scholarly journals Ammonium Cycling and Nitrification Stimulation during Oil Sludge Remediation by Gram-Positive Bacteria Lysinibacillus sphaericus Using Red Wiggler Earthworm Eisenia fetida

2020 ◽  
Vol 2 (4) ◽  
pp. 544-555
Author(s):  
Juan Diego Acevedo ◽  
Jenny Dussán
Keyword(s):  
Oil Sludge ◽  
Nitrifying Bacteria ◽  
Ammonium Concentration ◽  
Bacterial Populations ◽  
Lysinibacillus Sphaericus ◽  
Gram Positive Bacteria ◽  
Dna And Rna ◽  
Oil Biodegradation ◽  
Colony Forming Units ◽  
Soil Enhancement

The performance of a mixture between L. sphaericus and E. fetida was evaluated for ammonium cycling and nitrifying bacteria stimulation during oil sludge remediation. The addition of E. fetida significantly increased ammonium concentration (p = 0.0218) and total Colony-forming units (CFU) count p = 0.02848). However, oil sludge with worms and L. sphaericus reached lower ammonium concentrations and CFU counts than sludge with worms alone. Sludge inoculated only with L. sphaericus presented higher ammonium concentration than sludge without inoculum, but the bacterial population reached a lower density during the final days. Final DNA and RNA extractions from all treatments amplified for L. sphaericus putative amoA and Gram-negative nitrifying bacteria amoA genes correlated with diminished ammonium concentrations during the final days of the experiment. Final RNA extractions for L. sphaericus amplified for Molybdenum transporter gene suggesting possible nitrogen fixation by L. sphaericus. The addition of Red Wiggler Earthworm to oil sludge remediation systems may provide better conditions for bacterial populations to carry out hydrocarbon degradation. The addition of E. fetida to a L. sphaericus crude oil biodegradation system may improve soil ammonium concentrations and nitrifying activity, and this could be crucial in oil sludge remediation because of bacterial inhibition due to high C:N ratios. The final product of this process may be used for soil enhancement due to its richness in nutrients and beneficial bacterial populations.

scholarly journals Antimicrobial Activity and Mode of Action of Celastrol, a Nortriterpen Quinone Isolated from Natural Sources

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 591
Author(s):  
Nayely Padilla-Montaño ◽  
Leandro de León Guerra ◽  
Laila Moujir
Keyword(s):  
Antimicrobial Activity ◽  
Cytoplasmic Membrane ◽  
Bactericidal Effect ◽  
Inoculum Size ◽  
Bacterial Populations ◽  
Gram Positive Bacteria ◽  
Dna And Rna ◽  
Dna And Rna Synthesis ◽  
Natural Derivative ◽  
Interesting Alternative

Species of the Celastraceae family are traditionally consumed in different world regions for their stimulating properties. Celastrol, a triterpene methylene quinone isolated from plants of celastraceas, specifically activates satiety centers in the brain that play an important role in controlling body weight. In this work, the antimicrobial activity and mechanism of action of celastrol and a natural derivative, pristimerin, were investigated in Bacillus subtilis. Celastrol showed a higher antimicrobial activity compared with pristimerin, being active against Gram-positive bacteria with minimum inhibitory concentrations (MICs) that ranged between 0.16 and 2.5 µg/mL. Killing curves displayed a bactericidal effect that was dependent on the inoculum size. Monitoring of macromolecular synthesis in bacterial populations treated with these compounds revealed inhibition in the incorporation of all radiolabeled precursors, but not simultaneously. Celastrol at 3 µg/mL and pristimerin at 10 µg/mL affected DNA and RNA synthesis first, followed by protein synthesis, although the inhibitory action on the uptake of radiolabeled precursors was more dramatic with celastrol. This compound also caused cytoplasmic membrane disruption observed by potassium leakage and formation of mesosome-like structures. The inhibition of oxygen consumption of whole and disrupted cells after treatments with both quinones indicates damage in the cellular structure, suggesting the cytoplasmic membrane as a potential target. These findings indicate that celastrol could be considered as an interesting alternative to control outbreaks caused by spore-forming bacteria.

scholarly journals PSIX-18 Laurate and its glycerol monoester, monolaurin, as potential additives to control Listeria monocytogenes and tetracycline resistant Enterococcus faecalis in air-exposed silage

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 414-415
Author(s):  
Yamicela Castillo-Castillo ◽  
Marina Ontiveros ◽  
Eric J Scholljegerdes ◽  
Robin Anderson ◽  
Claudio Arzola-Alvarez ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Enterococcus Faecalis ◽  
Brain Heart Infusion ◽  
Bactericidal Effect ◽  
Complete Elimination ◽  
Gram Positive Bacteria ◽  
Viable Cells ◽  
Colony Forming Units ◽  
Feed Value ◽  
Risk Infection

Abstract Silages can harbor pathogenic and antimicrobial resistant microbes which risk infection of food-producing animals. Livestock producers need effective yet environmentally friendly interventions to preserve the feed value of these fermented materials. Medium chain fatty acids such as laurate and its glycerol monoester, monolaurin, are potent inhibitors of many Gram-positive bacteria and when tested at 5 mg/mL in anaerobic cultures (n = 3/treatment) inoculated with 105 colony forming units (CFU) of Listeria monocytogenes and grown at 37oC in ½ strength Brain Heart infusion broth achieved near complete elimination of viable cells after 6 h compared to a 2.2 ± 0.1 log10 CFU/mL increase observed in controls. Culture of a tetracycline-resistant Enterococcus faecalis with 5 mg laurate/mL likewise achieved near complete elimination of viable cells (5 log10 CFU/mL) by 6 h incubation. The bactericidal effect of 5 mg monolaurin was less against E. faecalis, achieving a decrease of 1.8 ± 0.2 log10 CFU/mL and not decreased further after 24 h. When tested against air-exposed silage, pH 7.53 (4 g), mixed with 4 mL water, 5 mg laurate or monolaurin decreased viability of experimentally-inoculated L. monocytogenes (105 CFU/g silage) more (P < 0.05) than untreated controls after 24 h aerobic incubation (22oC), with viable counts being decreased 6.3 ± 0.1, 5.9 ± 0.8 and 4.5 ± 0.1 log10 CFU/g, respectively. In contrast, viable recovery of the experimentally-inoculated (105 CFU/g) tetracycline-resistant E. faecalis was reduced more (P < 0.05) than controls (decreased 0.7 ± 0.1 log10 CFU/g) after 6 h incubation when similarly tested with laurate and monolaurin (1.7 ± 0.5 and 3.0 ± 0.9 log10 CFU/g, respectively) but counts after 24 h were similar, decreasing on average 2.0 ± 0.5 log10 CFU/g). Results indicate laurate and monolaurin may be useful in killing L. monocytogenes and tetracycline-resistant E. faecalis during silage feed-out.

scholarly journals Antibacterial Activity of Prismatomeris tetrandra K. Schum Root Extract against Antibiotic Resistance Bacteria

2018 ◽  
Vol 16 (5) ◽  
pp. 341-348
Author(s):  
On-Anong SOMSAP
Keyword(s):  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Culture Broth ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Root Extract ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Colony Forming Units

Antibiotic resistance bacteria has become an increasing problem now today due to many factors. This study investigates the efficacy of Prismatomeris tetrandra K. Schum root extract as a new source of antibacterial activity for antibiotic resistant bacteria using agar well diffusion method. The results showed that S. aureus TISTR517 exhibited more sensitivity to P. tetrandra K. Schum root extract than other Gram-positive bacteria indicator strains. On the other hand, Gram-negative bacteria exhibited resistance to P. tetrandra K. Schum root extract. The study further showed the activity between P. tetrandra K. Schum root extract and gentamycin (10 µg), it revealed that MRSA142 was resistant to gentamycin (10µg) but sensitive to P. tetrandra K. Schum root extract. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was evaluated by using S. aureus TISTR517 and MRSA142 as indicator strains. The MIC value was 0.59 mg/mL and 1.17 mg/mL for S. aureus TISTR517 and MRSA142, respectively. MBC assay demonstrated that the MBC value was 9.75 mg/mL and 150 mg/mL for S. aureus TISTR517 and MRSA142 respectively. The mode of action was investigated with the presence of P. tetrandra K. Schum root extract in the culture broth. The action of P. tetrandra K. Schum root extract was revealed of bacteriostatic activity due to the Optical density (OD) at 600 nm and Colony-Forming Units (CFU) of indicator strains were continuously decreased.

Characterization of microbial communities in exhaust air treatment systems of large-scale pig housing facilities

2010 ◽  
Vol 62 (7) ◽  
pp. 1551-1559 ◽  
Author(s):  
J. Haneke ◽  
N. M. Lee ◽  
T. W. Gaul ◽  
H. F. A. Van den Weghe
Keyword(s):  
Microbial Communities ◽  
Large Scale ◽  
Dust Particles ◽  
Nitrifying Bacteria ◽  
Ammonium Concentration ◽  
Nitrogen Compounds ◽  
Air Treatment ◽  
Fattening Period ◽  
Washing Water ◽  
Housing Facilities

Exhaust air treatment has gained importance as an essential factor in intensive livestock areas due to the rising emissions in the environment. Wet filter walls of multi-stage exhaust air treatment systems precipitate gaseous ammonia and dust particles from exhaust air in washing water. Microbial communities in the biomass developed in the washing water of five large-scale exhaust air treatment units of pig housing facilities, were investigated by fluorescence in situ hybridization (FISH) and 16S rDNA sequence analyses. No “standard” nitrifying bacteria were found in the washing water. Instead mainly α-Proteobacteria, aggregating β- and χ-Proteobacteria, a large number of Actinobacteria, as well as individual Planctomycetales and Crenarchaeota were detected after more than twelve months' operation. The main Proteobacteria species present were affiliated to the families Alcaligenaceae, Comamonadaceae and Xanthomonadaceae. Furthermore, we investigated the consumption of inorganic nitrogen compounds in the washing water of one exhaust air treatment unit during a fattening period with and without pH control. Maintaining the pH at 6.0 resulted in a ca. fivefold higher ammonium concentration and a ca. fourfold lower concentration of oxidized nitrogen compounds after the fattening period was finished.

Microbiological and Sensory Attributes of Retail Cuts of Beef Treated with Acetic and Lactic Acid Solutions

1994 ◽  
Vol 57 (8) ◽  
pp. 665-670 ◽  
Author(s):  
KATHRYN L. KOTULA ◽  
RAVINDRANATH THELAPPURATE
Keyword(s):  
Lactic Acid ◽  
Acid Treatment ◽  
Inhibitory Effect ◽  
Practical Significance ◽  
Bacterial Populations ◽  
E Coli ◽  
Microbial Inhibition ◽  
Colony Forming Units ◽  
Sensory Qualities ◽  
Retail Cuts

This research characterized the effect of 0.6 and 1.2% acetic and lactic acids applied for 20 and 120 s at a temperature of 1 to 2°C on total colony forming units (CFU) and Escherichia coli counts, and sensory qualities including shear value, expressible moisture, color and sensory panel of retail cuts of beef rib steaks. Microbial inhibition was directly proportional to the concentration and times of treatment with a 1.2% acid treatment for 120 s being the most effective treatment for reducing microbial counts, for both acids. Although there were significant reductions (p <0.05) in bacterial populations, these reductions which had a maximum of 2.0 log, were of questionable practical significance. The inhibitory effect of the acids decreased with storage time, up to 9 days. Treatment with both the acids resulted in paler meat (p <0.05) than the non-treated control. There were no significant differences (p >0.05) in shear values or expressible moisture due to acid treatment. Sensory panels reported only small differences between the samples. These results indicate that an aqueous acetic or lactic acid treatment of retail beef reduced total CFU and E. coli numbers immediately after treatment, but the magnitude was less than 1 log. However, a residual influence was observed so that after 3 and 9 days both acid treatments inhibited total CPU and E. coli growth by up to 2 logs compared with the non-treated control samples.

scholarly journals Assessment of airborne particles and bioaerosols concentrations in a waste recycling environment in Brazil

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Caroline Fernanda Hei Wikuats ◽  
Eduardo Henrique Duarte ◽  
Kátia Valéria Marques Cardoso Prates ◽  
Laura Lahr Lourenço Janiaski ◽  
Bárbara de Oliveira Gabriel ◽  
...  
Keyword(s):  
Waste Recycling ◽  
Outdoor Environment ◽  
Exposure Limits ◽  
Mean Values ◽  
Air Contamination ◽  
Gram Positive Bacteria ◽  
Indoor Sources ◽  
Colony Forming Units ◽  
Materials Recycling ◽  
Bacteria And Fungi

Abstract This study aims to assess the concentrations of size-fractioned particle mass (PM1.0, PM2.5, PM4.0, PM10) and number (PNC0.3, PNC0.5, PNC1.0, PNC2.5), bacteria, and fungi in a Materials Recycling Facility (MRF) in Brazil. The measurements were performed inside the waste processing shed (P1) and in the outdoor environment (P2) during working days in winter and spring of 2017, and summer of 2019. A total of 2,400 min of PM, 1,440 min of PNC, and 216 samples of bioaerosols were collected in the morning and afternoon. P1 has the strongest air contamination with mean values of 475.5 ± 563.7 µg m−3 for PM10, 58.6 ± 36.0 cm−3 for PNC0.3, 1,088.8 ± 825.2 colony-forming units per cubic meter (CFU m−3) for bacteria, and 2,738.3 ± 1,381.3 CFU m−3 for fungi. The indoor/outdoor ratios indicated the large influence of indoor sources due to the activities performed inside P1 that promote the generation and resuspension of pollutants. Gram-positive bacteria dominated with 58.6% of indoor samples. Overall, our results show a critical indoor air quality situation in a Brazilian MRF, which may cause several health risks for waste pickers. Finally, we call attention to the lack of occupational exposure limits for bioaerosols in industrial workplaces and mainly in MRFs.

scholarly journals Effects of pH and Oxygen and Ammonium Concentrations on the Community Structure of Nitrifying Bacteria from Wastewater

1998 ◽  
Vol 64 (10) ◽  
pp. 3584-3590 ◽  
Author(s):  
Alenka Prinčič ◽  
Ivan Mahne ◽  
France Megušar ◽  
Eldor A. Paul ◽  
James M. Tiedje
Keyword(s):  
Community Structure ◽  
Fatty Acid ◽  
Starter Culture ◽  
Treatment Plant ◽  
Acid Methyl Ester ◽  
Ssu Rdna ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizer ◽  
Ammonium Concentration ◽  
Rdna Sequencing

ABSTRACT Shifts in nitrifying community structure and function in response to different ammonium concentrations (50, 500, 1,000, and 3,000 mg of N liter−1), pH values (pH 6.0, 7.0, and 8.2), and oxygen concentrations (1, 7, and 21%) were studied in experimental reactors inoculated with nitrifying bacteria from a wastewater treatment plant. The abilities of the communities selected for these conditions to regain their original structures after conditions were returned to the original conditions were also determined. Changes in nitrifying community structure were determined by performing an amplified ribosomal DNA (rDNA) restriction analysis of PCR products obtained with ammonia oxidizer-specific rDNA primers, by phylogenetic probing, by small-subunit (SSU) rDNA sequencing, and by performing a cellular fatty acid analysis. Digestion of ammonia-oxidizer SSU rDNA with five restriction enzymes showed that a high ammonium level resulted in a great community structure change that was reversible once the ammonium concentration was returned to its original level. The smaller changes in community structure brought about by the two pH extremes, however, were irreversible. Sequence analysis revealed that the highest ammonium environment stimulated growth of a nitrifier strain that exhibited 92.6% similarity in a partial SSU rRNA sequence to its nearest relative, Nitrosomonas eutropha C-91, although the PCR product did not hybridize with a general phylogenetic probe for ammonia oxidizers belonging to the β subgroup of the classProteobacteria. A principal-component analysis of fatty acid methyl ester data detected changes from the starter culture in all communities under the new selective conditions, but after the standard conditions were restored, all communities produced the original fatty acid profiles.

Population Reductions of Gram-Negative Pathogens Following Treatments with Nisin and Chelators under Various Conditions

1995 ◽  
Vol 58 (9) ◽  
pp. 977-983 ◽  
Author(s):  
CATHERINE N. CUTTER ◽  
GREGORY R. SIRAGUSA
Keyword(s):  
Divalent Cations ◽  
Escherichia Coli O157 ◽  
Gram Negative Bacteria ◽  
Bacterial Populations ◽  
Gram Negative ◽  
E Coli ◽  
Transmission Electron ◽  
Colony Forming Units ◽  
Citrate Phosphate

When used in combination with chelating agents (EDTA, EGTA, citrate, phosphate), the bacteriocin nisin is effective for reducing populations of gram-negative bacteria in vitro. This study examined parameters (buffers, temperature presence of divalent cations) that affect nisin inhibition of Escherichia coli O157:H7 and Salmonella typhimurium. Approximately 7 log10 colony-forming units (CFU) per ml of E. coli and S. typhimurium were treated in PBS or MOPS buffers containing 50 μg/ml of purified nisin, alone or in combination with 500 mM lactate, 100 mM citrate, 50 mM EDTA, and 1% (wt/vol) sodium hexametaphosphate (pH 7.0) at 37°C for 60 min or 5°C for 30 min. Surviving bacterial populations were compared to untreated controls (buffers without nisin). Data indicated that treatments with nisin in buffers resulted in reductions of 4.30 and 2.30 log10 CFU/ml of E. coli and S. typhimurium, respectively, as compared to untreated controls. Population reductions ranging from 2.29 to 5.49 log10 CFU/ml were observed when cells were treated with nisin and chelator combinations at either 37°C for 60 min or 5°C for 30 min. The addition of magnesium and calcium to buffers with nisin decreased inhibition. Data obtained from spectrophotometric experiments indicated that treatments were causing the release of cellular constituents. However, transmission electron microscopy (TEM) analyses were inconclusive, since cellular membranes did not appear to be disrupted.

Degradation of antifouling booster biocides in water

2005 ◽  
Vol 85 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Hiroya Harino ◽  
Masaaki Kitano ◽  
Yoshiaki Mori ◽  
Kazuhiko Mochida ◽  
Akira Kakuno ◽  
...  
Keyword(s):  
Detection Limit ◽  
Water Samples ◽  
Uv Light ◽  
Agar Plate ◽  
Estuarine Water ◽  
Bacterial Populations ◽  
Sunlight Irradiation ◽  
Irgarol 1051 ◽  
Colony Forming Units ◽  
Copper Pyrithione

The concentrations of booster compounds were surveyed in the port of Osaka, Japan. The concentrations of Sea-Nine 211, Diuron and Irgarol 1051 in water samples from the port of Osaka were in the ranges <0·30–0·55 ng l−1, 13–350 ng l−1, 1·3–77 ng l−1, respectively. Pyrithiones were not detected in water samples. The levels of Diuron and Irgarol 1051 in the port of Osaka were high in the mooring area for small and medium-hull vessels with poor flushing.Susceptibility of bacterial populations in estuarine water to antifouling biocides was studied. Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione dissolved in dimethyl sulfoxide (DMSO) were added to estuarine water and number of colony forming units (CFU) of bacteria in estuarine water was counted using R2A agar plate. The CFU was not decreased at the concentration less than 1·0 mg/l of Diuron, Irgarol 1051 and Copper pyrithione. However, CFU was decreased at 0·1 mg/l of Sea-Nine 211. Degradation of Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione by bacteria in estuarine water was studied using a die-away method. At an initial concentrations of 0·1 mg/l, observed half-lives of Sea-Nine 211 and Copper pyrithione were 10 and 20 days, respectively. In contrast, Diuron and Irgarol 1051 were degraded scarcely during 60 days of culture.Photodegradation of these booster biocides by sunlight and UV light were studied. Under UV, all biocides were below detection limit after one day of irradiation. Under sunlight, Copper pyrithiones were also below detection limits after one day. Drastic decrease of Sea-Nine 211 concentration was observed after one day. Diuron and Irgarol 1051 scarcely decreased during 17 days of sunlight irradiation.

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