Janthinobacterium Sp Research Articles

Janthinobacterium CG23_2: Comparative Genome Analysis Reveals Enhanced Environmental Sensing and Transcriptional Regulation for Adaptation to Life in an Antarctic Supraglacial Stream.

As many bacteria detected in Antarctic environments are neither true psychrophiles nor endemic species, their proliferation in spite of environmental extremes gives rise to genome adaptations. Janthinobacterium sp. CG23_2 is a bacterial isolate from the Cotton Glacier stream, Antarctica. To understand how Janthinobacterium sp. CG23_2 has adapted to its environment, we investigated its genomic traits in comparison to genomes of 35 published Janthinobacterium species. While we hypothesized that genome shrinkage and specialization to narrow ecological niches would be energetically favorable for dwelling in an ephemeral Antarctic stream, the genome of Janthinobacterium sp. CG23_2 was on average 1.7 ± 0.6 Mb larger and predicted 1411 ± 499 more coding sequences compared to the other Janthinobacterium spp. Putatively identified horizontal gene transfer events contributed 0.92 Mb to the genome size expansion of Janthinobacterium sp. CG23_2. Genes with high copy numbers in the species-specific accessory genome of Janthinobacterium sp. CG23_2 were associated with environmental sensing, locomotion, response and transcriptional regulation, stress response, and mobile elements—functional categories which also showed molecular adaptation to cold. Our data suggest that genome plasticity and the abundant complementary genes for sensing and responding to the extracellular environment supported the adaptation of Janthinobacterium sp. CG23_2 to this extreme environment.

Complete genome sequence of Janthinobacterium sp. B9-8, a violacein-producing bacterium isolated from low-temperature sewage

Janthinobacterium sp. B9-8, isolated from low temperature-sewage in Xinjiang, China, is capable of producing violacein, a promising antibiotic. Here we report the genome sequence of B9-8, which consist of 4,726,850 bp with a G + C content of 48.72%. The violacein biosynthesis gene cluster vioABCDE was identified and analyzed based on the genomic data, which revealed relatively low query coverage (3–44%) and identity (66–87%) with existing strains. Janthinobacterium sp. B9-8 grew fast and reached a high cell density and violacein content within 24 h at 25 °C. The availability of this genome sequence will greatly benefit the industrial production of violacein and facilitate supplementary studies on the mechanism for violacein biosynthesis.

Purification of Cold-adapted Protease from Janthinobacterium sp.

Purification of Cold-adapted Protease from Janthinobacterium sp.

Draft Genome Sequence of Janthinobacterium sp. Strain ROICE36, a Putative Secondary Metabolite-Synthesizing Bacterium Isolated from Antarctic Snow.

ABSTRACTThe draft genome assembly of Janthinobacterium sp. strain ROICE36 has 207 contigs, with a total genome size of 5,977,006 bp and a G+C content of 62%. Preliminary genome analysis identified 5,363 protein-coding genes and a total of 7 secondary metabolic gene clusters (encoding bacteriocins, nonribosomal peptide-synthetase [NRPS], terpene, hserlactone, and other ketide synthases).

Expression, Purification, and Characterization of a Cold-adapted Lipase from Janthinobacterium sp.

Expression, Purification, and Characterization of a Cold-adapted Lipase from Janthinobacterium sp.

Highly efficient nitrogen removal of a coldness-resistant and low nutrient needed bacterium, Janthinobacterium sp. M-11

A novel heterotrophic nitrification-aerobic denitrification bacterium, identified as Janthinobacterium sp. M-11, was isolated from the Songhua River. When the initial ammonium concentration was 5 mg·L−1, 98% of ammonium was removed under cold condition (2 °C) with the C/N ratio of 5 at initial pH 7 and aerobic condition, which demonstrated the significant ammonium removal capacity of M-11 with low nutrient consumption at cold temperature. Denitrification processes under aerobic and anaerobic conditions were also investigated. 89% of nitrite and 89% of nitrate were removed under aerobic condition. Under anaerobic condition, 93% of nitrite and 98% of nitrate were removed. Interestingly, a high amount of nitrite accumulation was observed in the mid-stage of anaerobic denitrification for nitrate. This special phenomenon was probably because of the existence of narG gene amplified in the strain M-11, which would encode membrane-bound nitrate reductase and accelerate the nitrate conversion rate of M-11 under anaerobic condition.

Isolation and Characterization of the Lytic Cold-Active Bacteriophage MYSP06 from the Mingyong Glacier in China.

As unique ecological systems, glaciers are characterized by low temperatures and low nutrient levels, which allow them to be considered as “living fossils” for the purpose of researching the evolution of life and the environmental evolution of the earth. Glaciers are also natural microbial “reservoirs”. In this work, a lytic cold-active bacteriophage designated MYSP06 was isolated from Janthinobacterium sp. MYB06 from the Mingyong Glacier in China, and its major characteristics were determined. Electron microscopy revealed that bacteriophage MYSP06 had an isometric head (74 nm) and a long tail (10 nm in width, 210 nm in length). It was classified as a Siphoviridae with an approximate genome size of 65–70 kb. A one-step growth curve revealed that the latent and burst periods were 95 and 65 min, respectively, with an average burst size of 16 bacteriophage particles per infected cell. The bacteriophage particles (100 %) adsorbed to the host cells within 10 min after infection. Moreover, the pH value and thermal stability of bacteriophage MYSP06 were also investigated. The maximum stability of the bacteriophage was observed at the optimal pH 7.0, and the bacteriophage became completely unstable at the extremely alkaline pH 11.0; however, it was comparatively stable at the acidic alkaline pH 6.0. As MYSP06 is a cold-active bacteriophage with a lower production temperature, its characterization and its relationship with its host Janthinobacterium sp. MYB06 deserve further study.

Draft Genome of Janthinobacterium sp. RA13 Isolated from Lake Washington Sediment.

Sequencing the genome of Janthinobacterium sp. RA13 from Lake Washington sediment is announced. From the genome content, a versatile life-style is predicted, but not bona fide methylotrophy. With the availability of its genomic sequence, Janthinobacterium sp. RA13 presents a prospective model for studying microbial communities in lake sediments.

In situ enrichment of folate by microorganisms in beta-glucan rich oat and barley matrices

The objective was to study folate production of yeast strains, bacteria isolated from oat bran, and selected lactic acid bacteria as well as one propionibacterium in oat and barley based models. Simultaneously, we aimed at sustaining the stability of viscosity, representing the physicochemical state of beta-glucan. Total folate contents were determined microbiologically and vitamers for selected samples by UHPLC.Folate in yeast cells comprised mainly 5-methyltetrahydrofolate and tetrahydrofolate. Folate production by microbes in YPD medium was different to that in cereal fermentations where vitamers included 5-methyltetrahydrofolate, 5,10-methenyltetrahydrofolate and formylated derivatives. Microbes producing significant amounts of folate without affecting viscosity were Saccharomyces cerevisiae ALKO743 and Candida milleri ABM4949 among yeasts and Pseudomonas sp. ON8 and Janthinobacterium sp. RB4 among bacteria. Net folate production was up to 120ng/g after 24h fermentation and could increase during 2-week storage. Glucose addition increased the proportion of 5-methyltetrahydrofolate. Streptococcus thermophilus ABM5097, Lactobacillus reuteri, and Propionibacterium sp. ABM5378 produced folate but in lower concentrations.Both endogenous and added microbes contribute to folate enhancement. Selection of microbes with folate producing capability and limited hydrolytic activity will enable the development of products rich in folate and beta-glucan.

Antibacterial activity of the Antarctic bacterium Janthinobacterium sp. SMN 33.6 against multi-resistant Gram-negative bacteria

article i nfo Background: The increment of resistant strains to commonly used antibiotics in clinical practices places in evidencetheurgentneedtosearchfornewcompoundswith antibacterial activity.TheadaptationsthatAntarctic microorganismshavedeveloped,due tothe extremeenvironmentthattheyinhabit, promote themasa potential new source of active compounds for the control of microorganisms causing infections associated with health care.TheaimofthisstudywastoevaluatetheantibacterialactivityofanethanolextractoftheAntarcticbacterium Janthinobacterium sp., strain SMN 33.6, against nosocomial multi-resistant Gram-negative bacteria. Results: Inhibitory activity against human Gram-negative bacterial pathogens, with concentrations that varied between 0.5 and 16 μ gm l -1 , was demonstrated. Conclusions:The ethanolic extract of Janthinobacterium sp. SMN 33.6 possesses antibacterial activity against a chromosomal AmpC beta-lactamase-producing strain of Serratia marcescens, an extended-spectrum beta-lactamase-producing Escherichia coli and also against carbapenemase-producing strains of Acinetobacter baumannii and Pseudomonas aeruginosa. This becomes a potential and interesting biotechnological tool for the control of bacteria with multi-resistance to commonly used antibiotics.

Decaffeination and Measurement of Caffeine Content by AddictedEscherichia coliwith a RefactoredN-Demethylation Operon fromPseudomonas putidaCBB5

The widespread use of caffeine (1,3,7-trimethylxanthine) and other methylxanthines in beverages and pharmaceuticals has led to significant environmental pollution. We have developed a portable caffeine degradation operon by refactoring the alkylxanthine degradation (Alx) gene cluster from Pseudomonas putida CBB5 to function in Escherichia coli. In the process, we discovered that adding a glutathione S-transferase from Janthinobacterium sp. Marseille was necessary to achieve N 7 -demethylation activity. E. coli cells with the synthetic operon degrade caffeine to the guanine precursor, xanthine. Cells deficient in de novo guanine biosynthesis that contain the refactored operon are ″addicted″ to caffeine: their growth density is limited by the availability of caffeine or other xanthines. We show that the addicted strain can be used as a biosensor to measure the caffeine content of common beverages. The synthetic N-demethylation operon could be useful for reclaiming nutrient-rich byproducts of coffee bean processing and for the cost-effective bioproduction of methylxanthine drugs.

UV and cold tolerance of a pigment-producing Antarctic Janthinobacterium sp. Ant5-2

In this paper, we describe the UV and cold tolerance of a purple violet pigment (PVP)-producing Antarctic bacterium, Janthinobacterium sp. Ant5-2 (PVP(+)) and compared its physiological adaptations with a pigmentless mutant strain (PVP(-)). A spontaneous deletion of vioA that codes for tryptophan monooxygenase, the first gene involved in the biosynthesis of PVP was found in PVP(-) strain. The PVP(-) culture exhibited significantly reduced survival during exponential and stationary growth phase following exposure to UVB (320 nm) and UVC (254 nm) (dose range: 0-300 J/m²) when compared to wild-type (PVP(+)) cultures. In addition, upon biochemical inhibition of pigment synthesis by 2(5H)-furanone, wild-type PVP(+) cultures exhibited approximately 50-fold growth reduction at a higher dose (300 J/m²) of UV. Increased resistance to UV was observed upon inducing starvation state in both PVP(+) and PVP(-) cultures. There was 80% (SD = ±8) reduction in extrapolymeric substance (EPS) production in the PVP(-) cultures along with a compromised survival to freeze-thaw cycles when compared to the PVP(+) cultures. Perhaps synthesis of PVP and EPS are among the key adaptive features that define the survival of this bacterium in Antarctic extreme conditions, especially during austral summer months.

The Janthinobacterium sp. HH01 Genome Encodes a Homologue of the V. cholerae CqsA and L. pneumophila LqsA Autoinducer Synthases

Janthinobacteria commonly form biofilms on eukaryotic hosts and are known to synthesize antibacterial and antifungal compounds. Janthinobacterium sp. HH01 was recently isolated from an aquatic environment and its genome sequence was established. The genome consists of a single chromosome and reveals a size of 7.10 Mb, being the largest janthinobacterial genome so far known. Approximately 80% of the 5,980 coding sequences (CDSs) present in the HH01 genome could be assigned putative functions. The genome encodes a wealth of secretory functions and several large clusters for polyketide biosynthesis. HH01 also encodes a remarkable number of proteins involved in resistance to drugs or heavy metals. Interestingly, the genome of HH01 apparently lacks the N-acylhomoserine lactone (AHL)-dependent signaling system and the AI-2-dependent quorum sensing regulatory circuit. Instead it encodes a homologue of the Legionella- and Vibrio-like autoinducer (lqsA/cqsA) synthase gene which we designated jqsA. The jqsA gene is linked to a cognate sensor kinase (jqsS) which is flanked by the response regulator jqsR. Here we show that a jqsA deletion has strong impact on the violacein biosynthesis in Janthinobacterium sp. HH01 and that a jqsA deletion mutant can be functionally complemented with the V. cholerae cqsA and the L. pneumophila lqsA genes.

Formation of hydrogen-producing granules and microbial community analysis in a UASB reactor

The effect of substrate concentration on continuous H2 production from a sucrose-rich synthetic wastewater was investigated in this work. The maximum H2 production rate of 2.89 m3 H2/m3/d achieved at 7000 mg COD/L while the peak ethanol concentration of 2840 mg/L was observed at 5000 mg COD/L. The H2-producing granules with ethanol-type fermentation were successfully cultivated in an upflow anaerobic sludge blanket (UASB) reactor. Denaturing gradient gel electrophoresis analysis demonstrates that the substrate concentration had a considerable effect on the microbial community. After the mature H2-producing granules were formed, the microbial community structure in the UASB reactor tends to stabilize. The dominant bacterium in the mature H2-producing granules were composed of Janthinobacterium sp. WPCB148, Clostridium sp. HPB-4, Variovorax paradoxus strain SJ100, Variovorax sp. CN3b and Uncultured bacterium clone C2.

Microbial community and treatment ability investigation in AOAO process for the optoelectronic wastewater treatment using PCR-DGGE biotechnology

This study aimed to explore the microbial community variation and treatment ability of a full-scale anoxic-aerobic-anoxic-aerobic (AOAO) process used for optoelectronic wastewater treatment. The sludge samples in the biological treatment units were collected and subsequently subjected to polymerase chain reaction (PCR) amplification and denaturing gradient gel electrophoresis identification and the wastewater components such as BOD5 and NH3-N were evaluated during the processes. The group specific primers selected were targeting at the kingdom Bacteria, the Acidobacterium, the α-proteobacteria, the β-proteobacteria ammonia oxidizers, Actinobacteria and methyllotrophs, and the 16S rDNA clone libraries were established. Ten different clones were obtained using the Bacteria primers and eight different clones were obtained using the β-proteobacteria ammonia oxidizer primers. Over 95% of BOD5 and 90% of NH3-N were removed from the system. The microbial community analysis showed that the Janthinobacterium sp. An8 and Nitrosospira sp. were the dominant species throughout the AOAO process. Across the whole clone library, six clones showed closely related to Janthinobacterium sp. and these species seemed to be the dominant species with more than 50% occupancy of the total population. Nitrosospira sp. was the predominant species within the β-proteobacteria and occupied more than 30% of the total population in the system. These two strains were the novel species specific to the AOAO process for optoelectronic treatment, and they were found strongly related to the system capability of removing aquatic contaminants by inspecting the wastewater concentration variation across the system.

Antimicrobial activity of PVP from an Antarctic bacterium, Janthinobacterium sp. Ant5-2, on multi-drug and methicillin resistant Staphylococcus aureus

Multiple drug resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as a community acquired infection. As a result limited treatment options are available with conventional synthetic antibiotics. Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen. In this study, we have investigated the antimicrobial activity of a purple violet pigment (PVP) from an Antarctic bacterium, Janthinobacterium sp. Ant5-2 on 15 clinical MDR and MRSA strains. The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration (MIC90) of PVP against MDR and MRSA. The MIC90 ranged between 1.57 µg/mL and 3.13 µg/mL, which are significantly lower than many antimicrobials tested from natural sources against this pathogen. The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead® BacLight™ fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels. In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound. The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.

Genome Sequence of Janthinobacterium sp. Strain PAMC 25724, Isolated from Alpine Glacier Cryoconite

The draft genome of Janthinobacterium sp. strain PAMC 25724, which is a violacein-producing psychrotolerant bacterium, was determined. The strain was isolated from glacier cryoconite of the Alps mountain permafrost region. The sequence will allow identification and characterization of the genetic determination of its cold-adaptive properties.

The development of species-specific probes for a quantitative estimation of non-cultured bacteria in groundwater samples

The aim of this study was to quantify different bacteria in drinking water production wells that supply the city of Mainz (capital of Rhineland-Palatinate, Germany). Knowledge of the counts of individual microorganisms is important for the appraisal of the hygienic and sensory quality of drinking water. Specific 16S rRNA probes were designed for 14 previously identified but non-cultured bacterial species (Ferribacterium limneticum, Hydrogenophaga sp., Methylotenera sp., Janthinobacterium sp., Pseudomonas sp., Rhizobium selenireducens, Rhodoferax sp., Nitrosomonadaceae bacterium, Thauera sp. and five strains which could not be identified to species level). With fluorescence in situ hybridization the titer of these species was determined. Total bacterial counts were 4.3 × 104 cells/mL (April) and 4.0 × 104cells/mL (December). The highest relative counts were observed for Methylotenera sp. (4.6–21.7%), F. limneticum (6.1–10.2%), Janthinobacterium sp. (6.1–7.1%), strain K-S10-Sep02 (5.8–5.9%) and Nitrosomonadaceae bacterium (4.8–5.9%). These organisms accounted for 50% (April) and 29% (December) of the total counts. Finally, single water production wells that supply drinking water were studied for the counts of Methylotenera sp., F. limneticum and Janthinobacterium sp. These counts differed between the wells and did not reflect counts in the drinking water treatment plant.

Molecular and biochemical characterization of a new alkaline β-propeller phytase from the insect symbiotic bacterium Janthinobacterium sp. TN115

A phytase-encoding gene (phyA115) was cloned from Janthinobacterium sp. TN115, a symbiotic bacterial strain isolated from the gut contents of Batocera horsfieldi larvae (Coleoptera: Cerambycidae), and expressed in Escherichia coli. The 1,884-bp full-length gene encodes a 28-residue putative signal peptide and a 599-residue mature protein with a calculated mass of 64 kDa. The deduced PhyA115 shares low identity with known sequences (47% at most) and contains an N-terminal incomplete domain (residues 29-297; domain N) and a typical β-propeller phytase domain at the C terminus (residues 298-627; domain C). Distinct from other β-propeller phytases that have neutral pH optima (pH 6.0-7.5), purified recombinant PhyA115 exhibits maximal activity at pH 8.5 and 45°C in the presence of 1 mM Ca(2+) and is highly active over a wider pH range (pH 6.0-9.0). These results indicate that PhyA115 is a β-propeller phytase that has application potential in aquaculture feed. To our knowledge, this is the first report of cloning of a phytase gene from the symbiotic microbes of an insect digestive tract and from the genus Janthinobacterium. The N-terminal incomplete domain is found to have no phytase activity but can influence the pH property of PhyA115.

Structure and function of a cold shock domain fold protein, CspD, in Janthinobacterium sp. Ant5-2 from East Antarctica

A cold shock domain (CSD)-containing protein, CspD, of molecular mass ~7.28 kDa in a psychrotolerant Antarctic Janthinobacterium sp. Ant5-2 (ATCC BAA-2154) exhibited constitutive expression at 37, 22, 15, 4 and -1°C. The cspD gene encoding the CspD protein of Ant5-2 was cloned, sequenced and analyzed. The deduced protein sequence was highly similar to the conserved domains of the cold shock proteins (Csps) from bacteria belonging to the class Betaproteobacteria. Its expression was both time- and growth phase-dependent and increased when exposed to 37°C and UV radiation (UVC, dose: 1.8 and 2.8 mJ cm(-2)). The results from the electrophoretic mobility shift and subcellular localization study confirmed its single-stranded DNA-binding property. In silico analysis of the deduced tertiary structure of CspD from Ant5-2 showed a highly stable domain-swapped dimer, forming two similar monomeric Csp folds. This study established an overall framework of the structure, function and phylogenetic analysis of CspD from an Antarctic Janthinobacterium sp. Ant5-2, which may facilitate and stimulate the study of CSD fold proteins in the class Betaproteobacteria.