Degradation of 3-Phenoxybenzoic Acid in Soil byPseudomonas pseudoalcaligenes POB310(pPOB) and Two ModifiedPseudomonas Strains

1999 ◽  
Vol 65 (8) ◽  
pp. 3354-3359 ◽  
Author(s):  
Rolf U. Halden ◽  
Sandra M. Tepp ◽  
Barbara G. Halden ◽  
Daryl F. Dwyer
Keyword(s):  
Soil Formation ◽  
Dry Weight ◽  
Bacterial Survival ◽  
In Situ Bioremediation ◽  
Soil Microcosms ◽  
Genes Encoding ◽  
Bacterium Strain ◽  
Favorable Conditions ◽  
Water Holding

ABSTRACT Pseudomonas pseudoalcaligenes POB310(pPOB) andPseudomonas sp. strains B13-D5(pD30.9) and B13-ST1(pPOB) were introduced into soil microcosms containing 3-phenoxybenzoic acid (3-POB) in order to evaluate and compare bacterial survival, degradation of 3-POB, and transfer of plasmids to a recipient bacterium. Strain POB310 was isolated for its ability to use 3-POB as a growth substrate; degradation is initiated by POB-dioxygenase, an enzyme encoded on pPOB. Strain B13-D5 contains pD30.9, a cloning vector harboring the genes encoding POB-dioxygenase; strain B13-ST1 contains pPOB. Degradation of 3-POB in soil by strain POB310 was incomplete, and bacterial densities decreased even under the most favorable conditions (100 ppm of 3-POB, supplementation with P and N, and soil water-holding capacity of 90%). Strains B13-D5 and B13-ST1 degraded 3-POB (10 to 100 ppm) to concentrations of <50 ppb with concomitant increases in density from 106 to 108 CFU/g (dry weight) of soil. Thus, in contrast to strain POB310, the modified strains had the following two features that are important for in situ bioremediation: survival in soil and growth concurrent with removal of an environmental contaminant. Strains B13-D5 and B13-ST1 also completely degraded 3-POB when the inoculum was only 30 CFU/g (dry weight) of soil. This suggests that in situ bioremediation may be effected, in some cases, with low densities of introduced bacteria. In pure culture, transfer of pPOB from strains POB310 and B13-ST1 to Pseudomonas sp. strain B13 occurred at frequencies of 5 × 10−7 and 10−1 transconjugant per donor, respectively. Transfer of pPOB from strain B13-ST1 to strain B13 was observed in autoclaved soil but not in nonautoclaved soil; formation of transconjugant bacteria was more rapid in soil containing clay and organic matter than in sandy soil. Transfer of pPOB from strain POB310 to strain B13 in soil was never observed.

scholarly journals Feasibility study of in-situ bioremediation for nitrobenzene-contaminated groundwater

2017 ◽  
Vol 17 (4) ◽  
pp. 1160-1167 ◽  
Author(s):  
Na Liu ◽  
Yue Wang ◽  
Yonglei An ◽  
Feng Ding ◽  
Xiaolong Yu ◽  
...  
Keyword(s):  
Simulation Experiment ◽  
Laboratory Simulation ◽  
Contaminated Groundwater ◽  
Site Conditions ◽  
In Situ Bioremediation ◽  
Degrading Bacterium ◽  
Bacterium Strain ◽  
Negative Factors ◽  
Sufficient Oxygen

Although many studies have simulated in-situ bioremediation of contaminated groundwater, most of them have not considered hydrochemical conditions and indigenous microorganisms, thus potentially rendering results inapplicable to actual in-situ groundwater bioremediation projects. This study focused on a nitrobenzene-contaminated groundwater site located in Jilin City, China. The actual nitrobenzene-contaminated groundwater was taken from Jilin City to simulate in-situ groundwater bioremediation in the laboratory. The feasibility of in-situ bioremediation for nitrobenzene-contaminated groundwater was studied according to actual site conditions and characteristics of nitrobenzene-degrading microorganisms in groundwater. The results showed that nitrobenzene-degrading bacterium strain NB1 was the dominant species that could effectively and rapidly degrade nitrobenzene by a partial reductive pathway. No negative factors on the growth or degrading function of this strain in groundwater could be detected. During a laboratory simulation experiment, combined in-situ bioremediation technologies, namely air sparging and bioaugmentation, could readily remove approximately 89.56% of nitrobenzene from groundwater without adding nutrients; oxygen was found to be the important growth factor for strain NB1. As the substrate of nitroreductase, encoded by the nitrobenzene nitroreductase (nbzA) gene, nitrobenzene was likely to significantly affect the expression of this gene. In conclusion, in-situ bioremediation is a feasible way to solve the problem of nitrobenzene-contaminated groundwater in Jilin City as long as sufficient oxygen and biomass of strain NB1 is ensured.

scholarly journals Gammaproteobacterial Methanotrophs Dominate Cold Methane Seeps in Floodplains of West Siberian Rivers

2014 ◽  
Vol 80 (19) ◽  
pp. 5944-5954 ◽  
Author(s):  
Igor Y. Oshkin ◽  
Carl-Eric Wegner ◽  
Claudia Lüke ◽  
Mikhail V. Glagolev ◽  
Illiya V. Filippov ◽  
...  
Keyword(s):  
West Siberia ◽  
Dry Weight ◽  
Small Rivers ◽  
Type I ◽  
Content Type ◽  
Cell Counts ◽  
Genes Encoding ◽  
Irtysh Basin ◽  
Methane Fluxes

ABSTRACTA complex system of muddy fluid-discharging and methane (CH4)-releasing seeps was discovered in a valley of the river Mukhrinskaya, one of the small rivers of the Irtysh Basin, West Siberia. CH4flux from most (90%) of these gas ebullition sites did not exceed 1.45 g CH4h−1, while some seeps emitted up to 5.54 g CH4h−1. The δ13C value of methane released from these seeps varied between −71.1 and −71.3‰, suggesting its biogenic origin. Although the seeps were characterized by lowin situtemperatures (3.5 to 5°C), relatively high rates of methane oxidation (15.5 to 15.9 nmol CH4ml−1day−1) were measured in mud samples. Fluorescencein situhybridization detected 107methanotrophic bacteria (MB) per g of mud (dry weight), which accounted for up to 20.5% of total bacterial cell counts. Most (95.8 to 99.3%) methanotroph cells were type I (gammaproteobacterial) MB. The diversity of methanotrophs in this habitat was further assessed by pyrosequencing ofpmoAgenes, encoding particulate methane monooxygenase. A total of 53,828pmoAgene sequences of seep-inhabiting methanotrophs were retrieved and analyzed. Nearly all of these sequences affiliated with type I MB, including theMethylobacter-Methylovulum-Methylosomagroup, lake cluster 2, and several as-yet-uncharacterized methanotroph clades. Apparently, microbial communities attenuating methane fluxes from these local but strong CH4sources in floodplains of high-latitude rivers have a large proportion of potentially novel, psychrotolerant methanotrophs, thereby providing a challenge for future isolation studies.

In situ bioremediation of cyanide, PAHs and organic compounds using an engineered SEquenced REactive BARrier (SEREBAR)

2006 ◽  
Vol 14 (2) ◽  
pp. 478-482
Author(s):  
Jamie Robinson ◽  
Russell Thomas ◽  
Steve Wallace ◽  
Paddy Daly ◽  
Robert Kalin
Keyword(s):  
Organic Compounds ◽  
In Situ Bioremediation ◽  
Reactive Barrier

In Situ Bioremediation of Perchlorate in Groundwater

2009 ◽  
Author(s):  
Paul Hatzinger ◽  
Jay Diebold
Keyword(s):  
In Situ Bioremediation

On-site and in situ bioremediation of wood-preservative contaminated groundwater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  
Keyword(s):  
Iron Oxidation ◽  
Wood Preservative ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
In Situ Bioremediation ◽  
Contaminated Aquifer ◽  
Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

In‐situ Bioremediation

2021 ◽  
pp. 1-14
Author(s):  
Shamsul Haq ◽  
Asma Absar Bhatti ◽  
Suhail Ahmad Bhat ◽  
Shafat Ahmad Mir ◽  
Ansar ul Haq
Keyword(s):  
In Situ Bioremediation

scholarly journals The occurrence and ecology of microbial chain elongation of carboxylates in soils

2021 ◽  
Author(s):  
Sayalee Joshi ◽  
Aide Robles ◽  
Samuel Aguiar ◽  
Anca G. Delgado
Keyword(s):  
Microbial Ecology ◽  
Anaerobic Metabolism ◽  
Chain Elongation ◽  
Soil Microcosms ◽  
Soil Microbial ◽  
Anaerobic Soils ◽  
Clostridium Kluyveri ◽  
Substrate Concentrations ◽  
Elongation Activity

AbstractChain elongation is a growth-dependent anaerobic metabolism that combines acetate and ethanol into butyrate, hexanoate, and octanoate. While the model microorganism for chain elongation, Clostridium kluyveri, was isolated from a saturated soil sample in the 1940s, chain elongation has remained unexplored in soil environments. During soil fermentative events, simple carboxylates and alcohols can transiently accumulate up to low mM concentrations, suggesting in situ possibility of microbial chain elongation. Here, we examined the occurrence and microbial ecology of chain elongation in four soil types in microcosms and enrichments amended with chain elongation substrates. All soils showed evidence of chain elongation activity with several days of incubation at high (100 mM) and environmentally relevant (2.5 mM) concentrations of acetate and ethanol. Three soils showed substantial activity in soil microcosms with high substrate concentrations, converting 58% or more of the added carbon as acetate and ethanol to butyrate, butanol, and hexanoate. Semi-batch enrichment yielded hexanoate and octanoate as the most elongated products and microbial communities predominated by C. kluyveri and other Firmicutes genera not known to undergo chain elongation. Collectively, these results strongly suggest a niche for chain elongation in anaerobic soils that should not be overlooked in soil microbial ecology studies.

scholarly journals Dynamics of Methanotrophs during in situ Bioremediation

2001 ◽  
Vol 16 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Katsuji Tani ◽  
Tomotada Iwamoto ◽  
Kazuo Fujimoto ◽  
Masao Nasu
Keyword(s):  
In Situ Bioremediation
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