Introduction: Microbial endophytes colonizing internal tissues of living plants provide benefits to their host by promoting plant growth and protection against microbial infectious through the production of wide ranges of metabolites. Members of such endophytic community harbouring medicinally important plants are known to synthesize several antimicrobial compounds. The present study aims to explore bacterial endophytes of ethnomedicinal plant Rauvolfia serpentina (Apocynaceae) for producing novel antimicrobial metabolites of pharmaceutical and biotechnological importance. Materials and Methods: The culturable bacterial endophytic diversity of R. serpentina (L.) Benth. ex. Kurz. has been screened for producing antimicrobial compounds following cross-streak and agar well diffusion assay methods against several test microbial strains. The bioactive compound was isolated and partially purified from the cell-free culture filtrate following chromatographic methods. Results: The endophytes revealed low colonization frequency and isolation rates in the root and stem respectively. In vitro antimicrobial screening of 12 phenotypically distinguishable endophytes resulted in the selection of a potent antimicrobial isolate RAU 305 identified as Pseudomonas aeruginosa RAU 305 (Genbank accession number KR816098). Cell-free culture filtrate of RAU 305 showed broad spectrum of antimicrobial activity by inhibiting Paenibacillus, Micrococcus, Arthrobacter, Rhodobacter, Mycobacterium, Bacillus, Escherichia, Staphylococcus, Klebsiella, Aspergillus, Colletotrichum and Pythium. The antimicrobially active component extracted in butanol and chloroform was partially purified by column chromatography followed by a preparative thin layer chromatography and the homogeneity of the compound was confirmed using different solvent systems. Conclusions: More detailed characterization and identification of the active component is essential to explore the metabolic potential of this endophytic bacterium in future.

Atrazine Degradation Pathway and Genes of <i>Arthrobacter</i> sp. FM326

An Arthrobacter strain isolated from desert soils in the region of Shule River (China) can convert cellulose to potential biofuels

Objective To explore the characteristics of respiratory tract microbiota and its clinical significance in children with protracted bacterial bronchitis (PBB). Methods Twelve children aged from 5 months to 2 years old with PBB (PBB group) and 12 age-matched tracheomalacia(TM) children (TM group) were included in this study, who were admitted into the Respiratory Department of Shenzhen Children′s Hospital.Their bronchoalveolar lavage fluid (BALF) samples were collected.Bacterial DNA was extracted from their BALF samples and the 16S rRNA V3-V4 region was sequenced by using Illumina MiSeq TMII system, and the findings were analyzed by bioinformatics methods. Results Principal component analysis revealed the difference in microbiota composition between 2 groups.Compared with TM group, PBB group exhibited lower microbial diversity: the Shannon indices were also 1.683±0.703 and 2.324±0.142 for PBB group and TM group respectively, and the differences were also significant(all P<0.05), and the Simpson indices were 0.416±0.216 and 0.191±0.025 for PBB group and TM group, respectively, and the diffe-rences were also significant(all P<0.05). The relative abundance of Actinobacteria was significantly lower in PBB group [(0.215±0.228)%]than that in TM group [(3.028±0.592)%](P<0.01). The proportions of beneficial genera obviously decreased in PBB group, including Lactococcus [(13.464±7.319)% in PBB group, and (44.784±5.020)% in TM group, P<0.01], Lactobacillus [(0.153±0.076)% in PBB group, and (0.313±0.060)% in TM group, P<0.01], and Arthrobacter [(0.024±0.018)% in PBB group, and (2.970±0.584)% in TM group, P<0.01]. On the other hand, the relative abundances of opportunistic pathogenic genera increased in PBB group significantly, including Haemophilus[(14.319±29.532)% in PBB group, and (0.047±0.127)% in TM group, P<0.01], Pseudomonas[(10.406±25.439)% in PBB group, and (7.228±0.948)% in TM group, P<0.01], and Escherichia [(0.432±0.441)% in PBB group, and (0.055±0.035)% in TM group, P<0.01]. Conclusion These findings confirmed the existence of respiratory tract microbiotia dysbiosis in PBB, which probably was one of the pathogenetic mechanisms for PBB. Key words: Respiratory tract; Microbiota; Protracted bacterial bronchitis; Child; High-throughput sequencing

The Iberian lynx (Lynx pardinus) is an endangered species restricted to several areas of Spain and Portugal. Its low genetic diversity likely provokes immune depression and high susceptibility to infectious diseases. The intestinal microbiota is closely related to host health and nutrition. In order to contribute to the knowledge of the Iberian lynx intestinal microbiota, fecal microbiota of captive specimens from two breeding centers ("La Olivilla" and "El Acebuche"), located in Southern Spain, were studied by Denaturing Gradient Gel Electrophoresis (DGGE). Results grouped microbiota in two main clusters (I and III) which included DGGE patterns of 19 out of 36 specimens, cluster I being the most frequent in "La Olivilla" (50%) and cluster III in "El Acebuche" (55.55 %) specimens. Bacteroidetes, Firmicutes and Proteobacteria phyla were identified. Segregation of clusters I and III was attributed to different microorganism presence (Pseudomonas koreensis, Pseudomonas migulae, Carnobacterium sp., Arthrobacter, Robinsoniella peorensis and Ornithinibacillus sp.) and ability to use different carbon sources. Biolog EcoPlates® results indicate high functional diversity of fecal microbiota, it being higher in cluster III. The great impact of intestinal microbiota on host health supports the importance of its microbial composition understanding. This study is the first report of captive Iberian lynx fecal microbiota composition. [Int Microbiol 20(1): 31-41 (2017)].

Heterogeneity of Glycopolymers of the Cell Walls of Actinobacteria of the Polyphyletic Genus Arthrobacter

Molecular classification and comparative analysis of Arthrobacter genus plasmids

The condition of bacteria and Amaranthus viridis in gasoline-contaminated soil was surveyed. The soil was treated with different concentrations of petrol oil: 0 ml (control), 18, 56, 112, 168 and 224 ml. Each of the concentrations was in triplicates. Seventeen (17) bacterial isolates were recovered from the control soil while twenty (20) bacterial isolates were recovered from the polluted soil. A total of twenty four (24) different genera were recovered from the soil. The organisms areAcinetobacter ceticus, Actinomyces sp, Aerococcus viridians, Alcaligenes paradoxus, Arthrobacter, Bacillus cereus, Bacillus polymxa, Bacillus subtilis, Chromobacterium violaceum, Clostridium sp., Corynebacterium hydrocarbodastus, Corynebacterium kutsceri, Corynebacterium xerosis, Cytophaga sp., Erwinia sp., Flavobacterium sp., Micrococcus luteus, Proteus vulgaris, Pseudomonas fluorescens, Pseudomonas putida, Sarcina ventricule, Serratia sp., Staphylococcus aureus, and Streptococcus sp. The pH, temperature, organic matter content, moisture content and water holding capacity of the soil were determined. A. viridis had 100% germination in both the control (0 ml) and 18 ml gasoline-treated soils while it had delayed germination in the other treatments (56, 112, 168 and 224 ml). The results obtained in this study showed that gasoline spillage posses a great threat to the survival and development of plants. It also revealed that certain bacteria could survive the gasoline-contaminated soil and thus may be useful in biodegradation and/or bioremediation of gasoline contaminated soils. Key words: Surveillance, bacteria, Amaranthus viridis, gasoline, contaminated soil.

Microbiological calcium carbonate precipitation (MCP) has been investigated for its ability to improve the compressive strength of concrete mortar. However, very few studies have been conducted on the use of calcite-forming bacteria (CFB) to improve compressive strength. In this study, we discovered new bacterial genera that are capable of improving the compressive strength of concrete mortar. We isolated 4 CFB from 7 environmental concrete structures. Using sequence analysis of the 16S rRNA genes, the CFB could be partially identified as Sporosarcina soli KNUC401, Bacillus massiliensis KNUC402, Arthrobacter crystallopoietes KNUC403, and Lysinibacillus fusiformis KNUC404. Crystal aggregates were apparent in the bacterial colonies grown on an agar medium. Stereomicroscopy, scanning electron microscopy, and x-ray diffraction analyses illustrated both the crystal growth and the crystalline structure of the CaCO3 crystals. We used the isolates to improve the compressive strength of concrete mortar cubes and found that KNUC403 offered the best improvement in compressive strength.

To investigate the optimum growth conditions and screen atrazine-degrading strains, two atrazine-degrading strains named Z9 and Z42 were isolated from black earth in a cold area with a long-term application of atrazine by standard enrichment techniques. Z9 utilizes atrazine as both the nitrogen and carbon source whereas Z42 utilizes atrazine as the sole nitrogen source to grow. The atrazine degradation rates of the two strains reached 77.7% and 65.6%, respectively after 14 days culture in a liquid medium with an atrazine concentration of 100 mg/L. Z9 and Z42 were identified as Microbacterium sp . and Arthrobacter sp . The optimum inoculation amount and rotation speed for Z9 and Z42 to grow and degrade atrazine are 3% and 120 r/min respectively. Keywords : atrazine, isolation, identification, degradation characteristics DOI: 10.3965/j.issn.1934-6344.2009.03.027-032 Citation: Ying Zhang, Zhou Ning, Jiang Zhao, Peng Xinran, Ma Shuyan, Hu Miao. Isolation of two atrazine-degrading strains and their degradation characteristics. Int J Agric & Biol Eng, 2009; 2(3): 27

Glycine betaine is a unique compatible osmolyte which protects the photosystem II (PSII) complex from a variety of stresses. Synechococcus sp. PCC 7942 cells transformed with the codA gene for choline oxidize from Arthrobacter globiformis has been shown to provide protection against photoinhibition at low temperature. Here we demonstrate that accumulation of glycine betaine in the transformed cells also protected the oxygen-evolving machinery of PSII from inactivation by elevated temperature. Temperature critical for the thermal inactivation of oxygen-evolving machinery of the transformed cells was approximately 7°C higher than that of the control cells. The transformed and the control cells grew at about same rate at 30°C and at 38°C, but between 40°C to 46°C the transformed cells grew faster than control cells that lacked the ability to accumulate glycine betaine. Thus accumulation of glycine betaine in vivo also seems to provide the transformed cells of ability to acclimate elevated temperature.

Extracellular endo-inulinase of Arthrobacter sp. S37 was purified 63-fold, giving a single band on PAGE with activity staining. The Mr was estimated as 75 kDa by SDS-PAGE. The first 31 amino acids of the N-terminal sequence was determined. The endo-inulinase hydrolyzed inulin mainly into inulo-triose (F3), inulo-tetraose (F4) and inulo-pentaose (F5) optimally at pH 7.5 and 50°C. © Rapid Science Ltd. 1998

5478733 Process for producing L-alanine by fermentation with Arthrobacter

The DEX gene encoding an extracellular dextranase was isolated from the genomic DNA library of Penicillium minioluteum by hybridization using the dextranase cDNA as a probe. Comparison of the gene and cDNA sequences revealed that the DEX gene does not contain introns. Amino acid sequences comparison of P. minioluteum dextranase with other reported dextranases reveals a significant homology (29% identity) with a dextranase from Arthrobacter sp. CB-8. The DEX gene fragment encoding a mature protein of 574 amino acids was expressed in the methylotrophic yeast Pichia pastoris by using the SUC2 gene signal sequence from Saccharomyces cerevisiae under control of the alcohol oxidase-1 (AOX1) promoter. Over 3.2 g/l of enzymatically active dextranase was secreted into the medium after induction by methanol. The yeast product was indistinguishable from the native enzyme in specific activity and the N-terminus of both proteins were identical.

Coal-solubilizing agents produced byTrametes versicolor, Phanerochaete chrysosporium, Aspergillus sp., a bacterial consortium, and a bacterial isolate,Arthrobacter sp., from that consortium were compared in terms of pH dependence, thermostability, molecular mass, mechanism of action, and product diversity. The thermostability and low molecular weights exhibited by the coal-solubilizing agents indicated a non-enzymatic mechanism of action. Competition studies using cupric copper indicated that coal solubilization by these agents involved metal chelation. Results demonstrated that oxalate could account for some but not all of the coal solubilization observed forT.versicolor andP.chrysosporium. The very low levels of oxalate detected inAspergillus sp. and the bacterial cultures indicated that oxalate is not an important factor in coal solubilization by these microbes. When subjected to gel permeation chromatography, the soluble coal products generated by each microbial coal-solubilizing agent yielded unique molecular mass profiles suggesting substantial product diversity. Such diversity increases the possibility of identifying potentially valuable compounds and extending the commercial utilization of coal.

Arthrobactersp.K-1の生産するβ-フラクトフラノシダーゼの粗酵素液を酵素剤として用い,受容体として乳糖の存在下ショ糖に作用させ転移生成物を得た.転移生成物は非還元性であることおよび酵素分解などの結果より,フラクトシル基が乳糖のグルコース部分の1位にβ- 2,1結合したラクトシルフラクトシド(ラクトシュクロース)であることがわかった.ラクトシュクロースは乳糖とショ糖の比を1:1とし,酵素をショ糖19あたり7.5～10単位,pHを6.0付近,固形分濃度を40%,反応温度を55～60℃ とし,6～9時間反応することにより,最適に生産された.その反応液から活性炭カラムクロマトグラフィーによる分画により純度98%のラクトシュクロースを得ることができた. ラクトシュクロースはショ糖の30%と低甘味であり,良質な味質を有していた.ネオシュガーPと比較して酸性域でも安定であり,また弱酸性での長期保存性にもすぐれていた.またLS-98は凍結乾燥により粉末化可能であった.粉末品は吸湿性は高く,高い溶解度(367g/100ml以上)を示した.液状での保水性は高く,水分活性は0.87であった.

Journal Article Acil, a unique restriction endonuclease from Arthrobacter citreus which recognizes 5′ CCGC 3′ Get access Carol Polisson, Carol Polisson New England Biolabs32 Tozer Road, Beverly, MA 01915, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar Richard D. Morgan Richard D. Morgan New England Biolabs32 Tozer Road, Beverly, MA 01915, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar Nucleic Acids Research, Volume 18, Issue 19, 11 October 1990, Page 5911, https://doi.org/10.1093/nar/18.19.5911 Published: 11 October 1990 Article history Received: 16 August 1990 Published: 11 October 1990