Biodegradation of Chloromethane by Pseudomonas aeruginosa Strain NB1 under Nitrate-Reducing and Aerobic Conditions

ABSTRACT Pseudomonas aeruginosa strain NB1 uses chloromethane (CM) as its sole source of carbon and energy under nitrate-reducing and aerobic conditions. The observed yield of NB1 was 0.20 (±0.06) (mean ± standard deviation) and 0.28 (±0.01) mg of total suspended solids (TSS) mg of CM−1 under anoxic and aerobic conditions, respectively. The stoichiometry of nitrate consumption was 0.75 (±0.10) electron equivalents (eeq) of NO3 − per eeq of CM, which is consistent with the yield when it is expressed on an eeq basis. Nitrate was stoichiometrically converted to dinitrogen (0.51 ± 0.05 mol of N2 per mol of NO3 −). The stoichiometry of oxygen use with CM (0.85 ± 0.21 eeq of O2 per eeq of CM) was also consistent with the aerobic yield. Stoichiometric release of chloride and minimal accumulation of soluble metabolic products (measured as chemical oxygen demand) following CM consumption, under anoxic and aerobic conditions, indicated complete biodegradation of CM. Acetylene did not inhibit CM use under aerobic conditions, implying that a monooxygenase was not involved in initiating aerobic CM metabolism. Under anoxic conditions, the maximum specific CM utilization rate (k) for NB1 was 5.01 (±0.06) μmol of CM mg of TSS−1 day−1, the maximum specific growth rate (μmax) was 0.0506 day−1, and the Monod half-saturation coefficient (Ks ) was 0.067 (±0.004) μM. Under aerobic conditions, the values for k, μ max , and Ks were 10.7 (±0.11) μmol of CM mg of TSS−1 day−1, 0.145 day−1, and 0.93 (±0.042) μM, respectively, indicating that NB1 used CM faster under aerobic conditions. Strain NB1 also grew on methanol, ethanol, and acetate under denitrifying and aerobic conditions, but not on methane, formate, or dichloromethane.

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Characterization of an Isolate That Uses Vinyl Chloride as a Growth Substrate under Aerobic Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.66.8.3535-3542.2000 ◽

2000 ◽

Vol 66 (8) ◽

pp. 3535-3542 ◽

Cited By ~ 63

Author(s):

Matthew F. Verce ◽

Ricky L. Ulrich ◽

David L. Freedman

Keyword(s):

Vinyl Chloride ◽

Suspended Solids ◽

Specific Growth ◽

Enrichment Culture ◽

Initial Step ◽

Aerobic Biodegradation ◽

Utilization Rate ◽

Rrna Gene ◽

Donor Source

ABSTRACT An aerobic enrichment culture was developed by using vinyl chloride (VC) as the sole organic carbon and electron donor source. VC concentrations as high as 7.3 mM were biodegraded without apparent inhibition. VC use did not occur when nitrate was provided as the electron acceptor. A gram-negative, rod-shaped, motile isolate was obtained from the enrichment culture and identified based on biochemical characteristics and the sequence of its 16S rRNA gene asPseudomonas aeruginosa, designated strain MF1. The observed yield of MF1 when it was grown on VC was 0.20 mg of total suspended solids (TSS)/mg of VC. Ethene, acetate, glyoxylate, and glycolate also served as growth substrates, while ethane, chloroacetate, glycolaldehyde, and phenol did not. Stoichiometric release of chloride and minimal accumulation of soluble metabolites following VC consumption indicated that the predominant fate for VC is mineralization and incorporation into cell material. MF1 resumed consumption of VC after at least 24 days when none was provided, unlike various mycobacteria that lost their VC-degrading ability after brief periods in the absence of VC. When deprived of oxygen for 2.5 days, MF1 did not regain the ability to grow on VC, and a portion of the VC was transformed into VC-epoxide. Acetylene inhibited VC consumption by MF1, suggesting the involvement of a monooxygenase in the initial step of VC metabolism. The maximum specific VC utilization rate for MF1 was 0.41 μmol of VC/mg of TSS/day, the maximum specific growth rate was 0.0048/day, and the Monod half-saturation coefficient was 0.26 μM. A higher yield and faster kinetics occurred when MF1 grew on ethene. When grown on ethene, MF1 was able to switch to VC as a substrate without a lag. It therefore appears feasible to grow MF1 on a nontoxic substrate and then apply it to environments that do not exhibit a capacity for aerobic biodegradation of VC.

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REDUCTION OF TOTAL SUSPENDED SOLIDS AND CHEMICAL OXYGEN DEMAND FROM PALM OIL MILL EFFLUENTS USING THE ELECTROCOAGULATION PROCESS

Environmental Engineering and Management Journal ◽

10.30638/eemj.2015.307 ◽

2015 ◽

Vol 14 (12) ◽

pp. 2897-2903

Author(s):

Abdul Aziz Abdul Raman ◽

Firdaus Ghazali ◽

Shaliza Ibrahim ◽

Diya'uddeen Basheer Hasan

Keyword(s):

Chemical Oxygen Demand ◽

Palm Oil ◽

Suspended Solids ◽

Oxygen Demand ◽

Total Suspended Solids ◽

Electrocoagulation Process ◽

Palm Oil Mill

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Effects of Mucin, Haemoglobin and Collagen on the Maximum Specific Growth Rate, Biomass and Hydrolytic Enzyme Production ofPorphyromonas gingivalisin Continuous Culture

Microbial Ecology in Health and Disease ◽

10.3402/mehd.v4i5.7714 ◽

1991 ◽

Vol 4 (5) ◽

Author(s):

T. Minhas ◽

J. Greenman ◽

A. G. Schaffer

Keyword(s):

Growth Rate ◽

Specific Growth Rate ◽

Continuous Culture ◽

Enzyme Production ◽

Specific Growth ◽

Hydrolytic Enzyme ◽

Maximum Specific Growth Rate

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Aeration and Water Hyacinths in Waste Stabilization Ponds

Water Science & Technology ◽

10.2166/wst.1987.0155 ◽

1987 ◽

Vol 19 (12) ◽

pp. 265-271

Author(s):

P. R. Thomas ◽

H. O. Phelps

Keyword(s):

Biochemical Oxygen Demand ◽

Suspended Solids ◽

Oxygen Demand ◽

Total Suspended Solids ◽

Substantial Improvement ◽

Additional Treatment ◽

Coliform Bacteria ◽

Effluent Quality ◽

Stabilization Ponds ◽

Water Hyacinths

The investigation was based on two facultative stabilization ponds initially designed to operate in parallel, and now receive wastewater in excess of their capacities from a fast expanding housing estate in the Caribbean Island of Trinidad. Because of the deterioration of the effluent quality relative to acceptable standards, an attempt was made to upgrade the ponds using water hyacinths at the early stages. However, from the results, it was clear that the introduction of water hyacinths in the test pond did not lead to any substantial improvement in the effluent because of the high loading on the pond. Therefore the ponds were modified to operate in series with surface aerators installed in the first pond. Initially, the effluent quality was monitored in terms of total suspended solids, volatile suspended solids, biochemical oxygen demand, faecal coliform bacteria, pH and dissolved oxygen with aeration in the first pond and no aquatic plants in the second pond. Although there was a significant improvement in the effluent quality, the values remained above the standards. As a result, water hyacinths were introduced in the second pond and the effluent quality monitored together with aeration in the first pond. The effluent quality improved with total suspended solids and biochemical oxygen demand values both as low as 10 mg/l in certain months, but additional treatment was needed to reduce faecal conforms.

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Management of Dairy Waste in the Sonoran Desert Using Constructed Wetland Technology

Water Science & Technology ◽

10.2166/wst.1999.0136 ◽

1999 ◽

Vol 40 (3) ◽

pp. 57-65 ◽

Cited By ~ 6

Author(s):

Martin M. Karpiscak ◽

Robert J. Freitas ◽

Charles P. Gerba ◽

Luis R. Sanchez ◽

Eylon Shamir

Keyword(s):

Sonoran Desert ◽

Suspended Solids ◽

Waste Treatment ◽

Oxygen Demand ◽

Dairy Wastewater ◽

Chemical Parameters ◽

Treatment Facility ◽

Physical Chemical ◽

Scirpus Validus ◽

Surface Wetland

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.

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CONTINUOUS CULTURE OF BRUCELLA ABORTUS S.19

Canadian Journal of Microbiology ◽

10.1139/m61-059 ◽

1961 ◽

Vol 7 (4) ◽

pp. 491-505 ◽

Cited By ~ 12

Author(s):

Andreas H. W. Hauschild ◽

Hilliard Pivnick

Keyword(s):

Growth Rate ◽

Continuous Culture ◽

Dilution Rate ◽

Brucella Abortus ◽

Specific Growth ◽

Limiting Factor ◽

Continuous Growth ◽

Viable Cells ◽

Metabolic Products ◽

Growth Of Bacteria

An apparatus is described for the continuous growth of bacteria. Brucella abortus S.19 has been grown in continuous culture for periods up to 3 weeks with populations up to 2 × 1011viable cells per ml and without the establishment of nonsmooth variants.Concentrations between 3 × 109and 2 × 1011cells per ml could be maintained as a function of the dilution rate without the requirement of a known limiting factor in the medium. In a series of steady-state conditions, the specific growth rate increased steadily up to 0.28 hour−1with decreasing population levels.Incidence of mutants was governed by the dilution rate and could also be reduced by various chelating substances.In continuous growth combined with continuous dialysis, population levels were approximately twice those obtained in continuous growth without dialysis. The effect of dialysis appears to be the continuous removal of growth-limiting metabolic products.

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Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

Water Practice & Technology ◽

10.2166/wpt.2012.016 ◽

2012 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

S. S. Fatima ◽

S. Jamal Khan

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plant ◽

Suspended Solids ◽

Treatment Plant ◽

Oxygen Demand ◽

Full Scale ◽

Operational Parameter ◽

Mixed Liquor ◽

Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

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