scholarly journals Aerobic polychlorinated biphenyl-degrading bacteria isolated from the Tohoku region of Japan are not regionally endemic

2022 ◽  
pp. 1-12
Author(s):  
Tomijiro Hara ◽  
Yumiko Takatsuka

In the Tohoku region of Japan, 72% of the land comprises mountain forest zones. During winter, severe climatic conditions include heavy snowfall. In such an environment, which is considered high in biodiversity, we assumed that aerobic bacteria would be diverse and would possess the ability to degrade polychlorinated biphenyls (PCBs). In this study, 78 environmental samples were collected from the Tohoku region and 56 aerobic PCB-degrading bacterial strains were isolated. They belonged to the genera Achromobacter, Rhodococcus, Pseudomonas, Stenotrophomonas, Comamonas, Pigmentiphaga, Xenophilus, Acinetobacter, and Pandoraea. Previously reported aerobic PCB-degrading bacterial strains isolated in Japan belonged to the same genera, except that the genera Acidovorax and Bacillus were not identified in the present study. In particular, the isolated Comamonas testosteroni strains YAZ2 and YU14-111 had high PCB-degrading abilities. Analysis of the sequences of the YAZ2 and YU14-111 strains showed that the gene structures of the bph operon, which encode enzymes associated with PCB degradation, were the same as those of the Acidovorax sp. KKS102 strain. Moreover, 2,3-biphenyl dioxygenase activity was responsible for the degradation characteristics of all the isolated strains. Overall, this study suggests that aerobic PCB-degrading bacteria are not specifically endemic to the Tohoku region but distributed across Japan.

1995 ◽  
Vol 41 (7) ◽  
pp. 612-619 ◽  
Author(s):  
Bindu Joshi ◽  
Satish Walia

In this study, we isolated and characterized biphenyl (BP) and polychlorinated biphenyl (PCB) degrading bacterial strains found in PCB-contaminated soil from an auto manufacturing plant located in Syracuse, New York. Twenty-one BP and PCB-degrading bacteria were randomly selected to form a representative sample of the bacterial population present at the site. Of the 21 bacteria, 13 were identified as Comamonas testosteroni, constituting about 60% of the bacterial population examined. Other PCB degraders identified were Acidovorax facilis, Alcaligenes xylosoxydans, Bacillus sphericus, Hydrogenophaga pseudoflava, Pseudomonas avanae, and Rhodococcus fascians. Owing to the abundance of C. testosteroni at this site, only these isolates were further characterized for their PCB congener degradation profile, 2,3-dihydroxybiphenyl 1,2-dioxygenase activity, and genetic relatedness by polymerase chain reaction (PCR) analysis. The PCB congener degradation pattern revealed a high degree of variability among the C. testosteroni isolates. The majority of the C. testosteroni isolates tested could degrade more than 95% of the PCB congeners up to pentachiorinated biphenyl. Only four isolates could degrade more than 80% of hexachlorobiphenyl. All 12 isolates of C. testosteroni tested were able to attack 2,3,4,5,6,3′,4′-heptachlorobiphenyl, indicating involvement of biphenyl 2,3-dioxygenase, while 2,3,5,6,2′,3′,6′-heptach!orobiphenyl was attacked by 6 strains, suggesting an oxidation reaction mediated by 3,4-dioxygenase. 2,3-Dihydroxybiphenyl 1,2-dioxygenase activity was also found to vary among the C. testosteroni isolates tested in this study. Eleven strains showed 2,3-dihydroxybiphenyl 1,2-dioxygenase activity specific for 2,3-dihydroxybiphenyl, whereas isolate BW169 could metabolize both 2,3-dihydroxybiphenyl and 4-methylcatechol, and isolate BW74 had the ability to metabolize all three substrates (2,3-dihydroxybiphenyl, 4-chlorocatechol, and 4-methylcatechol). Further molecular characterization of these isolates was done by a PCR-based assay, random amplified polymorphic DNA (RAPD) analysis. Amplifications of common DNA fragments of 450 dp using primer OPJ6 and 650 bp using primer OPJ14 were identified in the C. testosteroni isolates, although a distinct RAPD pattern was obtained for all of the isolates using primer OPJ14, and a combination of the two primers. Therefore, the results presented in this study demonstrate that RAPD can be used to fingerprint the C. testosteroni isolates.Key words: comamonas testosteroni, polychlorinated biphenyl, arbitrary primer-PCR.


2002 ◽  
Vol 68 (11) ◽  
pp. 5756-5759 ◽  
Author(s):  
Andrew C. Singer ◽  
Charles S. Wong ◽  
David E. Crowley

ABSTRACT Five polychlorinated biphenyl (PCB)-degrading bacteria were tested for the ability to differentiate between the enantiomers of four atropisomeric PCB congeners (2,2′,3,6-tetra-CB; 2,2′,3,3′,6-penta-CB; 2,2′,3,4′,6-penta-CB; and 2,2′,3,5′,6-penta-CB) after growth in the presence of tryptone-soytone, biphenyl, carvone, or cymene. Enantioselectivity was shown to vary with respect to strain, congener, and cosubstrate.


2015 ◽  
Vol 84 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Silvia Barazorda Romero ◽  
Alois Čížek ◽  
Martina Masaříková ◽  
Zdeněk Knotek

The aims of this study were to characterize the choanal and cloacal aerobic bacterial flora in healthy captive green iguanas and to compare it with the bacterial flora of the biofilm present in the water container of each terrarium. Samples were collected from the choana and the cloaca of 20 healthy captive adult green iguanas and from the biofilm of 15 water containers. The final identification of aerobic bacteria was performed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.Salmonellapositive samples were serotyped. The most common strains observed at each test location were from 1) choanae:Staphylococcusspp.,Enterobacter cloacaeandComamonas testosteroni; 2) cloacae:Citrobacterspp.,Salmonellaspp. andCorynebacteriumspp.; and 3) biofilms:Pseudomonasspp.,Salmonellaspp. andAcidovoraxspp. We showed that apart fromSalmonellaspp., the choanal and cloacal bacterial flora differed from the microorganisms present in the biofilm of the animal’s water container. These data revealed that healthy captive adult green iguanas harbored several aerobic bacterial strains that in immunosuppressed reptiles may act as opportunistic pathogens. Also, several of the aerobic bacteria identified in samples are potential zoonotic agents. Characterization of the normal background flora in captive reptiles and their environment can contribute to an understanding of the spread of bacterial contamination and the risk of potential zoonotic diseases for people in contact with these animals.


2020 ◽  
Vol 36 (4) ◽  
pp. 126-135
Author(s):  
T.V. Shushkova ◽  
D.O. Epiktetov ◽  
S.V. Tarlachkov ◽  
I.T. Ermakova ◽  
A.A. Leontievskii

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.


2016 ◽  
Vol 47 (3) ◽  
pp. 536-541 ◽  
Author(s):  
Jianjun Shuai ◽  
Xurun Yu ◽  
Jing Zhang ◽  
Ai-sheng Xiong ◽  
Fei Xiong

Author(s):  
Ch. N. Sambyla ◽  
N. M. Bessonova ◽  
R. B. Chysyma

The Republic of Tyva is a region in the geographical center of Asia, which located at the junction of the Siberian taiga and Central Asian desert-steppe landscapes, in a wide band of mountains and intermountain plains. The mountain-forest area of Tyva has long been considered a natural habitat for antler deer, one of which is the maral (Cervus elaphus sibiricus). In order to restore maral breeding and increase the number of marals in the former limits, marals of the Altai-Sayan breed have been imported to the Republic of Tyva from the Republic of Altai. The preservation of productive traits, reproductive function and the realization of the genetic potential of animals introduced to new climatic conditions largely depends on the ability of these animals to adapt to existing environments. We have assessed in this paper the natural resistance of the marals of Altai-Sayan breed during introduction in the Tyva Republic in comparison with the indicators of the marals have been bred in the Altai Republic. The researches have been carried out in 2019. The research material was blood samples of marals of Altai-Sayan breed imported to the Republic of Tuva (n=27) and marals of the same breed bred in the Republic of Altai (n=17). Studies have shown some deviations in the blood leukogram of imported marals, such as a decrease in the number of eosinophils and rod nuclear neutrophils (P < 0,001), the increase in the number of segmented nuclear neutrophils and lymphocytes (P < 0,05). The number of monocytes have been increased in 18,6 times compared to the Altai marals. The change in the number of monocytes exceeded the physiological norm by 24,7 %. The indicator of adaptation evaluation in imported marals had higher values (6,8), which were in 1,7 times higher than in marals bred in the Altai Republic (4,1), which indicates the intensity of adaptive mechanisms in imported animals during adaptation. Analysis of phagocytic activity and phagocytic index revealed intensive phagocytosis in imported marals: phagocytic activity – by 12,4 % (P < 0,05), phagocytic index – by 5,1 %, and the increase in the content of lysosomal and cationic proteins by 12,8 % (P < 0,05). Analysis of the bactericidal activity of blood serum has shown its lower level in imported animals (45,97±1,36 %), compared with marals of the same breed bred in the Altai Republic (52,19±2,15 at P < 0,05). Thus, according to most indicators of natural resistance marals of Altai-Sayan breed imported to Tyva have a fairly high level of natural protection, which indicates that they can be adapted to the natural climatic and feeding conditions of the Republic of Tyva.


2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Masae Horinouchi ◽  
Hiroyuki Koshino ◽  
Michal Malon ◽  
Hiroshi Hirota ◽  
Toshiaki Hayashi

ABSTRACT Comamonas testosteroni TA441 degrades steroids via aromatization of the A ring, followed by degradation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, mainly by β-oxidation. In this study, we revealed that 7β,9α-dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-coenzyme A (CoA) ester is dehydrogenated by (3S)-3-hydroxylacyl CoA-dehydrogenase, encoded by scdE (ORF27), and then the resultant 9α-hydroxy-7,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is converted by 3-ketoacyl-CoA transferase, encoded by scdF (ORF23). With these results, the whole cycle of β-oxidation on the side chain at C-8 of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid is clarified; 9-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is dehydrogenated at C-6 by ScdC1C2, followed by hydration by ScdD. 7β,9α-Dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-CoA ester then is dehydrogenated by ScdE to be converted to 9α-hydroxy-17-oxo-1,2,3,4,5,6,10,19-octanorandrostan-7-oic acid-CoA ester and acetyl-CoA by ScdF. ScdF is an ortholog of FadA6 in Mycobacterium tuberculosis H37Rv, which was reported as a 3-ketoacyl-CoA transferase involved in C ring cleavage. We also obtained results suggesting that ScdF is also involved in C ring cleavage, but further investigation is required for confirmation. ORF25 and ORF26, located between scdF and scdE, encode enzymes belonging to the amidase superfamily. Disrupting either ORF25 or ORF26 did not affect steroid degradation. Among the bacteria having gene clusters similar to those of tesB to tesR, some have both ORF25- and ORF26-like proteins or only an ORF26-like protein, but others do not have either ORF25- or ORF26-like proteins. ORF25 and ORF26 are not crucial for steroid degradation, yet they might provide clues to elucidate the evolution of bacterial steroid degradation clusters. IMPORTANCE Studies on bacterial steroid degradation were initiated more than 50 years ago primarily to obtain materials for steroid drugs. Steroid-degrading bacteria are globally distributed, and the role of bacterial steroid degradation in the environment as well as in relation to human health is attracting attention. The overall aerobic degradation of the four basic steroidal rings has been proposed; however, there is still much to be revealed to understand the complete degradation pathway. This study aims to uncover the whole steroid degradation process in Comamonas testosteroni TA441 as a model of steroid-degrading bacteria. C. testosteroni is one of the most studied representative steroid-degrading bacteria and is suitable for exploring the degradation pathway, because the involvement of degradation-related genes can be determined by gene disruption. Here, we elucidated the entire β-oxidation cycle of the cleaved B ring. This cycle is essential for the following C and D ring cleavage.


2009 ◽  
Vol 75 (20) ◽  
pp. 6457-6461 ◽  
Author(s):  
Dario De Medici ◽  
Fabrizio Anniballi ◽  
Gary M. Wyatt ◽  
Miia Lindström ◽  
Ute Messelhäußer ◽  
...  

ABSTRACT Botulinum neurotoxin (BoNT), the most toxic substance known, is produced by the spore-forming bacterium Clostridium botulinum and, in rare cases, also by some strains of Clostridium butyricum and Clostridium baratii. The standard procedure for definitive detection of BoNT-producing clostridia is a culture method combined with neurotoxin detection using a standard mouse bioassay (SMB). The SMB is highly sensitive and specific, but it is expensive and time-consuming and there are ethical concerns due to use of laboratory animals. PCR provides a rapid alternative for initial screening for BoNT-producing clostridia. In this study, a previously described multiplex PCR assay was modified to detect all type A, B, E, and F neurotoxin genes in isolated strains and in clinical, food, environmental samples. This assay includes an internal amplification control. The effectiveness of the multiplex PCR method for detecting clostridia possessing type A, B, E, and F neurotoxin genes was evaluated by direct comparison with the SMB. This method showed 100% inclusivity and 100% exclusivity when 182 BoNT-producing clostridia and 21 other bacterial strains were used. The relative accuracy of the multiplex PCR and SMB was evaluated using 532 clinical, food, and environmental samples and was estimated to be 99.2%. The multiplex PCR was also used to investigate 110 freshly collected food and environmental samples, and 4 of the 110 samples (3.6%) were positive for BoNT-encoding genes.


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.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yan-Ling Liang ◽  
Zheng Zhang ◽  
Min Wu ◽  
Yuan Wu ◽  
Jia-Xun Feng

From different natural reserves in the subtropical region of China, a total of 245 aerobic bacterial strains were isolated on agar plates containing sugarcane bagasse pulp as the sole carbon source. Of the 245 strains, 22 showed hydrolyzing zones on agar plates containing carboxymethyl cellulose after Congo-red staining. Molecular identification showed that the 22 strains belonged to 10 different genera, with theBurkholderiagenus exhibiting the highest strain diversity and accounting for 36.36% of all the 22 strains. Three isolates among the 22 strains showed higher carboxymethyl cellulase (CMCase) activity, and isolate ME27-1 exhibited the highest CMCase activity in liquid culture. The strain ME27-1 was identified asPaenibacillus terraeon the basis of 16S rRNA gene sequence analysis as well as physiological and biochemical properties. The optimum pH and temperature for CMCase activity produced by the strain ME27-1 were 5.5 and 50°C, respectively, and the enzyme was stable at a wide pH range of 5.0–9.5. A 12-fold improvement in the CMCase activity (2.08 U/mL) of ME27-1 was obtained under optimal conditions for CMCase production. Thus, this study provided further information about the diversity of cellulose-degrading bacteria in the subtropical region of China and foundP. terraeME27-1 to be highly cellulolytic.


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