Analysis of the bacterial community within carrot wash water

2011 ◽  
Vol 57 (5) ◽  
pp. 447-452 ◽  
Author(s):  
Lena Hausdorf ◽  
Antje Fröhling ◽  
Oliver Schlüter ◽  
Michael Klocke

Vegetables are washed after harvest to remove unwanted organic and inorganic particles, but wash water contaminated with certain pathogenic microorganisms can potentially contaminate produce. In this study, the microbial diversity of wash water was analyzed in samples taken from a carrot-processing facility. A 16S rRNA gene library with 427 clones was constructed and analyzed by amplified rDNA restriction analysis. For taxonomic classification, the 16S rRNA gene nucleotide sequences of 94 amplified rDNA restriction analysis fingerprints were determined. Each fingerprint indicates a distinct group of microorganisms. The nucleotide sequences were assigned to corresponding reference species. The most prevalent genus was Tolumonas , with 26% of the clones, followed by Acinetobacter and Flacobacterium , with 11% each. The latter two genera contain species that are known to cause nosocomial infections. The fourth most common genus was Arcobacter , comprising 9% of all clones. Some species of Arcobacter are considered to be emerging food pathogens, mainly associated with the contamination of meat products. So far, they have not been considered as contaminants of fresh produce. Based on the sequence data, an Arcobacter-specific PCR assay was developed to facilitate the detection of vegetable-associated Arcobacter strains.


2013 ◽  
Vol 62 (4) ◽  
pp. 391-400 ◽  
Author(s):  
RAJU RAJASABAPATHY ◽  
CHELLANDI MOHANDASS ◽  
AJAKKALAMOOLE SRINIVAS VIJAYARAJ ◽  
VARSHA VINAYAK MADIVAL ◽  
RAM MURTI MEENA

Based on distinct colony morphology, color, size, shape and certain other traits, 92 bacterial isolates were investigated to understand their managerial ability on iron from the Arabian Sea and Equatorial Indian Ocean samples. The ARDRA (amplified rDNA restriction analysis) applied to eliminate the duplication of the bacterial strains, resulted 39 different banding patterns. The 16S rRNA gene sequencing data indicate the dominancy of three phylogenetic groups, alpha-Proteobacteria (10.25%), gamma-Proteobacteria (35.89%) and Bacilli (53.84%) in these waters. Marinobacter and Bacillus were the only common genera from both of the regions. Pseudoalteromonas, Halomonas, Rheinheimera, Staphylococcus and Idiomarina were some of the other genera obtained from the Arabian Sea. Erythrobacter, Roseovarius, Sagittula and Nitratireductor were found mostly in Equatorial Indian Ocean. In addition, 16S rRNA gene sequence data of some of our iron bacterial strains belong to novel species and one isolate ASS2A could form a new genus. Close to 23% of the isolates were able to produce high affinity sets of ligands like siderophores to mediate iron transport into the cell. The current study indicated that the Equatorial Indian Ocean species were well adapted to oxidize iron as an electron acceptor and the Arabian Sea species preferably go through siderophore production.





Algologia ◽  
2021 ◽  
Vol 31 (1) ◽  
pp. 93-113
Author(s):  
A.R. Nur Fadzliana ◽  
◽  
W.O. Wan Maznah ◽  
S.A.M. Nor ◽  
Choon Pin Foong ◽  
...  

Cyanobacteria are the most widespread group of photosynthetic prokaryotes. They are primary producers in a wide variety of habitats and are able to thrive in harsh environments, including polluted waters; therefore, this study was conducted to explore the cyanobacterial populations inhabiting river tributaries with different levels of pollution. Sediment samples (epipelon) were collected from selected tributaries of the Pinang River basin. Air Terjun (T1) and Air Itam rivers (T2) represent the upper streams of Pinang River basin, while Dondang (T3) and Jelutong rivers (T4) are located at in the middle of the river basin. The Pinang River (T5) is located near the estuary and is subjected to saline water intrusion during high tides. Cyanobacterial community was determined by identifying the taxa via 16S rRNA gene amplicon sequence data. 16S rRNA gene amplicons generated from collected samples were sequenced using illumina Miseq, with the targeted V3 and V4 regions yielding approximately 1 mln reads per sample. Synechococcus, Phormidium, Arthronema and Leptolyngbya were found in all samples. Shannon-Weiner diversity index was highest (H’ = 1.867) at the clean upstream station (T1), while the moderately polluted stream (T3) recorded the lowest diversity (H’ = 0.399), and relatively polluted stations (T4 and T5) recorded fairly high values of H’. This study provides insights into the cyanobacterial community structure in Pinang River basin via cultivation-independent techniques using 16S rRNA gene amplicon sequence. Occurrence of some morphospecies at specific locations showed that the cyanobacterial communities are quite distinct and have specific ecological demands. Some species which were ubiquitous might be able to tolerate varied environmental conditions.



2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 723-731 ◽  
Author(s):  
Ronel Roberts ◽  
Emma T. Steenkamp ◽  
Gerhard Pietersen

Greening disease of citrus in South Africa is associated with ‘Candidatus Liberibacter africanus’ (Laf), a phloem-limited bacterium vectored by the sap-sucking insect Trioza erytreae (Triozidae). Despite the implementation of control strategies, this disease remains problematic, suggesting the existence of reservoir hosts to Laf. The current study aimed to identify such hosts. Samples from 234 trees of Clausena anisata, 289 trees of Vepris lanceolata and 231 trees of Zanthoxylum capense were collected throughout the natural distribution of these trees in South Africa. Total DNA was extracted from samples and tested for the presence of liberibacters by a generic Liberibacter TaqMan real-time PCR assay. Liberibacters present in positive samples were characterized by amplifying and sequencing rplJ, omp and 16S rRNA gene regions. The identity of tree host species from which liberibacter sequences were obtained was verified by sequencing host rbcL genes. Of the trees tested, 33 specimens of Clausena, 17 specimens of Vepris and 10 specimens of Zanthoxylum tested positive for liberibacter. None of the samples contained typical citrus-infecting Laf sequences. Phylogenetic analysis of 16S rRNA gene sequences indicated that the liberibacters obtained from Vepris and Clausena had 16S rRNA gene sequences identical to that of ‘Candidatus Liberibacter africanus subsp. capensis’ (LafC), whereas those from Zanthoxylum species grouped separately. Phylogenetic analysis of the rplJ and omp gene regions revealed unique clusters for liberibacters associated with each tree species. We propose the following names for these novel liberibacters: ‘Candidatus Liberibacter africanus subsp. clausenae’ (LafCl), ‘Candidatus Liberibacter africanus subsp. vepridis’ (LafV) and ‘Candidatus Liberibacter africanus subsp. zanthoxyli’ (LafZ). This study did not find any natural hosts of Laf associated with greening of citrus. While native citrus relatives were shown to be infected with Laf-related liberibacters, nucleotide sequence data suggest that these are not alternative sources of Laf to citrus orchards, per se.



mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Marc A. Sze ◽  
Begüm D. Topçuoğlu ◽  
Nicholas A. Lesniak ◽  
Mack T. Ruffin ◽  
Patrick D. Schloss

ABSTRACT Colonic bacterial populations are thought to have a role in the development of colorectal cancer with some protecting against inflammation and others exacerbating inflammation. Short-chain fatty acids (SCFAs) have been shown to have anti-inflammatory properties and are produced in large quantities by colonic bacteria that produce SCFAs by fermenting fiber. We assessed whether there was an association between fecal SCFA concentrations and the presence of colonic adenomas or carcinomas in a cohort of individuals using 16S rRNA gene and metagenomic shotgun sequence data. We measured the fecal concentrations of acetate, propionate, and butyrate within the cohort and found that there were no significant associations between SCFA concentration and tumor status. When we incorporated these concentrations into random forest classification models trained to differentiate between people with healthy colons and those with adenomas or carcinomas, we found that they did not significantly improve the ability of 16S rRNA gene or metagenomic gene sequence-based models to classify individuals. Finally, we generated random forest regression models trained to predict the concentration of each SCFA based on 16S rRNA gene or metagenomic gene sequence data from the same samples. These models performed poorly and were able to explain at most 14% of the observed variation in the SCFA concentrations. These results support the broader epidemiological data that questions the value of fiber consumption for reducing the risks of colorectal cancer. Although other bacterial metabolites may serve as biomarkers to detect adenomas or carcinomas, fecal SCFA concentrations have limited predictive power. IMPORTANCE Considering that colorectal cancer is the third leading cancer-related cause of death within the United States, it is important to detect colorectal tumors early and to prevent the formation of tumors. Short-chain fatty acids (SCFAs) are often used as a surrogate for measuring gut health and for being anticarcinogenic because of their anti-inflammatory properties. We evaluated the fecal SCFA concentrations of a cohort of individuals with different colonic tumor burdens who were previously analyzed to identify microbiome-based biomarkers of tumors. We were unable to find an association between SCFA concentration and tumor burden or use SCFAs to improve our microbiome-based models of classifying people based on their tumor status. Furthermore, we were unable to find an association between the fecal community structure and SCFA concentrations. Our results indicate that the association between fecal SCFAs, the gut microbiome, and tumor burden is weak.



2011 ◽  
Vol 32 (2) ◽  
pp. 66 ◽  
Author(s):  
Peter Kampfer ◽  
Stefanie P Glaeser

The initial step in prokaryote species and genera descriptions is now largely based on the 16S rRNA gene sequencing approach followed often by a very restricted additional phenotypic characterisation of the representatives of the potential novel taxa. Despite the advantages of the sequence-based approaches, there appears to be a tendency to classify new species on the basis of comparative sequence analyses of 16S rRNA gene sequences and other gene sequence data (multilocus sequence analyses, MLSA), contrary to the indications of other data. However, the biological meaning behind these sequence data is not always clear, and one should be careful with comprehensive taxonomic rearrangements until there is better insight of these data.



2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Sangam Kandel ◽  
Supaphen Sripiboon ◽  
Piroon Jenjaroenpun ◽  
David W. Ussery ◽  
Intawat Nookaew ◽  
...  

ABSTRACT Here, we present a 16S rRNA gene amplicon sequence data set and profiles demonstrating the bacterial diversity of baby and adult elephants from four different geographical locations in Thailand. The dominant phyla among baby and adult elephants were Bacteroidetes, Firmicutes, Proteobacteria, Kiritimatiellaeota, Euryarchaeota, and Tenericutes.



2000 ◽  
Vol 66 (3) ◽  
pp. 1098-1106 ◽  
Author(s):  
Steven P. Djordjevic ◽  
Wendy A. Forbes ◽  
Lisa A. Smith ◽  
Michael A. Hornitzky

ABSTRACT Twenty-five unique CfoI-generated whole-cell DNA profiles were identified in a study of 30 Paenibacillus alvei isolates cultured from honey and diseased larvae collected from honeybee (Apis mellifera) colonies in geographically diverse areas in Australia. The fingerprint patterns were highly variable and readily discernible from one another, which highlighted the potential of this method for tracing the movement of isolates in epidemiological studies. 16S rRNA gene fragments (length, 1,416 bp) for all 30 isolates were enzymatically amplified by PCR and subjected to restriction analysis with DraI, HinfI,CfoI, AluI, FokI, andRsaI. With each enzyme the restriction profiles of the 16S rRNA genes from all 30 isolates were identical (one restriction fragment length polymorphism [RFLP] was observed in theHinfI profile of the 16S rRNA gene from isolate 17), which confirmed that the isolates belonged to the same species. The restriction profiles generated by using DraI,FokI, and HinfI differentiated P. alvei from the phylogenetically closely related speciesPaenibacillus macerans and Paenibacillus macquariensis. Alveolysin gene fragments (length, 1,555 bp) were enzymatically amplified from some of the P. alvei isolates (19 of 30 isolates), and RFLP were detected by using the enzymesCfoI, Sau3AI, and RsaI. Extrachromosomal DNA ranging in size from 1 to 10 kb was detected in 17 of 30 (57%) P. alvei whole-cell DNA profiles. Extensive biochemical heterogeneity was observed among the 28 P. alvei isolates examined with the API 50CHB system. All of these isolates were catalase, oxidase, and Voges-Proskauer positive and nitrate negative, and all produced acid when glycerol, esculin, and maltose were added. The isolates produced variable results for 16 of the 49 biochemical tests; negative reactions were recorded in the remaining 30 assays. The genetic and biochemical heterogeneity inP. alvei isolates may be a reflection of adaptation to the special habitats in which they originated.



2019 ◽  
Vol 8 (29) ◽  
Author(s):  
Takeshi Yamada ◽  
Masako Hamada ◽  
Misaki Kurobe ◽  
Jun Harada ◽  
Surya Giri ◽  
...  

Little information on poly(l-lactic acid) (PLLA) treatment-associated microbiota in thermophilic anaerobic digestion reactors is available. Here, we provide 16S rRNA gene sequence data on microbiota in a thermophilic anaerobic digestion reactor converting PLLA to methane for 336 days. Data comprising 99,566 total high-quality reads were tabulated at the taxonomic class level.



2020 ◽  
Vol 9 (22) ◽  
Author(s):  
Kasumi Ishida-Kuroki ◽  
Nachiko Takeshita ◽  
Yoshihiro Nitta ◽  
Takehisa Chuma ◽  
Ken Maeda ◽  
...  

ABSTRACT We report 16S rRNA amplicon sequence data from feces from 58 wild boars, 60 feral raccoons, 9 wild Japanese badgers, 21 wild masked palm civets, and 8 wild raccoon dogs in Japan. The predominant bacterial taxa in the fecal microbiota were similar in part but varied among the animal species.



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