg/L efficiently within 12 days, thus utilising endosulfan as the sole carbon and energy source. Degradation of endosulfan occurred concomitantly with bacterial growth. The bacteria immobilised in Caalginate beads in batch shake flask system were tested for their ability to degrade endosulfan at different concentrations (350.24±0.83, 450.39±1.95 and 550.85±1.84 μg/L). A total of 125 mL of Broth minimal medium of pH 7 was inoculated with 5 g of wet Ca-alginate beads (derived from a 3-mL cell suspension of 0.72 OD at 610 nm) for the study. Almost similar trends of degradation efficiencies were shown by the immobilised cells toward different concentrations of endosulfan. The complete removal of alpha and beta-isomers of endosulfan at different initial endosulfan concentrations was observed between 9 and 11 days of the experiment. Additionally, the degradation rate in batch reactors with Ca-alginate-immobilised cells also derived from a 3-mL cell suspension of 0.72 OD at 610 nm was tested and found to be marginally higher than that of free cells. Ca-alginate immobilised cells in packed bed reactors operated in a semi-continuous mode could degrade toxic alpha and beta-isomers of endosulfan (350.38±1.18 μg/L) within 6 days. Thus, the method proved effective for biodegradation of endosulfan. The metabolites formed indicated that the degradation of the pesticide follows a hydrolytic pathway.

show abstract

Section: Comparison Between the Efficiency Of Free And Immobilised Cellssupporting

confidence: 59%

Biodegradation of Endosulfan by Pseudomonas fluorescens

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Artificially immobilized (entrapped in calcium alginate beads) cells of E. coli, Staphylococcus aureus, and Pseudomonas putida tolerated higher phenol concentrations than free cells. The number of generations of the immobilized cells as well as the formation of microcolonies and cell aggregates were reported to be the main reasons for the observed increase in phenol tolerance (16,19). Zymomonas mobilis biofilms have been reported to be tolerant against benzaldehyde.…”

Section: Discussionmentioning

confidence: 99%

“…Numerous studies have reported that bacterial cells in biofilms or cells artificially entrapped in a matrix are more resistant to environmental stresses (e.g., antimicrobial substances, heavy metals, toxic chemicals, organic acids, etc.) than their planktonic or freely swimming counterparts (7,9,16,19,29,40). There has been growing interest in recent years in the exploitation of these robust catalysts for biotechnological applications (e.g., biotransformations) to produce value-added chemicals (10,11,12,27).…”

mentioning

confidence: 99%

Real-Time Solvent Tolerance Analysis ofPseudomonassp. Strain VLB120ΔC Catalytic Biofilms

Halan

Schmid

Buehler

2011

Appl Environ Microbiol

View full text Add to dashboard Cite

Biofilms are ubiquitous surface-associated microbial communities embedded in an extracellular polymeric (EPS) matrix, which gives the biofilm structural integrity and strength. It is often reported that biofilm-grown cells exhibit enhanced tolerance toward adverse environmental stress conditions, and thus there has been a growing interest in recent years to use biofilms for biotechnological applications. We present a time-and locus-resolved, noninvasive, quantitative approach to study biofilm development and its response to the toxic solvent styrene. Pseudomonas sp. strain VLB120⌬C-BT-gfp1 was grown in modified flow-cell reactors and exposed to the solvent styrene. Biofilmgrown cells displayed stable catalytic activity, producing (S)-styrene oxide continuously during the experimental period. The pillar-like structure and growth rate of the biofilm was not influenced by the presence of the solvent. However, the cells experience severe membrane damage during styrene treatment, although they obviously are able to adapt to the solvent, as the amount of permeabilized cells decreased from 75 to 80% down to 40% in 48 h. Concomitantly, the fraction of concanavalin A (ConA)-stainable EPS increased, substantiating the assumption that those polysaccharides play a major role in structural integrity and enhanced biofilm tolerance toward toxic environments. Compared to control experiments with planktonic grown cells, the Pseudomonas biofilm adapted much better to toxic concentrations of styrene, as nearly 65% of biofilm cells were not permeabilized (viable), compared to only 7% in analogous planktonic cultures. These findings underline the robustness of biofilms under stress conditions and its potential for fine chemical syntheses.

show abstract

“…It has been well established that immobilization of the degrading organisms improves their efficiency and such systems have been exploited, during the last few decades, for elimination of a variety of pollutant chemicals (Keweloh et al, 1989;Cassidy et al, 1996). There have been several reports on degradation of phenol individually by several immobilized microbial systems (Agarry et al, 2008;Basha et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Simultaneous degradation of phenol and 3-chlorobenzoate by a mixture of separately immobilized cells of two strainsof Pseudomonas – A preliminary study

Yossouff¹,

Abdulla²

2011

MJM

View full text Add to dashboard Cite

Simultaneous degradation of halogenated and non-halogenated aromatic compounds that are catabolised through different cleavage pathways is generally difficult due to biochemical incompatibility. However, free cells of a mixed culture of Pseudomonas sp. CP4 that degrades phenol through meta-pathway and Pseudomonas aeruginosa strain 3mT that degrades 3-chlorobenzoate through ortho-pathway was shown, earlier, to degrade mixtures of phenol/cresols and 3-chlorobenzoate in shake flasks. In the present study the degrading efficiency of these strains when immobilized (separately) in Ca-alginate gel beads was tested using a fluidized bed reactor. Complete mineralization of up to 5 mM equimolar mixture of phenol and 3-chlorobenzoate was observed when the beads were used at 1:1 ratio. From a 10 mM equimolar mixture although phenol was completely mineralized 3-chlorobenzoate degradation was not complete as evidenced by accumulation of some intermediary metabolites and the release of only 86% of inorganic chloride (Cl¯). Degradation rates of both the compounds by the immobilized cells, in general, were far better than that by the free cells. With further studies to select suitable gel matrices and optimization of bioreactor conditions these strains can be effectively deployed for treatment of heterogeneous aromatic wastes.

show abstract

Protection of bacteria against toxicity of phenol by immobilization in calcium alginate

Cited by 151 publications

References 15 publications

Biodegradation of Endosulfan by Pseudomonas fluorescens

Biodegradation of Endosulfan by Pseudomonas fluorescens

Real-Time Solvent Tolerance Analysis ofPseudomonassp. Strain VLB120ΔC Catalytic Biofilms

Simultaneous degradation of phenol and 3-chlorobenzoate by a mixture of separately immobilized cells of two strainsof Pseudomonas – A preliminary study

Contact Info

Product

Resources

About