Death of Pseudomonas aeruginosa in soil

1982 ◽  
Vol 28 (7) ◽  
pp. 788-794 ◽  
Author(s):  
James M. Zechman ◽  
L. E. Casida Jr.
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Water Content ◽  
Pure Culture ◽  
Death Rate ◽  
Soil Microbes ◽  
Initial Rate ◽  
Resistant Form ◽  
Dry Soil ◽  
Short Time

When incubated in natural (nonsterilized) soil, Pseudomonas aeruginosa died initially at a rate which approximated the rate for starvation of a pure culture in buffer. Predation by other soil microbes or phage did not appear to be involved, and pycocyanin either was not produced or was ineffective. The initial rate of death was followed by a second, considerably slower rate. Cells initially added in low numbers to soil also underwent biphasic death as above. Slow drying of the soil caused a period of rapid death of P. aeruginosa, but this then slowed to give residual numbers and a death rate similar to the second death rate noted for soil not allowed to dry. The cells in the dry soil had not changed genetically to a desiccation-resistant form. Pseudomonas aeruginosa died out completely in a relatively short time when the soil was first quickly dried to a water content similar to that obtained initially through slow drying and then further allowed to dry slowly. These observations appear to point to a dormant form, in some ways resembling a cyst, for P. aeruginosa in soil.

Biodegradation of chlorophenols by immobilized pure-culture microorganisms

1996 ◽  
Vol 34 (10) ◽  
pp. 67-72 ◽  
Author(s):  
Lu Chih-Jen ◽  
Lee Chi-Mei ◽  
Huang Chiou-Zong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Putida ◽  
Pure Culture ◽  
The Other ◽  
Batch Reactors ◽  
Agrobacterium Radiobacter ◽  
Culture Cells ◽  
Lag Period

The biodegradation of phenol and chlorophenols by immobilized pure-culture cells was conducted by a series of batch reactors. The microorganisms used in this study were Pseudomonas putida, Psuedomonas testosteroni, Pseudomonas aeruginosa, and Agrobacterium radiobacter. All four species showed the ortho-cleavage pathway to metabolize chlorophenols. Among the four species, P. testosteroni, P. putida, and P. aeruginosa could effectively remove phenol at 200 mg/l. P. testosteroni could effectively remove 2-chlorophenol at 10mg/l. However, the other three species, P. putida, P. aeruginosa, and A. radiobacter, could not effectively remove 2-chlorophenol. Although 3-chlorophenol is a recalcitrant compound, P. testosteroni also could rapidly metabolize 3-chlorophenol at 10 mg/l. The removal of 4-chlorophenol at 10 mg/l by P. testosteroni reached 98% within one day. P. aeruginosa and A. radiobacter also could metabolize 4-chlorophenol after 2 and 7 days of lag period, respectively.

scholarly journals Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

2016 ◽  
Vol 82 (16) ◽  
pp. 5026-5038 ◽  
Author(s):  
Erick M. Bosire ◽  
Lars M. Blank ◽  
Miriam A. Rosenbaum
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Pure Culture ◽  
Bioelectrochemical Systems ◽  
Content Type ◽  
Mediated Electron Transfer ◽  
Phenazine Production ◽  
Model Strain

ABSTRACTPseudomonas aeruginosais an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions ofP. aeruginosawith fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency ofP. aeruginosain mediated current production is strongly dependent on the strain ofP. aeruginosa. We compared levels of phenazine production by the previously investigated model strainP. aeruginosaPA14, the alternative model strainP. aeruginosaPAO1, and the BES isolatePseudomonassp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2with ∼150 μg ml−1phenazine carboxylic acid as a redox mediator). Surprisingly,P. aeruginosaPAO1 showed very low phenazine production and electrochemical activity under all tested conditions.IMPORTANCEMicrobial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example,Pseudomonas aeruginosamight enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of threePseudomonasstrains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells.

scholarly journals Effects of soil water depletion on the water relations in tropical kudzu

1999 ◽  
Vol 34 (7) ◽  
pp. 1151-1157
Author(s):  
Adaucto Bellarmino de Pereira-Netto ◽  
Antonio Celso Novaes de Magalhães ◽  
Hilton Silveira Pinto
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Content ◽  
Soil Water ◽  
Cover Crop ◽  
Soil Water Depletion ◽  
Pueraria Phaseoloides ◽  
Water Depletion ◽  
Relative Water ◽  
Dry Soil

Tropical kudzu (Pueraria phaseoloides (Roxb.) Benth., Leguminosae: Faboideae) is native to the humid Southeastern Asia. Tropical kudzu has potential as a cover crop in regions subjected to dryness. The objective of this paper was to evaluate the effect of soil water depletion on leaflet relative water content (RWC), stomatal conductance (g) and temperature (T L) in tropical kudzu. RWC of waterstressed plants dropped from 96 to 78%, following a reduction in SWC from 0.25 to 0.17 g (H2O).g (dry soil)-1.Stomatal conductance of stressed plants decreased from 221 to 98 mmol.m-2.s-1, following the reduction in soil water content (SWC). The day after re-irrigation, g of water stressed plants was 15% lower than g of unstressed plants. Differences in T L between waterstressed and unstressed plants (deltaT L) rose linearly from 0.1 to 2.2ºC following progressive water deficit. RWC and T L of waterstressed plants paralled RWC and T L of unstressed plants the day after reirrigation. The strong decrease in SWC found in this study only induced moderate water stress in tropical kudzu. In addition, tropical kudzu recover rapidly from the induced water stress after the re-irrigation.

Soil solarisation combined with low rates of soil fumigants controls clubroot of cauliflowers, caused by Plasmodiophora brassicae Woron

1991 ◽  
Vol 31 (6) ◽  
pp. 843 ◽  
Author(s):  
IJ Porter ◽  
PR Merriman ◽  
PJ Keane
Keyword(s):  
Population Density ◽  
Water Content ◽  
Methyl Bromide ◽  
Plasmodiophora Brassicae ◽  
Moist Soil ◽  
Combined Treatments ◽  
Disease Rating ◽  
Dry Soil ◽  
Type Water ◽  
Soil Fumigants

The effect of solarisation combined with low rates of soil fumigants on the severity of clubroot and yield of cauliflowers was determined at 2 locations in southern Victoria. The effectiveness of treatments was shown to be dependent on location; on the type, water content and temperature of soil; and on the population density of Plasmodiophora brassicae. Yields were reduced depending upon the disease severity, usually within 60 days after transplanting. Propagules of P. brassicae could survive for more than 28 days in ovens at 45�C when in dry soil but died within 14 days at 40�C in moist soil. At Werribee in 1985 on a red brown earth, solarisation combined with dazomet (100 kg dazomet/ha) gave significantly better control than either treatment alone. This treatment reduced P. brassicae in the 0-10 cm layer, reduced the disease rating from 2.7 to 0.9 (0-3), and increased yield from 2.4 to 47 t/ha compared with controls. In 1986, solarisation combined with 98% methyl bromide-2% chloropicrin (100 and 250 kg/ha) reduced the population density of P. brassicae in the 0-10 and 10-20 cm layers of soil, reduced the disease rating from 3 to 1.8, and increased yield from 0 to 22 t/ha. These treatments were more effective than solarisation and dazomet used alone or in combination. At Keysborough in 1985 on a grey sand, separate treatments of solarisation or dazomet (100 and 250 kg dazometha) were as effective as combined treatments and significantly reduced disease and increased yields compared to controls. Solarisation combined with either fumigant significantly reduced the distribution and total number of weeds at all sites and was generally more effective than separate treatments.

Factors affecting colour removal from reactive dye bath by ozonation

2002 ◽  
Vol 45 (12) ◽  
pp. 261-270 ◽  
Author(s):  
I. Kabdaşlı ◽  
T. Ölmez ◽  
O. Tünay
Keyword(s):  
Initial Rate ◽  
Chelating Agent ◽  
Reactive Dye ◽  
Slight Effect ◽  
Colour Removal ◽  
Factors Affecting ◽  
Synthetic Dye ◽  
Ozone Dose ◽  
Short Time

A reactive dye bath sample containing a mixture of dyes was ozonated and colour removal was obtained in a relatively short time of 30 min at 605 mgl-1 of ozone utilisation. The factors affecting ozonation were assessed by comparing the results of dye bath and synthetic samples. Results from dye bath and synthetic dye solution ozonation were found to be significantly different. NaCl and Na2CO3 were determined to have a slight effect only on the initial rate of ozonation. However, the effect of the chelating agent in terms of both time and ozone dose was significant and explained the differences between the results of the dye bath and dye solution ozonation.

On the larval migration of some parasitic nematodes in the body of the host and its biological significance

1929 ◽  
Vol 7 (1) ◽  
pp. 15-26 ◽  
Author(s):  
F. Fülleborn
Keyword(s):  
Pure Culture ◽  
Subcutaneous Tissue ◽  
Biological Significance ◽  
Culture Method ◽  
The Body ◽  
Parasitic Nematodes ◽  
Healthy Skin ◽  
Suitable Host ◽  
Nematode Larvae ◽  
Short Time

As Looss has shown, the larvæ of Ancylostoma can infect a suitable host by penetrating the healthy skin. If we place the infective material on the surface of the skin, after a short time we find the larvæ in the subcutaneous tissue. The same behaviour is shown by the filariform larvæ of Strongyloides siercoralis, which provide more convenient material for examination, because they can be collected very easily in pure culture and free from fluid by the special culture-method described by me (1924), the principle of which depends on the well-known fact that the filariform larvæ of Strongyloides and other nematode larvæ, accumulate in the form of white filaments of several millimetres in length (fig. 3), each consisting of thousands of individual larvæ, on little prominences in their vicinity, all being guided to similar places by the same sets of “tropisms” (Fülleborn, 1924).

A comparison between ethanol and methanol as carbon sources for denitrification

1994 ◽  
Vol 30 (6) ◽  
pp. 83-90 ◽  
Author(s):  
Magnus Christensson ◽  
Ewa Lie ◽  
Thomas Welander
Keyword(s):  
Growth Rate ◽  
Carbon Source ◽  
Pure Culture ◽  
Carbon Sources ◽  
Culture Studies ◽  
Adaptation Time ◽  
Synthetic Media ◽  
Short Time

Ethanol and methanol were compared for their performance as carbon sources for denitrification. The study was carried out in two chemostats, operated in parallel on synthetic media containing ethanol and methanol respectively as carbon sources. In addition, pure culture studies were performed on one ethanol- and one methanol-utilizing denitrifier. Ethanol was found to be considerably more readily available as a carbon source for denitrification than was methanol. An efficient denitrification with ethanol was established in a short time, while denitrification with methanol required a substantial adaptation time and never showed the same stability as denitrification with ethanol. The growth rate of denitrifiers with ethanol as carbon source was 2–3 times higher than with methanol. The amount of COD required to denitrify a certain amount of nitrate was somewhat lower for ethanol (3.85 g/gN) than for methanol (4.45 g/gN) in the continuous experiments, while it was considerably higher for ethanol (6.1 g/gN) than for methanol (4.1 g/gN) in pure culture batch cultivations.

scholarly journals Post-drying of energy sorrel in a grate stock

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 15-22
Author(s):  
P. Hutla ◽  
J. Mazancová
Keyword(s):  
Water Content ◽  
Electric Energy ◽  
Energy Crop ◽  
Yield Potential ◽  
High Yield ◽  
Large Capacity ◽  
The Czech Republic ◽  
Time Switching ◽  
Operational Conditions ◽  
Short Time

Energy sorrel is a crop with high-yield potential and belongs among the most promissing energy crop for the Czech Republic. The suitable processing technology is harvest by the harvesting cutter with subsequent short-time storage and post-drying of chopped material in the large-capacity hayloft. For chopped sorrel were found-out hydraulic air losses during its passing through the stored layer and they were compared with values for stored forage. Two methods of drying ventilators controlling in the large-capacity heyloft were compared with the regime of time switching within chopped sorrel drying. Electric energy comsumption for ventilators drive in different regimes depends on water content in the material. Method of ventilators or time switching controlling has no effect on drying process result, thus even on water content reduction in the dried material. Under operational conditions the possibility of the chopped energy sorrel in large-capacity heyloft was verified.

scholarly journals Accelerated transformation of 1,3-dichloropropene in loamy soils.

1989 ◽  
Vol 37 (3) ◽  
pp. 173-183
Author(s):  
J.H. Smelt ◽  
W. Teunissen ◽  
S.J.H. Crum ◽  
M. Leistra
Keyword(s):  
Half Life ◽  
Time Lag ◽  
Transformation Rate ◽  
Nematode Control ◽  
Loamy Soil ◽  
First Order ◽  
Initial Content ◽  
Dry Soil ◽  
Pseudo First Order ◽  
Short Time

Inadequate nematode control on some loamy soils after fumigation with 1,3-dichloropropene prompted further study of transformation in these soils. The rate of transformation of (Z)- and (E)-1,3-dichloropropene was measured in moist soils incubated at 15 degrees C in fumigant-tight systems. In six loamy soils, transformation was gradual and pseudo first-order during 3 to 6 days but thereafter it was very fast. At an initial content in dry soil of 62-80 mg/kg the remaining amounts were less than 0.2% of the dose after a week. The greatly accelerated transformation after a short time lag suggests that the soils contained microorganisms that can transform 1,3-dichloropropene effectively. The fast transformation was measured in soil from fields once or twice fumigated previously as well as from fields never treated. In one of these loamy soils, a fast transformation (less than 0.2% remaining after 7 days) was measured at initial contents of 3.7, 18 and 92 mg/kg. But when the initial content was 470 mg/kg, the transformation rate was markedly suppressed (half-life 33 days). In another loamy soil, which showed no accelerated transformation patterns, the pseudo half-lives substantially increased from 4.3 to 36 days when the initial content of 1,3-dichloropropene was raised from 3.7 to 470 mg/kg. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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