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Toxics Apr 2023Chromium (Cr) is a major pollutant affecting the environment and human health and microbial remediation is considered to be the most promising technology for the...
Chromium (Cr) is a major pollutant affecting the environment and human health and microbial remediation is considered to be the most promising technology for the restoration of the heavily metal-polluted soil. However, the difference between rhizosphere and endophytic bacteria on the potential of crop safety production in Cr-contaminated farmland is not clearly elucidated. Therefore, eight Cr-tolerant endophytic strains of three species: (SR-1~2), (LB-1~5) and (PA-1) were isolated from rice and maize. Additionally, one Cr-tolerant strain of (AF-1) was isolated from the rhizosphere of maize. A randomized group pot experiment with heavily Cr-contaminated (a total Cr concentration of 1020.18 mg kg) paddy clay soil was conducted and the effects of different bacteria on plant growth, absorption and accumulation of Cr in lettuce ( var. Hort) were compared. The results show that: (i) the addition of SR-2, PA-1 and LB-5 could promote the accumulation of plant fresh weight by 10.3%, 13.5% and 14.2%, respectively; (ii) most of the bacteria could significantly increase the activities of rhizosphere soil catalase and sucrase, among which LB-1 promotes catalase activity by 224.60% and PA-1 increases sucrase activity by 247%; (iii) AF-1, SR-1, LB-1, SR-2, LB-2, LB-3, LB-4 and LB-5 strains could significantly decrease shoot the Cr concentration by 19.2-83.6%. The results reveal that Cr-tolerant bacteria have good potential to reduce shoot Cr concentration at the heavily contaminated soil and endophytic bacteria have the same or even better effects than rhizosphere bacteria; this suggests that bacteria in plants are more ecological friendly than bacteria in soil, thus aiming to safely produce crops in Cr-polluted farmland and alleviate Cr contamination from the food chain.
PubMed: 37112598
DOI: 10.3390/toxics11040371 -
Microorganisms Mar 2023Picolinic acid (PA) is a typical mono-carboxylated pyridine derivative produced by human/animals or microorganisms which could be served as nutrients for bacteria. Most...
Picolinic acid (PA) is a typical mono-carboxylated pyridine derivative produced by human/animals or microorganisms which could be served as nutrients for bacteria. Most strains are pathogens causing pertussis or respiratory disease in humans and/or various animals. Previous studies indicated that strains harbor the PA degradation gene cluster. However, the degradation of PA by strains remains unknown. In this study, a reference strain of genus , RB50, was investigated. The organization of gene cluster of strain RB50 was found to be similar with that of , in which the sequence similarities of each Pic proteins are between 60% to 80% except for PicB2 (47% similarity). The 3,6-dihydroxypicolinic acid (3,6DHPA) decarboxylase gene (, designated as ) of strain RB50 was synthesized and over-expressed in BL21(DE3). The PicC showed 75% amino acid similarities against known PicC from . The purified PicC can efficiently transform 3,6DHPA to 2,5-dihydroxypyridine. The PicC exhibits optimal activities at pH 7.0, 35 °C, and the and values of PicC for 3,6DHPA were 20.41 ± 2.60 μM and 7.61 ± 0.53 S, respectively. The present study provided new insights into the biodegradation of PA by pathogens of spp.
PubMed: 37110277
DOI: 10.3390/microorganisms11040854 -
International Immunopharmacology Apr 2023Alcaligenes faecalis was previously identified as an intestinal lymphoid tissue-resident commensal bacteria, and our subsequent studies showed that lipopolysaccharide...
Alcaligenes faecalis was previously identified as an intestinal lymphoid tissue-resident commensal bacteria, and our subsequent studies showed that lipopolysaccharide and its core active element (i.e., lipid A) have a potent adjuvant activity to promote preferentially antigen-specific Th17 response and antibody production. Here, we compared A. faecalis lipid A (ALA) with monophosphoryl lipid A, a licensed lipid A-based adjuvant, to elucidate the immunological mechanism underlying the adjuvant properties of ALA. Compared with monophosphoryl lipid A, ALA induced higher levels of MHC class II molecules and costimulatory CD40, CD80, and CD86 on dendritic cells (DCs), which in turn resulted in strong T cell activation. Moreover, ALA more effectively promoted the production of IL-6 and IL-23 from DCs than did monophosphoryl lipid A, thus leading to preferential induction of Th17 and Th1 cells. As underlying mechanisms, we found that the ALA-TLR4 axis stimulated both MyD88- and TRIF-mediated signaling pathways, whereas monophosphoryl lipid A was biased toward TRIF signaling. These findings revealed the effects of ALA on DCs and T cells and its induction pattern on signaling pathways.
Topics: Lipid A; Myeloid Differentiation Factor 88; Toll-Like Receptor 4; Antigen Presentation; Alcaligenes; Signal Transduction; Adjuvants, Immunologic; Cell Differentiation; Adaptor Proteins, Vesicular Transport; Dendritic Cells
PubMed: 36806039
DOI: 10.1016/j.intimp.2023.109852 -
Microbiology Resource Announcements Jan 2023The complete genome sequence of Alcaligenes faecalis strain NLF5-7, which was isolated from livestock wastewater, is reported. The genome of strain NLF5-7 contains genes...
The complete genome sequence of Alcaligenes faecalis strain NLF5-7, which was isolated from livestock wastewater, is reported. The genome of strain NLF5-7 contains genes for assimilatory sulfate reduction, dissimilatory sulfate reduction and oxidation, and an SOX system, based on its functional genetic characteristics.
PubMed: 36598248
DOI: 10.1128/mra.00999-22 -
Cureus Nov 2022() is a Gram-negative, rod-shaped, oxidase(+) and catalase(+), obligate aerobe commonly found in soil or water. It has also been found in human intestinal microbiota...
() is a Gram-negative, rod-shaped, oxidase(+) and catalase(+), obligate aerobe commonly found in soil or water. It has also been found in human intestinal microbiota and more rarely in hospital settings and is typically associated with opportunistic infections. Although it has intrinsic resistance to many commonly used antibiotics, it is increasingly found to have developed antibiotic resistance. We present a rare case of osteomyelitis in a patient with a chronic diabetic foot ulcer.
PubMed: 36505151
DOI: 10.7759/cureus.31172 -
Indian Journal of Microbiology Dec 2022Degradation of nitriles by mixed biofilms of nitrile-hydrolyzing bacteria 2 and gt 1 grown on basalt and carbon carriers, in a submerged packed-bed reactor was...
UNLABELLED
Degradation of nitriles by mixed biofilms of nitrile-hydrolyzing bacteria 2 and gt 1 grown on basalt and carbon carriers, in a submerged packed-bed reactor was studied. It was shown the formation of a massive mixed biofilm of 2 and gt 1 and the effective removal of nitriles and products of their degradation from the reaction medium. After the accumulation of carboxylic acid and some of the unprocessed substrate, the system adapts to 600-1000 h of biofilter operation, which is expressed in a decrease in the content of substrate and reaction products in the medium. The rate of acetonitrile and acrylonitrile utilization was 0.072-0.086 and 0.039-0.215 g/h, respectively, and acrylonitrile utilization with maximum rate was realized by a mixed biofilm on carbon fibers. Biofilms grown on mixed fibers in a "sandwich"-type reactor had the best characteristics for the transformation of aceto- and acrylonitrile (removal capacity of 99.6-99.9%, nitrile utilization rate of 0.080-0.095 g/h). Biofilms grown on basalt fiber with a diameter of 4-12 μm are also well suited for the degradation of acetonitrile (removal capacity of 100%, nitrile utilization rate of 0.086 g/h). The results of metagenomic analysis showed the resistance of 2 and gt 1 mixed biofilms against leaching from a biofilter and to competitive growth in an open system, indicating the advantages of biofilms over homogeneous biomass for wastewater treatment from nitrile compounds. Biofilms of two species of nitrile hydrolyzing bacteria on basalt and carbon fibers effectively purify water from nitriles in a submerged packed-bed reactor.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s12088-022-01030-z.
PubMed: 36458224
DOI: 10.1007/s12088-022-01030-z -
Microbiology Resource Announcements Jan 2023Whole-genome sequence data for clinically relevant Gram-negative bacteria from the African continent are scarce. In this report, we present the draft genome sequence...
Antibiotic Profiles and Draft Genome Sequences of Kerstersia gyiorum, Providencia stuartii, Providencia vermicola, and Alcaligenes faecalis Strains Recovered from Soft Tissue Biopsy Samples in Ghana.
Whole-genome sequence data for clinically relevant Gram-negative bacteria from the African continent are scarce. In this report, we present the draft genome sequence data and antibiograms of four species, namely, Kerstersia gyiorum, Providencia vermicola, Providencia stuartii, and Alcaligenes faecalis, that were recovered from human soft tissue biopsy samples.
PubMed: 36453948
DOI: 10.1128/mra.00893-22 -
Vavilovskii Zhurnal Genetiki I Selektsii Oct 2022Alkanmonooxygenase enzymes AlkB and Cyp153 are responsible for the aerobic degradation of n-alkanes of petroleum and petroleum products. To prove the usage of n-alkanes...
Alkanmonooxygenase enzymes AlkB and Cyp153 are responsible for the aerobic degradation of n-alkanes of petroleum and petroleum products. To prove the usage of n-alkanes from oil and petroleum products by hydrocarbon-oxidizing bacteria isolated from aviation kerosene TS-1 and automobile gasoline AI-95, the detection of the key genes alkB, Alk1, Alk2, Alk3 and Cyp153 encoding alkanmonooxygenases AlkB and Cyp153 (responsible for the oxidation of hydrocarbons with a certain chain length) was carried out. It was found that bacterial strains isolated from TS-1 jet fuel, except Deinococcus sp. Bi7, had at least one of the studied n-alkane degradation genes. The strains Sphingobacterium multivorum Bi2; Alcaligenes faecalis Bi3; Rhodococcus sp. Bi4; Sphingobacterium sp. Bi5; Rhodococcus erythropolis Bi6 contained the alkB gene. In the strains of hydrocarbon-oxidizing bacteria isolated from gasoline AI- 95, this alkanmonooxygenase gene was not detected. Using the real-time PCR method, the activity of the alkB gene in all bacterial strains isolated from petroleum products was analyzed and the number of its copies was determined. By real-time PCR using a primer with a different sequence of nucleotides to detect the alkB gene, its activity was established in all bacterial strains isolated from gasoline AI-95; besides, the strain Paenibacillus agaridevorans Bi11 was assigned to the group with a high level of its activity (1290 copies/ml). According to the assessment of the growth of isolated hydrocarbon-oxidizing bacteria on a solid Evans mineral medium with the addition of the model mixture of hydrocarbons, the strains were divided into three groups. The distributions of strains of hydrocarbon-oxidizing bacteria in the groups based on the activity of the alkB gene and groups formed based on the growth ability and use of the model mixture of hydrocarbons and petroleum products were found to be consistent. The results obtained indicate that we need to use a complex of molecular and physiological methods for a comprehensive analysis of the distribution of the studied genes in bacteria and to assess their activity in the strains of hydrocarbon-oxidizing bacteria capable of biodegradation of petroleum hydrocarbons.
PubMed: 36313823
DOI: 10.18699/VJGB-22-70 -
Environmental Health Insights 2022Antimicrobial resistance (AMR) is one of the top 10 public health threats. One approach to tackling the AMR menace could involve expanding the range of AMR surveillance...
BACKGROUND
Antimicrobial resistance (AMR) is one of the top 10 public health threats. One approach to tackling the AMR menace could involve expanding the range of AMR surveillance domains to include hospital wastewater (HWW), a domain that has largely been overlooked by researchers.
AIM
To evaluate the occurrence of multidrug-resistant bacteria in hospital wastewater of the Korle Bu Teaching Hospital (KBTH).
METHODOLOGY
This was a longitudinal study involving 288 HWW samples consecutively collected across 12 weeks from the pool of wastewater emanating from 2 critical care units of KBTH-The Child Health Unit and the Maternity Unit-on Mondays and Thursdays, each week. The samples were cultured for bacteria, which were identified using the Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) technique and subjected to antimicrobial susceptibility testing via the Kirby-Bauer method.
RESULTS
In total, 294 bacteria of 23 different types, all being Gram-negative, were isolated from the 288 samples. The predominant ones were (30.6%, n = 90), (11.2%, n = 33), (10.9%, n = 32), (5.8%, n = 17), and (5.4%, n = 16). The prevalence of multidrug resistance among the isolates was 55.4% (n = 163). Moreover, the prevalence of extended-spectrum beta-lactamase (ESBL) producers was 15.6% (n = 46). accounted for the most ESBL-producing organisms (28.9%, n = 26).
CONCLUSION
The wastewater generated by the Maternity and Child Health Units of KBTH harbored a wide range of multidrug resistant bacteria, with a good proportion of these being ESBL producers, and the predominant one being . The study thus identifies the wastewater of KBTH as an important source of multidrug resistant organisms, and underscores the significance of appropriate treatment of wastewater of the hospital and other clinical, and related settings prior to its discharge.
PubMed: 36311334
DOI: 10.1177/11786302221130613 -
Microorganisms Oct 2022Polyhydroxyalkanoate (PHA), a biodegradable and plastic-like biopolymer, has been receiving research and industrial attention due to severe plastic pollution, resource...
Polyhydroxyalkanoate (PHA), a biodegradable and plastic-like biopolymer, has been receiving research and industrial attention due to severe plastic pollution, resource depletion, and global waste issues. This has spurred the isolation and characterisation of novel PHA-producing strains through cultivation and non-cultivation approaches, with a particular interest in genes encoding PHA synthesis pathways. Since sea sponges and sediment are marine benthic habitats known to be rich in microbial diversity, sponge tissues ( and ) and sediment samples were collected in this study from Redang and Bidong islands located in the Malaysian Coral Triangle region. PHA synthase () genes were identified from sediment-associated bacterial strains using a cultivation approach and from sponge-associated bacterial metagenomes using a non-cultivation approach. In addition, phylogenetic diversity profiling was performed for the sponge-associated bacterial community using 16S ribosomal ribonucleic acid (16S rRNA) amplicon sequencing to screen for the potential presence of PHA-producer taxa. A total of three genes from the bacterial metagenome of and three genes from sediment isolates ( UMTKB-6, UMTKB-7, UMTKB-8) were identified. Produced PHA polymers were shown to be composed of 5C to C monomers, with previously unreported PHA-producing ability of the strain, as well as a 3-hydroxyvalerate-synthesising ability without precursor addition by the strain.
PubMed: 36296332
DOI: 10.3390/microorganisms10102057