scholarly journals Comparative Bacterial Metagenomics of Cnidoscolus aconitifolius (Mill.) I. M. Johnston and Other Leafy Vegetables

Author(s):  
Nkechi Gloria Ogbuji ◽  
Eromosele Anthony Ataga

Aims: Vegetables provide a favourable habitat for diverse populations of microorganisms. Some vegetables, especially the ones used in salads are ready-to-eat food products and some phyllosphere bacteria might contribute to the prolonged presence of human food-borne pathogens in these vegetables. Methodology: Phyllosphere bacteria associated with Cnidoscolus aconitifolius were evaluated using a culture-independent approach, Illumina MiSeq platform of 16S rRNA gene sequencing and then compared with publicly available data obtained from Spinacia oleracea (spinach) and Lactuca sativa (lettuce) on GenBank. Results: The results from this study showed that the three vegetables harbor diverse bacterial organisms. Eighty-three (83) Operational Taxonomic Units (OTUs) assigned to five phyla were obtained from C. aconitifolius phyllosphere. The most predominant phyla across studied vegetables were: Proteobacteria (74.79%), Actinobacteria (8.69%) and Firmicutes (7.37%). Potential human pathogenic species such as Bacillus spp., Enterococcus spp., Staphylococcus spp., Klebsiella spp., and Pseudomonas spp. were also present in lettuce and spinach. Bacteria with potential for antibiotic production, anti-microbial and antibiotic resistant genes belong to the families Bacillaceae, Streptomycetaceae, Pseudomonaceae, Enterobacteriaceae, Staphylococcaceae, Enterococcaceae and Streptococcaceae. The most abundant taxa obtained from this study were Pseudomonas, Erwinia, Brachybacterium, Megasphaera, Janthinobacterium, Sphingomonas and Lactobacillus. Conclusion: Our result successfully determined the relative abundance of potential human and plant pathogens in the leafy vegetables and also showed the bacterial community structure in the studied vegetables.

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1344
Author(s):  
Naima Lemjiber ◽  
Khalid Naamani ◽  
Annabelle Merieau ◽  
Abdelhi Dihazi ◽  
Nawal Zhar ◽  
...  

Bacterial burn is one of the major diseases affecting pear trees worldwide, with serious impacts on producers and economy. In Morocco, several pear trees (Pyrus communis) have shown leaf burns since 2015. To characterize the causal agent of this disease, we isolated fourteen bacterial strains from different parts of symptomatic pear trees (leaves, shoots, fruits and flowers) that were tested in planta for their pathogenicity on Louise bonne and Williams cultivars. The results showed necrotic lesions with a significant severity range from 47.63 to 57.77% on leaves of the Louise bonne cultivar inoculated with isolate B10, while the other bacterial isolates did not induce any disease symptom. 16S rRNA gene sequencing did not allow robust taxonomic discrimination of the incriminated isolate. Thus, we conducted whole-genome sequencing (WGS) and phylogenetic analyzes based on gyrA, gyrB and cdaA gene sequences, indicating that this isolate belongs to the Bacillus altitudinis species. This taxonomic classification was further confirmed by the Average Nucleotide Identity (ANI) and the in silico DNA-DNA hybridization (isDDH) analyzes compared to sixty-five Bacillus spp. type strains. The genome was mined for genes encoding carbohydrate-active enzymes (CAZymes) known to play a role in the vegetal tissue degradation. 177 candidates with functions that may support the in planta phytopathogenicity results were identified. To the best of our knowledge, this is the first data reporting B. altitudinis as agent of leaf burn in P. communis in Morocco. Our dataset will improve our knowledge on spread and pathogenicity of B. altitudinis genotypes that appears as emergent phytopathogenic agent, unveiling virulence factors and their genomic location (i.e., within genomic islands or the accessory genome) to induce trees disease.


2020 ◽  
Vol 6 (3) ◽  
pp. 170
Author(s):  
Vadim Yu Kryukov ◽  
Elena Kosman ◽  
Oksana Tomilova ◽  
Olga Polenogova ◽  
Ulyana Rotskaya ◽  
...  

Various insect bacterial associates are involved in pathogeneses caused by entomopathogenic fungi. The outcome of infection (fungal growth or decomposition) may depend on environmental factors such as temperature. The aim of this study was to analyze the bacterial communities and immune response of Galleria mellonella larvae injected with Cordyceps militaris and incubated at 15 °C and 25 °C. We examined changes in the bacterial CFUs, bacterial communities (Illumina MiSeq 16S rRNA gene sequencing) and expression of immune, apoptosis, ROS and stress-related genes (qPCR) in larval tissues in response to fungal infection at the mentioned temperatures. Increased survival of larvae after C. militaris injection was observed at 25 °C, although more frequent episodes of spontaneous bacteriosis were observed at this temperature compared to 15 °C. We revealed an increase in the abundance of enterococci and enterobacteria in the midgut and hemolymph in response to infection at 25 °C, which was not observed at 15 °C. Antifungal peptide genes showed the highest expression at 25 °C, while antibacterial peptides and inhibitor of apoptosis genes were strongly expressed at 15 °C. Cultivable bacteria significantly suppressed the growth of C. militaris. We suggest that fungi such as C. militaris may need low temperatures to avoid competition with host bacterial associates.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benedicte Ella Zranseu Aka ◽  
Theodore N’dede Djeni ◽  
Simon Laurent Tiemele Amoikon ◽  
Jan Kannengiesser ◽  
Naaila Ouazzani ◽  
...  

AbstractPalm Oil Mill Effluents (POME) are complex fermentative substrates which habour diverse native microbial contaminants. However, knowledge on the microbiota community shift caused by the anthropogenic effects of POME in the environment is up to date still to be extensively documented. In this study, the bacterial and archaeal communities of POME from two palm oil processing systems (artisanal and industrial) were investigated by Illumina MiSeq Platform. Despite the common characteristics of these wastewaters, we found that their microbial communities were significantly different with regard to their diversity and relative abundance of their different Amplicon Sequence Variants (ASV). Indeed, POME from industrial plants harboured as dominant phyla Firmicutes (46.24%), Bacteroidetes (34.19%), Proteobacteria (15.11%), with the particular presence of Spirochaetes, verrucomicrobia and Synergistetes, while those from artisanal production were colonized by Firmicutes (92.06%), Proteobacteria (4.21%) and Actinobacteria (2.09%). Furthermore, 43 AVSs of archaea were detected only in POME from industrial plants and assigned to Crenarchaeota, Diapherotrites, Euryarchaeota and Nanoarchaeaeota phyla, populated mainly by many methane-forming archaea. Definitively, the microbial community composition of POME from both type of processing was markedly different, showing that the history of these ecosystems and various processing conditions have a great impact on each microbial community structure and diversity. By improving knowledge about this microbiome, the results also provide insight into the potential microbial contaminants of soils and rivers receiving these wastewaters.


2013 ◽  
Vol 80 (2) ◽  
pp. 757-765 ◽  
Author(s):  
Amber M. Koskey ◽  
Jenny C. Fisher ◽  
Mary F. Traudt ◽  
Ryan J. Newton ◽  
Sandra L. McLellan

ABSTRACTGulls are prevalent in beach environments and can be a major source of fecal contamination. Gulls have been shown to harbor a high abundance of fecal indicator bacteria (FIB), such asEscherichia coliand enterococci, which can be readily detected as part of routine beach monitoring. Despite the ubiquitous presence of gull fecal material in beach environments, the associated microbial community is relatively poorly characterized. We generated comprehensive microbial community profiles of gull fecal samples using Roche 454 and Illumina MiSeq platforms to investigate the composition and variability of the gull fecal microbial community and to measure the proportion of FIB.EnterococcaceaeandEnterobacteriaceaewere the two most abundant families in our gull samples. Sequence comparisons between short-read data and nearly full-length 16S rRNA gene clones generated from the same samples revealedCatellicoccus marimammaliumas the most numerous taxon among all samples. The identification of bacteria from gull fecal pellets cultured on membrane-Enterococcusindoxyl-β-d-glucoside (mEI) plates showed that the dominant sequences recovered in our sequence libraries did not represent organisms culturable on mEI. Based on 16S rRNA gene sequencing of gull fecal isolates cultured on mEI plates, 98.8% were identified asEnterococcusspp., 1.2% were identified asStreptococcusspp., and none were identified asC. marimammalium. Illumina deep sequencing indicated that gull fecal samples harbor significantly higher proportions ofC. marimammalium16S rRNA gene sequences (>50-fold) relative to typical mEI culturableEnterococcusspp.C. marimammaliumtherefore can be confidently utilized as a genetic marker to identify gull fecal pollution in the beach environment.


2017 ◽  
Vol 25 (4) ◽  
pp. 262-266
Author(s):  
Gopinath Rana ◽  
Tanusri Mandal

AbstractExperimental studies have been made to find out Cyanobacterias’ biophotonical response in gaseous-fuelation and carbon dioxide fixation during photo-anaerobic digestion. A new horizontal type photo-bioreactor has been designed by using environment hazard plastic bottles and it works ideally for anoxygenic cyanobacterial growth. Through ‘V3-metagenomics’ of 16S rRNA gene sequencing by paired-end Illumina MiSeq and downstream analysis by QIIME program, we have identified anaerobic cyanobacteria, represent the orders YS2 and Streptophyta. OTUs have been identified by aligning against Greengenes and Silva databases, separately. The flame temperature of the fuel gas is 860°C and the percent-content of carbon dioxide (CO2) is 17.6%.


2019 ◽  
Vol 65 (10) ◽  
pp. 762-774 ◽  
Author(s):  
Alejandro Penaloza-Vazquez ◽  
Li Maria Ma ◽  
Patricia Rayas-Duarte

Probiotics have become one of the potential solutions to global restriction on antibiotic use in food animal production. Bacillus species have been attractive probiotics partially due to their long-term stability during storage. In this study, 200 endospore-forming bacteria isolates were recovered from sourdough and the gastrointestinal tract (GIT) of young broiler chicks. Based on the production of a series of exoenzymes and survivability under stress conditions similar to those in the poultry GIT, 42 isolates were selected and identified by 16S rRNA gene sequencing. Seven strains with a profile of high enzymatic activities were further evaluated for sporulation efficiency, biofilm formation, compatibility among themselves (Bacillus spp.), and antagonistic effects against three bacteria pathogenic to poultry and humans: Enterococcus cecorum, Salmonella enterica, and Shiga-toxin-producing Escherichia coli. The strains from sourdough were identified as Bacillus amyloliquefaciens whereas the ones from the chicks’ GIT were Bacillus subtilis. These strains demonstrated remarkable potential as probiotics for poultry.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 941
Author(s):  
Nawal Benttoumi ◽  
Mariantonietta Colagiero ◽  
Samira Sellami ◽  
Houda Boureghda ◽  
Abdelaziz Keddad ◽  
...  

Fungi and bacteria associated to phytoparasitic nematodes Globodera rostochiensis and Meloidogyne spp. in Algeria were identified and characterized. Trichoderma spp. showed the highest prevalence in the cysts of G. rostochiensis. A number of isolates were identified through PCR amplification and the sequencing of the internal transcribed spacer (ITS)1-2 and Rpb2 gene regions. The most represented species were T. harzianum and T. afroharzianum. The latter and T. hirsutum were reported for the first time in Algeria. Fusarium spp., including F. oxysporum and F. solani, comprised a second group of fungi found in cysts. Taxa associated to females of Meloidogyne spp. included T. harzianum, Fusarium spp. and other hyphomycetes. To assess the efficacy of Trichoderma spp., two assays were carried out in vitro with the culture filtrates of two T. afroharzianum and T. harzianum isolates, to check their toxicity versus the second stage juveniles of M. incognita. After 24–48 h exposure, a mortality significantly higher than the control was observed for both filtrates at 1% dilutions. The TRI genes involved in the production of trichothecenes were also amplified with the PCR from some Trichoderma spp. isolates and sequenced, supporting a putative role in nematode toxicity. Bacteria isolated from the cysts of G. rostochiensis included Brucella, Rhizobium, Stenotrophomonas and Bacillus spp., identified through 16S rRNA gene sequencing. The potential of the microbial isolates identified and their mechanisms of action are discussed, as part of a sustainable nematode management strategy.


2020 ◽  
Vol 10 (1) ◽  
pp. 3-16
Author(s):  
Nguyen Van Minh ◽  
Nguyen Hoang Tuan Duy ◽  
Do Phuong Quynh ◽  
Tran Thi A Ni ◽  
Tran Kien Duc ◽  
...  

In this study, we isolated 28 strains of Bacillus spp. from water samples, catfish pond mud samples and earthworm manure (Perionyx excavates). By the cross-streak agar methods, 22 Bacillus strains showed the inhibition ability to Edwardsiella ictaluri, which caused Bacillary Necrosis Pangasius (BNP) in catfish (Pangasianodon hypophthalmus). Both Bacillus sp. Q16 and Q111 strains showed the highest inhibition to E. ictaluri by the double-layer agar methods. Finally, two Bacillus strains (Q16, Q111) were selected as a source of potential probiotic because of the ability of extracellular enzyme secretion (protease, amylase, cellulose) strong growth at 0,1-1% salt concentrations, survival within the pH range 6-8, resistance to low pH and low bile salts, inability to produce haemolysin enzyme, sensitivity to eight antibiotics in the three impacting groups (inhibition of wall synthesis, inhibition mechanism of protein synthesis, inhibition of nucleic acid synthesis). Two Bacillus strains (Q16, Q111) were identified that they belong to Bacillus subtilis by biochemical method and 16S rRNA gene sequencing method. This study indicated that two Bacillus strains (Q16, Q111) isolated from catfish pond can be applied as high potential probiotics that used to farm catfish.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Matan Masasa ◽  
Ariel Kushmaro ◽  
Esti Kramarsky-Winter ◽  
Muki Shpigel ◽  
Roy Barkan ◽  
...  

Abstract Background Algivorous sea urchins can obtain energy from a diet of a single algal species, which may result in consequent changes in their gut microbe assemblies and association networks. Methods To ascertain whether such changes are led by specific microbes or limited to a specific region in the gut, we compared the microbial assembly in the three major gut regions of the sea urchin Tripneustes gratilla elatensis when fed a mono-specific algal diet of either Ulva fasciata or Gracilaria conferta, or an algal-free diet. DNA extracts from 5 to 7 individuals from each diet treatment were used for Illumina MiSeq based 16S rRNA gene sequencing (V3–V4 region). Niche breadth of each microbe in the assembly was calculated for identification of core, generalist, specialist, or unique microbes. Network analyzers were used to measure the connectivity of the entire assembly and of each of the microbes within it and whether it altered with a given diet or gut region. Lastly, the predicted metabolic functions of key microbes in the gut were analyzed to evaluate their potential contribution to decomposition of dietary algal polysaccharides. Results Sea urchins fed with U. fasciata grew faster and their gut microbiome network was rich in bacterial associations (edges) and networking clusters. Bacteroidetes was the keystone microbe phylum in the gut, with core, generalist, and specialist representatives. A few microbes of this phylum were central hub nodes that maintained community connectivity, while others were driver microbes that led the rewiring of the assembly network based on diet type through changes in their associations and centrality. Niche breadth agreed with microbes' richness in genes for carbohydrate active enzymes and correlated Bacteroidetes specialists to decomposition of specific polysaccharides in the algal diets. Conclusions The dense and well-connected microbial network in the gut of Ulva-fed sea urchins, together with animal's rapid growth, may suggest that this alga was most nutritious among the experimental diets. Our findings expand the knowledge on the gut microbial assembly in T. gratilla elatensis and strengthen the correlation between microbes’ generalism or specialism in terms of occurrence in different niches and their metabolic arsenal which may aid host nutrition.


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