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

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.

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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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Phylogeography in an “oyster” shell provides first insights into the genetic structure of an extinct Ostrea edulis population

Scientific Reports ◽

10.1038/s41598-021-82020-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sarah Hayer ◽

Dirk Brandis ◽

Alexander Immel ◽

Julian Susat ◽

Montserrat Torres-Oliva ◽

...

Keyword(s):

Large Scale ◽

Wadden Sea ◽

Atlantic Coast ◽

Phylogenetic Reconstruction ◽

Oyster Shell ◽

Glacial Refugia ◽

Late Nineteenth Century ◽

Ostrea Edulis ◽

Geographic Ranges ◽

The North

AbstractThe historical phylogeography of Ostrea edulis was successfully depicted in its native range for the first time using ancient DNA methods on dry shells from museum collections. This research reconstructed the historical population structure of the European flat oyster across Europe in the 1870s—including the now extinct population in the Wadden Sea. In total, four haplogroups were identified with one haplogroup having a patchy distribution from the North Sea to the Atlantic coast of France. This irregular distribution could be the result of translocations. The other three haplogroups are restricted to narrow geographic ranges, which may indicate adaptation to local environmental conditions or geographical barriers to gene flow. The phylogenetic reconstruction of the four haplogroups suggests the signatures of glacial refugia and postglacial expansion. The comparison with present-day O. edulis populations revealed a temporally stable population genetic pattern over the past 150 years despite large-scale translocations. This historical phylogeographic reconstruction was able to discover an autochthonous population in the German and Danish Wadden Sea in the late nineteenth century, where O. edulis is extinct today. The genetic distinctiveness of a now-extinct population hints at a connection between the genetic background of O. edulis in the Wadden Sea and for its absence until today.

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Attapulgite and processed oyster shell powder effectively reduce cadmium accumulation in grains of rice growing in a contaminated acidic paddy field

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2020.111840 ◽

2021 ◽

Vol 209 ◽

pp. 111840

Author(s):

Lizhi He ◽

Jun Meng ◽

Yan Wang ◽

Xianjin Tang ◽

Xingmei Liu ◽

...

Keyword(s):

Paddy Field ◽

Oyster Shell ◽

Cadmium Accumulation ◽

Oyster Shell Powder ◽

Shell Powder

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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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Surface and Internalized Escherichia coli O157:H7 on Field-Grown Spinach and Lettuce Treated with Spray-Contaminated Irrigation Water

Journal of Food Protection ◽

10.4315/0362-028x-73.6.1023 ◽

2010 ◽

Vol 73 (6) ◽

pp. 1023-1029 ◽

Cited By ~ 122

Author(s):

MARILYN C. ERICKSON ◽

CATHY C. WEBB ◽

JUAN CARLOS DIAZ-PEREZ ◽

SHARAD C. PHATAK ◽

JOHN J. SILVOY ◽

...

Keyword(s):

Escherichia Coli ◽

Irrigation Water ◽

Enrichment Culture ◽

Field Studies ◽

Plate Count ◽

Escherichia Coli O157 ◽

Adaxial Side ◽

Abaxial Side ◽

E Coli ◽

Contaminated Irrigation Water

Numerous field studies have revealed that irrigation water can contaminate the surface of plants; however, the occurrence of pathogen internalization is unclear. This study was conducted to determine the sites of Escherichia coli O157:H7 contamination and its survival when the bacteria were applied through spray irrigation water to either field-grown spinach or lettuce. To differentiate internalized and surface populations, leaves were treated with a surface disinfectant wash before the tissue was ground for analysis of E. coli O157:H7 by direct plate count or enrichment culture. Irrigation water containing E. coli O157:H7 at 102, 104, or 106 CFU/ml was applied to spinach 48 and 69 days after transplantation of seedlings into fields. E. coli O157:H7 was initially detected after application on the surface of plants dosed at 104 CFU/ml (4 of 20 samples) and both on the surface (17 of 20 samples) and internally (5 of 20 samples) of plants dosed at 106 CFU/ml. Seven days postspraying, all spinach leaves tested negative for surface or internal contamination. In a subsequent study, irrigation water containing E. coli O157:H7 at 108 CFU/ml was sprayed onto either the abaxial (lower) or adaxial (upper) side of leaves of field-grown lettuce under sunny or shaded conditions. E. coli O157:H7 was detectable on the leaf surface 27 days postspraying, but survival was higher on leaves sprayed on the abaxial side than on leaves sprayed on the adaxial side. Internalization of E. coli O157:H7 into lettuce leaves also occurred with greater persistence in leaves sprayed on the abaxial side (up to 14 days) than in leaves sprayed on the adaxial side (2 days).

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