Fig 8 - available from: AMB Express
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Degradation of caprolactam in soil by A. citreus. For the study of biodegradation of caprolactam in soil, fertile garden soil was used. 5 g of dry sterile soil (autoclaved twice) or fertile-non sterile soil (10 11 cfu of natural soil flora/g dry soil) in 50 ml sterilised vials, was mixed with 10 mg caprolactam and a minimal amount of sterile water, inoculated (filled square) with A. citreus (10 8 cfu/g soil) and incubated at 30 (± 2) °C for 7 days. Soil not inoculated with culture (filled diamond) was kept as control. By addition of sterile water the soil was kept sufficiently moist. At various time intervals, 5 ml of sterile water was added to the entire system, the contents were vigorously vortexed and the aqueous extract was centrifuged at 10,000×g for 20 min and the supernatant was used for estimation of caprolactam
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ε-Caprolactam-a toxic xenobiotic compound present in industrial polyamide waste was found to be degraded by caprolactam-degrading bacteria. Arthrobacter citreus was able to utilize up to 20 g ε-caprolactam/l as the sole source of carbon more efficiently as compared to the other Gram positive caprolactam-degrading bacteria Rhodococcus rhodochrous an...
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... assess whether A. citreus was suitable for treatment of the caprolactam in soil, soil with caprolactam was inoculated with A. citreus and caprolactam was the sole carbon and nitrogen source added. The soil used was either sterile soil (autoclaved twice) or non sterile (10 11 cfu/g dry soil). Caprolactam was found to be degraded at end of 7 days (Fig. 8). Thus the A. citreus strain used in our study can be used for degrading caprolactam present in oligomer waste which is disposed on land near nylon-6 polymer production plants. Fig. 4 HPTLC of culture supernatant of A. citreus during utilisation of caprolactam. Detection of spots on chromatogram was done using ninhydrin reagent. After ...
Citations
... [44] Arthrobacter strain NOR5 has exhibited remarkable proficiency in facilitating the complete degradation of nornicotine [45], a direct precursor of tobacco-specific nitrosamines (TSNAs) known for their potent carcinogenic properties. [46] Furthermore, Arthrobacter citreus strains can metabolize caprolactam, thereby generating glutamate [47]-an important excitatory neurotransmitter in the central nervous system. Based on these findings, it becomes conceivable that Arthrobacter holds probiotic potential. ...
Emerging evidence highlights the potential impact of intratumoral microbiota on cancer. However, the microbial composition and function in glioma remains elusive. Consequently, our study aimed to investigate the microbial community composition in glioma tissues and elucidate its role in glioma development. We parallelly performed microbial profiling, transcriptome sequencing and metabolomics detection on tumor and adjacent normal brain tissues obtained from 50 glioma patients. We employed immunohistochemistry, multicolor immunofluorescence and FISH staining to observe the presence and location of bacteria. Furthermore, an animal model was employed to validate the impact of key bacteria on glioma development. Six genera were found to be significantly enriched in glioma tissues compared to its adjacent normal brain tissues, including Fusobacterium, Longibaculum, Intestinimonas, Pasteurella, Limosilactobacillus and Arthrobacter. Both bacterial RNA and LPS were observed in glioma tissues. Multicolor immunofluorescence analysis showed higher bacterial LPS levels in tumor cells than in macrophages and in glioma tissue than in adjacent normal brain tissue. Integrated microbiomics, transcriptomics, and metabolomics revealed that genes associated with intratumoral microbes were enriched in multiple synapse-associated pathways and that metabolites associated with intratumoral microbes were (R)-N-methylsalsolinol, N-acetylaspartylglutamic acid, and N-acetyl-L-aspartic acid. Further mediation analysis suggested that intratumoral microbiome may affect the expression of neuron-related genes through bacteria-associated metabolites. In addition, a glioma mouse model suggested that Fusobacterium nucleatum promoted glioma growth by increasing the levels of N-acetylneuraminic acid and the expression levels of CCL2, CXCL1, and CXCL2. In conclusion, our findings shed light on the intricate interplays between intratumoral bacteria and glioma.
... We have shown that the ability of Pseudomonas bacteria to utilize CAP is determined by plasmids (CAP plasmids), which carry genetic information required for the complete mineralization of the xenobiotic [11,28]. Later works described caprolactamutilizing bacteria of the genera Alcaligenes, Corynebacterium, Acinetobacter, Achromobacter, Arthrobacter, Microbacterium, Bacillus, and others [6,[8][9][10]29]. A phylogenetic study of CAP degraders isolated from nylon-6 production wastes attributed them to three phyla: Proteobacteria (Beta-and Gammaproteobacteria), Actinobacteria, and Firmicutes [7]. ...
epsilon-Caprolactam (Caprolactam, CAP), a monomer of the synthetic non-degradable polymer nylon-6, is the major wastewater component in the production of caprolactam and nylon-6. Biological treatment of CAP, using microbes could be a potent alternative to the current waste utilization techniques. This work focuses on the characterization and potential use of caprolactam-degrading bacterial strain BS3 isolated from soils polluted by CAP production wastes. The strain was identified as Brevibacterium epidermidis based on the studies of its morphological, physiological, and biochemical properties and 16S rRNA gene sequence analysis. This study is the first to report the ability of Brevibacterium to utilize CAP. Strain BS3 is an alcalo- and halotolerant organism, that grows within a broad range of CAP concentrations, from 0.5 up to 22.0 g/L, optimally at 1.0–2.0 g/L. A caprolactam biodegradation experiment using gas chromatography showed BS3 to degrade 1.0 g/L CAP over 160 h. In contrast to earlier characterized narrow-specific CAP-degrading bacteria, strain BS3 is also capable of utilizing linear nylon oligomers (oligomers of 6-aminohexanoic acid), CAP polymerization by-products, as sole sources of carbon and energy. The broad range of utilized toxic pollutants, the tolerance for high CAP concentrations, as well as the physiological properties of B. epidermidis BS3, determine the prospects of its use for the biological cleanup of CAP and nylon-6 production wastes that contain CAP, 6-aminohexanoic acid, and low molecular weight oligomer fractions.
Pek çok hayvan ve bitki vücutlarının içerisinde simbiyotik mikroorganizmalara sahiptir ve bu ortaklar arasında yakın etkileşimler meydana gelmektedir. Böcekler ise en büyük hayvan grubu oluşturmaktadırlar ve zorunlu mutualizm’den fakültatif parazitizm’e kadar değişen çeşitli endosimbiyotik ilişkileri içermektedirler. Böceklerdeki endosimbiyotik bakterilerin beslenme, üreme, savunma, iletişim, davranış ve gelişim gibi pek çok farklı rolleri bulunmaktadır. Bu çalışmada böceklerdeki simbiyotik bakterileri tanımlamak için model organizma olarak Malacosoma castrensis seçilmiştir. Bu böceğin larvalarında yer alan bakteriler izole edilmiş ve 16S rRNA sekans analizi ile tanımlanmıştır. Toplam olarak 6 adet bakteri izole edilmiş ve bunlar Staphylococcus sp. MM-1, Micrococcus sp. MM-2, Rhodococcus sp. MM-3, Arthrobacter citreus MM-4, Bacillus sp. MM-5 ve Pseudomonas sp. MM-6 olarak tanımlanmıştır. Elde edilen sonuçların böcek-bakteri ilişkilerinin belirlenmesinde ve böceklerdeki endosimbiyotik bakterilerinin rollerinin aydınlatılmasında faydalı olacağı düşünülmektedir.
Removals of petroleum contaminants from soil is an environmental necessity due to the
negative impacts on human and other living organisms. In environmental and economic
aspects, biodegradation is the best treating methods for in-situ removal of hydrocarbons
from contaminated soil. In this method, application of indigenous microorganisms could
minimize perturbation of the soil ecosystem, and thus the treated soil could maintain biological activities for agriculture prepuces after the treatment. In this study, the potential of removal of crude oil contamination from soil by biodegradation process was evaluated in mud pit zones in Naft Shahr resource. In order to evaluate biostimulation, two treatments were applied; plowing alone and plowing together with 0.1 kg/m2 of urea as a source of nitrogen. In order to evaluate bioagumentation, in addition to plowing and adding urea, a suspension of native microbial consortium (consisting of Bacillus thuringiensis, Arthrobacter citreus, and Candida catenulata (a biosurfactant producer yeast)) was added to the soil in an amount of 100 mL/m2. The results indicated that the total petroleum hydrocarbon (TPH) removal was increased from 10.73% to 53.83% after 120 days by the biostimulation treatment. Also, bioagumentation could remove up to 74% of TPH at the same conditions. In this study, removals of main heavy hydrocarbons (> C12) and higher biodegradation rate were the advantages of bioagumentation process by the microbial consortium.
Gulosibacter molinativorax ON4T is the only known organism to produce molinate hydrolase (MolA), which catalyses the breakdown of the thiocarbamate herbicide into azepane-1-carboxylic acid (ACA) and ethanethiol. A combined genomic and transcriptomic strategy was used to fully characterize the strain ON4T genome, particularly the molA genetic environment, to identify the potential genes encoding ACA degradation enzymes. Genomic data revealed that molA is the only catabolic gene of a novel composite transposon (Tn6311), located in a novel low copy number plasmid (pARLON1) harbouring a putative T4SS of the class FATA. pARLON1 had an ANI value of 88.2% with contig 18 from Agrococcus casei LMG 22410T draft genome. Such results suggest that pARLON1 is related to genomic elements of other Actinobacteria, although Tn6311 was observed only in strain ON4T. Furthermore, genomic and transcriptomic data demonstrated that the genes involved in ACA degradation are chromosomal. Based on their overexpression when growing in the presence of molinate, the enzymes potentially involved in the heterocyclic ring breakdown were predicted. Among these, the activity of a protein related to caprolactone hydrolase was demonstrated using heterologous expression. However, further studies are needed to confirm the role of the other putative enzymes.
Subsidence caused by underground coal mining results in soil degradation. However, little is known about bacterial community structure and its response to a 1-year-old coal mining subsidence area in arid and semiarid areas northwest China. Soil samples from 5 unexplored areas (MC, RC, YC, LC and ZC) and a 1-year-old subsidence area above a coal working face were collected and soil biogeochemical properties and bacterial community structure were determined. Results showed electrical conductivity (EC), soil water content (SWC), soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), dissolved organic carbon (DOC), available nitrogen (AN), available phosphorus (AP) and available potassium (AK) decreased with depth. The microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and the activity of β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG), alkaline phosphatase (PP) and catalase (CAT) were also reduced. The nutrients, BG, PP and MBC in subsidence of marginal zone of a coal working face were significantly lower than those in control, suggesting subsidence led to a loss in nutrients and a reduction in microbial biomass. High-throughput sequencing revealed that the Sphingomonas, Gemmatimonas, Pseudomonas and Gp6, involved in C and N nutrient cycles, were dominant in this region. The relative abundances of Sphingomonas, Pseudomonas and Arthrobacter were decreased in subsidence due to the nutrient leakage and microbial biomass reduction. The predicted abundances of genes for metabolisms of xenobiotics via cytochrome P450 pathways and nitrogen were low in marginal zone, while peroxidase was high, indicating low capacities of degrading for xenobiotics and polycyclic aromatic hydrocarbons (PAHs) occurred marginal zone, while resistance to hydrogen peroxide was strengthened. Redundancy analysis (RDA) revealed EC, SWC and soil depth governed bacterial community structure. Overall, subsidence caused losses in soil water, nutrients and microbial biomass, alteration of bacterial community structure, and ultimately reduced soil nutrient conversion. Therefore, the cracks in the subsidence area should be filled manually in time, especially in marginal zone.
