scholarly journals Identification of New Aflatoxin B1-Degrading Bacteria from Iran

2018 ◽  
Vol 12 (3) ◽  
pp. 39-44
Author(s):  
Fahimeh Sangi ◽  
◽  
Abbas Mohammadi ◽  
Nazar Afzali3 ◽  
Mansoureh Mirabolfathy ◽  
...  

Background: Aflatoxin B1 (AFB1) is a mutagenic and carcinogenic compound mainly produced by the Aspergillus parasiticus, A. flavus, A. nomius, A. tamari, and A. pseudotamarii. AFB1 biodegradation is the most important strategy for reducing AFB1 in plant tissues. Bacteria can deactivate and biodegrade AFB1 for effective detoxification of contaminated products. The present study investigated the efficiency of AFB1 degradation by soil bacteria from the Southern Khorasan Province in Eastern Iran by thin-layer and high-performance liquid chromatography during 2014–2015. Methods: DNA was extracted from AFB1-degrading isolates by the cetyltrimethylammonium bromide method and the 16S rRNA gene was amplified with the 27f and 1492r general bacterial primers and the sequences were used to identify the isolates based on their similarity to Gene Bank sequences of known bacterial species. Results: We isolated five strains from four species of AFB1-degrading bacteria from Birjand plain, including Bacillus pumilus, two isolates of Ochrobactrum pseudogrigonens, Pseudomonas aeruginosa, and Enterobacter cloace, which had AFB1-degrading activities of 88%, 78%, 61%, 58%, and 51%, respectively. Conclusion: We provide the first demonstration of AFB1 degradation by B. pumilus in from Iran and the first report identifying O. pseudogrigonens and E. cloace species as having AFB1-degrading activity.

2010 ◽  
Vol 56 (12) ◽  
pp. 1040-1049 ◽  
Author(s):  
Michal Slany ◽  
Martina Vanerkova ◽  
Eva Nemcova ◽  
Barbora Zaloudikova ◽  
Filip Ruzicka ◽  
...  

High-resolution melting analysis (HRMA) is a fast (post-PCR) high-throughput method to scan for sequence variations in a target gene. The aim of this study was to test the potential of HRMA to distinguish particular bacterial species of the Staphylococcus genus even when using a broad-range PCR within the 16S rRNA gene where sequence differences are minimal. Genomic DNA samples isolated from 12 reference staphylococcal strains ( Staphylococcus aureus , Staphylococcus capitis , Staphylococcus caprae , Staphylococcus epidermidis , Staphylococcus haemolyticus , Staphylococcus hominis , Staphylococcus intermedius , Staphylococcus saprophyticus , Staphylococcus sciuri , Staphylococcus simulans , Staphylococcus warneri , and Staphylococcus xylosus ) were subjected to a real-time PCR amplification of the 16S rRNA gene in the presence of fluorescent dye EvaGreen™, followed by HRMA. Melting profiles were used as molecular fingerprints for bacterial species differentiation. HRMA of S. saprophyticus and S. xylosus resulted in undistinguishable profiles because of their identical sequences in the analyzed 16S rRNA region. The remaining reference strains were fully differentiated either directly or via high-resolution plots obtained by heteroduplex formation between coamplified PCR products of the tested staphylococcal strain and phylogenetically unrelated strain.


2016 ◽  
Vol 29 (2) ◽  
pp. 84-88
Author(s):  
A Hakim ◽  
S Hoque ◽  
SM Ullah

Ten effluent samples from two different sites located at Hazaribagh tannery belt and Dhaka EPZ, Savar were collected. This study aimed to compare the bacterial composition isolated from tannery and textile effluents and to investigate the occurrence of metal toxicity tolerant and dye degrading bacteria and to select the potential strains for the use in bioremediation. The average bacterial count of HT and DETDE varied in between 3.35×106 and 5.45×106 cfu/mL and 4.8×106 and 7.75×106cfu/mL, respectively. A total of 12 bacterial isolates were characterized as strains of Bacillus, Staphylococcus, and Pseudomonas. A few, however, were re-cultured on other recommended media for verification of diagnostic characteristics. Maximum numbers of bacterial species were isolated from textile effluent. The results showed that a Gram-positive bacillus with a yellow pigment was considered as a major group of the population. Among them three isolates were identified based on alignments of partial sequence of 16S rRNA gene. These are also being used in different wastewater and metal treatment plants all over the world.Bangladesh J Microbiol, Volume 29, Number 2, Dec 2012, pp 84-88


2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Maki Teramoto ◽  
Zhenyu Zhai ◽  
Ayumi Komatsu ◽  
Keigo Shibayama ◽  
Masato Suzuki

Some bacterial species of the genus Tenacibaculum , including Tenacibaculum ovolyticum , have been known as fish pathogens in the sea. So far, the only published genome sequence for this genus is for Tenacibaculum dicentrarchi , which could also be a fish pathogen. Strain da5A-8, showing 100% identity to the 16S rRNA gene sequence of T. ovolyticum DSM 18103 T , was isolated from seawater at a depth of 344 m in Kochi, Japan, and grew optimally at 10 to 20°C. The genome sequence of strain da5A-8 revealed the possible virulence genes commonly observed in the genus Tenacibaculum .


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

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).


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246533
Author(s):  
Mo Ping ◽  
Zhao Yun-Lin ◽  
Liu Jun ◽  
Gao Jian ◽  
Xu Zheng-Gang

The taxonomic relationship of Lentzea atacamensis and Lentzea deserti were re-evaluated using comparative genome analysis. The 16S rRNA gene sequence analysis indicated that the type strains of L. atacamensis and L. deserti shared 99.7% sequence similarity. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the genomes of two type strains were 88.6% and 98.8%, respectively, greater than the two recognized thresholds values of 70% dDDH and 95–96% ANI for bacterial species delineation. These results suggested that L. atacamensis and L. deserti should share the same taxonomic position. And this conclusion was further supported by similar phenotypic and chemotaxonomic features between them. Therefore, we propose that L. deserti is a later heterotypic synonym of L. atacamensis.


2021 ◽  
Vol 368 (18) ◽  
Author(s):  
Cheikh Ibrahima Lo ◽  
Niokhor Dione ◽  
Aminata Mbaye ◽  
Patricia Fernández-Mellado Gómez ◽  
Issa Isaac Ngom ◽  
...  

ABSTRACT Strain Marseille-P3519T isolated from the fecal flora of a 25-year-old healthy French woman was a Gram-positive anaerobic bacterium, non-motile and non-spore forming. The 16S rRNA gene sequence of Marseille-P3519 showed 97.73% of sequence similarity with Limosilactobacillus reuteri DSM 20016, the closest species, phylogenetically. Furthermore, the average nucleotide identity of strain Marseille-3519 with its closest related species was 75.8% that was very below the recommended threshold (>95–96%). Its genome had 2 237 367 bp with 45.42 mol% of G + C content. Major fatty acids were C16:0 (50.8%), C18:1n9 (18.0%), C18:2n6 (9.8%) and C19:1n9 (8.9%). It was catalase negative and fermented glycerol, glucose, fructose, D-maltose, lactose and mannose. These findings support that strain Marseille-P3519 ( = CSURP3519 = CECT 30110) is a new member of the genus Limosilactobacillus for which the name Limosilactobacillus caccae sp. nov., is proposed.


Toxins ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 330 ◽  
Author(s):  
Xian Shu ◽  
Yuting Wang ◽  
Qing Zhou ◽  
Minghao Li ◽  
Hao Hu ◽  
...  

(1) Background: Aflatoxin contamination in food and grain poses serious problems both for economic development and public health protection, thus leading to a focus on an effective approach to control it; (2) Methods: Aflatoxin B1 (AFB1) degrading bacteria were isolated using a medium containing coumarin as the sole carbon source, and the biodegradation of AFB1 by the isolate was examined by high performance liquid chromatography, and liquid chromatography mass spectrometry; (3) Results: a bacterial strain exhibiting strong AFB1 degradation activity (91.5%) was isolated and identified as Bacillus velezensis DY3108. The AFB1 degrading activity was predominantly attributed to the cell-free supernatant of strain DY3108. Besides, it was heat-stable and resistant to proteinase K treatment but sensitive to sodium dodecyl sulfate treatment. The optimal temperature for the maximal degradation of AFB1 was 80 °C. Even more notable, the supernatant showed a high level of activity over a broad pH (4.0 to 11.0) and exhibited the highest degradation (94.70%) at pH 8.0. Cytotoxicity assays indicated that the degradation products displayed significantly (p < 0.05) lower cytotoxic effects than the parent AFB1; (4) Conclusions: B. velezensis DY3108 might be a promising candidate for exploitation in AFB1 detoxification and bioremediation in food and feed matrices.


2016 ◽  
Vol 42 (2) ◽  
pp. 67-77 ◽  
Author(s):  
Onyedikachi Ubani ◽  
Harrison Ifeanyichukwu Atagana ◽  
Mapitsi Silvester Thantsha ◽  
Adeleke Rasheed

AbstractCompounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs) are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR) of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR). The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the generaBacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus.The results showed thatBacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.


2012 ◽  
Vol 58 (6) ◽  
pp. 719-727 ◽  
Author(s):  
Rajesh P. Rastogi ◽  
Sunita Kumari ◽  
Richa ◽  
Taejun Han ◽  
Rajeshwar P. Sinha

Phylogenetic analysis of 4 cyanobacterial strains isolated from hot springs in Rajgir, India, was carried out using the 16S rRNA gene (1400 bp). These strains were identified as members of Chroococcales ( Cyanothece sp. strain HKAR-1) and Nostocales ( Nostoc sp. strain HKAR-2, Scytonema sp. strain HKAR-3, and Rivularia sp. strain HKAR-4). Furthermore, we evaluated the presence of ultraviolet-screening and (or) photoprotective compounds, such as mycosporine-like amino acids (MAAs) and scytonemin, in these cyanobacteria by using high-performance liquid chromatography. Well-characterized MAAs, including the critical and highly polar compounds shinorine, porphyra-334, and mycosporine-glycine, as well as several unknown MAAs, were found in these hot-spring-inhabiting microorganisms. The presence of scytonemin was detected only in Scytonema sp. strain HKAR-3 and Rivularia sp. strain HKAR-4. The results indicate that hot spring cyanobacteria, namely Cyanothece, Nostoc, Scytonema, and Rivularia, belonging to different groups possess various photoprotective compounds to cope up with the negative impacts of damaging radiations.


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