scholarly journals Polychlorinated Biphenyl (PCB)-Degrading Bacteria Associated with Trees in a PCB-Contaminated Site

2006 ◽  
Vol 72 (4) ◽  
pp. 2331-2342 ◽  
Author(s):  
Mary Beth Leigh ◽  
Petra Prouzová ◽  
Martina Macková ◽  
Tomáš Macek ◽  
David P. Nagle ◽  
...  

ABSTRACT The abundance, identities, and degradation abilities of indigenous polychlorinated biphenyl (PCB)-degrading bacteria associated with five species of mature trees growing naturally in a contaminated site were investigated to identify plants that enhance the microbial PCB degradation potential in soil. Culturable PCB degraders were associated with every plant species examined in both the rhizosphere and root zone, which was defined as the bulk soil in which the plant was rooted. Significantly higher numbers of PCB degraders (2.7- to 56.7-fold-higher means) were detected in the root zones of Austrian pine (Pinus nigra) and goat willow (Salix caprea) than in the root zones of other plants or non-root-containing soil in certain seasons and at certain soil depths. The majority of culturable PCB degraders throughout the site and the majority of culturable PCB degraders associated with plants were identified as members of the genus Rhodococcus by 16S rRNA gene sequence analysis. Other taxa of PCB-degrading bacteria included members of the genera Luteibacter and Williamsia, which have not previously been shown to include PCB degraders. PCB degradation assays revealed that some isolates from the site have broad congener specificities; these isolates included one Rhodococcus strain that exhibited degradation abilities similar to those of Burkholderia xenovorans LB400. Isolates with broad congener specificity were widespread at the site, including in the biostimulated root zone of willow. The apparent association of certain plant species with increased abundance of indigenous PCB degraders, including organisms with outstanding degradation abilities, throughout the root zone supports the notion that biostimulation through rhizoremediation is a promising strategy for enhancing PCB degradation in situ.

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Pankaj Kumar Arora ◽  
Alok Srivastava ◽  
Vijay Pal Singh

Eighteen bacterial strains, isolated from a waste water sample collected from a chemically contaminated site, Patancheru (17°32′N 78°16′E/17.53°N 78.27°E), India, were able to decolorize 4-chloro-2-nitrophenol (4C2NP) in the presence of an additional carbon source. These eighteen 4C2NP-decolorizing strains have been identified as members of four different genera, includingBacillus,Paenibacillus,Pseudomonas, andLeuconostocbased on the 16S rRNA gene sequencing and phylogenetic analysis. Most of the bacteria (10) belonged to the genusBacillusand contributed 56% of the total 4C2NP-degrading bacteria, whereas the members of generaPaenibacillusandPseudomonasrepresented 22% and 17%, respectively, of total 4C2NP-degrading isolates. There was only one species ofLeuconostoccapable of degrading 4C2NP. This is the first report of the diversity of 4C2NP-decolorizing bacteria in a waste water sample. Furthermore, one bacterium,Bacillus aryabhattaistrain PC-7, was able to decolorize 4C2NP up to a concentration of 2.0 mM. Gas chromatography-mass spectrometry analysis identified 5-chloro-2-methylbenzoxazole as the final product of 4C2NP decolorization in strain PC-7.


1996 ◽  
Vol 33 (4-5) ◽  
pp. 309-313
Author(s):  
Jan Šálek ◽  
František Marcián ◽  
Iman Elazizy

Vegetative root zone methods are based on self-purifying processes that take place in the soil, wetland and vegetation containing water media. Our studies are concentrated on the course of puryfying in relation with the length of the filtration bed and on the progress of eliminating the ammoniacal pollution. The research proved that the essential part of the puryfying process takes place within the inlet zone (Figs 1 and 2). The decomposition of ammonia proceeds very slowly. The process of nitrification is affected by the lack of oxygen in the filtration media. To improve the effectiveness of vegetative root zone methods we suggest specific steps: an adjustment of the inlet zone, a system of cascades, a water level pulsation system and combinations of different types and arrangements of vegetative root zones.


2021 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Mayumi Minamisawa ◽  
Takuma Suzumura ◽  
Sudeep Bose ◽  
Tetsuyuki Taniai ◽  
Gota Kawai ◽  
...  

The effect of limonoids and spermine (Spm) extracted from yuzu (Citrus junos) seeds on the gut and the brain in a mouse model with Sandhoff disease (SD) was investigated. Wild-type and SD mice were fed a normal diet, or a diet supplemented with limonoid, Spm, or limonoid + Spm for 14–18 weeks, and then 16S rRNA gene amplicon sequencing with extracted DNA from their feces was executed. For SD control mice, intestinal microbiota was mostly composed of Lactobacillus and linked to dysbiosis. For SD and wild-type mice fed with limonoids + Spm or limonoids alone, intestinal microbiota was rich in mucin-degrading bacteria, including Bacteroidetes, Verrucomicrobia, and Firmicutes, and displayed a higher production of short-chain fatty acids and immunoglobulin A. Additionally, SD mice fed with limonoids + Spm or limonoids alone had less inflammation in hypothalamic tissues and displayed a greater number of neurons. Administration of limonoids and/or Spm improved the proportions of beneficial intestinal microbiota to host health and reduced neuronal degeneration in SD mice. Yuzu seed limonoids and Spermine may help to maintain the homeostasis of intestinal microbiota and hypothalamic tissue in the SD mouse model.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Expedito K. A. Camboim ◽  
Arthur P. Almeida ◽  
Michelle Z. Tadra-Sfeir ◽  
Felício G. Junior ◽  
Paulo P. Andrade ◽  
...  

The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L−1sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker.Pseudomonas fluorescens(strain DSM 8341) was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing asPigmentiphaga kullae(ECPB08) andAncylobacter dichloromethanicus(ECPB09). These bacteria degraded sodium fluoroacetate, releasing 20 mmol L−1of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L−1of SF. There are no previous reports of fluoroacetate dehalogenase activity forP. kullaeandA. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way,P. kullaeandA. dichloromethanicusmay be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants.


2015 ◽  
Vol 77 (24) ◽  
Author(s):  
Najwa Husna Sanusi ◽  
Phang Ing Chia ◽  
Noor Faizul Hadry Nordin

Contamination of soil and groundwater pollution is a severe problem, has been attracting considerable public attention over the last decades. With the demand for green and cleaner technology for remediation process, there is an increased interest in moving away from conventional technologies towards bioremediation technologies. Rhizospheric zone is a suitable place for harboring bacteria that are capable to utilize chemical compounds which will be used either to facilitate growth of bacteria or the host plants. Identification of the specific microbial members should allow for better strategies to enhance biodegradation. This study aimed to isolate and identify the rhizospheric associated microbes of lemongrass (Cymbopogon citratus), a plant that commonly available in South East Asia, which could be used in future research on degradation studies of dibenzofuran. This probably is due to their ability to harbor large numbers of bacteria on their highly branched root systems. A total of 68 strains of dibenzofuran (DF)- degrading bacteria isolated from the rhizospheric soil of lemon grass from 2 different unpolluted sites were characterized. The isolates showed the ability to utilize dibenzofuran as the sole carbon and energy source up to 40 ppm. Identification of the isolates based on 16S rRNA gene sequence assigned them as members of the phyla Proteobacteria and Firmicutes, among which those of the genera, Proteobacteria were most abundant. The presented results indicated the potential of these bacterial isolates in bioremediation of dibenzofuran-contaminated soil.


Author(s):  
Sinchan Banerjee ◽  
Anna Bedics ◽  
Péter Harkai ◽  
Balázs Kriszt ◽  
Nagaraju Alpula ◽  
...  

AbstractTo develop effective bioremediation strategies, it is always important to explore autochthonous microbial community diversity using substrate-specific enrichment. The primary objective of this present study was to reveal the diversity of aerobic xylene-degrading bacteria at a legacy BTEX-contaminated site where xylene is the predominant contaminant, as well as to identify potential indigenous strains that could effectively degrade xylenes, in order to better understand the underlying facts about xylene degradation using a multi-omics approach. Henceforward, parallel aerobic microcosms were set up using different xylene isomers as the sole carbon source to investigate evolved bacterial communities using both culture-dependent and independent methods. Research outcome showed that the autochthonous community of this legacy BTEX-contaminated site has the capability to remove all of the xylene isomers from the environment aerobically employing different bacterial groups for different xylene isomers. Interestingly, polyphasic analysis of the enrichments disclose that the community composition of the o-xylene-degrading enrichment community was utterly distinct from that of the m- and p-xylene-degrading enrichments. Although in each of the enrichments Pseudomonas and Acidovorax were the dominant genera, in the case of o-xylene-degrading enrichment Rhodococcus was the main player. Among the isolates, two Hydogenophaga strains, belonging to the same genomic species, were obtained from p-xylene-degrading enrichment, substantially able to degrade aromatic hydrocarbons including xylene isomers aerobically. Comparative whole-genome analysis of the strains revealed different genomic adaptations to aromatic hydrocarbon degradation, providing an explanation on their different xylene isomer-degrading abilities.


2007 ◽  
Vol 73 (17) ◽  
pp. 5683-5686 ◽  
Author(s):  
Dana M. Cook ◽  
Emily DeCrescenzo Henriksen ◽  
Rima Upchurch ◽  
Joy B. Doran Peterson

ABSTRACT The Tipula abdominalis larval hindgut microbial community presumably facilitates digestion of the lignocellulosic diet. The microbial community was investigated through characterization of bacterial isolates and analysis of 16S rRNA gene clone libraries. This initial study revealed novel bacteria and provides a framework for future studies of this symbiosis.


2020 ◽  
Vol 80 (2) ◽  
pp. 354-361 ◽  
Author(s):  
S. D. Lima ◽  
A. F. Oliveira ◽  
R. Golin ◽  
V. C. P. Lopes ◽  
D. S. Caixeta ◽  
...  

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.


2000 ◽  
Vol 19 (12) ◽  
pp. 2968-2981 ◽  
Author(s):  
Gladys L. Stephenson ◽  
Nicola Koper ◽  
Glenn F. Atkinson ◽  
Keith R. Solomon ◽  
Richard P. Scroggins

2015 ◽  
Vol 50 (3) ◽  
pp. 193-198
Author(s):  
M Aslam ◽  
HM Nasrullah ◽  
M Akhtar ◽  
B Ali ◽  
M Akram ◽  
...  

Sesame is a well known oil seed crop in arid and semiarid region of Pakistan and its productivity is affected due to sensitiveness to water logging in the root zones. The experiment was conducted at research area of Agronomic Research Station, Bahawalpur during the year 2010 and 2011. The crop was sown by three different planting techniques i.e. flat sowing with 45cm apart rows, ridge sowing with 45cm apart, bed sowing with 60/30 cm i.e. 60 cm wide beds with 30 cm furrow between the beds. The data revealed that maximum number of plants wilted in flat planting as compared to other methods of planting were taken in this experiment. It was also recorded that bed planting at 90cm apart beds gave maximum grain yield of 843 kg ha-1 followed by ridge planting (seed spreading by broadcast and with augmented furrows) with a grain yield of 811 kg ha-1. The lowest yield was obtained from conventional method of sowing which gave 349 kg ha-1 grain yield. Water logging stress in the root zone can successfully be avoided by planting sesame on beds or ridges under climatic conditions of Bahawalpur.Bangladesh J. Sci. Ind. Res. 50(3), 193-198, 2015


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