Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T.

A cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

Identification and characterization of a novel extracellular polyhydroxyalkanoate depolymerase in the complete genome sequence of Undibacterium sp. KW1 and YM2 strains.

Polyhydroxyalkanoate (PHA) is a biodegradable polymer that is synthesized by a wide range of microorganisms. One of the derivatives of PHA, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) has flexible material properties and low melting temperature. We have previously demonstrated that PHBH is degradable in a freshwater environment via the formation of biofilm on the surface of the PHBH film. Undibacterium sp. KW1 and YM2, which were isolated from the biofilm present on the PHBH film in the freshwater sample, were shown to have PHBH-degrading activity. In this study, the complete genome sequence of KW1 and YM2 revealed that the extracellular PHA depolymerase gene, designated as phaZUD, was present in their chromosomes. Sequence analysis revealed that PhaZUD contained four domains: a signal peptide, catalytic domain, linker domain, and substrate-binding domain. Escherichia coli harboring a PhaZUD-expressing plasmid showed PHBH-degrading activity in LB medium containing 1 wt% PHBH powder. The recombinant His-tagged PhaZUD from KW1 and YM2 was purified from the culture supernatant and shown to have PHBH-degrading activity at the optimum temperature of 35 and 40°C, respectively. When the degradation product in the PHBH solution was treated with PhaZUD and assayed by LC-TOF-MS, we detected various oligomer structures, but no more than pentamers, which consist of 3-hydroxybutyrate and 3-hydroxyhexanoate. These results demonstrated that PhaZUD may have an endo-type extracellular PHA depolymerase activity.

Ultrafast Excited-State Deactivation of the Bacterial Pigment Violacein.

The photophysical properties of the natural pigment violacein extracted from an Antarctic organism adapted to high exposure levels of UV radiation were measured in a combined steady-state and time-resolved spectroscopic study for the first time. In the low-viscosity solvents methanol and acetone, violacein exhibits low fluorescence quantum yields on the order of 1 × 10-4, and femtosecond transient absorption measurements reveal excited-state lifetimes of 3.2 ± 0.2 and 4.5 ± 0.2 ps in methanol and acetone, respectively. As solvent viscosity is increased, both the fluorescence quantum yield and excited-state lifetime of this intensely colored pigment increase dramatically, and stimulated emission decays 30-fold more slowly in glycerol than in methanol at room temperature. Excited-state deactivation is suggested to occur via a molecular-rotor mechanism in which torsion about an interring bond leads to a conical intersection with the ground state.

Molecular and Biochemical Characterization of a Novel Xylanase from Massilia sp. RBM26 Isolated from the Feces of Rhinopithecus bieti.

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37°C and could maintain at least 96% activity after being placed at 37°C for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, Km, Vmax, and kcat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 µmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

Violacein, an indole-derived purple-colored natural pigment produced by Janthinobacterium lividum, inhibits the growth of head and neck carcinoma cell lines both in vitro and in vivo.

Violacein (VIO; 3-[1,2-dihydro-5-(5-hydroxy-1H-indol-3-yl)-2-oxo-3H-pyrrol-3-ylidene]-1,3-dihydro-2H-indol-2-one), an indole-derived purple-colored pigment, produced by a limited number of Gram-negative bacteria species, including Chromobacterium violaceum and Janthinobacterium lividum, has been demonstrated to have anti-cancer activity, as it interferes with survival transduction signaling pathways in different cancer models. Head and neck carcinoma (HNC) represents the sixth most common and one of the most fatal cancers worldwide. We determined whether VIO was able to inhibit head and neck cancer cell growth both in vitro and in vivo. We provide evidence that VIO treatment of human and mouse head and neck cancer cell lines inhibits cell growth and induces autophagy and apoptosis. In fact, VIO treatment increased PARP-1 cleavage, the Bax/Bcl-2 ratio, the inhibition of ERK1 and ERK2 phosphorylation, and the expression of light chain 3-II (LC3-II). Moreover, VIO was able to induce p53 degradation, cytoplasmic nuclear factor kappa B (NF-κB) accumulation, and reactive oxygen species (ROS) production. VIO induced a significant increase in ROS production. VIO administration was safe in BALB/c mice and reduced the growth of transplanted salivary gland cancer cells (SALTO) in vivo and prolonged median survival. Taken together, our results indicate that the treatment of head and neck cancer cells with VIO can be useful in inhibiting in vivo and in vitro cancer cell growth. VIO may represent a suitable tool for the local treatment of HNC in combination with standard therapies.

High-level production of violacein by the newly isolated Duganella violaceinigra str. NI28 and its impact on Staphylococcus aureus.

A violacein-producing bacterial strain was isolated and identified as a relative of Duganella violaceinigra YIM 31327 based upon phylogenetic analyses using the 16S rRNA, gyrB and vioA gene sequences and a fatty acid methyl ester (FAME) analysis. This new strain was designated D. violaceinigra str. NI28. Although these two strains appear related based upon these analyses, the new isolate was phenotypically different from the type strain as it grew 25% faster on nutrient media and produced 45-fold more violacein. When compared with several other violacein producing strains, including Janthinobacterium lividum, D. violaceinigra str. NI28 was the best violacein producer. For instance, the crude violacein yield with D. violaceinigra str. NI28 was 6.0 mg/OD at 24 hours, a value that was more than two-fold higher than all the other strains. Finally, the antibacterial activity of D. violaceinigra str. NI28 crude violacein was assayed using several multidrug resistant Staphylococcus aureus. Addition of 30 µM crude violacein led to a 96% loss in the initial S. aureus population while the minimum inhibitory concentration was 1.8 µM. Consequently, this novel isolate represents a phenotypic variant of D. violaceinigra capable of producing much greater quantities of crude violacein, an antibiotic effective against multidrug resistant S. aureus.

Current functional metagenomic approaches only expand the existing protease sequence space, but does not presently add any novelty to it.

Proteases are a fundamental function in many organisms and thus many ecosystems and yet they are rarely obtained in functional metagenomic screens. Here, we have isolated an active protease gene (M1-2; 613 amino acids) which resided in a 38.4 kb fosmid clone that showed a classical protease-positive phenotype. It was classified as a zinc-dependent metalloprotease, with the closest annotated sequence as a neutral protease from Collimonas fungivorans (62 % similarity and 72 % homology). Further characterisation showed that its optimum temperature and pH were 42 °C and 8.0, respectively. Activity was inhibited by EDTA, but inhibition started to be reversed by excess Zn(2+). A putative signal peptide was identified bioinformatically and this may be why this protease was successfully isolated using a functional metagenomic screen. Bioinformatic analysis shows that this does not represent a novel protease, but simply expands the current sequence space of known proteases.

Antibacterial activity of the Antarctic bacterium Janthinobacterium sp: SMN 33. 6 against multi-resistant Gram-negative bacteria

Background The increment of resistant strains to commonly used antibiotics in clinical practices places in evidence the urgent need to search for new compounds with antibacterial activity. The adaptations that Antarctic microorganisms have developed, due to the extreme environment that they inhabit, promote them as a potential new source of active compounds for the control of microorganisms causing infections associated with health care. The aim of this study was to evaluate the antibacterial activity of an ethanol extract of the Antarctic bacterium 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 µg ml- 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.

Duganella phyllosphaerae sp. nov., isolated from the leaf surface of Trifolium repens and proposal to reclassify Duganella violaceinigra into a novel genus as Pseudoduganella violceinigra gen. nov., comb. nov.

A bright yellow pigmented bacterium was isolated from the leaf surface of Trifolium repens in Germany. Comparative analysis of 16S rRNA gene sequences showed that this bacterium is most closely related to Duganella zoogloeoides IAM 12670(T), with a similarity of 99.3%, but revealed only a moderate similarity (96.8%) to the second Duganella species, Duganella violaceinigra YIM 31327(T). Strain T54(T) is clearly different from D. zoogloeoides IAM 12670(T) in that DNA-DNA hybridization revealed a similarity value of 46% (reciprocal 42%). Ubiquinone (Q-8) was the respiratory quinone and the predominant polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, three unknown phospholipids and one aminolipid. Strain T54(T) can be distinguished from D. zoogloeoides by the carbon substrate utilization tests of d-trehalose, cis-aconitate, trans-aconitate, glutarate and dl-3-hydroxybutyrate, and 4-hydroxybenzoate in addition to a different polar lipid profile. The name Duganella phyllosphaerae sp. nov. is proposed for this novel species, with the type strain T54(T) (=LMG 25994 = CCM 7824(T)) [corrected]. In addition, it is proposed to reclassify D. violaceinigra into a novel genus Pseudoduganella gen. nov. as the novel species Pseudoduganella violaceinigra comb. nov. because of the low 16S rRNA gene sequence similarities to the other Duganella species (<97%) and striking differences in chemotaxonomic (lipid profiles and fatty acid patterns) and other phenotypic features, including the colony pigmentation.

Massilia oculi sp. nov., isolated from a human clinical specimen.

A gram-negative, rod-shaped, non-spore-forming bacterium (strain CCUG 43427A(T)) was isolated from a patient suffering from endophthalmitis and its taxonomic position was studied. 16S rRNA gene sequence analysis indicated that this strain was a member of the genus Massilia. Strain CCUG 43427A(T) was most closely related to the type strains of Massilia timonae (97.4 % 16S rRNA gene sequence similarity) and Massilia aurea (97.2 %); levels of similarity to the type strains of all other recognized Massilia species were below 97.0 %. Chemotaxonomic data [Q-8 as major ubiquinone; phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as major polar lipids; and summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH), C(16 : 0), C(18 : 1)ω7c, C(12 : 0) and C(10 : 0) 3-OH as major fatty acids] supported the affiliation of the isolate to the genus Massilia. Levels of DNA-DNA relatedness of strain CCUG 43427A(T) with M. timonae CCUG 45783(T) and M. aurea AP13(T) were 60.6 % (reciprocal, 55.8 %) and 58.1 % (reciprocal, 34.0 %), respectively. Strain CCUG 43427A(T) could be differentiated from its closest phylogenetic neighbours based on a range of phenotypic characteristics. Strain CCUG 43427A(T) is therefore considered to represent a novel species of the genus Massilia, for which the name Massilia oculi sp. nov. is proposed. The type strain is CCUG 43427A(T) ( = CCM 7900(T)).

Bacteria attachment to surfaces--AFM force spectroscopy and physicochemical analyses.

Understanding bacterial adhesion to surfaces requires knowledge of the forces that govern bacterial-surface interactions. Biofilm formation on stainless steel 316 (SS316) by three bacterial species was investigated by examining surface force interaction between the cells and metal surface using atomic force microscopy (AFM). Bacterial-metal adhesion force was quantified at different surface delay time from 0 to 60s using AFM tip coated with three different bacterial species: Gram-negative Massilia timonae and Pseudomonas aeruginosa, and Gram-positive Bacillus subtilis. The results revealed that bacterial adhesion forces on SS316 surface by Gram-negative bacteria is higher (8.53±1.40 nN and 7.88±0.94 nN) when compared to Gram-positive bacteria (1.44±0.21 nN). Physicochemical analysis on bacterial surface properties also revealed that M. timonae and P. aeruginosa showed higher hydrophobicity and surface charges than B. subtilis along with the capability of producing extracellular polymeric substances (EPS). The higher hydrophobicity, surface charges, and greater propensity to form EPS by M. timonae and P. aeruginosa led to high adhesive force on the metal surface.

The antiproliferative function of violacein-like purple violet pigment (PVP) from an Antarctic Janthinobacterium sp. Ant5-2 in UV-induced 2237 fibrosarcoma.

BACKGROUND: In this study, we have investigated the chemotherapeutic potential of a purple violet pigment (PVP), which was isolated from a previously undescribed Antarctic Janthinobacterium sp. (Ant5-2), against murine UV-induced 2237 fibrosarcoma and B16F10 melanoma cells. METHODS: The 2237, B16F10, C50, and NIH3T3 cells were treated with PVP at different doses and for different times, and their proliferation and viability were detected by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle arrest induced by PVP in 2237 fibrosarcoma cells was assessed by flow cytometry and expression analysis of cell cycle regulatory proteins were done by Western blot. Apoptosis induced by PVP in 2237 cells was observed by annexin-V/propidium iodide double staining flow cytometry assay and fluorescence microscopy. To further determine the molecular mechanism of apoptosis induced by PVP, the changes in expression of Bcl-2, Bax and cytochrome c were detected by Western blot. The loss of mitochondrial membrane potential in PVP treated 2237 cells was assessed by staining with JC-1 dye following flow cytometry. Caspase-3, Caspase-9 and PARP cleavage were analyzed by Western blot and Caspase-3 and -9 activities were measured by colorimetric assays. RESULTS: In vitro treatment of murine 2237 cells with the PVP resulted in decreased cell viability (13-79%) in a time (24-72 h) and dose (0.1-1 µM)-dependent manner. The PVP-induced growth inhibition in 2237 cells was associated with both G0/G1 and G2/M phase arrest accompanied with decrease in the expression of cyclin dependent kinases (Cdks) and simultaneous increase in the expression of cyclin dependent kinase inhibitors (Cdki) - Cip1/p21 and Kip1/p27. Further, we observed a significant increase in the apoptosis of the 2237 fibrosarcoma cells which was associated with an increased expression of pro-apoptotic protein Bax, decreased expression of anti-apoptotic proteins Bcl-2, disruption of mitochondrial membrane potential, cytochrome c release, activation of caspase-3, caspase-9 and poly-ADP-ribose-polymerase (PARP) cleavage. CONCLUSIONS: We describe the anti-cancer mechanism of the PVP for the first time from an Antarctic bacterium and suggest that the PVP could be used as a potent chemotherapeutic agent against nonmelanoma skin cancers.

Molecular and biochemical characterization of a new alkaline ß-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 ß-propeller phytase domain at the C terminus (residues 298-627; domain C). Distinct from other ß-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 ß-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.

Hit-and-run stimulation: a novel concept to reactivate latent HIV-1 infection without cytokine gene induction.

Current antiretroviral therapy (ART) efficiently controls HIV-1 replication but fails to eradicate the virus. Even after years of successful ART, HIV-1 can conceal itself in a latent state in long-lived CD4(+) memory T cells. From this latent reservoir, HIV-1 rebounds during treatment interruptions. Attempts to therapeutically eradicate this viral reservoir have yielded disappointing results. A major problem with previously utilized activating agents is that at the concentrations required for efficient HIV-1 reactivation, these stimuli trigger high-level cytokine gene expression (hypercytokinemia). Therapeutically relevant HIV-1-reactivating agents will have to trigger HIV-1 reactivation without the induction of cytokine expression. We present here a proof-of-principle study showing that this is a possibility. In a high-throughput screening effort, we identified an HIV-1-reactivating protein factor (HRF) secreted by the nonpathogenic bacterium Massilia timonae. In primary T cells and T-cell lines, HRF triggered a high but nonsustained peak of nuclear factor kappa B (NF-kappaB) activity. While this short NF-kappaB peak potently reactivated latent HIV-1 infection, it failed to induce gene expression of several proinflammatory NF-kappaB-dependent cellular genes, such as those for tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), and gamma interferon (IFN-gamma). Dissociation of cellular and viral gene induction was achievable, as minimum amounts of Tat protein, synthesized following application of a short NF-kappaB pulse, triggered HIV-1 transactivation and subsequent self-perpetuated HIV-1 expression. In the absence of such a positive feedback mechanism, cellular gene expression was not sustained, suggesting that strategies modulating the NF-kappaB activity profile could be used to selectively trigger HIV-1 reactivation.

Isolation, characterization and heterologous expression of a novel chitosanase from Janthinobacterium sp. strain 4239.

BACKGROUND: Chitosanases (EC 3.2.1.132) hydrolyze the polysaccharide chitosan, which is composed of partially acetylated beta-(1,4)-linked glucosamine residues. In nature, chitosanases are produced by a number of Gram-positive and Gram-negative bacteria, as well as by fungi, probably with the primary role of degrading chitosan from fungal and yeast cell walls for carbon metabolism. Chitosanases may also be utilized in eukaryotic cell manipulation for intracellular delivery of molecules formulated with chitosan as well as for transformation of filamentous fungi by temporal modification of the cell wall structures.However, the chitosanases used so far in transformation and transfection experiments show optimal activity at high temperature, which is incompatible with most transfection and transformation protocols. Thus, there is a need for chitosanases, which display activity at lower temperatures. RESULTS: This paper describes the isolation of a chitosanase-producing, cold-active bacterium affiliated to the genus Janthinobacterium. The 876 bp chitosanase gene from the Janthinobacterium strain was isolated and characterized. The chitosanase was related to the Glycosyl Hydrolase family 46 chitosanases with Streptomyces chitosanase as the closest related (64% amino acid sequence identity). The chitosanase was expressed recombinantly as a periplasmic enzyme in Escherichia coli in amounts about 500 fold greater than in the native Janthinobacterium strain. Determination of temperature and pH optimum showed that the native and the recombinant chitosanase have maximal activity at pH 5-7 and at 45 degrees C, but with 30-70% of the maximum activity at 10 degrees C and 30 degrees C, respectively. CONCLUSIONS: A novel chitosanase enzyme and its corresponding gene was isolated from Janthinobacterium and produced recombinantly in E. coli as a periplasmic enzyme. The Janthinobacterium chitosanase displayed reasonable activity at 10 degrees C to 30 degrees C, temperatures that are preferred in transfection and transformation experiments.

Naxibacter varians sp. nov. and Naxibacter haematophilus sp. nov., and emended description of the genus Naxibacter.

Six Gram-negative, rod-shaped, non-spore-forming bacteria isolated from clinical specimens and water samples were investigated for their taxonomic allocation. On the basis of 16S rRNA gene sequence similarities, these strains (CCUG 35299(T), CCUG 24677A, CCUG 48018, CCUG 49054, CCUG 48700A and CCUG 38318(T)) were shown to belong to the Betaproteobacteria, closely related to Naxibacter alkalitolerans (97.9-98.8 % sequence similarity to the type strain). Chemotaxonomic data (major ubiquinone Q-8; major polyamines hydroxyputrescine and putrescine; major polar lipids phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol; major fatty acids C(16 : 1)omega7c and C(16 : 0), with 3-OH C(10 : 0) and 2-OH C(12 : 0) as hydroxylated fatty acids) supported the affiliation of the isolates to the genus Naxibacter. The results of DNA-DNA hybridization and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolates from the described Naxibacter species. Isolates CCUG 35299(T), CCUG 24677A, CCUG 48018, CCUG 49054 and CCUG 48700A were closely related on the basis of DNA-DNA reassociation experiments and therefore represent a single novel species, for which the name Naxibacter varians sp. nov. is proposed, with the type strain CCUG 35299(T) (=CCM 7478(T)). Strain CCUG 38318(T) represents a second novel Naxibacter species, for which we propose the name Naxibacter haematophilus sp. nov. (type strain CCUG 38318(T) =CCM 7480(T)).

Reclassification of Pseudomonas mephitica Claydon and Hammer 1939 as a later heterotypic synonym of Janthinobacterium lividum (Eisenberg 1891) De Ley et al. 1978.

Pseudomonas mephitica CCUG 2513(T) has been reinvestigated to clarify its taxonomic position. 16S rRNA gene sequence comparisons demonstrated that this strain clusters phylogenetically closely with Janthinobacterium lividum (99.8% sequence similarity to the type strain). Investigation of fatty acid patterns, polar lipid profiles, polyamine patterns and quinone systems supported this delineation. Substrate utilization profiles and biochemical characteristics displayed no differences from the type strain of J. lividum, CCUG 2344(T). Therefore, the reclassification of Pseudomonas mephitica as a later heterotypic synonym of Janthinobacterium lividum is proposed, based upon the estimated phylogenetic position derived from 16S rRNA gene sequence data and chemotaxonomic and biochemical data.

Herminiimonas saxobsidens sp. nov., isolated from a lichen-colonized rock.

A Gram-negative, rod-shaped, non-spore-forming bacterium (strain NS11T) was isolated from a lichen-colonized rock surface. On the basis of 16S rRNA gene sequence similarity, strain NS11T was shown to belong to the Betaproteobacteria, and was most closely related to Herminiimonas arsenicoxydans ULPAs1T (98.8%), Herminiimonas aquatilis CCUG 36956T (98.0%) and Herminiimonas fonticola S-94T (98.0%). Major whole-cell fatty acids were C16:0, C17:0 cyclo and C16:1omega7c. Strain NS11T also contained high proportions of C10:0 3-OH and C18:1omega7c. This pattern is typical for members of the genus Herminiimonas. The results of DNA-DNA hybridization experiments and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NS11T from the three recognized Herminiimonas species. It is therefore concluded that strain NS11T represents a novel species of the genus Herminiimonas, for which the name Herminiimonas saxobsidens sp. nov. is proposed. The type strain is NS11T (=DSM 18748T=CCM 7436T).