scholarly journals Identification of Multiple Dehalogenase Genes Involved in Tetrachloroethene-to-Ethene Dechlorination in aDehalococcoides-Dominated Enrichment Culture

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Mohamed Ismaeil ◽  
Naoko Yoshida ◽  
Arata Katayama
Keyword(s):  
Amino Acid ◽  
Novel Species ◽  
Enrichment Culture ◽  
Bacterial Species ◽  
The Other ◽  
Rrna Gene ◽  
Amino Acid Similarity ◽  
Reductive Dehalogenase ◽  
Per Gene ◽  
Complete Dechlorination

Chloroethenes (CEs) are widespread groundwater toxicants that are reductively dechlorinated to nontoxic ethene (ETH) by members ofDehalococcoides. This study established aDehalococcoides-dominated enrichment culture (designated “YN3”) that dechlorinates tetrachloroethene (PCE) to ETH with high dechlorination activity, that is, complete dechlorination of 800 μM PCE to ETH within 14 days in the presence ofDehalococcoidesspecies at5.7±1.9×107 copies of 16S rRNA gene/mL. The metagenome of YN3 harbored 18rdhAgenes (designatedYN3rdhA1–18) encoding the catalytic subunit of reductive dehalogenase (RdhA), four of which were suggested to be involved in PCE-to-ETH dechlorination based on significant increases in their transcription in response to CE addition. The predicted proteins for two of these four genes, YN3RdhA8 and YN3RdhA16,showed 94% and 97% of amino acid similarity with PceA and VcrA, which are well known to dechlorinate PCE to trichloroethene (TCE) and TCE to ETH, respectively. The other twordhAs,YN3rdhA6andYN3rdhA12,which were never proved asrdhAfor CEs, showed particularly high transcription upon addition of vinyl chloride (VC), with75±38and16±8.6mRNA copies per gene, respectively, suggesting their possible functions as novel VC-reductive dehalogenases. Moreover, metagenome data indicated the presence of three coexisting bacterial species, including novel species of the genusBacteroides, which might promote CE dechlorination byDehalococcoides.

scholarly journals Taxonomic study of Halorubrum distributum and proposal of Halorubrum terrestre sp. nov.

2004 ◽  
Vol 54 (2) ◽  
pp. 389-392 ◽  
Author(s):  
Antonio Ventosa ◽  
M. Carmen Gutiérrez ◽  
Masahiro Kamekura ◽  
Irina S. Zvyagintseva ◽  
Aharon Oren
Keyword(s):  
16S Rrna ◽  
Dna Hybridization ◽  
Type Strain ◽  
Novel Species ◽  
The Other ◽  
Saline Soils ◽  
Rrna Gene ◽  
Taxonomic Study ◽  
16S Rrna Gene Sequences ◽  
Phenotypic Features

Halorubrum distributum (basonym, Halobacterium distributum) is an extremely halophilic, aerobic archaeon isolated from saline soils, which was described on the basis of phenotypic features of several strains. The designated type strain of the species (1mT=VKM B-1733T=JCM 9100T) was shown recently to differ from the other strains. In this study, Halorubrum distributum isolates have been characterized with regard to phenotypic features, polar lipid content, comparison of 16S rRNA gene sequences and DNA–DNA hybridization. On the basis of these data, a novel species that includes the other isolates is proposed, with the name Halorubrum terrestre sp. nov. The type strain of this novel species is 4pT (=VKM B-1739T=JCM 10247T). The DNA G+C content of this novel species is 64·2–64·9 mol% (64·4 mol% for the type strain).

scholarly journals Mucilaginibacter polysacchareus sp. nov., an exopolysaccharide-producing bacterial species isolated from the rhizoplane of the herb Angelica sinensis

2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 632-637 ◽  
Author(s):  
Song-Ih Han ◽  
Hyo-Jin Lee ◽  
Hae-Ran Lee ◽  
Ki-Kwang Kim ◽  
Kyung-Sook Whang
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Dna Hybridization ◽  
Gene Sequence ◽  
Novel Species ◽  
Bacterial Species ◽  
Angelica Sinensis ◽  
Rrna Gene ◽  
The 16S Rrna Gene ◽  
Sequence Similarities

Three exopolysaccharide-producing bacteria, designated strains DRP28T, DRP29 and DRP31, were isolated from the rhizoplane of Angelica sinensis from the Geumsan, Republic of Korea. Cells were straight rods, Gram reaction-negative, aerobic, non-motile, and catalase- and oxidase- positive. Flexirubin-type pigments were absent. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Mucilaginibacter in the phylum Bacteroidetes. 16S rRNA gene sequence similarities to strains of recognized species of the genus Mucilaginibacter were 93.8–97.4 %. The major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The strains contained MK-7 as the major isoprenoid quinone. Strains DRP28T, DRP29 and DRP31 formed a single, distinct genomospecies with DNA G+C contents of 41.9–42.7 mol% and DNA hybridization values of 82.6–86.8 %; the strains exhibited DNA–DNA hybridization values of only 20.4–41.3 % with related species of the genus Mucilaginibacter. On the basis of evidence presented in this study, strains DRP28T, DRP29 and DRP31 were considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter polysacchareus sp. nov. is proposed. The type strain is DRP28T ( = KACC 15075T  = NBRC 107757T).

scholarly journals A Novel Reductive Dehalogenase, Identified in a Contaminated Groundwater Enrichment Culture and in Desulfitobacterium dichloroeliminans Strain DCA1, Is Linked to Dehalogenation of 1,2-Dichloroethane

2007 ◽  
Vol 73 (9) ◽  
pp. 2990-2999 ◽  
Author(s):  
Massimo Marzorati ◽  
Francesca de Ferra ◽  
Hilde Van Raemdonck ◽  
Sara Borin ◽  
Elena Allifranchini ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Enrichment Culture ◽  
Gene Copy Number ◽  
Gene Clusters ◽  
Amino Acid Identity ◽  
Chlorinated Ethenes ◽  
Gene Copy ◽  
Direct Pcr ◽  
Reductive Dehalogenase

ABSTRACT A mixed culture dechlorinating 1,2-dichloroethane (1,2-DCA) to ethene was enriched from groundwater that had been subjected to long-term contamination. In the metagenome of the enrichment, a 7-kb reductive dehalogenase (RD) gene cluster sequence was detected by inverse and direct PCR. The RD gene cluster had four open reading frames (ORF) showing 99% nucleotide identity with pceB, pceC, pceT, and orf1 of Dehalobacter restrictus strain DSMZ 9455T, a bacterium able to dechlorinate chlorinated ethenes. However, dcaA, the ORF encoding the catalytic subunit, showed only 94% nucleotide and 90% amino acid identity with pceA of strain DSMZ 9455T. Fifty-three percent of the amino acid differences were localized in two defined regions of the predicted protein. Exposure of the culture to 1,2-DCA and lactate increased the dcaA gene copy number by 2 log units, and under these conditions the dcaA and dcaB genes were actively transcribed. A very similar RD gene cluster with 98% identity in the dcaA gene sequence was identified in Desulfitobacterium dichloroeliminans strain DCA1, the only known isolate that selectively dechlorinates 1,2-DCA but not chlorinated ethenes. The dcaA gene of strain DCA1 possesses the same amino acid motifs as the new dcaA gene. Southern hybridization using total genomic DNA of strain DCA1 with dcaA gene-specific and dcaB- and pceB-targeting probes indicated the presence of two identical or highly similar dehalogenase gene clusters. In conclusion, these data suggest that the newly described RDs are specifically adapted to 1,2-DCA dechlorination.

scholarly journals Feeding a Low-protein Maternal Diet Affects Qinghai Bamei Piglet Jejunal Microbiome-metabolome Response

2021 ◽  
Author(s):  
Jipeng Jin ◽  
Liping Zhang ◽  
Qian Chen ◽  
Cunming Ma ◽  
Jianlei Jia ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Species ◽  
Relative Weight ◽  
Integrated Approach ◽  
Intestinal Microbiome ◽  
Rrna Gene ◽  
Metabolic Profiles ◽  
Microbial Composition ◽  
Suckling Piglets

Abstract This experiment investigated the impacts of feeding a maternal low-CP concentration diet having iso-essential amino acids on new born suckling piglets intestinal microbial composition and metabolic profiles. The Bamei swine breed was selected due to high meat quality and flavor, but demonstrates slower growth rates which may be related to jejunal nutrient supply. Forty randomly selected purebred Bamei sows were divided into two groups and fed a low dietary CP (12%, LP) or a normal CP (14%, CON) diet, respectively, but formulated to contain similar (iso-) essential amino acid concentrations per current recommendations. At 21 days, 12 piglets were randomly selected from each treatment and euthanized with jejunum content samples collected. The 16S rRNA gene sequencing and mass spectrometry-based metabolomics profiling were combined as an integrated approach for evaluating the functional impact of maternal CP concentrations on piglet intestinal microbiome. Even though piglets demonstrated similar 0 to 21 d ADG among treatments, the jejunum relative weight, villus width, crypt depth and muscular thickness were increased (P < 0.05), while villus height, and villus height:crypt depth were reduced (P < 0.05) for the material LP compared to the maternal fed CON diet. Maternal CP concentrations can modify the intestinal microbial composition of Bamei suckling piglets. The relative abundances of the bacterial species Escherichia-Shigella, Actinobacillus, Clostridium_sensu_stricto_1, Veillonella, and Turicibacter were increased (P < 0.05) in the maternal LP fed diet compared with the maternal fed CON diet. Jejunal digesta metabolomics analysis indicated that several amino acids were metabolized (i.e. cys, met, tyr phe and trp), biosynthesized (arg phe, tyr, and trp), or degraded (lys) were enriched (P < 0.05) for the maternal fed LP compared with the maternal fed CON. Correlation analysis demonstrated that certain intestinal bacterial genera were highly related to the histomorphology and altered intestinal microbiota metabolites. In conclusion, maternal dietary CP concentrations in excess of protein and amino acid requirements not only altered suckling Bamei piglets histomorphology, microbial composition and function, but also modulated jejunum microbial metabolic profiles, which aids in understanding the beneficial effects when feeding a maternal LP diet on piglet intestinal health.

scholarly journals Synergistic Degradation of Linuron by a Bacterial Consortium and Isolation of a Single Linuron-Degrading Variovorax Strain

2003 ◽  
Vol 69 (3) ◽  
pp. 1532-1541 ◽  
Author(s):  
Winnie Dejonghe ◽  
Ellen Berteloot ◽  
Johan Goris ◽  
Nico Boon ◽  
Katrien Crul ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Enrichment Culture ◽  
Bacterial Community Composition ◽  
Sole Source ◽  
Bacterial Consortium ◽  
The Other ◽  
Rrna Gene ◽  
Comamonas Testosteroni ◽  
Isolation And Identification

ABSTRACT The bacterial community composition of a linuron-degrading enrichment culture and the role of the individual strains in linuron degradation have been determined by a combination of methods, such as denaturing gradient gel electrophoresis of the total 16S rRNA gene pool, isolation and identification of strains, and biodegradation assays. Three strains, Variovorax sp. strain WDL1, Delftia acidovorans WDL34, and Pseudomonas sp. strain WDL5, were isolated directly from the linuron-degrading culture. In addition, subculture of this enrichment culture on potential intermediates in the degradation pathway of linuron (i.e., N,O-dimethylhydroxylamine and 3-chloroaniline) resulted in the isolation of, respectively, Hyphomicrobium sulfonivorans WDL6 and Comamonas testosteroni WDL7. Of these five strains, only Variovorax sp. strain WDL1 was able to use linuron as the sole source of C, N, and energy. WDL1 first converted linuron to 3,4-dichloroaniline (3,4-DCA), which transiently accumulated in the medium but was subsequently degraded. To the best of our knowledge, this is the first report of a strain that degrades linuron further than the aromatic intermediates. Interestingly, the rate of linuron degradation by strain WDL1 was lower than that for the consortium, but was clearly increased when WDL1 was coinoculated with each of the other four strains. D. acidovorans WDL34 and C. testosteroni WDL7 were found to be responsible for degradation of the intermediate 3,4-DCA, and H. sulfonivorans WDL6 was the only strain able to degrade N,O-dimethylhydroxylamine. The role of Pseudomonas sp. strain WDL5 needs to be further elucidated. The degradation of linuron can thus be performed by a single isolate, Variovorax sp. strain WDL1, but is stimulated by a synergistic interaction with the other strains isolated from the same linuron-degrading culture.

scholarly journals Thalassolituus oleivorans gen. nov., sp. nov., a novel marine bacterium that obligately utilizes hydrocarbons

2004 ◽  
Vol 54 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michail M. Yakimov ◽  
Laura Giuliano ◽  
Renata Denaro ◽  
Ermanno Crisafi ◽  
Tatiana N. Chernikova ◽  
...  
Keyword(s):  
Marine Bacterium ◽  
Gene Sequence ◽  
Sea Water ◽  
Enrichment Culture ◽  
Sequence Similarity ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Pseudomonas Oleovorans ◽  
Rrna Gene Sequence ◽  
Gene Sequence Analysis

An aerobic, heterotrophic, Gram-negative, curved bacterial strain, designated MIL-1T, was isolated by extinction dilution from an n-tetradecane enrichment culture that was established from sea water/sediment samples collected in the harbour of Milazzo, Italy. In the primary enrichment, the isolate formed creamy-white, medium-sized colonies on the surface of the agar. The isolate did not grow in the absence of NaCl; growth was optimal at 2·7 % NaCl. Only a narrow spectrum of organic compounds, including aliphatic hydrocarbons (C7–C20), their oxidized derivatives and acetate, were used as growth substrates. The isolate was not able to grow under denitrifying conditions. The DNA G+C content and genome size of strain MIL-1T were estimated to be 53·2 mol% and 2·2 Mbp, respectively. The major cellular and phospholipid fatty acids were palmitoleic, palmitic and oleic acids (33·5, 29·5 and 11·0 % and 18, 32 and 31 %, respectively). 3-Hydroxy lauric acid was the only hydroxy fatty acid detected. Thirteen different compounds that belonged to two types of phospholipid (phosphatidylethylamine and phosphatidylglycerol) were identified. 16S rRNA gene sequence analysis revealed that this isolate represents a distinct phyletic lineage within the γ-Proteobacteria and has about 94·4 % sequence similarity to Oceanobacter kriegii (the closest bacterial species with a validly published name). The deduced protein sequence of the putative alkane hydrolase, AlkB, of strain MIL-1T is related to the corresponding enzymes of Alcanivorax borkumensis and Pseudomonas oleovorans (81 and 80 % similarity, respectively). On the basis of the analyses performed, Thalassolituus oleivorans gen. nov., sp. nov. is described. Strain MIL-1T (=DSM 14913T=LMG 21420T) is the type and only strain of T. oleivorans.

scholarly journals Brevibacterium celere sp. nov., isolated from degraded thallus of a brown alga

2004 ◽  
Vol 54 (6) ◽  
pp. 2107-2111 ◽  
Author(s):  
Elena P. Ivanova ◽  
Richard Christen ◽  
Yulia V. Alexeeva ◽  
Natalia V. Zhukova ◽  
Natalia M. Gorshkova ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Brown Alga ◽  
Novel Species ◽  
Enrichment Culture ◽  
Sequence Similarity ◽  
Diaminopimelic Acid ◽  
Aerobic Bacteria ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Nutrient Media

Two whitish yellow, Gram-positive, non-motile, aerobic bacteria were isolated from enrichment culture during degradation of the thallus of the brown alga Fucus evanescens. The bacteria studied were chemo-organotrophic, mesophilic and grew well on nutrient media containing up to 15 % (w/v) NaCl. The DNA G+C content was 61 mol%. The two isolates exhibited a conspecific DNA–DNA relatedness value of 98 %, indicating that they belong to the same species. A comparative analysis of 16S rRNA gene sequences revealed that strain KMM 3637T formed a distinct phyletic lineage in the genus Brevibacterium (family Brevibacteriaceae, class Actinobacteria) and showed the highest sequence similarity (about 97 %) to Brevibacterium casei. DNA–DNA hybridization experiments demonstrated 45 % binding with the DNA of B. casei DSM 20657T. Physiological and chemotaxonomic characteristics (meso-diaminopimelic acid in the peptidoglycan, major cellular fatty acids 15 : 0ai and 17 : 0ai) of the bacteria studied were consistent with the genomic and phylogenetic data. On the basis of the results of this study, a novel species, Brevibacterium celere sp. nov., is proposed. The type strain is KMM 3637T (=DSM 15453T=ATCC BAA-809T).

scholarly journals Kordiimonas gwangyangensis gen. nov., sp. nov., a marine bacterium isolated from marine sediments that forms a distinct phyletic lineage (Kordiimonadales ord. nov.) in the ‘Alphaproteobacteria’

2005 ◽  
Vol 55 (5) ◽  
pp. 2033-2037 ◽  
Author(s):  
Kae Kyoung Kwon ◽  
Hee-Soon Lee ◽  
Sung Hyun Yang ◽  
Sang-Jin Kim
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Marine Bacterium ◽  
Enrichment Culture ◽  
Sequence Similarity ◽  
Bacterial Species ◽  
Carbon Sources ◽  
Optimal Growth ◽  
Rrna Gene ◽  
Respiratory Quinone

A marine bacterium, designated strain GW14-5T, capable of degrading high-molecular-mass polycyclic aromatic hydrocarbons was isolated from the sediments of Gwangyang Bay, Republic of Korea, after enrichment culture for 2 years with a mixture of benzo[a]pyrene and pyrene. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate forms a phyletic lineage that is distinct from the seven known orders within the ‘Alphaproteobacteria’. 16S rRNA gene sequence similarity of strain GW14-5T to all recognized bacterial species was not greater than 92 %. The dominant fatty acids of the isolate were i-17 : 1 (46·2 %), i-15 : 0 (15·1 %) and i-17 : 0 (12·6 %). The major respiratory quinone was MK-5, and the DNA G+C content was 39·3 mol%. Cells of strain GW14-5T were Gram-negative, motile, catalase-positive, oxidase-positive and weakly halophilic. Glucose, N-acetylglucosamine and maltose were utilized as sole carbon sources. The strain was positive for β-glucosidase activity. Optimal growth of strain GW14-5T was at pH 7·0 and 37–40 °C and required the presence of 2 % (w/v) NaCl. On the basis of this evidence, strain GW14-5T represents a novel genus and species in the ‘Alphaproteobacteria’ for which the name Kordiimonas gwangyangensis gen. nov., sp. nov. is proposed. The novel order Kordiimonadales is proposed for the distinct phyletic line represented by the genus Kordiimonas. The type strain is GW14-5T (=KCCM 42021T=JCM 12864T).

scholarly journals Combining Culture-Dependent and Independent Approaches for the Optimization of Epoxiconazole and Fludioxonil-Degrading Bacterial Consortia

2021 ◽  
Vol 9 (10) ◽  
pp. 2109
Author(s):  
Diogo Alexandrino ◽  
Ana Mucha ◽  
Maria Paola Tomasino ◽  
C. Marisa R. Almeida ◽  
Maria Carvalho
Keyword(s):  
Agricultural Soil ◽  
Enrichment Culture ◽  
Bacterial Species ◽  
The Other ◽  
Microbial Consortia ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Bacterial Consortia ◽  
First Time ◽  
Culture Dependent

Epoxiconazole (EPO) and fludioxonil (FLU) are two widely used fluorinated pesticides known to be highly persistent and with high ecotoxicological potential, turning them into pollutants of concern. This work aimed to optimize two degrading bacterial consortia, previously obtained from an agricultural soil through enrichment with EPO and FLU, by characterizing the contribution of their corresponding bacterial isolates to the biodegradation of these pesticides using both culture-dependent and independent methodologies. Results showed that a co-culture of the strains Hydrogenophaga eletricum 5AE and Methylobacillus sp. 8AE was the most efficient in biodegrading EPO, being able to defluorinate ca. 80% of this pesticide in 28 days. This catabolic performance is likely the result of a commensalistic cooperation, in which H. eletricum may be the defluorinating strain and Methylobacillus sp. may assume an accessory, yet pivotal, catabolic role. Furthermore, 16S rRNA metabarcoding analysis revealed that these strains represent a minority in their original consortium, showing that the biodegradation of EPO can be driven by less abundant phylotypes in the community. On the other hand, none of the tested combinations of bacterial strains showed potential to biodegrade FLU, indicating that the key degrading strains were not successfully isolated from the original enrichment culture. Overall, this work shows, for the first time, the direct involvement of two bacterial species, namely H. eletricum and Methylobacillus sp., in the biodegradation of EPO, while also offering insight on how they might cooperate to accomplish this process. Moreover, the importance of adequate culture-dependent approaches in the engineering of microbial consortia for bioremediation purposes is also emphasized.

scholarly journals Litoricola marina sp. nov.

2010 ◽  
Vol 60 (6) ◽  
pp. 1303-1306 ◽  
Author(s):  
Ahyoung Choi ◽  
Kiyoung Lee ◽  
Hyun-Myung Oh ◽  
Jing Feng ◽  
Jang-Cheon Cho
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Marine Bacterium ◽  
Novel Species ◽  
Bacterial Species ◽  
The Yellow Sea ◽  
Rrna Gene ◽  
Gene Sequence Analysis ◽  
Type Strains

A Gram-negative, non-pigmented, non-motile, chemoheterotrophic marine bacterium, designated strain IMCC2782T, was isolated from a surface seawater sample of the Yellow Sea, Korea. On the basis of 16S rRNA gene sequence analysis and phenotypic and genotypic characterization, strain IMCC2782T is shown to represent a novel species of the genus Litoricola. Strain IMCC2782T grew at 15–37 °C and tolerated 7.5 % NaCl. Based on 16S rRNA gene sequences, strain IMCC2782T was related most closely to the type strain of Litoricola lipolytica (97.1 % similarity) but showed less than 90 % similarity to the type strains of other bacterial species. The predominant fatty acids were mono-unsaturated C18 : 1 and C16 : 1. The G+C content of the DNA of strain IMCC2782T was 59.6 mol%. A low level of DNA–DNA relatedness (28.1 %) together with several phenotypic characteristics, including enzyme activities, served to differentiate strain IMCC2782T from the type strain of L. lipolytica. Therefore, strain IMCC2782T is considered to represent a novel species of the genus Litoricola, for which the name Litoricola marina sp. nov. is proposed. The type strain is IMCC2782T (=KCTC 22683T =NBRC 105824T).

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