scholarly journals Electrochemical Bacterial Enrichment from Natural Seawater and Its Implications in Biocorrosion of Stainless-Steel Electrodes

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2327
Author(s):  
María José De La Fuente ◽  
Leslie K. Daille ◽  
Rodrigo De la Iglesia ◽  
Magdalena Walczak ◽  
Francisco Armijo ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Bacterial Community ◽  
Community Analysis ◽  
Rrna Gene ◽  
Natural Seawater ◽  
Bacterial Enrichment ◽  
Significant Difference ◽  
Significant Enrichment ◽  
The Impact ◽  
Steel Electrodes

Microbial electrochemical technologies have revealed the opportunity of electrochemical enrichment for specific bacterial groups that are able to catalyze reactions of interest. However, there are unsolved challenges towards their application under aggressive environmental conditions, such as in the sea. This study demonstrates the impact of surface electrochemical potential on community composition and its corrosivity. Electrochemical bacterial enrichment was successfully carried out in natural seawater without nutrient amendments. Experiments were carried out for ten days of exposure in a closed-flow system over 316L stainless steel electrodes under three different poised potentials (−150 mV, +100 mV, and +310 mV vs. Ag/AgCl). Weight loss and atomic force microscopy showed a significant difference in corrosion when +310 mV (vs. Ag/AgCl) was applied in comparison to that produced under the other tested potentials (and an unpoised control). Bacterial community analysis conducted using 16S rRNA gene profiles showed that poised potentials are more positive as +310 mV (vs. Ag/AgCl) resulted in strong enrichment for Rhodobacteraceae and Sulfitobacter. Hence, even though significant enrichment of the known electrochemically active bacteria from the Rhodobacteraceae family was accomplished, the resultant bacterial community could accelerate pitting corrosion in 316 L stainless steel, thereby compromising the durability of the electrodes and the microbial electrochemical technologies.

scholarly journals Impact of Diagnosed and Undiagnosed Respiratory Pseudomonas on VAP and VAE During Long-Term Acute Care

2020 ◽  
Vol 41 (S1) ◽  
pp. s258-s259
Author(s):  
James Harrigan ◽  
Ebbing Lautenbach ◽  
Emily Reesey ◽  
Magda Wernovsky ◽  
Pam Tolomeo ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Acute Care ◽  
Statistical Significance ◽  
Rrna Gene ◽  
Care Hospital ◽  
16S Sequencing ◽  
Increased Risk ◽  
Wide Range ◽  
The Impact

Background: Clinically diagnosed ventilator-associated pneumonia (VAP) is common in the long-term acute-care hospital (LTACH) setting and may contribute to adverse ventilator-associated events (VAEs). Pseudomonas aeruginosa is a common causative organism of VAP. We evaluated the impact of respiratory P. aeruginosa colonization and bacterial community dominance, both diagnosed and undiagnosed, on subsequent P. aeruginosa VAP and VAE events during long-term acute care. Methods: We enrolled 83 patients on LTACH admission for ventilator weaning, performed longitudinal sampling of endotracheal aspirates followed by 16S rRNA gene sequencing (Illumina HiSeq), and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed-effects models were fit to relate the abundance of respiratory Psa on admission to clinically diagnosed VAP and VAE events. Results: Of the 83 patients included, 12 were diagnosed with P. aeruginosa pneumonia during the 14 days prior to LTACH admission (known P. aeruginosa), and 22 additional patients received anti–P. aeruginosa antibiotics within 48 hours of admission (suspected P. aeruginosa); 49 patients had no known or suspected P. aeruginosa (unknown P. aeruginosa). Among the known P. aeruginosa group, all 12 patients had P. aeruginosa detectable by 16S sequencing, with elevated admission P. aeruginosa proportional abundance (median, 0.97; IQR, 0.33–1). Among the suspected P. aeruginosa group, all 22 patients had P. aeruginosa detectable by 16S sequencing, with a wide range of admission P. aeruginosa proportional abundance (median, 0.0088; IQR, 0.00012–0.31). Of the 49 patients in the unknown group, 47 also had detectable respiratory Psa, and many had high P. aeruginosa proportional abundance at admission (median, 0.014; IQR, 0.00025–0.52). Incident P. aeruginosa VAP was observed within 30 days in 4 of the known P. aeruginosa patients (33.3%), 5 of the suspected P. aeruginosa patients (22.7%), and 8 of the unknown P. aeruginosa patients (16.3%). VAE was observed within 30 days in 1 of the known P. aeruginosa patients (8.3%), 2 of the suspected P. aeruginosa patients (9.1%), and 1 of the unknown P. aeruginosa patients (2%). Admission P. aeruginosa abundance was positively associated with VAP and VAE risk in all groups, but the association only achieved statistical significance in the unknown group (type S error <0.002 for 30-day VAP and <0.011 for 30-day VAE). Conclusions: We identified a high prevalence of unrecognized respiratory P. aeruginosa colonization among patients admitted to LTACH for weaning from mechanical ventilation. The admission P. aeruginosa proportional abundance was strongly associated with increased risk of incident P. aeruginosa VAP among these patients.Funding: NoneDisclosures: None

scholarly journals Toolbox Approaches Using Molecular Markers and 16S rRNA Gene Amplicon Data Sets for Identification of Fecal Pollution in Surface Water

2015 ◽  
Vol 81 (20) ◽  
pp. 7067-7077 ◽  
Author(s):  
W. Ahmed ◽  
C. Staley ◽  
M. J. Sadowsky ◽  
P. Gyawali ◽  
J. P. S. Sidhu ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Water Samples ◽  
High Throughput Sequencing ◽  
Community Analysis ◽  
Fecal Pollution ◽  
Rrna Gene ◽  
Potential Sources

ABSTRACTIn this study, host-associated molecular markers and bacterial 16S rRNA gene community analysis using high-throughput sequencing were used to identify the sources of fecal pollution in environmental waters in Brisbane, Australia. A total of 92 fecal and composite wastewater samples were collected from different host groups (cat, cattle, dog, horse, human, and kangaroo), and 18 water samples were collected from six sites (BR1 to BR6) along the Brisbane River in Queensland, Australia. Bacterial communities in the fecal, wastewater, and river water samples were sequenced. Water samples were also tested for the presence of bird-associated (GFD), cattle-associated (CowM3), horse-associated, and human-associated (HF183) molecular markers, to provide multiple lines of evidence regarding the possible presence of fecal pollution associated with specific hosts. Among the 18 water samples tested, 83%, 33%, 17%, and 17% were real-time PCR positive for the GFD, HF183, CowM3, and horse markers, respectively. Among the potential sources of fecal pollution in water samples from the river, DNA sequencing tended to show relatively small contributions from wastewater treatment plants (up to 13% of sequence reads). Contributions from other animal sources were rarely detected and were very small (<3% of sequence reads). Source contributions determined via sequence analysis versus detection of molecular markers showed variable agreement. A lack of relationships among fecal indicator bacteria, host-associated molecular markers, and 16S rRNA gene community analysis data was also observed. Nonetheless, we show that bacterial community and host-associated molecular marker analyses can be combined to identify potential sources of fecal pollution in an urban river. This study is a proof of concept, and based on the results, we recommend using bacterial community analysis (where possible) along with PCR detection or quantification of host-associated molecular markers to provide information on the sources of fecal pollution in waterways.

scholarly journals Probiotic modulation of the gut bacterial community of juvenile Litopenaeus vannamei challenged with Vibrio parahaemolyticus CAIM 170

2017 ◽  
Vol 43 (4) ◽  
pp. 766-775
Author(s):  
Irasema E. Luis-Villaseñor ◽  
Domenico Voltolina ◽  
Bruno Gomez-Gil ◽  
Felipe Ascencio ◽  
Ángel I. Campa-Córdova ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Litopenaeus Vannamei ◽  
Vibrio Parahaemolyticus ◽  
Single Strand Conformation Polymorphism ◽  
Positive Control ◽  
Negative Control ◽  
Rrna Gene ◽  
Protective Effects ◽  
Probiotic Treatment ◽  
Significant Difference

The protective effects of two probiotic mixtures was studied using the fingerprints of the bacterial community of Litopenaeus vannamei juveniles exposed to probiotics and challenged with Vibrio parahaemolyticus CAIM 170. Fingerprints were constructed using 16S rRNA gene and the PCR-SSCP (Single strand conformation polymorphism) technique, and the probiotics used were an experimental Bacillus mixture (Bacillus tequilensis YC5-2 + B. endophyticus C2-2 and YC3-B) and the commercial probiotic Alibio. The DNA for PCR-SSCP analyses was extracted directly from the guts of shrimps treated for 20 days with the probiotics and injected with 2.5×105 CFU g-1 of V. parahaemolyticus one week after suspension of the probiotic treatment. Untreated shrimps served as positive (injected with V. parahaemolyticus) and negative (not injected) controls Analysis of the bacterial community carried out after inoculation and 12 and 48 h later confirmed that V. parahaemolyticus was present in shrimps of the positive control , but not in the negative control or treated with the probiotic mixtures. A significant difference in the diversity of the bacterial community was observed between times after infection. The band patterns in 0-12 h were clustered into a different group from that determined after 48 h, and suggested that during bacterial infection the guts of whiteleg shrimp were dominated by gamma proteobacteria represented by Vibrio sp. and Photobacterium sp. Our results indicate that the experimental and the commercial mixtures are suitable to modulate the bacterial community of L. vannamei and could be used as a probiotic to control vibriosis in juvenile shrimp.

scholarly journals The leaf bacterial microbiota of female and male kiwifruit plants in distinct seasons: assessing the impact of Pseudomonas syringae pv. actinidiae

2021 ◽  
Author(s):  
Aitana Ares ◽  
Joana Pereira ◽  
Eva Garcia ◽  
Joana Costa ◽  
Igor Tiago
Keyword(s):  
Bacterial Community ◽  
Pseudomonas Syringae ◽  
Relative Abundance ◽  
Bacterial Communities ◽  
Defense Mechanisms ◽  
Abiotic Factors ◽  
Illumina Miseq ◽  
Rrna Gene ◽  
Sequencing Platform ◽  
The Impact

The pandemic Pseudomonas syringae pv. actinidiae (Psa) has been compromising the production of the kiwifruit industry in major producing countries. Abiotic factors and plant gender are known to influence the disease outcome. To better understand their impact, we have determined the diversity of the leafs bacterial communities using the V5-V6 region of the 16S rRNA gene amplicon on the Illumina MiSeq sequencing platform. Healthy and diseased female and male kiwifruit plants were analyzed in two consecutive seasons: spring and autumn. This work describes whether the season, plant gender and the presence of Psa can affect the leaves bacterial community. Fifty bacterial operational taxonomic units (OTUs) were identified and assigned to five phyla distributed by 14 different families and 23 genera. The leaves of healthy female and male kiwi plants share most of the identified bacterial populations, that undergoes major seasonal changes. In both cases a substantial increase of the relative abundance of genus Methylobacterium is observed in autumn. The presence of Psa induced profound changes on leaves bacterial communities structure translated into a reduction in the relative abundance of previously dominant genera that had been found in healthy plants, namely Hymenobacter, Sphingomonas and Massilia. The impact of Psa was less pronounced in the bacterial community structure of male plants in both seasons. Some of the naturally occurring genera have the potential to act as an antagonist or as enhancers of the defense mechanisms paving the way for environmentally friendly and sustainable disease control.

scholarly journals Influence of hydropower stations on the water microbiota in the downstream of Jinsha River, China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9500
Author(s):  
Xiaojuan Chen ◽  
Da He ◽  
Lianfeng Zhou ◽  
Yankun Cao ◽  
Zhanjing Li
Keyword(s):  
Algal Blooms ◽  
Sequence Similarity ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Jinsha River ◽  
Kegg Pathways ◽  
Significant Difference ◽  
The Impact ◽  
Hydropower Stations

Construction of hydropower stations has been an important approach to meet China’s increasing power demand, but the impact of construction of hydropower stations on river microbiota is not fully understood. To evaluate this, the microbial composition from 18 sampling sites in the downstream of Jinsha River of China, upstream and downstream of two completed and two under-construction hydropower stations, were analyzed using high-throughput 16S rRNA gene sequencing. Three independent samples from each site were analyzed. A total of 18,683 OTUs from 1,350 genera were identified at 97% sequence similarity. Our results showed that the completion of hydropower stations would significantly increase the relative abundances of Acidobacteria, Chlorobi, Chloroflexi, Cyanobacteria, Nitrospirae, and Planctomycetes, especially the relative abundance of Synechococcus dOTUs and thus increase the risk of algal blooms. PCA based on all KEGG pathways and the significantly different KEGG pathways showed the predicted metabolic characteristics of the water microbiota by PICRUSt in the activated hydropower station group were significant difference to the other groups. Results from canonical correspondence analysis showed that water temperature and dissolved oxygen had significant effects on microbiota composition. These results are important for assessing the impact of hydropower stations on river microbiota and their potential environmental risks.

scholarly journals Investigation of Oral Microbiome in Donkeys and the Effect of Dental Care on Oral Microbial Composition

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2245
Author(s):  
Yiping Zhu ◽  
Wuyan Jiang ◽  
Reed Holyoak ◽  
Bo Liu ◽  
Jing Li
Keyword(s):  
Dental Treatment ◽  
16S Rrna Gene Sequencing ◽  
Oral Microbiome ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Dental Procedures ◽  
Significant Difference ◽  
Dental Diseases ◽  
Rrna Gene Sequencing ◽  
The Impact

The objective of this study was to investigate the oral microbial composition of the donkey and whether basic dental treatment, such as dental floating, would make a difference to the oral microbial environment in donkeys with dental diseases using high-throughput bacterial 16S rRNA gene sequencing. Oral swab samples were collected from 14 donkeys with various dental abnormalities on day 0 (before treatment) and day 20 (twenty days after treatment). It is the first report focusing on the oral microbiome in donkeys with dental diseases and the impact of common dental procedures thereon. Identified in group Day 0 and group Day 20, respectively, were 60,439.6 and 58,579.1 operational taxonomic units (OTUs). Several taxa in Day 0 differed significantly from Day 20 at the phylum and genus levels, but no statistically significant difference was observed in richness and diversity of Day 0 and Day 20. The results also indicated that a larger-scale study focusing on healthy donkey oral microbiome, as well as the correlation of dental diseases and oral microbiomes at different time frames following more specific and consistent dental treatment, are warranted.

scholarly journals Adaptation of the Cecal Bacterial Microbiome of Growing Pigs in Response to Resistant Starch Type 4

2015 ◽  
Vol 81 (24) ◽  
pp. 8489-8499 ◽  
Author(s):  
Barbara U. Metzler-Zebeli ◽  
Stephan Schmitz-Esser ◽  
Evelyne Mann ◽  
Dietmar Grüll ◽  
Timea Molnar ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Resistant Starch ◽  
Control Diet ◽  
Short Chain Fatty Acids ◽  
Growing Pigs ◽  
Short Chain ◽  
Rrna Gene ◽  
Content Type ◽  
Linear Discriminant ◽  
The Impact

ABSTRACTResistant starch (RS) exacerbates health benefits on the host via modulation of the gut bacterial community. By far, these effects have been less well explored for RS of type 4. This study aimed at gaining a community-wide insight into the impact of enzymatically modified starch (EMS) on the cecal microbiota and hindgut fermentation in growing pigs. Castrated male pigs (n= 12/diet; 29-kg body weight) were fed diets with either 70% EMS or control starch for 10 days. The bacterial profile of each cecal sample was determined by sequencing of the V345 region of the 16S rRNA gene using the Illumina MiSeq platform. EMS diet reduced short-chain fatty acid concentrations in cecum and proximal colon compared to the control diet. Linear discriminant analyses andKmeans clustering indicated diet-specific cecal community profiles, whereby diversity and species richness were not different among diets. Pigs showed host-specific variation in their most abundant phyla,Firmicutes(55%),Proteobacteria(35%), andBacteroidetes(10%). The EMS diet decreased abundance ofRuminococcus,Parasutterella,Bilophila,Enterococcus, andLactobacillusoperational taxonomic units (OTU), whereasMeniscusandActinobacillusOTU were increased compared to those with the control diet (P< 0.05). Quantitative PCR confirmed results for host effect onEnterobacteriaceaeand diet effect on members of theLactobacillusgroup. The presence of less cecal short-chain fatty acids and the imputed metabolic functions of the cecal microbiome suggested that EMS was less degradable for cecal bacteria than the control starch. The present EMS effects on the bacterial community profiles were different than the previously reported RS effects and can be linked to the chemical structure of EMS.

scholarly journals Alteration of Soil Rhizosphere Communities following Genetic Transformation of White Spruce

2007 ◽  
Vol 73 (13) ◽  
pp. 4128-4134 ◽  
Author(s):  
Philippe M. LeBlanc ◽  
Richard C. Hamelin ◽  
Martin Filion
Keyword(s):  
Genetic Transformation ◽  
Microbial Communities ◽  
Genetic Marker ◽  
Genetically Modified ◽  
Ecological Impact ◽  
White Spruce ◽  
Marker Genes ◽  
Rrna Gene ◽  
Significant Difference ◽  
The Impact

ABSTRACT The application of plant genetic manipulations to agriculture and forestry with the aim of alleviating insect damage through Bacillus thuringiensis transformation could lead to a significant reduction in the release of pesticides into the environment. However, many groups have come forward with very valid and important questions related to potentially adverse effects, and it is crucial to assess and better understand the impact that this technology might have on ecosystems. In this study, we analyzed rhizosphere soil samples collected from the first B. thuringiensis-transformed trees [with insertion of the CryIA(b) toxin-encoding gene] grown in Canada (Val-Cartier, QC, Canada) as part of an ecological impact assessment project. Using a robust amplified rRNA gene restriction analysis approach coupled with 16S rRNA gene sequencing, the rhizosphere-inhabiting microbial communities of white spruce (Picea glauca) genetically modified by biolistic insertion of the cryIA(b), uidA (beta-glucuronidase), and nptII genes were compared with the microbial communities associated with non-genetically modified counterparts and with trees in which only the genetic marker genes uidA and nptII have been inserted. Analysis of 1,728 rhizosphere bacterial clones (576 clones per treatment) using a Cramér-von Mises statistic analysis combined with a Monte Carlo comparison clearly indicated that there was a statistically significant difference (P < 0.05) between the microbial communities inhabiting the rhizospheres of trees carrying the cryIA(b), uidA, and nptII transgenes, trees carrying only the uidA and nptII transgenes, and control trees. Clear rhizosphere microbial community alterations due to B. thuringiensis tree genetic modification have to our knowledge never been described previously and open the door to interesting questions related to B. thuringiensis genetic transformation and also to the impact of commonly used uidA and nptII genetic marker genes.

scholarly journals Impact of Virioplankton on Archaeal and Bacterial Community Richness as Assessed in Seawater Batch Cultures

2004 ◽  
Vol 70 (2) ◽  
pp. 804-813 ◽  
Author(s):  
Christian Winter ◽  
Arjan Smit ◽  
Gerhard J. Herndl ◽  
Markus G. Weinbauer
Keyword(s):  
Bacterial Community ◽  
Bacterial Communities ◽  
Rflp Analysis ◽  
Rrna Gene ◽  
Tropical Atlantic ◽  
Viral Lysis ◽  
Batch Cultures ◽  
Operational Taxonomic Units ◽  
The Impact

ABSTRACT During cruises in the tropical Atlantic Ocean (January to February 2000) and the southern North Sea (December 2000), experiments were conducted to monitor the impact of virioplankton on archaeal and bacterial community richness. Prokaryotic cells equivalent to 10 to 100% of the in situ abundance were inoculated into virus-free seawater, and viruses equivalent to 35 to 360% of the in situ abundance were added. Batch cultures with microwave-inactivated viruses and without viruses served as controls. The apparent richness of archaeal and bacterial communities was determined by terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR-amplified 16S rRNA gene fragments. Although the estimated richness of the prokaryotic communities generally was greatly reduced within the first 24 h of incubation due to confinement, the effects of virus amendment were detected at the level of individual operational taxonomic units (OTUs) in the T-RFLP patterns of both groups, Archaea and Bacteria. One group of OTUs was detected in the control samples but was absent from the virus-treated samples. This negative response of OTUs to virus amendment probably was caused by viral lysis. Additionally, we found OTUs not responding to the amendments, and several OTUs exhibited variable responses to the addition of inactive or active viruses. Therefore, we conclude that individual members of pelagic archaeal and bacterial communities can be differently affected by the presence of virioplankton.

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