scholarly journals Interaction of Soil Microbes with Organoclays and their Impact on the Immobilization of Hg under Aerobic Conditions

2021 ◽  
Vol 232 (4) ◽  
Author(s):  
Timothy E. Egbo ◽  
Alexander Johs ◽  
Rajnish Sahu ◽  
Yazeed Abdelmageed ◽  
Jeffrey Ogbudu ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Soil Bacteria ◽  
Bacterial Strains ◽  
Natural Ecosystems ◽  
Culture Studies ◽  
Burkholderia Thailandensis ◽  
Aerobic Conditions ◽  
Remediation Strategies ◽  
East Fork Poplar Creek ◽  
Environmental Microbes

AbstractImmobilization of mercury (Hg) leaching from bank soils of East Fork Poplar Creek (EFPC) is considered part of remediation strategies to mitigate the amount of Hg entering the creek. Different approaches are currently being evaluated, such as utilizing engineered sorbents to immobilize Hg species in EFPC bank soils. However, the influence of environmental microbes on the immobilization of Hg by sorbents is unknown. Organocation-modified phyllosilicate clay minerals (organoclays) are widely used as sorbents for the immobilization of contaminants. This study evaluates the interactions of Serratia marcescens and Burkholderia thailandensis with the sorbent Organoclay PM-199 and their impact on the immobilization of Hg under aerobic conditions. We evaluated the competitive binding of Hg between sorbents and selected microorganisms in a series of pure culture studies using bacterial strains identified in EFPC bank soil samples. Our results suggest that Hg sorption by Organoclay PM-199 is not significantly impacted by common soil bacteria present in EFPC, specifically Serratia marcescens and Burkholderia thailandensis, which are known to form biofilms. These findings suggest that sorbent amendments are an effective strategy for the remediation of Hg contamination in natural ecosystems.

Biodegradation of organophosphorus Pollutants by Soil Bacteria: Biochemical Aspects and Unsolved Problems

2020 ◽  
Vol 36 (4) ◽  
pp. 126-135
Author(s):  
T.V. Shushkova ◽  
D.O. Epiktetov ◽  
S.V. Tarlachkov ◽  
I.T. Ermakova ◽  
A.A. Leontievskii
Keyword(s):  
Genome Sequencing ◽  
Soil Bacteria ◽  
Activity Regulation ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Russian Science ◽  
Degrading Bacteria ◽  
Phosphorus Source ◽  
Glyphosate Herbicide ◽  
Enzymatic Pathways

The degradation of persistent organophosphorus pollutants have been studied in 6 soil bacterial isolates and in 3 bacterial strains adapted for utilization of glyphosate herbicide (GP) under laboratory conditions. Significant differences in the uptake of organophosphonates were found in taxonomically close strains possessing similar enzymatic pathways of catabolism of these compounds, which indicates the existence of unknown mechanisms of activity regulation of these enzymes. The effect of adaptation for GP utilization as a sole phosphorus source on assimilation rates of several other phosphonates was observed in studied bacteria. The newly found efficient stains provided up to 56% of GP decomposition after application to the soil in the laboratory. The unresolved problems of microbial GP metabolism and the trends for further research on the creation of reliable biologicals capable of decomposing organophosphonates in the environment are discussed. organophosphonates, glyphosate, biodegradation, bioremediation, C-P lyase, phosphonatase, degrading bacteria Investigation of phosphonatase and genome sequencing were supported by Russian Science Foundation Grant no. 18-074-00021.

scholarly journals Microbiology of brewing production - bacteria of the order Enterobacterales and culture methods for their detection

2020 ◽  
Vol 66 (5) ◽  
pp. 345-350
Author(s):  
Petra Kubizniaková ◽  
Martina Brožová ◽  
Kateřina Štulíková ◽  
Eva Vontrobová ◽  
Katarína Hanzalíková ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Serratia Marcescens ◽  
Klebsiella Oxytoca ◽  
Enterobacter Cloacae ◽  
Citrobacter Freundii ◽  
Culture Methods ◽  
Aerobic Conditions ◽  
Rahnella Aquatilis ◽  
Raoultella Terrigena ◽  
Incubation Temperatures

The growth of 7 strains belonging to the order of Enterobacterales, represented by the species of Citrobacter Freundii, Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca, Obesumbacterium proteus, Rahnella aquatilis, Raoultella terrigena, Serratia marcescens and Shimwellia pseudoproteus, was monitored on selected cultivation media. Three types of agars - Endo, MacConkey and Chromocult Coliform agar together with two incubation temperatures of 28 and 37 °C were tested under aerobic conditions. The aim of the study was to detect such essential enterobacteria harmful to beer that cannot be proven at 37 °C, which is the temperature usually used in operational laboratories in breweries. Our results showed that most of the tested strains of enterobacteria were able to grow at 28 °C on all selected types of agar. The exception was just the representatives detection of which is problematic at 37 °C. Nevertheless, a little or no growth was always observed on just one of the tested media.

scholarly journals Applying indirect open-circuit calorimetry to study energy expenditure in gnotobiotic mice harboring different human gut microbial communities

Microbiome ◽  
2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Ilia G. Halatchev ◽  
David O’Donnell ◽  
Matthew C. Hibberd ◽  
Jeffrey I. Gordon
Keyword(s):  
Microbial Communities ◽  
Energy Homeostasis ◽  
Open Circuit ◽  
Microbial Consortia ◽  
Illustrative Case ◽  
Bacterial Strains ◽  
Human Gut ◽  
New Methods ◽  
Gnotobiotic Mice ◽  
Environmental Microbes

AbstractGiven the increasing use of gnotobiotic mouse models for deciphering the effects of human microbial communities on host biology, there is a need to develop new methods for characterizing these animals while maintaining their isolation from environmental microbes. We describe a method for performing open-circuit indirect calorimetry on gnotobiotic mice colonized with gut microbial consortia obtained from different human donors. In this illustrative case, cultured collections of gut bacterial strains were obtained from obese and lean co-twins. The approach allows microbial contributions to host energy homeostasis to be characterized.

scholarly journals Identification, Phylogenetic Analysis, and Biological Characterization of Serratia marcescens Strains Causing Cucurbit Yellow Vine Disease

2003 ◽  
Vol 93 (10) ◽  
pp. 1233-1239 ◽  
Author(s):  
J. Rascoe ◽  
M. Berg ◽  
U. Melcher ◽  
F. L. Mitchell ◽  
B. D. Bruton ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Serratia Marcescens ◽  
16S Rdna ◽  
Acid Methyl Ester ◽  
Bacterial Strains ◽  
Metabolic Functions ◽  
Distinct Cluster ◽  
Cucurbit Yellow Vine Disease ◽  
Vine Decline ◽  
Reference Strains

A serious vine decline of cucurbits known as cucurbit yellow vine disease (CYVD) is caused by rod-shaped bacteria that colonize the phloem elements. Sequence analysis of a CYVD-specific polymerase chain reaction (PCR)-amplified 16S rDNA product showed the microbe to be a γ-proteobacterium related to the genus Serratia. To identify and characterize the bacteria, one strain each from watermelon and zucchini and several noncucurbit-derived reference strains were subjected to sequence analysis and biological function assays. Taxonomic and phylogenetic placement was investigated by analysis of the groE and 16S rDNA regions, which were amplified by PCR and directly sequenced. For comparison, eight other bacterial strains identified by others as Serratia spp. also were sequenced. These sequences clearly identified the CYVD strains as Serratia marcescens. However, evaluation of metabolic and biochemical features revealed that cucurbit-derived strains of S. marcescens differ substantially from strains of the same species isolated from other environmental niches. Cucurbit strains formed a distinct cluster, separate from other strains, when their fatty acid methyl ester profiles were analyzed. In substrate utilization assays (BIOLOG, Vitek, and API 20E), the CYVD strains lacked a number of metabolic functions characteristic for S. marcescens, failing to catabolize 25 to 30 compounds that were utilized by S. marcescens reference strains. These biological differences may reflect gene loss or repression that occurred as the bacterium adapted to life as an intracellular parasite and plant pathogen.

Mechanism of boron tolerance in soil bacteria

2010 ◽  
Vol 56 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Iftikhar Ahmed ◽  
Toru Fujiwara
Keyword(s):  
Soil Bacteria ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Soil Samples ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Tolerance Mechanisms ◽  
Boron Tolerance ◽  
Rrna Gene Sequencing ◽  
Comparative Phylogenetic Analysis

Boron (B) is toxic to living cells at levels above a certain threshold. We isolated several B-tolerant bacterial strains from soil samples and studied them for possible mechanisms of B tolerance. 16S rRNA gene sequencing and comparative phylogenetic analysis demonstrated that the isolates belong to the following 6 genera: Arthrobacter , Rhodococcus , Lysinibacillus , Algoriphagus , Gracilibacillus , and Bacillus . These isolates exhibited B-tolerance levels of 80, 100, 150, 300, 450, and 450 mmol/L, respectively, whilst maintaining a significantly lower intracellular B concentration than in the medium. Statistical analysis showed a negative correlation between the protoplasmic B concentration and the degree of tolerance to a high external B concentration. The kinetic assays suggest that the high B efflux and (or) exclusion are the tolerance mechanisms against a high external B concentration in the isolated bacteria.

scholarly journals Root-specific camalexin biosynthesis controls the plant growth-promoting effects of multiple bacterial strains

2019 ◽  
Vol 116 (31) ◽  
pp. 15735-15744 ◽  
Author(s):  
Anna Koprivova ◽  
Stefan Schuck ◽  
Richard P. Jacoby ◽  
Irene Klinkhammer ◽  
Bastian Welter ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Bacterial Strains ◽  
Natural Ecosystems ◽  
Promoting Effect ◽  
Gene Encoding ◽  
A Genome ◽  
Sulfatase Activity ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plants in their natural ecosystems interact with numerous microorganisms, but how they influence their microbiota is still elusive. We observed that sulfatase activity in soil, which can be used as a measure of rhizosphere microbial activity, is differently affected by Arabidopsis accessions. Following a genome-wide association analysis of the variation in sulfatase activity we identified a candidate gene encoding an uncharacterized cytochrome P450, CYP71A27. Loss of this gene resulted in 2 different and independent microbiota-specific phenotypes: A lower sulfatase activity in the rhizosphere and a loss of plant growth-promoting effect by Pseudomonas sp. CH267. On the other hand, tolerance to leaf pathogens was not affected, which agreed with prevalent expression of CYP71A27 in the root vasculature. The phenotypes of cyp71A27 mutant were similar to those of cyp71A12 and cyp71A13, known mutants in synthesis of camalexin, a sulfur-containing indolic defense compound. Indeed, the cyp71A27 mutant accumulated less camalexin in the roots upon elicitation with silver nitrate or flagellin. Importantly, addition of camalexin complemented both the sulfatase activity and the loss of plant growth promotion by Pseudomonas sp. CH267. Two alleles of CYP71A27 were identified among Arabidopsis accessions, differing by a substitution of Glu373 by Gln, which correlated with the ability to induce camalexin synthesis and to gain fresh weight in response to Pseudomonas sp. CH267. Thus, CYP71A27 is an additional component in the camalexin synthesis pathway, contributing specifically to the control of plant microbe interactions in the root.

scholarly journals Anaerobic and Aerobic Degradation of Cyanophycin by the Denitrifying Bacterium Pseudomonas alcaligenes Strain DIP1 and Role of Three Other Coisolates in a Mixed Bacterial Consortium

2008 ◽  
Vol 74 (11) ◽  
pp. 3434-3443 ◽  
Author(s):  
Ahmed Sallam ◽  
Alexander Steinbüchel
Keyword(s):  
High Performance ◽  
Physiological Role ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Strictly Anaerobic ◽  
Bacterial Strains ◽  
Direct Role ◽  
Aerobic Conditions ◽  
Pseudomonas Alcaligenes

ABSTRACT Four bacterial strains were isolated from a cyanophycin granule polypeptide (CGP)-degrading anaerobic consortium, identified by 16S rRNA gene sequencing, and assigned to species of the genera Pseudomonas, Enterococcus, Clostridium, and Paenibacillus. The consortium member responsible for CGP degradation was assigned as Pseudomonas alcaligenes strain DIP1. The growth of and CGP degradation by strain DIP1 under anaerobic conditions were enhanced but not dependent on the presence of nitrate as an electron acceptor. CGP was hydrolyzed to its constituting β-Asp-Arg dipeptides, which were then completely utilized within 25 and 4 days under anaerobic and aerobic conditions, respectively. The end products of CGP degradation by strain DIP1 were alanine, succinate, and ornithine as determined by high-performance liquid chromatography analysis. The facultative anaerobic Enterococcus casseliflavus strain ELS3 and the strictly anaerobic Clostridium sulfidogenes strain SGB2 were coisolates and utilized the β-linked isodipeptides from the common pool available to the mixed consortium, while the fourth isolate, Paenibacillus odorifer strain PNF4, did not play a direct role in the biodegradation of CGP. Several syntrophic interactions affecting CGP degradation, such as substrate utilization, the reduction of electron acceptors, and aeration, were elucidated. This study demonstrates the first investigation of CGP degradation under both anaerobic and aerobic conditions by one bacterial strain, with regard to the physiological role of other bacteria in a mixed consortium.

scholarly journals Growth in Coculture Stimulates Metabolism of the Phenylurea Herbicide Isoproturon by Sphingomonas sp. Strain SRS2

2002 ◽  
Vol 68 (7) ◽  
pp. 3478-3485 ◽  
Author(s):  
Sebastian R. Sørensen ◽  
Zeev Ronen ◽  
Jens Aamand
Keyword(s):  
Amino Acids ◽  
Soil Bacteria ◽  
Soil Microflora ◽  
Rrna Gene ◽  
Culture Collections ◽  
Culture Studies ◽  
Phenylurea Herbicide ◽  
Previously Treated ◽  
The 16S Rrna Gene

ABSTRACT Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the β-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of 14C-labeled isoproturon to 14CO2 and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent.

scholarly journals Distribution of Camphor Monooxygenase Genes in Soil Bacteria

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
N. Ngadiman ◽  
Hikaru Suenaga ◽  
Masatoshi Goto ◽  
Kensuke Furukawa
Keyword(s):  
Pseudomonas Putida ◽  
Microbial Degradation ◽  
Genomic Dna ◽  
Soil Bacteria ◽  
Southern Analysis ◽  
Bacterial Strains ◽  
Gene Distribution

In microbial degradation of camphor, the first step is oxidation by multiunit enzyme, camphormonooxygenase, encoded by cam genes (camA,B,C). Seven camphor-utilizing bacterial strains have been isolatedfrom soil at various locations. CamA,B,C genes of Pseudomonas putida strain PpG1 and strain GF2001 were used asprobes to explore their abundance in the camphor-utilizing bacteria. Southern analysis revealed that all of thecam genes of GF2001 could hybridize well to the SpeI-digested genomic DNA of strains tested, whereas PpG1 camgenes were not. This result suggested that the GF2001 type cam genes are widely distributed among the camphorutilizingstrains in the environment. Thus strain GF2001 and seven newly isolated strains share a commonevolutionary origin.Key words: Camphor monooxygenase genes, gene distribution, sail bacteria.

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