scholarly journals Microbial growth in biobeds for treatment of residual pesticide in banana plantations

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12200
Author(s):  
Verónica I. Domínguez-Rodríguez ◽  
Eduardo Baltierra-Trejo ◽  
Rodolfo Gómez-Cruz ◽  
Randy H. Adams
Keyword(s):  
Rural Communities ◽  
Microbial Activity ◽  
Degradation Process ◽  
Exchange Capacity ◽  
Microbial Populations ◽  
Bacterial Cells ◽  
Total Recovery ◽  
Banana Production ◽  
Cell Counts ◽  
Banana Stem

Background High doses of ethylenebisdithiocarbamate (EBDC) are used in banana production, and unused pesticide mixture (solution) is often disposed of improperly. This can result in soil and water contamination and present an undue risk to rural communities and the environment. An alternative to reduce the environmental impacts caused by pesticide residues is the biobeds treatment. It is necessary to establish if the composition of the proposed biomixtures supports microbial activity to degrade pesticides in biobeds. This research aimed to evaluate the EBDC effect on the distribution and abundance of microbial populations in polluted biomixtures . Methods For this purpose, a biomixture based on banana stem, mulch, and Fluvisol soil (50:25:25% v/v) was prepared and polluted with 1,000 mg L−1 EBDC. The response variables kinetics were determined every 14 days for three months, such as pH, organic matter, moisture, cation exchange capacity, microbial colonies, and cell counts at three depths within the experimental units. Results EBDC reduced the number of microbial colonies by 72%. Bacterial cells rapidly decreased by 69% and fungi 89% on the surface, while the decrease was gradual and steady at the middle and bottom of the biobed. The microbial populations stabilized at day 42, and the bacteria showed a total recovery on day 84, but the fungi slightly less. At the end of the experiment, the concentration of EBDC in the biomixture was 1.3–4.1 mg L−1. A correlation was found between fungal count (colonies and cells) with EBDC concentration. A replacement of the biomixture is suggested if the bacterial population becomes less than 40 × 106 CFU mL−1 and the fungal population less than 8 × 104 CFU mL−1 or if the direct cell count becomes lower than 50 × 104 cells mL−1 in bacteria and 8 × 102 cells mL−1 in fungi. Conclusion The biomixture based on banana stem supports the microbial activity necessary for the degradation of the EBDC pesticide. It was found that fungi could be used as indicators of the pollutant degradation process in the biomixtures. Microbial counts were useful to establish the mobility and degradation time of the pesticide and the effectiveness of the biomixture. Based on the results, it is appropriate to include the quantification of microbial populations to assess the effectiveness of pesticide degradation and the maturity level of the biomixture.

scholarly journals Analysis of Mechanisms Involved in the Cucumber mosaic virus Satellite RNA-mediated Transgenic Resistance in Tomato Plants

2004 ◽  
Vol 17 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Fabrizio Cillo ◽  
Mariella M. Finetti-Sialer ◽  
Maria A. Papanice ◽  
Donato Gallitelli
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
Resistance Mechanism ◽  
Degradation Process ◽  
Transgenic Tomato ◽  
Satellite Rna ◽  
Total Recovery ◽  
Tomato Plants ◽  
Free Strain

Transgenic tomato (Lycopersicon esculentum Mill. cv. UC82) plants expressing a benign variant of Cucumber mosaic virus satellite RNA (CMV Tfn-satRNA) were generated. The transformed plants did not produce symptoms when challenged with a satRNA-free strain of CMV (CMV-FL). The same plant lines initially were susceptible to necrosis elicited by a CMV strain supporting a necrogenic variant of satRNA (CMV-77), but a phenotype of total recovery from the necrosis was observed in the newly developing leaves. The features of the observed resistance were analyzed and are consistent with two different mechanisms of resistance. In transgenic plants inoculated with CMV-FL strain, the symptomless phenotype was correlated to the down-regulation of CMV by Tfn-satRNA, amplified from the transgene transcripts, as the first resistance mechanism. On the other hand, the delayed resistance to CMV-77 in transgenic tomato lines was mediated by a degradation process that targets satRNAs in a sequence-specific manner. Evidence is provided for a correlation between a reduced accumulation level of transgenic messenger Tfn-satRNA, the accumulation of small (approximately 23 nucleotides) RNAs with sequence homology to satRNAs, the progressively reduced accumulation of 77-satRNA in infected tissues, and the transition in infected plants from diseased to healthy. Thus, events leading to the degradation of satRNA sequences indicate a role for RNA silencing as the second mechanism determining resistance of transgenic tomato lines.

scholarly journals Potential Use of Silica Nanoparticles for the Microbial Stabilisation of Wine: An In Vitro Study Using Oenococcus oeni as a Model

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1338
Author(s):  
Kamila Pachnowska ◽  
Krzysztof Cendrowski ◽  
Xymena Stachurska ◽  
Paweł Nawrotek ◽  
Adrian Augustyniak ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Oenococcus Oeni ◽  
Chemical Oxidation ◽  
Alternative Methods ◽  
Bacterial Cells ◽  
Silica Nanospheres ◽  
Cell Counts ◽  
Transmission Electron ◽  
Phosphate Buffered Saline

The emerging trend towards the reduction of SO2 in winemaking has created a need to look for alternative methods to ensure the protection of wine against the growth of undesired species of microorganisms and to safely remove wine microorganisms. This study describes the possible application of silica nanospheres as a wine stabilisation agent, with Oenococcus oeni (DSM7008) as a model strain. The experiment was conducted firstly on model solutions of phosphate-buffered saline and 1% glucose. Their neutralising effect was tested under stirring with the addition of SiO2 (0.1, 0.25, and 0.5 mg/mL). Overall, the highest concentration of nanospheres under continuous stirring resulted in the greatest decrease in cell counts. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses showed extensive damage to the bacterial cells after stirring with silica nanomaterials. Then, the neutralising effect of 0.5 mg/mL SiO2 was tested in young red wine under stirring, where cell counts were reduced by over 50%. The obtained results suggest that silica nanospheres can serve as an alternative way to reduce or substitute the use of sulphur dioxide in the microbial stabilisation of wine. In addition, further aspects of following investigations should focus on the protection against enzymatic and chemical oxidation of wine.

scholarly journals Simultaneous Rapid Detection and Serotyping of Cronobacter sakazakii Serotypes O1, O2, and O3 by Using Specific Monoclonal Antibodies

2016 ◽  
Vol 82 (8) ◽  
pp. 2300-2311 ◽  
Author(s):  
Eva J. Scharinger ◽  
Richard Dietrich ◽  
Ina Kleinsteuber ◽  
Erwin Märtlbauer ◽  
Kristina Schauer
Keyword(s):  
Monoclonal Antibodies ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Powdered Infant Formula ◽  
Bacterial Cells ◽  
Cronobacter Sakazakii ◽  
Content Type ◽  
Cell Counts

ABSTRACTCronobacter sakazakiiis a foodborne pathogen associated with rare but often lethal infections in neonates. Powdered infant formula (PIF) represents the most frequent source of infection. Out of the identified serotypes (O1 to O7), O1, O2, and O3 are often isolated from clinical and PIF samples. Serotype-specific monoclonal antibodies (MAbs) suitable for application in enzyme immunoassays (EIAs) for the rapid detection ofC. sakazakiihave not yet been developed. In this study, we created specific MAbs with the ability to bind toC. sakazakiiof serotypes O1, O2, and O3. Characterization by indirect EIAs, immunofluorescence, motility assays, and immunoblotting identified lipopolysaccharide (LPS) and exopolysaccharide (EPS) as the antigenic determinants of the MAbs. The established sandwich EIAs were highly sensitive and were able to detect between 2 × 103and 9 × 106CFU/ml. Inclusivity tests confirmed that 93% of serotype O1 strains, 100% of O2 strains, and 87% of O3 strains were detected at low cell counts. No cross-reactivity with >100 strains ofCronobacterspp. and otherEnterobacteriaceaewas observed, except for that withC. sakazakiiserotype O3 andCronobactermuytjensiiserotype O1. Moreover, the sandwich EIAs detectedC. sakazakiiin PIF samples artificially contaminated with 1 to 10 bacterial cells per 10 g of sample after 15 h of preenrichment. The use of these serotype-specific MAbs not only allows the reliable detection ofC. sakazakiistrains but also enables simultaneous serotyping in a simple sandwich EIA method.

scholarly journals Development of a Rapid Assay for Determining the Relative Abundance of Bacteria

2005 ◽  
Vol 71 (12) ◽  
pp. 8481-8490 ◽  
Author(s):  
Arlene K. Rowan ◽  
Russell J. Davenport ◽  
Jason R. Snape ◽  
David Fearnside ◽  
Michael R. Barer ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Microbial Populations ◽  
Ammonia Oxidizing Bacteria ◽  
Bacterial Cells ◽  
Target Region ◽  
E Coli ◽  
Sandwich Hybridization ◽  
Sandwich Hybridization Assay ◽  
Rrna Sequences

ABSTRACT A sandwich hybridization assay for high-throughput, rapid, simple, and inexpensive quantification of specific microbial populations was evaluated. The assay is based on the hybridization of a target rRNA with differentially labeled capture and detector probes. Betaproteobacterial ammonia-oxidizing bacteria (AOB) were selected as the target group for the study, since they represent a phylogenetically coherent group of organisms that perform a well-defined geochemical function in natural and engineered environments. Reagent concentrations, probe combinations, and washing, blocking, and hybridization conditions were optimized to improve signal and reduce background. The detection limits for the optimized RNA assay were equivalent to approximately 103 to 104 and 104 to 105 bacterial cells, respectively, for E. coli rRNA and RNA extracted from activated sludge, by using probes targeting the majority of bacteria. Furthermore, the RNA assay had good specificity, permitted discrimination of rRNA sequences that differed by a 2-bp mismatch in the probe target region, and could distinguish the sizes of AOB populations in nitrifying and nonnitrifying wastewater treatment plants.

Microbial Populations in a 110 Ton-Scale Column for the Recovery of Metals from Black Schist Ores

2007 ◽  
Vol 20-21 ◽  
pp. 170-170 ◽  
Author(s):  
Kevin B. Hallberg ◽  
D. Barrie Johnson ◽  
Jörg Langwaldt ◽  
Catherine Joulian
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Large Scale ◽  
Sulfide Minerals ◽  
Total Cell ◽  
Microbial Populations ◽  
Low Grade ◽  
Cell Counts ◽  
Solid Media ◽  
One Year ◽  
Black Schist

Black schist ores in Finland are often enriched with sulfide minerals, containing a variety of base metals such as nickel, copper, zinc and cobalt. As these ores are low grade with respect to the metals contained and the sulfide minerals cannot be effectively concentrated from the schists, they are currently being studied with regard to their suitability for bioleaching [1]. As part of this investigation, a large-scale column measuring 3 x 3 x 9 m was built and filled with 110 tons of the crushed black schist ore. A solution was circulated in the column for 95 weeks; this solution was adjusted to 1.8 prior to entry in the column and averaged 2.7 when leaving the column. During this time, approximately 22% of Mn, 10% of Ni and 5% of Zn were leached from the ore. Iron was also leached, but precipitated in the column. Any soluble iron in the effluent was mainly Fe (II). During this same time period, total cell counts averaged 3.6 x 107 cells/ml of effluent. On three different occasions over nearly a one-year period, culturable cells were enumerated on a variety of solid media [2] and represented only about 1% of the total cell counts. Of the culturable cells, ironoxidizing acidophiles (namely Acidithiobacillus ferrooxidans) far outnumbered any other acidophile by at least a factor of ten. Changes in populations were also monitored by molecular means (T-RFLP and SSCP) on five different occasions during the same year; again, populations in early samples were dominated by Acidithiobacillus ferrooxidans (at least two strains/sub-species). As the temperature of the column was increased from ~20 to 35°C by heating both the recirculated liquor and the air used for column aeration, the relative abundance of At. ferrooxidans-like bacteria decreased while the abundance of unidentified bacteria increased. Some of these bacteria have also been detected in lab-scale column experiments using the same ore [3]. Total cell counts varied little as the temperature increased, nor was there any change in the rate of metal leaching. It was apparent that even though the leaching of metals from black schist ores was not greatly influenced by increases of temperature in the column, active microbial populations were present and were influenced by temperature.

scholarly journals Recent Advanced Technologies for the Characterization of Xenobiotic-Degrading Microorganisms and Microbial Communities

2021 ◽  
Vol 9 ◽  
Author(s):  
Sandhya Mishra ◽  
Ziqiu Lin ◽  
Shimei Pang ◽  
Wenping Zhang ◽  
Pankaj Bhatt ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Complex Mixture ◽  
Nitrogen Sources ◽  
Degradation Process ◽  
Microbial Populations ◽  
Novel Proteins ◽  
Catabolic Genes ◽  
Xenobiotic Compounds ◽  
Metabolic Activities

Global environmental contamination with a complex mixture of xenobiotics has become a major environmental issue worldwide. Many xenobiotic compounds severely impact the environment due to their high toxicity, prolonged persistence, and limited biodegradability. Microbial-assisted degradation of xenobiotic compounds is considered to be the most effective and beneficial approach. Microorganisms have remarkable catabolic potential, with genes, enzymes, and degradation pathways implicated in the process of biodegradation. A number of microbes, including Alcaligenes, Cellulosimicrobium, Microbacterium, Micrococcus, Methanospirillum, Aeromonas, Sphingobium, Flavobacterium, Rhodococcus, Aspergillus, Penecillium, Trichoderma, Streptomyces, Rhodotorula, Candida, and Aureobasidium, have been isolated and characterized, and have shown exceptional biodegradation potential for a variety of xenobiotic contaminants from soil/water environments. Microorganisms potentially utilize xenobiotic contaminants as carbon or nitrogen sources to sustain their growth and metabolic activities. Diverse microbial populations survive in harsh contaminated environments, exhibiting a significant biodegradation potential to degrade and transform pollutants. However, the study of such microbial populations requires a more advanced and multifaceted approach. Currently, multiple advanced approaches, including metagenomics, proteomics, transcriptomics, and metabolomics, are successfully employed for the characterization of pollutant-degrading microorganisms, their metabolic machinery, novel proteins, and catabolic genes involved in the degradation process. These technologies are highly sophisticated, and efficient for obtaining information about the genetic diversity and community structures of microorganisms. Advanced molecular technologies used for the characterization of complex microbial communities give an in-depth understanding of their structural and functional aspects, and help to resolve issues related to the biodegradation potential of microorganisms. This review article discusses the biodegradation potential of microorganisms and provides insights into recent advances and omics approaches employed for the specific characterization of xenobiotic-degrading microorganisms from contaminated environments.

scholarly journals Bactericidal Activity of ACH-702 against Nondividing and Biofilm Staphylococci

2012 ◽  
Vol 56 (7) ◽  
pp. 3812-3818 ◽  
Author(s):  
Steven D. Podos ◽  
Jane A. Thanassi ◽  
Melissa Leggio ◽  
Michael J. Pucci
Keyword(s):  
Protein Synthesis ◽  
Stationary Phase ◽  
Bactericidal Activity ◽  
Bacterial Infections ◽  
De Novo ◽  
Viable Cell ◽  
Bacterial Cells ◽  
Protein Synthesis Inhibitors ◽  
Content Type ◽  
Cell Counts

ABSTRACTMany bacterial infections involve slow or nondividing bacterial growth states and localized high cell densities. Antibiotics with demonstrated bactericidal activity rarely remain bactericidal at therapeutic concentrations under these conditions. The isothiazoloquinolone (ITQ) ACH-702 is a potent, bactericidal compound with activity against many antibiotic-resistant pathogens, including methicillin-resistantStaphylococcus aureus(MRSA). We evaluated its bactericidal activity under conditions where bacterial cells were not dividing and/or had slowed their growth. AgainstS. aureuscultures in stationary phase, ACH-702 showed concentration-dependent bactericidal activity and achieved a 3-log-unit reduction in viable cell counts within 6 h of treatment at ≥16× MIC values; in comparison, the bactericidal quinolone moxifloxacin and the additional comparator compounds vancomycin, linezolid, and rifampin at 16× to 32× MICs showed little or no bactericidal activity against stationary-phase cells. ACH-702 at 32× MIC retained bactericidal activity against stationary-phaseS. aureusacross a range of inoculum densities. ACH-702 did not kill cold-arrested cells yet remained bactericidal against cells arrested by protein synthesis inhibitors, suggesting that its bactericidal activity against nondividing cells requires active metabolism but notde novoprotein synthesis. ACH-702 also showed a degree of bactericidal activity at 16× MIC againstS. epidermidisbiofilm cells that was superior to that of moxifloxacin, rifampin, and vancomycin. The bactericidal activity of ACH-702 against stationary-phase staphylococci and biofilms suggests potential clinical utility in infections containing cells in these physiological states.

Improved bioluminescent assay of somatic cell counts in raw milk

2008 ◽  
Vol 75 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Valery G Frundzhyan ◽  
Inna M Parkhomenko ◽  
Lubov Y Brovko ◽  
Natalia N Ugarova
Keyword(s):  
Somatic Cell ◽  
Somatic Cells ◽  
Raw Milk ◽  
Superior Performance ◽  
Bacterial Cells ◽  
Bioluminescent Assay ◽  
Direct Microscopy ◽  
Cell Counts ◽  
Simple Protocol

Somatic cell count (SCC) in milk is considered to be a valuable indicator of cow mastitis. For assessment of SCC in milk, the bioluminescent assay based on determination of ATP from somatic cells ([ATPsom]) in milk was proposed earlier. However, this assay is still not widely used in practice owing to lower reliability compared with conventional methods such as direct microscopy and flow cytometry. We revised the bioluminescent SCC assay and developed a simple protocol based on determination of the total non-bacterial ATP concentration in milk. It was shown that the novel ATP-releasing agent Neonol-10 (oxy-ethylated iso-nonyl phenol) has superior performance providing 100% lysis of somatic cells while not disrupting bacterial cells of milk at a concentration of 1·5% w/w. There was high correlation (R2=0·99) between measured bioluminescence and SCC as measured by direct microscopy. The observed detection limit of the bioluminescent milk SCC assay was as low as 900 cell/ml, time of analysis was 2–3 min per sample. The proposed method has high potential for on-site mastitis diagnostics.

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