Simultaneous growth and poly(3-hydroxybutyrate) (PHB) accumulation in a Plasticicumulans acidivorans dominated enrichment culture

Since 1975, different patterns of the growth of Fragilaria and Cyanobacteria in the mid or late summer have been observed in the Saidenbach Reservoir. In most of the years, there was a mutual exclusion of mass growths of these two groups. High yields of Fragilaria caused low yields of blue-greens and vice versa. In the first years, Fragilaria was always the first to achieve a mass growth, followed by the Cyanobacteria. Then, in the last years, the blue-greens were succeeded by Fragilaria. Only in some years, there was a large and simultaneous growth of both groups. It has been shown, that the supply of silicon and phosphorus immediately before controlled the pattern of succession in the midsummer period. Mostly, the Si:P ratio was the regulating factor, but there were also years in which the absolute concentration level of these two nutrients were either non-limiting high or below the minimum resource concentration necessary to compensate for the losses. In these cases, the Si:P ratio lost its controlling function. Other influencing factors are discussed, in particular the effect of turbulent mixing. The special nutrient conditions in the midsummer were not only determined by the external load but also by the Si depletion during the spring mass development of diatoms other than Fragilaria, which mostly is physically controlled. Therefore, the succession pattern in the midsummer is sensitive to the meteorological conditions to a large extent.

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Enrichment and characterization of an anaerobic methyl ethyl ketoxime degrading culture from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor

Water Science & Technology ◽

10.2166/wst.1998.0590 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 95-98 ◽

Cited By ~ 1

Author(s):

Nancy G. Love ◽

Mary E. Rust ◽

Kathy C. Terlesky

Keyword(s):

Energy Source ◽

Activated Sludge ◽

Electron Acceptor ◽

Sequencing Batch Reactor ◽

Enrichment Culture ◽

Batch Reactor ◽

Nitrification Inhibitor ◽

Time Frame ◽

Methyl Ethyl

An anaerobic enrichment culture was developed from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor using methyl ethyl ketoxime (MEKO), a potent nitrification inhibitor, as the sole carbon and energy source in the absence of molecular oxygen and nitrate. The enrichment culture was gradually fed decreasing amounts of biogenic organic compounds and increasing concentrations of MEKO over 23 days until the cultures metabolized the oxime as the sole carbon source; the cultures were maintained for an additional 41 days on MEKO alone. Turbidity stabilized at approximately 100 mg/l total suspended solids. Growth on selective media plates confirmed that the microorganisms were utilizing the MEKO as the sole carbon and energy source. The time frame required for growth indicated that the kinetics for MEKO degradation are slow. A batch test indicated that dissolved organic carbon decreased at a rate comparable to MEKO consumption, while sulfate was not consumed. The nature of the electron acceptor in anaerobic MEKO metabolism is unclear, but it is hypothesized that the MEKO is hydrolyzed intracellularly to form methyl ethyl ketone and hydroxylamine which serve as electron donor and electron acceptor, respectively.

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Biotransformation of nitrocellulose under methanogenic conditions

Water Science & Technology ◽

10.2166/wst.1996.0567 ◽

1996 ◽

Vol 34 (5-6) ◽

pp. 327-334 ◽

Cited By ~ 2

Author(s):

David L. Freedman ◽

Bryan M. Caenepeel ◽

Byung J. Kim

Keyword(s):

Biological Treatment ◽

Enrichment Culture ◽

Basal Medium ◽

Anaerobic Biodegradation ◽

Anaerobic Treatment ◽

Acid Digestion ◽

Energetic Compounds ◽

Nitrate Ester ◽

Digestion Technique ◽

Aerobic And Anaerobic

Treatment of wastewater containing nitrocellulose (NC) fines is a significant hazardous waste problem currently facing manufacturers of energetic compounds. Previous studies have ruled out the use of biological treatment, since NC has appeared to be resistant to aerobic and anaerobic biodegradation. The objective of this study was to examine NC biotransformation in a mixed methanogenic enrichment culture. A modified cold-acid digestion technique was used to measure the percentage of oxidized nitrogen (N) remaining on the NC. After 11 days of incubation in cultures amended with NC (10 g/L) and methanol (9.9 mM), the % N (w/w) on the NC decreased from 13.3% to 10.1%. The presence of NC also caused a 16% reduction in methane output. Assuming the nitrate ester on NC was reduced to N2, the decrease in CH4 represented almost exactly the amount of reducing equivalents needed for the observed decrease in oxidized N. An increase in the heat of combustion of the transformed NC correlated with the decrease in % N. There was no statistically significant decrease in % N when only NC was added to the culture, or in controls that contained only the sulfide-reduced basal medium. The biotransformed NC has a % N comparable to nonexplosive nitrated celluloses, suggesting that anaerobic treatment may be a technically feasible process for rendering NC nonhazardous.

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Salmonella Persistence within the Peripheral Lymph Nodes of Cattle following Experimental Inoculation

Journal of Food Protection ◽

10.4315/0362-028x.jfp-15-325 ◽

2016 ◽

Vol 79 (6) ◽

pp. 1032-1035 ◽

Cited By ~ 6

Author(s):

T. S. EDRINGTON ◽

G. H. LONERAGAN ◽

K. J. GENOVESE ◽

D. L. HANSON ◽

D. J. NISBET

Keyword(s):

Body Weight ◽

Lymph Node ◽

Lymph Nodes ◽

Enrichment Culture ◽

Lower Leg ◽

Challenge Strain ◽

Peripheral Lymph ◽

Experimental Inoculation ◽

Duration Of Infection

ABSTRACT Utilizing a transdermal method of inoculation developed in our laboratory, the duration of infection of Salmonella in the peripheral lymph nodes of steers was examined. Thirty-six Holstein steers (mean body weight of 137 kg) were inoculated with Salmonella Montevideo (day 0) on each lower leg and both sides of the back and abdomen. Calves were euthanized beginning at 6 h and subsequently on each of days 1, 2, 4, 7, 9, 11, 14, and 21 postinoculation (four animals each time). The subiliac, popliteal, and superficial cervical (prescapular) lymph nodes were collected and cultured (quantitatively and qualitatively) for the challenge strain of Salmonella. The challenge strain was detected via direct culture within the lymph nodes at 6 h postinoculation and on each subsequent necropsy date. Salmonella levels in lymph node were 0.8 to 1.8 log CFU/g. Lymph nodes were generally positive after enrichment culture throughout the experiment. Salmonella elimination appeared to begin approximately 14 days postinoculation. However, elimination was not completed by day 21; therefore, a second experiment was conducted identical to the first except that the time from inoculation to necropsy was extended. Salmonella was recovered via direct culture on each of the necropsy days, and results in general were similar to those of experiment I, except that on days 20, 24, and 28 isolates from serogroups C2 and E1 were identified in addition to the inoculation strain C1 in multiple animals. The data from both experiments indicate that after a single inoculation event, Salmonella would be completely cleared by approximately 28 days. Further research with expanded times between inoculation and necropsy is required for verification.

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Accelerated adsorption of tetracyclines and microbes with FeOn(OH)m modified oyster shell: its application on biotransformation of oxytetracycline in anaerobic enrichment culture

Chemical Engineering Journal ◽

10.1016/j.cej.2021.130499 ◽

2021 ◽

pp. 130499

Author(s):

Shujuan Lian ◽

Xiaoshuang Shi ◽

Mingyi Lu ◽

Mengdan Zhang ◽

Xiaohuan Dong ◽

...

Keyword(s):

Enrichment Culture ◽

Oyster Shell

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Identifying Hidden Viable Bacterial Taxa in Tropical Forest Soils Using Amplicon Sequencing of Enrichment Cultures

Biology ◽

10.3390/biology10070569 ◽

2021 ◽

Vol 10 (7) ◽

pp. 569

Author(s):

Chakriya Sansupa ◽

Sara Fareed Mohamed Wahdan ◽

Terd Disayathanoowat ◽

Witoon Purahong

Keyword(s):

Bacterial Community ◽

Forest Soil ◽

Culture Media ◽

Enrichment Culture ◽

Sequence Similarity ◽

Illumina Miseq ◽

Amplicon Sequencing ◽

Soil Samples ◽

Enrichment Cultures ◽

Total Community

This study aims to estimate the proportion and diversity of soil bacteria derived from eDNA-based and culture-based methods. Specifically, we used Illumina Miseq to sequence and characterize the bacterial communities from (i) DNA extracted directly from forest soil and (ii) DNA extracted from a mixture of bacterial colonies obtained by enrichment cultures on agar plates of the same forest soil samples. The amplicon sequencing of enrichment cultures allowed us to rapidly screen a culturable community in an environmental sample. In comparison with an eDNA community (based on a 97% sequence similarity threshold), the fact that enrichment cultures could capture both rare and abundant bacterial taxa in forest soil samples was demonstrated. Enrichment culture and eDNA communities shared 2% of OTUs detected in total community, whereas 88% of enrichment cultures community (15% of total community) could not be detected by eDNA. The enrichment culture-based methods observed 17% of the bacteria in total community. FAPROTAX functional prediction showed that the rare and unique taxa, which were detected with the enrichment cultures, have potential to perform important functions in soil systems. We suggest that enrichment culture-based amplicon sequencing could be a beneficial approach to evaluate a cultured bacterial community. Combining this approach together with the eDNA method could provide more comprehensive information of a bacterial community. We expected that more unique cultured taxa could be detected if further studies used both selective and non-selective culture media to enrich bacteria at the first step.

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