Arthrobacter Crystallopoietes Research Articles

Innovative synthesis and molecular modeling of actinomycetes-derived silver nanoparticles for biomedical applications

The rising demand for innovative antimicrobial solutions has shifted focus towards silver nanoparticles (AgNPs), especially those produced through eco-friendly methods. This study introduces a novel approach utilizing actinomycetes strains—Streptomyces albus, Micromonospora maris, and Arthrobacter crystallopoietes—to biosynthesize AgNPs with remarkable antibacterial properties. Through molecular characterization, we identified unique features of these nanoparticles, and computational modeling suggested significant ion-ligand interactions with proteins 6REV and 3K07. Our research highlights the promise of these biogenically synthesized nanoparticles in advancing biomedical applications. Actinomycetes were sourced and screened for their ability to produce metallic nanoparticles, revealing that among 35 samples, only six showed this capability. Notably, Streptomyces albus strain smmdk14 (OR685674), Micromonospora maris strain smmdk13 (OR685672), and Arthrobacter crystallopoietes strain smmdk12 (OR685674) were identified as effective silver nanoparticle producers. The synthesized nanoparticles demonstrated potent antibacterial activity against common pathogens including E. coli, Pseudomonas aeruginosa, Klebsiella spp., Enterococcus faecalis, Staphylococcus aureus, and Acinetobacter spp. The data obtained from color change observation, UV–visible spectrophotometry, Zeta potential, FTIR spectroscopy, and transmission electron microscopy (TEM) characterized AgNPs potentiality. The nanoparticles were spherical, with sizes ranging from 6.46 nm to 24.7 nm. Optimization of production conditions, comparison of antimicrobial effects with antibiotics, evaluation of potential toxicity, and assessment of wound-healing capabilities were also conducted. The biosynthesized AgNPs exhibited superior antibacterial properties compared to traditional antibiotics and significantly accelerated wound healing by approximately 66.4 % in fibroblast cell cultures. Additionally, computational analysis predicted interactions between various metal ions and specific amino acid residues in proteins 6REV and 3K07. Overall, this study demonstrates the successful creation of AgNPs with notable antibacterial and wound-healing properties, underscoring their potential for medical applications.

Isolation and selection of nodulating bacteria from the rhizosphere of legume (mash - Vigna radiata) and bean (Phaseolus lunatus) plants and to enhance specific properties through induced mutagenesis methods

The aim of the research is to create a collection of PGPR properties of bacteria for legume plants, as well as to increase their growth—stimulating activity by methods of induced mutagenesis. In this article, studies have been conducted on the isolation of microorganisms from the rhizosphere of legumes. And also, to increase the PGPR growth-stimulating properties of rhizosphere microorganisms using methods of physical and chemical mutagenesis. A collection of active rhizosphere bacteria has been created from 4 strains of the genus Bacillus megaterium, Arthrobacter globiformis, Arthrobacter crystallopoietes and Bacillus spp. Dining the screening, bacteria with PGPR properties Bacillus megaterium, Arthrobacter globiformis, and Arthrobacter crystallopoietes were isolated, as these strains stimulated the growth of legume plants.

Metallic nanoparticles production by Actinomycetes and their Impact against some human pathogens

The Study Investigated Metallic Nanoparticles Synthesized extracellularly. Using actinomycetes isolated from different environments as (The Mediterranean Sea, Some Fields, stagnant water, underground water, and rainfall water). Checking for Microorganisms Only six actinomycetes could be retrieved from the thirty-five samples that were gathered for the biosynthesis of metallic nanoparticles, and of those six, only three showed the ability to synthesis AgNPs with antibacterial activity. We identified these powerful isolates as Arthrobacter crystallopoietes strain smmdk12 (OR685674), Micromonospora maris strain smmdk13 (OR685672), and Streptomyces albus strain smmdk14 (OR685674) based on their features. On the basis of 16rRNA sequences along with morphological and physiological properties. The proliferation of medically significant pathogenic bacteria was considerably influenced and suppressed by the biosynthesized AgNPS. Silver nitrate (1 mM) was added to the culture supernatant to create biosynthesized AgNPS, which were then characterised using transmission electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet visible spectrophotometer. The AgNPS particle size and spherical shape that were obtained (6.46nm-24.7nm). Evaluations were conducted on the antimicrobial impact of AgNPs. The results of the wound healing process showed that after being exposed to Ag-NPs for 24 hours, fibroblasts progressed toward the opening to seal the scratch wound by around 66.4%, significantly speeding up the healing process.

Biodegradation of low-density polyethylene by novel halophilic bacteria from mangrove ecosystem

Low-density polyethylene (LDPE) is identified as the primary constituent (approximately 18.9%) in plastic waste pollution. Crystalline structure, high molecular weight, and hydrophobic nature make LDPE recalcitrant to degradation. In the current study, the biodegradation of LDPE was studied by using three novel Malaysian mangrove bacterial isolates Brevundimonas naejangsanensis (strain MGS1), Arthrobacter crystallopoietes (strain SW4), and Arthrobacter pokkalii (strain PD2). Biodegradation of UV-treated LDPE was determined by the gradual increase in microbial count and production of laccase and lipase enzymes over a period of thirty days. All the isolates reduced the weight of the residual polymer and modified the chemical structure of LDPE by forming carbonyl and hydroxyl groups as a result of oxidation reactions by enzymes. Strain MGS1 reduced the maximum weight by 4.64 ± 0.5% and produced maximum laccase (2.19 ± 0.15 U/mL) and lipase enzyme (1.35 ± 0.05 U/mL). Field emission scanning electron microscopy (FESEM) showed visual images of bacterial colonization, and surface erosion (cracks/holes) on the LDPE surface. The production of enzymes reduced the hydrophobicity of the LDPE as evidenced by the biofilm formation, addition of new functional groups, surface erosion, and weight loss. The study is significant in addressing the biodegradation of plastic waste in Malaysia by exploring the mangrove microbiome.

State of the Lung Microbiota in С57bl/6 Mice in the Experimental Tuberculosis Model

The objective: to study the changes in the lung microbiota in inbred C57BL/6 mice after aerogenic infection with M. tuberculosis in an experimental tuberculosis model.Subjects and Methods. This study was carried out on 20 female mice of inbred line C57BL/6 weighing 20-22 grams which were infected in a Glas-Col aerosol chamber (USA) with the culture of M. tuberculosis of virulent strain H37Rv at the dose of 400 CFU/lung. Morphological and microbiological assessment of the lungs state was performed before (day 0) (n=5) and 7 (n=5), 30 (n=5) and 60 (n=5) days after the infection. The results obtained were subjected to statistical processing using ANOVA test and Student t-test.Results. 7, 30, and 60 days after aerosol infection with M. tuberculosis against the background of successive morphological and microbiological changes typical of the experimental tuberculosis model, we established an imbalance of bacterial population in the lung microbiota. Before infection with M. tuberculosis, a scanty biotope was recorded with a predominance of lactobacilli –Lactobacillus murinus, Lactobacillus apodeme. 7, 30 and 60 days after infection with M. tuberculosis, consistent changes were recorded, such as increase in the number and diversity of the bacterial population. The most indicative markers of the recorded imbalance were: Streptococcus thoraltensis, Streptococcus acidominiminus, Arthrobacter crystallopoietes, Staphylococcus hominis, Micrococcus luteus.Conclusion. Tuberculosis infection is a significant factor affecting the state of the lung microbiota. With increased duration of the infection with M. tuberculosis, imbalance of the bacterial flora is formed in the lungs of C57BL/6 mice, accompanied by characteristic tissue inflammation and growing mycobacterial load.

Cell Wall Glycopolymers as a Diagnostic Trait of Arthrobacter crystallopoietes

Cell Wall Glycopolymers as a Diagnostic Trait of Arthrobacter crystallopoietes

Metagenomic Analysis of Rhizosphere Bacteria in Desert Plant Calotropis procera

The microbial community of complex association of plant is vital for the health of the plant. Plants able to form the microbiome of their rhizosphere as the new advanced research in plant-microbe interaction is revealed. Also, the recent research suggested the fact that the microbial communities help some desert plants in drought tolerance by microbial water production. This study focused on the characterization of rhizosphere bacteria of desert plant Calotropis procera to investigate the relationship between this plant and its rhizosphere microbial communities. The study was achieved via deep sequencing of the V3–V4 regions (∼415 bp) of bacterial 16S rRNA. A total of 2173 operational taxonomic units (OTUs) were assigned sequence tags across samples with at least 97% similarity. A total of 24 OUT is selected with cutoff 1000 abundance. The results showed that the most popular phyla are Acidobacteria (two genera), Actinobacteria (fourteen genera), Bacteroidetes (one genus), Proteobacteria (6 genera), and Firmicutes (nine genera). Highly abundant genera included Ammoniphilus, Bacillus, Iamia (which reported for a first time in soil), Microvirga, Nocardia, Streptomyces, Defluviicoccus, Mycobacterium, Nocardioides, Sphingomonas, Bryobacter, Ammoniphilus, Stenotrophobacter, Arthrobacter, Actinomadura, and Marmoricola. At the species level, high abundance of Nocardia cyriacigeorgica, Rhodospirillales bacterium WX36, and Arthrobacter crystallopoietes in C. procera rhizosphere. These results show that there are at least 20 unknown species (identified at genus or family levels) in C. procera rhizosphere which are not found in rhizosphere free plants.

Evaluating the combined effect of biochar and PGPR inoculants on the bacterial community in acidic sandy soil

Biochar is used to improve soil fertility and mitigate climate change by carbon sequestration. The potential of using biochar together with plant growth promoting rhizobacteria (PGPR) as a soil fertilization technique, offers an alternative way for sustainable agriculture. In the present study biochar and acid stress adapted PGPR inoculants were applied in three different quantities in order to improve soil fertility to enhance maize growth and crop yield in an acidic sandy soil (pH 4.4). The objective of the study was to monitor the effect of biochar on soil biota and on the inoculated PGP bacteria. Soil bacterial community structure was characterized with the genotyping sequence-aided terminal restriction fragment length polymorphism (T-RFLP) technique and the phenotyping phospholipid fatty acid analysis (PLFA). T-RFLP method was applied also for detecting and estimating the relative abundance of the inoculated PGP bacteria. Inocula immobilized on the biochar surface, as well as high doses of biochar treatments positively influenced the applied Azospirillum brasilense and Arthrobacter crystallopoietes abundances. In case of Azospirillum brasilense, the positive effect proved to be statistically significant (1–6 times higher relative abundances as compared to the control and small dose). The bacterial community structure in the rhizosphere was significantly influenced both by maize growth stage and by high doses (15 and 30 Mg ha−1) of biochar treatment. In the case of the immobilized PGP bacteria on the biochar surface treatment the maize above-ground biomass was significantly enhanced (2.6–3.2 times of the control). This study revealed that high doses of biochar treatment influenced the abundance of those bacterial groups that might play important roles in soil nutrient cycles.

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida).

Investigations on the biochemical relationship between Doriprismatica stellata (Chromodorididae, Doridoidea) nudibranchs, their egg ribbons, and the associated dietary sponge Spongia cf. agaricina (Demospongiae, Porifera) led to the isolation of the structurally new scalarane-type sesterterpene 12-deacetoxy-4-demethyl-11,24-diacetoxy-3,4-methylenedeoxoscalarin, with an unprecedented position of the cyclopropane ring annelated to the ring A. Unlike other scalaranes, which are most often functionalized at C-12 of ring C, it bears two acetoxy groups at C-11 and C-24 instead. The compound was present in all three samples, supporting the dietary relationship between chromodorid nudibranchs of the genus Doriprismatica and scalarane-containing dictyoceratid sponges of the Spongiidae family. The results also indicate that D. stellata passes the scalarane metabolite on to its egg ribbons, most likely for protective purposes. The scalarane showed antibacterial activity against the Gram-positive bacteria Arthrobacter crystallopoietes (DSM 20117) and Bacillus megaterium (DSM 32).

Optimization of the biological soil improvement procedure

Biocalcification is a developing method in the realm of bio-geotechnics, potentially invaluable for soil stabilization. The method is based on microbial-induced calcite precipitation. Hydrolysis of urea by the urease enzyme discharging from bacteria in the presence of Ca2+ is one of the most notable methods for calcium carbonate precipitation. However, partial clogging may occur as a result of premature bacterial activity that hinders free flow of the mixture, prohibiting spatial homogeneity of the sediment formation, thus limiting the extent of calcification. In order to circumvent clogging, bacterial activity was suppressed in this study prior to injection by lowering the temperature of the suspension and the reaction to 3 °C prior to mixture, delaying CaCO3 precipitation and thus allowing more uniform dispersion of the mixture. Sporosarcina pasteurii and Arthrobacter crystallopoietes were cultured in two different media and injected with reactant agent into samples of non-cohesive sand. The effect of culture media and temperature was studied on the rate and volume of CaCO3 precipitation. Furthermore, the effect of cementation of each batch on the shear strength of the treated soil was evaluated in unconfined compression test. Compressive strengths in excess of 400 kPa were recorded for samples that were injected in two phases, an hour apart. Whereas the highest compressive strength obtained from a single-phase injection at room temperature was approximately 80 kPa. By lowering the temperature of the bacterial suspension and the reactant solution prior to injection, the compressive strength of the sample treated in a single phase was increased to 230 kPa.

Degradation of 2,6-dimethylpyridine by Arthrobacter crystallopoietes

Degradation of 2,6-dimethylpyridine by Arthrobacter crystallopoietes

Identification of d-carbamoylase for biocatalytic cascade synthesis of d-tryptophan featuring high enantioselectivity

In this study, an enantioselective d-carbamoylase (AcHyuC) was identified from Arthrobacter crystallopoietes with optimum pH of 8.5, much more compatible with hydantoinase process than other reported d-N-carbamoylases. AcHyuC has a substrate preference for aromatic carbamoyl-compounds. The dynamic kinetic resolution (DKR) cascade was developed by combining this AcHyuC with hydantoin racemase from Arthrobacter aurescens (AaHyuA) and d-hydantoinase from Agrobacterium tumefaciens (AtHyuH) for enantioselective resolution of l-indolylmethylhydantoin into d-Trp. The optimum pH of DKR cascade reaction was determined to be 8.0, and PEG 400 could facilitate the reaction. As much as 80mM l-indolylmethylhydantoin could be fully converted to d-Trp within 12h at 0.5L scale, with 99.4% yield, >99.9% e.e. and productivity of 36.6gL−1d−1. This study provides a new d-carbamoylase compatible with the DKR cascade for efficient production of optically pure d-Trp from l-indolylmethylhydantoin.

Novel teichulosonic acid and glycosyl 1-phosphate polymers from the cell walls of Arthrobacter sp., strains VKM Ac-2549 and VKM Ac-2550, phylogenetically close to Arthrobacter crystallopoietes

Novel teichulosonic acid with the repeating unit →6)-β-D-GlcpNAc-(1→8)-α-Kdn-(2→ has been found in the cell walls of two Arthrobacter strains, VKM Ac-2549 and VKM Ac-2550. The teichulosonic acid was revealed in representatives of the genus Arthrobacter for the first time. Two other polymers identified in the above strains were poly(monoglycosyl 1-phosphate) and poly(diglycosyl 1-phosphate) of hitherto unknown structures, i.e., -6)-α-D-GalpNAc-(1-P-, and -6)-β-D-GlcpNAc-(1→3)-α-D-Galp-(1-P-. The structures of all three polymers were established by using chemical, NMR spectroscopic and ESI-MS methods. The strains studied in this work differ in the cell wall composition from the type strain of phylogenetically closely related species A. crystallopoietes which was reported to contain a teichoic acid and supposedly had a glycosyl 1-phosphate polymer.

Toward a cell-free hydantoinase process: screening for expression optimization and one-step purification as well as immobilization of hydantoinase and carbamoylase

The hydantoinase process is applied for the industrial synthesis of optically pure amino acids via whole cell biocatalysis, providing a simple and well-established method to obtain the catalyst. Nevertheless, whole cell approaches also bear disadvantages like intracellular degradation reactions, transport limitations as well as low substrate solubility. In this work the hydantoinase and carbamoylase from Arthrobacter crystallopoietes DSM 20117 were investigated with respect to their applicability in a cell-free hydantoinase process. Both enzymes were heterologously expressed in Escherichia coli BL21DE3. Cultivation and induction of the hydantoinase under oxygen deficiency resulted in markedly higher specific activities and a further increase in expression was achieved by codon-optimization. Further expression conditions of the hydantoinase were tested using the microbioreactor system BioLector®, which showed a positive effect upon the addition of 3% ethanol to the cultivation medium. Additionally, the hydantoinase and carbamoylase were successfully purified by immobilized metal ion affinity using Ni Sepharose beads as well as by functionalized magnetic beads, while the latter method was clearly more effective with respect to recovery and purification factor. Immobilization of both enzymes via functionalized magnetic beads directly from the crude cell extract was successful and resulted in specific activities that turned out to be much higher than those of the purified free enzymes.

Chemical synthesis and enzymatic, stereoselective hydrolysis of a functionalized dihydropyrimidine for the synthesis of β-amino acids.

A novel substrate, 6-(4-nitrophenyl)dihydropyrimidine-2,4(1H,3H)-dione (pNO2PheDU), was chemically synthesized and analytically verified for the potential biocatalytic synthesis of enantiopure β-amino acids. The hydantoinase (EC 3.5.2.2) from Arthrobacter crystallopoietes DSM20117 was chosen to prove the enzymatic hydrolysis of this substrate, since previous investigations showed activities of this enzyme toward 6-monosubstituted dihydrouracils. Whole cell biotransformations with recombinant Escherichia coli expressing the hydantoinase showed degradation of pNO2PheDU. Additionally, the corresponding N-carbamoyl-β-amino acid (NCarbpNO2βPhe) was chemically synthesized, an HPLC-method with chiral stationary phases for detection of this product was established and thus (S)-enantioselectivity toward pNO2PheDU has been shown. Consequently this novel substrate is a potential precursor for the enantiopure β-amino acid para-nitro-β-phenylalanine (pNO2βPhe).Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-015-0174-8) contains supplementary material, which is available to authorized users.

Azo Dye Decolorization under Microaerophilic Conditions by a Bacterial Mixture Isolated from Anthropogenic Dye‐Contaminated Soil

ABSTRACTSoil samples isolated from dye-contaminated sites were exploited for isolation of dye decolorizing microorganisms. A novel bacterial mixture, RkNb1, was selected based on its efficiency, showing maximum and faster decolorization of textile dyes. Seven bacterial strains were isolated and identified from the bacterial mixture as Ochrobactrum intermedium (HM480365), Ochrobactrum intermedium strain M16-10-4 (HM030758), Enterococcus faecalis (HM480367), Arthrobacter crystallopoietes (HM480368), Kocuria flavus (HM480369), Bacillus beijingensis (HM480370), and Citrobacter freundii (HM480371) by 16S rRNA gene sequence analysis. This bacterial mixture showed 98.17% decolorization of Reactive Violet 5 (400 mg L−1) within 8 h. The culture exhibited good decolorization ability at pH 8 and at a temperature of 37°C. Malt extract and peptone was found to enhance the decolorization rate of Reactive Violet 5. Plackett-Burman experimental design was used for elucidation of medium components affecting Reactive Violet 5 decolorization. Dye degradation products obtained during the course of decolorization were analyzed by high-performance thin-layer chromatography (HPTLC), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR). The potential of this bacterial mixture to decolorize Reactive Violet 5 dye from manufacturing industry effluent is to be carried out using appropriate bioreactors.

Evolution of histamine oxidase activity for biotechnological applications

Histamine is present to various degrees in many foods, and concentrations in fish samples are considered a good indicator of freshness and hygienic food quality. Seeking for innovative methods to quantify histamine in foods, we used a synthetic gene designed on the sequence of histamine oxidase from Arthrobacter crystallopoietes (HOD) as the starting point in this study to develop a biosensor. HOD was expressed in Escherichia coli cells with a yield of ∼7mg protein/L of fermentation broth. Recombinant wild-type HOD oxidized histamine and tyramine whereas it was inactive toward putrescine and cadaverine (two amines present in fish samples). The putative residues involved in substrate binding were identified by an in silico docking procedure based on a model of the structure of HOD: site-saturation mutagenesis was performed on 8 positions. The most significant changes in kinetic properties were observed for the P143M HOD: this variant showed higher histamine affinity and lower substrate inhibition by tyramine than wild-type enzyme. Biosensor prototypes were produced using both the wild-type and the P143M variant HOD. These biosensors showed a good sensitivity and selectivity with respect to biogenic amines present in food specimens. Accordingly, the HOD-based biosensor was successfully used to assess histamine in fish samples, yielding values in good agreement with those obtained by HPLC analyses but in a few seconds and at a significantly lower cost per analysis.

Application of MALDI-TOF mass spectrometry for differentiation of closely related species of the “Arthrobacter crystallopoietes” phylogenetic group

MALDI mass spectra were generated for the type strain of Arthrobacter crystallopoietes VKM Ac-1107T and for closely related (99.6–100% 16S rRNA gene similarity) halotolerant Arthrobacter strains, as well as for some other Arthrobacter species. Results of the cluster analysis of the spectra were in agreement with the genotypic characteristics of bacteria (DNA-DNA hybridization and BOX-PCR). The data obtained in this study indicate that the halotolerant strains belong to two new Arthrobacter species. Specific peaks which can serve as chemotaxonomic markers of the species composing the phylogenetic group “Arthrobacter crystallopoietes” were revealed.

The exposition of a calcareous Mediterranean soil to toxic concentrations of Cr, Cd and Pb produces changes in the microbiota mainly related to differential metal bioavailability

The involvement of the bacterial community of an agricultural Mediterranean calcareous soil in relation to several heavy metals has been studied in microcosms under controlled laboratory conditions. Soil samples were artificially polluted with Cr(VI), Cd(II) and Pb(II) at concentrations ranging from 0.1 to 5000mgkg−1 and incubated along 28d. The lowest concentrations with significant effects in soil respirometry were 10mgkg−1 Cr and 1000mgkg−1 Cd and Pb. However, only treatments showing more than 40% inhibition of respirometric activity led to significant changes in bacterial composition, as indicated by PCR–DGGE analyses. Presumable Cr- and Cd-resistant bacteria were detected in polluted microcosms, but development of the microbiota was severely impaired at the highest amendments of both metals. Results also showed that bioavailability is an important factor determining the impact of the heavy metals assayed, and even an inverted potential toxicity ranking could be achieved if their soluble fraction is considered instead of the total concentration. Moreover, multiresistant bacteria were isolated from Cr-polluted soil microcosms, some of them showing the capacity to reduce Cr(VI) concentrations between 26% and 84% of the initial value. Potentially useful strains for bioremediation were related to Arthrobacter crystallopoietes, Stenotrophomonas maltophilia and several species of Bacillus.

Application of Alkaliphilic Biofilm-Forming Bacteria to Improve Compressive Strength of Cement-Sand Mortar

The application of microorganisms in the field of construction material is rapidly increasing worldwide; however, almost all studies that were investigated were bacterial sources with mineral-producing activity and not with organic substances. The difference in the efficiency of using bacteria as an organic agent is that it could improve the durability of cement material. This study aimed to assess the use of biofilm-forming microorganisms as binding agents to increase the compressive strength of cement-sand material. We isolated 13 alkaliphilic biofilmforming bacteria (ABB) from a cement tetrapod block in the West Sea, Korea. Using 16S RNA sequence analysis, the ABB were partially identified as Bacillus algicola KNUC501 and Exiguobacterium marinum KNUC513. KNUC513 was selected for further study following analysis of pH and biofilm formation. Cement-sand mortar cubes containing KNUC513 exhibited greater compressive strength than mineral-forming bacteria (Sporosarcina pasteurii and Arthrobacter crystallopoietes KNUC403). To determine the biofilm effect, Dnase I was used to suppress the biofilm formation of KNUC513. Field emission scanning electron microscopy image revealed the direct involvement of organic-inorganic substance in cement-sand mortar.