A bacterial strain that utilized o-chloronitrobenzene (o-CNB) as the sole carbon, nitrogen and energy sources was isolated from an activated sludge collected from an industrial waste treatment plant. It was identifi...A bacterial strain that utilized o-chloronitrobenzene (o-CNB) as the sole carbon, nitrogen and energy sources was isolated from an activated sludge collected from an industrial waste treatment plant. It was identified as Pseudomonas putida based on its morphology, physiological, and biochemical characteristics with an automatic biometrical system and the 16S rRNA sequence analysis. Microcosm study showed that the biodegradation of o-CNB was optimized at culture medium pH 8.0 and 32℃. At these conditions, the strain degraded 85% of o-CNB at a starting concentration of 1.1 mmol/L in 42 h. o-Chloroaniline was identified as the major metabolite with high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The study showed that o-CNB degradation by Pseudomonas putida OCNB-1 was initiated by aniline dioxyenase, nitrobenzene reductase and catechol-l,2- dioxygenase.展开更多
The majority of nanoparticles tend to agglomerate in bacterial growth media. Thus, nanoparticle-specific characteristics can get lost. To investigate the influence of nanoparticles on bacteria, these particles should ...The majority of nanoparticles tend to agglomerate in bacterial growth media. Thus, nanoparticle-specific characteristics can get lost. To investigate the influence of nanoparticles on bacteria, these particles should remain in their nanoparticulate state. The present study demonstrates the stabilization of commercially available zinc oxide (ZnO) with sodiumhexametaphosphate (SHMP) in bacterial growth medium (LB) to avoid agglomeration of these particles after the addition to LB. This established method is appropriate to stabilize ZnO agglomerates as small as 43 nm. The method of fractionated centrifugation was used to obtain stable agglomerates (also stable in the presence of bacteria) with different mean diameters. The SHMP-stabilized ZnO inhibits the growth of Pseudomonas putida with increasing concentration (up to 500 mg/L) and decreasing agglomerate size (43 - 450 nm).展开更多
The export oriented agricultural and horticultural crops depends on the export of residue free produce and has created a great potential and demand for the incorporation of biopesticides in crop protection. PGPR with ...The export oriented agricultural and horticultural crops depends on the export of residue free produce and has created a great potential and demand for the incorporation of biopesticides in crop protection. PGPR with wide scope for commercialization includes Pseudomonas putida. Pseudomonas putida was effective in reducing die back caused by a fungus Botryodiplodia theobromae and phomopsis or arm death, caused by a fungus, Phomopsis viticola of grapevine in vitro and in vivo. Pseudomonas putida showed optimum Siderophore pseudobactin production at 72 h, and growth peak at 120 h. glycerol as a source of carbon and yeast as a source of nitrogen Pseudomonas putida was formulated using polysaccharide dextran starch, which led to the elongation of conservation and the effectiveness of the biofungicide. Pseudomonas putida was very effective as biocontrol agents to reduce the die back and phomopsis diseases on grapevine. The obtained results showed that both bacterial treatments significantly increased the growth parameters as well as fruits dry weights and yield of grapevine.展开更多
Pseudomonas putida KT217 was grown on a complex medium comprised of co-products of the ethanol and biodiesel industries to assess the organism's capability to produce medium-chain-length polyhydroxyalkanoate (mcl-...Pseudomonas putida KT217 was grown on a complex medium comprised of co-products of the ethanol and biodiesel industries to assess the organism's capability to produce medium-chain-length polyhydroxyalkanoate (mcl-PHA). The growth phase was carried out in a medium containing 400 g/L condensed corn solubles (CCS), supplemented with ammonium hydroxide as a nitrogen source. Following the exponential phase, co-products of the biodiesel industry (soapstock and glycerin) were fed into the reactor to trigger PHA production. When glycerin was added to the bioreactor (75 g/L total addition), the final cell dry weight (CDW) and PHA content were 30 g/L and 31%, respectively. The monomeric composition in the PHA formed was relatively uniform throughout incubation with 3-hydroxydecanoate dominating. When a total of 153 g/L of sunflower soapstock was added to the bioreactor in a fed-batch manner, the final CDW and PHA content were 17 g/L and 17%, respectively. Following addition of soapstock the monomeric composition of the polymer changed dramatically, with the 3-hydroxyoctanoate monomer becoming dominant and greater unsaturation present in the PHA.展开更多
A bacterial strain designated in this study as POXN01 was found to be capable of degrading the synthetic organophosphorus pesticides paraoxon and methyl parathion. The strain was initially isolated through enrichment ...A bacterial strain designated in this study as POXN01 was found to be capable of degrading the synthetic organophosphorus pesticides paraoxon and methyl parathion. The strain was initially isolated through enrichment technique from rice field soil near Harlingen, Texas. Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene alignments identified the POXN01 isolate as a new strain of Pseudomonas putida, which is closely related to the recently discovered nicotine-degrading strain Pseudomonas putida S16. While being unable to metabolize nicotine, the POXN01 isolate was observed to actively proliferate using monocyclic aromatic hydrocarbons, in particular toluene, as nutrients. Search for the genetic determinants of paraoxon catabolism revealed the presence of organophosphorus-degrading gene, opd, identical to the one from Sphingobium fuliginis (former Flavobacterium sp. ATCC 27551). Assimilation of aromatic compounds likely relies on phc ARKLMNOPQ gene cluster for phenol, benzene and toluene catabolism, and on benRABCDKGEF cluster for benzoate catabolism. The observed versatility of POXN01 strain in degradation of xenobiotics makes it useful for the multi-purpose bioremediation of contaminated sites in both agricultural and industrial environmental settings.展开更多
Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not b...Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not been completely described.Furthermore,research on whether FB can function as phosphorus accumulating organisms(PAOs)is limited.In this study,a pure strain,a Pseudomonas putida PAO-1(P.putida PAO-1)isolate with phosphorus removal functions was isolated from the biofilm of an alternating anaerobic/aerobic biofilter(AABF),and its physiological characteristics were studied.Nitrate or nitrite could be used by the strain P.putida PAO-1 as electron acceptors for denitrification during phosphorus anoxic uptake,and 0.63 mg NO-3-N was consumed to reduce 1 mg soluble orthophosphate(SOP)by P.putida PAO-1.The strain P.putida PAO-1 consumed phosphorus within the optimal pH range of 6 to 8 and the temperature range of 25℃to 35℃.Cell deformity was a main morphological trait of the strain P.putida PAO-1,and it could elongate(with an elongation rate of 300%-500%)when it was subjected to oligotrophic or high-salt stress(15 g·L-1 NaCl).The findings in this study provide a microbiological reference for understanding the special characteristics of a denitrifying PAO.展开更多
Removal efficiency of phenol from aqueous solutions was determined using Pseudomonas putida (NCIM 2102). Experiments were made as a function of pH (4 - 9), temperature (28 - 36oC), and agitation speed (100 - 200 rpm)....Removal efficiency of phenol from aqueous solutions was determined using Pseudomonas putida (NCIM 2102). Experiments were made as a function of pH (4 - 9), temperature (28 - 36oC), and agitation speed (100 - 200 rpm). Optimization of these three process parameters for phenol degradation was studied. Statistically designed experiments using response surface methodology was used to get more information about the significant effects and the interactions between these three parameters. A 23 full-factorial central composite design was employed for experimental design and for analysis of the results. A second order polynomial regression model, has been developed using the experimental data. It was found that the degrading potential of P.putida (NCIM 2102) was strongly affected by the variations in pH, temperature and agitation speed. The experimental values were in good agreement with the predicted values and the correlation coefficient was found to be 0.9871. The optimum process conditions for maximizing phenol degradation were recognized as follows: pH (7.49), temperature (29.99oC), and agitation speed (138.89) rpm.展开更多
基金supported by the National Natural Sci- ence Foundation of China (No. 50278036)the National Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z378)
文摘A bacterial strain that utilized o-chloronitrobenzene (o-CNB) as the sole carbon, nitrogen and energy sources was isolated from an activated sludge collected from an industrial waste treatment plant. It was identified as Pseudomonas putida based on its morphology, physiological, and biochemical characteristics with an automatic biometrical system and the 16S rRNA sequence analysis. Microcosm study showed that the biodegradation of o-CNB was optimized at culture medium pH 8.0 and 32℃. At these conditions, the strain degraded 85% of o-CNB at a starting concentration of 1.1 mmol/L in 42 h. o-Chloroaniline was identified as the major metabolite with high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The study showed that o-CNB degradation by Pseudomonas putida OCNB-1 was initiated by aniline dioxyenase, nitrobenzene reductase and catechol-l,2- dioxygenase.
文摘The majority of nanoparticles tend to agglomerate in bacterial growth media. Thus, nanoparticle-specific characteristics can get lost. To investigate the influence of nanoparticles on bacteria, these particles should remain in their nanoparticulate state. The present study demonstrates the stabilization of commercially available zinc oxide (ZnO) with sodiumhexametaphosphate (SHMP) in bacterial growth medium (LB) to avoid agglomeration of these particles after the addition to LB. This established method is appropriate to stabilize ZnO agglomerates as small as 43 nm. The method of fractionated centrifugation was used to obtain stable agglomerates (also stable in the presence of bacteria) with different mean diameters. The SHMP-stabilized ZnO inhibits the growth of Pseudomonas putida with increasing concentration (up to 500 mg/L) and decreasing agglomerate size (43 - 450 nm).
文摘The export oriented agricultural and horticultural crops depends on the export of residue free produce and has created a great potential and demand for the incorporation of biopesticides in crop protection. PGPR with wide scope for commercialization includes Pseudomonas putida. Pseudomonas putida was effective in reducing die back caused by a fungus Botryodiplodia theobromae and phomopsis or arm death, caused by a fungus, Phomopsis viticola of grapevine in vitro and in vivo. Pseudomonas putida showed optimum Siderophore pseudobactin production at 72 h, and growth peak at 120 h. glycerol as a source of carbon and yeast as a source of nitrogen Pseudomonas putida was formulated using polysaccharide dextran starch, which led to the elongation of conservation and the effectiveness of the biofungicide. Pseudomonas putida was very effective as biocontrol agents to reduce the die back and phomopsis diseases on grapevine. The obtained results showed that both bacterial treatments significantly increased the growth parameters as well as fruits dry weights and yield of grapevine.
文摘Pseudomonas putida KT217 was grown on a complex medium comprised of co-products of the ethanol and biodiesel industries to assess the organism's capability to produce medium-chain-length polyhydroxyalkanoate (mcl-PHA). The growth phase was carried out in a medium containing 400 g/L condensed corn solubles (CCS), supplemented with ammonium hydroxide as a nitrogen source. Following the exponential phase, co-products of the biodiesel industry (soapstock and glycerin) were fed into the reactor to trigger PHA production. When glycerin was added to the bioreactor (75 g/L total addition), the final cell dry weight (CDW) and PHA content were 30 g/L and 31%, respectively. The monomeric composition in the PHA formed was relatively uniform throughout incubation with 3-hydroxydecanoate dominating. When a total of 153 g/L of sunflower soapstock was added to the bioreactor in a fed-batch manner, the final CDW and PHA content were 17 g/L and 17%, respectively. Following addition of soapstock the monomeric composition of the polymer changed dramatically, with the 3-hydroxyoctanoate monomer becoming dominant and greater unsaturation present in the PHA.
文摘A bacterial strain designated in this study as POXN01 was found to be capable of degrading the synthetic organophosphorus pesticides paraoxon and methyl parathion. The strain was initially isolated through enrichment technique from rice field soil near Harlingen, Texas. Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene alignments identified the POXN01 isolate as a new strain of Pseudomonas putida, which is closely related to the recently discovered nicotine-degrading strain Pseudomonas putida S16. While being unable to metabolize nicotine, the POXN01 isolate was observed to actively proliferate using monocyclic aromatic hydrocarbons, in particular toluene, as nutrients. Search for the genetic determinants of paraoxon catabolism revealed the presence of organophosphorus-degrading gene, opd, identical to the one from Sphingobium fuliginis (former Flavobacterium sp. ATCC 27551). Assimilation of aromatic compounds likely relies on phc ARKLMNOPQ gene cluster for phenol, benzene and toluene catabolism, and on benRABCDKGEF cluster for benzoate catabolism. The observed versatility of POXN01 strain in degradation of xenobiotics makes it useful for the multi-purpose bioremediation of contaminated sites in both agricultural and industrial environmental settings.
基金National Natural Science Foundation of China(No.21777024)National Key Research and Development Project,China(No.2019YFC0408503)。
文摘Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not been completely described.Furthermore,research on whether FB can function as phosphorus accumulating organisms(PAOs)is limited.In this study,a pure strain,a Pseudomonas putida PAO-1(P.putida PAO-1)isolate with phosphorus removal functions was isolated from the biofilm of an alternating anaerobic/aerobic biofilter(AABF),and its physiological characteristics were studied.Nitrate or nitrite could be used by the strain P.putida PAO-1 as electron acceptors for denitrification during phosphorus anoxic uptake,and 0.63 mg NO-3-N was consumed to reduce 1 mg soluble orthophosphate(SOP)by P.putida PAO-1.The strain P.putida PAO-1 consumed phosphorus within the optimal pH range of 6 to 8 and the temperature range of 25℃to 35℃.Cell deformity was a main morphological trait of the strain P.putida PAO-1,and it could elongate(with an elongation rate of 300%-500%)when it was subjected to oligotrophic or high-salt stress(15 g·L-1 NaCl).The findings in this study provide a microbiological reference for understanding the special characteristics of a denitrifying PAO.
文摘Removal efficiency of phenol from aqueous solutions was determined using Pseudomonas putida (NCIM 2102). Experiments were made as a function of pH (4 - 9), temperature (28 - 36oC), and agitation speed (100 - 200 rpm). Optimization of these three process parameters for phenol degradation was studied. Statistically designed experiments using response surface methodology was used to get more information about the significant effects and the interactions between these three parameters. A 23 full-factorial central composite design was employed for experimental design and for analysis of the results. A second order polynomial regression model, has been developed using the experimental data. It was found that the degrading potential of P.putida (NCIM 2102) was strongly affected by the variations in pH, temperature and agitation speed. The experimental values were in good agreement with the predicted values and the correlation coefficient was found to be 0.9871. The optimum process conditions for maximizing phenol degradation were recognized as follows: pH (7.49), temperature (29.99oC), and agitation speed (138.89) rpm.