Synchronous anaerobic and aerobic degradation of DDT by an immobilized mixed culture system

Beunink, Jürgen; Rehm, Hans‐Jürgen

doi:10.1007/bf00258354

Cited by 73 publications

(24 citation statements)

References 23 publications

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“…Nevertheless, a few strains with this ability have been reported, including strains that dechlorinate polychlorinated biphenyls (1), dichlorodiphenyltrichloroethane (DDT) (9), toxaphene (29) and PCE (36). In addition, it appears that tolerance of high concentrations of halogenated compounds may be a characteristic of Enterobacter species.…”

Section: Discussionmentioning

confidence: 99%

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Shan¹,

Kurtz

Mykytczuk

et al. 2010

Appl Environ Microbiol

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A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two Pantoea spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B 12 (approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO 2 , and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation.Chloroform (CF) is a toxic organic compound that is frequently detected in groundwater. In the 2007 "CERCLA Priority List of Hazardous Substances," CF ranks eleventh overall and is the third highest among chlorinated organics after vinyl chloride and polychlorinated biphenyls (4). When present at hazardous waste sites, CF is often a focal point for evaluating the feasibility of bioremediation, since it is toxic to many obligate anaerobic prokaryotes (44). For example, 1 mg/liter of CF completely inhibited dechlorination of tetrachloroethene (PCE) by a chlororespiring anaerobic isolate (32). Inhibition of reductive dechlorination of chloroethenes by CF is a general problem for sites cocontaminated with CF, which can only be overcome by first removing the CF (6).In spite of major recent advances in bioremediation of chlorinated organic compounds, treatment of CF, especially at high concentrations (e.g., Ͼ100 mg/liter), remains challenging. Although aerobic biotransformation of CF is possible (e.g., cometabolism by a butane-grown strain) (14), CF is more difficult to cometabolize than trichloroethene (42). Biotransformation of CF by mixed or pure cultures under methanogenic (5, 21) and sulfate-reducing (20) conditions has been reported, however, only at low-mg/liter CF concentrations.Corrinoids such as vitamin B 12 (i.e., cyanocobalamin) are effective catalysts for increasing the rate of halomethane biotransformation under anaerobic conditions. Addition of vitamin B 12 also shifts the pathway away from reductive dechlorination and toward hydrolytic and substitutive reactions, forming CO, CO 2 , and organic acids as the major products (8,23,24). With low levels of B 12 added (3 to 5% molar ratios of CF), an enrichment culture grown on dichloromethane (DCM) as the sole substrate (8) and a lactate-grown sulfate-reducing enrichment culture (18) were able to biotransform up ...

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Section: Discussionmentioning

confidence: 99%

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Shan¹,

Kurtz

Mykytczuk

et al. 2010

Appl Environ Microbiol

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“…These effects may be due to the rapid growth promoted by high concentrations of inorganic phosphate. Cells, metabolizing and growing close to and on the outer surfaces, can withdraw substrates and oxygen from the ceils inside the beads Rehm 1986, 1988;Beunink and Rehm 1988;Beunink et al 1989). Reduced metabolic activity and cell growth as a result of phosphate limitation could thus enable more interior growth, as noticed in the case of low phosphate concentrations.…”

Section: Discussionmentioning

confidence: 99%

Influence of inorganic phosphate and immobilization on Claviceps purpurea

Lohmeyer

Dierkes

Rehm

1990

Appl Microbiol Biotechnol

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The influence of inorganic phosphate and immobilization on cells of Claviceps purpurea strain 1029/N5 producing ergot peptides in shake culture was examined. Immobilization in Ca-alginate beads resulted in a marked reduction of some metabolic activities, i.e. the periods of alkaloid formation and cell growth were prolonged. High concentrations of inorganic phosphate (1 g/l KHzPO4) could reduce or stop alkaloid formation both by free and immobilized cells at any time during fermentation. The optimum phosphate concentration for alkaloid production by immobilized cells (about 0.5 mM) was a quarter of that required by free cells. This optimum shift was attributed to (i) the diminished phosphate demand of immobilized cells, due to their reduced metabolic activities, and (ii) the phosphate-dependent morphological behaviour of the biocatalyst. The observed decrease in alkaloid concentrations during later periods of the fermentation supported the idea of alkaloid-degradative enzymes, activated by high phosphate concentrations. Immobilization showed an advantageous influence on this undesirable effect.

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“…A collective anaerobic and aerobic treatment by immobilized microorganisms was first shown [66,67] using calcium-alginate-immobilized co-cultures of a facultative anaerobic strain of Enterobacter cloacae. Reaction actually took place in the middle of the alginate beads.…”

Section: Immobilized Bacteria Under Aerobic-anaerobic Conditionmentioning

confidence: 99%

Decolorization of Azo Dyes by Immobilized Bacteria

Khan

Banerjee

2010

The Handbook of Environmental Chemistry

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Synthetic organic dyes are essential for satisfying the ever growing demand in terms of quality, variety, and speed of coloration of large number of substances. Because of the xenobiotic nature of dyes, they are toxicant to biological system and causes serious damage to environment. Ever-increasing concerns about color in the effluent lead to the worldwide efforts to build up effective procedure for color elimination. Biodegradation is gaining popularity to clean up hazardous waste because of the clear picture of the costs and the benefits of microbial degradation. Removal of dyes from waste water is reviewed with respect to biological decolorization. Promising techniques with reference to biological treatment of wastewater are immobilization of microorganisms on different supports. Immobilization increases the stabilities of the enzyme at high pH and tolerance to elevated temperatures and to make the enzyme less vulnerable to inhibitors. Generally the covalent bonds during immobilization enhance stabilities of enzymes due to the limitation of conformational changes.

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Synchronous anaerobic and aerobic degradation of DDT by an immobilized mixed culture system

Cited by 73 publications

References 23 publications

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Influence of inorganic phosphate and immobilization on Claviceps purpurea

Decolorization of Azo Dyes by Immobilized Bacteria

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