Herbaspirillum chlorophenolicum sp. nov., a 4-chlorophenol-degrading bacterium

Significance of Herbaspirillum sp. in biodegradation and biodetoxification of herbicides, pesticides, hydrocarbons and heavy metals - A review

In today's industrialized world, contamination of soil and water with various substances has emerged as a pressing concern. Bioremediation, with its advantages of degradation or detoxification, non-polluting nature, and cost-effectiveness, has become a promising method due to technological advancements. Among the bioremediation agents, bacteria have been highly explored and documented as a productive organism. Recently, few studies have reported on the significance of Herbaspirillum sp., a Gram-negative bacterium, in bioremediating herbicides, pesticides, polycyclic aromatic hydrocarbons, metalloids, and heavy metals, as well as its role in augmenting phytoremediation efforts. Herbaspirillum sp. GW103 leached 66% of Cu from ore materials and significantly enhanced the phytoaccumulation of Pb and Zn in plumule and radical tissues of Zea mays L. plants. Additionally, Herbaspirillum sp. WT00C reduced Se6+ into Se0, resulting in an increased Se0 content in tea plants. Also, Herbaspirillum sp. proved effective in degrading 0.6 mM of 4-chlorophenol, 92.8% of pyrene, 77.4% of fluoranthene, and 16.4% of trifluralin from aqueous solution and soil-water system. Considering these findings, this review underscores the need for further exploration into the pathways of pollutant degradation, the enzymes pivotal in the degradation or detoxification processes, the influence of abiotic factors and pollutants on crucial gene expression, and the potential toxicity of intermediate products generated during the degradation process. This perspective reframes the numerical data to underscore the underutilized potential of Herbaspirillum sp. within the broader context of addressing a significant research gap. This shift in emphasis aligns more closely with the problem-necessity for solution-existing unexplored solution framework.

Biodegradation of p-hydroxybenzoic acid in Herbaspirillum aquaticum KLS-1 isolated from tailing soil: Characterization and molecular mechanism

The wide distribution of p-hydroxybenzoic acid (PHBA) in the environments has attracted great concerns due to its potential risks to organisms. Bioremediation is considered a green way to remove PHBA from environment. Here, a new PHBA-degrading bacterium Herbaspirillum aquaticum KLS-1was isolated and its PHBA degradation mechanisms were fully evaluated. Results showed that strain KLS-1 could utilize PHBA as the sole carbon source and completely degrade 500 mg/L PHBA within 18 h. The optimal conditions for bacterial growth and PHBA degradation were pH values of 6.0-8.0, temperatures of 30 °C-35 °C, shaking speed of 180 rpm, Mg²⁺ concentration of 2.0 mM and Fe²⁺ concentration of 1.0 mM. Draft genome sequencing and functional gene annotations identified three operons (i.e., pobRA, pcaRHGBD and pcaRIJ) and several free genes possibly participating in PHBA degradation. The key genes pobA, ubiA, fadA, ligK and ubiG involved in the regulation of protocatechuate and ubiquinone (UQ) metabolisms were successfully amplified in strain KLS-1 at mRNA level. Our data suggested that PHBA could be degraded by strain KLS-1 via the protocatechuate ortho-/meta-cleavage pathway and UQ biosynthesis pathway. This study has provided a new PHBA-degrading bacterium for potential bioremediation of PHBA pollution.

Comparative Proteomic Analysis of an Ethyl Tert-Butyl Ether-Degrading Bacterial Consortium

A bacterial consortium capable of degrading ethyl tert-butyl ether (ETBE) as a sole carbon source was enriched and isolated from gasoline-contaminated water. Arthrobacter sp., Herbaspirillum sp., Pseudacidovorax sp., Pseudomonas sp., and Xanthomonas sp. were identified as the initial populations with the 16S rDNA analysis. The consortium aerobically degraded 49% of 50 mg/L of ETBE, in 6 days. The ETBE degrading efficiency of the consortium increased to 98% even with the higher concentrations of ETBE (1000 mg/L) in the subsequent subcultures, which accumulated tert-butyl alcohol (TBA). Xanthomonas sp. and Pseudomonas sp. were identified as the predominant ETBE degrading populations in the final subculture. The metaproteome of the ETBE-grown bacterial consortium was compared with the glucose-grown bacterial consortium, using 2D-DIGE. Proteins related to the ETBE metabolism, stress response, carbon metabolism and chaperones were found to be abundant in the presence of ETBE while proteins related to cell division were less abundant. The metaproteomic study revealed that the ETBE does have an effect on the metabolism of the bacterial consortium. It also enabled us to understand the responses of the complex bacterial consortium to ETBE, thus revealing interesting facts about the ETBE degrading bacterial community.

Keystone Microorganisms Regulate the Methanogenic Potential in Coals with Different Coal Ranks

Microorganisms are the core drivers of coal biogeochemistry and are closely related to the formation of coalbed methane. However, it remains poorly understood about the network relationship and stability of microbial communities in coals with different ranks. In this study, a high-throughput sequencing data set was analyzed to understand the microbial co-occurrence network in coals with different ranks including anthracite, medium-volatile bituminous, and high-volatile bituminous. The results showed similar topological properties for the microbial networks among coals with different ranks, but a great difference was found in the microbial composition in different large modules among coals with different ranks, and these three networks had three, four, and four large modules with seven, nine, and nine phyla, respectively. Among these networks, a total of 46 keystone taxa were identified in large modules, and these keystone taxa were different in coals with different ranks. Bacteria dominated the keystone taxa in the microbial network, and these bacterial keystone taxa mainly belonged to phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Besides, the removal of the key microbial data could reduce the community stability of microbial communities in bituminous coals. A partial least-squares path model further showed that these bacterial keystone taxa indirectly affected methanogenic potential by maintaining the microbial community stability and bacterial diversity. In summary, these results showed that keystone taxa played an important role in determining the community diversity, maintaining the microbial community stability, and controlling the methanogenic potential, which is of great significance for understanding the microbial ecology and the geochemical cycle of coal seams.

The gut microbiome analysis of Anastrepha obliqua reveals inter-kingdom diversity: bacteria, fungi, and archaea

The fruit fly Anastrepha obliqua is an economically important pest. The sterile insect technique to control it involves mass production and release of sterile flies to reduce the reproduction of the wild population. As noted in different Tephritidae, the performance of sterile males may be affected by the assimilation of nutrients under mass-rearing conditions. In the wild, the fly's life cycle suggests the acquisition of different organisms that could modulate its fitness and physiology. For A. obliqua, there is no information regarding microorganisms other than bacteria. This study analyzed bacteria, fungal, and archaea communities in the A. obliqua gut through denaturing gradient gel electrophoresis (DGGE) profiles of 16S (using a different set of primers for bacteria and archaea) and 18S ribosomal DNA markers. We found that wild flies presented higher microbial diversity related to fructose assimilation than laboratory species, suggesting that microorganisms have led to a specialized metabolism to process nutrients associated with an artificial diet. We identified species that have not been previously described in this fruit fly, especially actinobacteria and archaea, by employing different primer sets aimed at the same molecular marker but targeting diverse hypervariable regions of 16S rDNA. The possibility that Archaea affect fly fitness should not be ignored. This report on the intestinal microbial (bacteria, archaea, and fungi) composition of A. obliqua contributes to our understanding of the role of microorganisms in the development and physiology of the flies.

Carbon-Nitrogen-Sulfur-Related Microbial Taxa and Genes Maintained the Stability of Microbial Communities in Coals

Coal microbes are the predominant form of life in the subsurface ecosystem, which play a vital role in biogeochemical cycles. However, the systematic information about carbon-nitrogen-sulfur (C-N-S)-related microbial communities in coal seams is limited. In this study, 16S rRNA gene data from a total of 93 microbial communities in coals were collected for meta-analysis. The results showed that 718 functional genera were related to the C-N-S cycle, wherein N₂ fixation, denitrification, and C degradation groups dominated in relative abundance, Chao1 richness, Shannon diversity, and niche width. Genus Pseudomonas having the most C-N-S-related functions showed the highest relative abundance, and genus Herbaspirillum with a higher abundance participated in C degradation, CH₄ oxidation, N₂ fixation, ammoxidation, and denitrification. Such Herbaspirillum was a core genus in the co-occurrence network of microbial prokaryotes and showed higher levels in weight degree, betweenness centrality, and eigenvector centrality. In addition, most of the methanogens could fix N₂ and dominated in the N₂ fixation groups. Among them, genera Methanoculleus and Methanosaeta showed higher levels in the betweenness centrality index. In addition, the genus Clostridium was linked to the methanogenesis co-occurrence network module. In parallel, the S reduction gene was present in the highest total relative abundance of genes, followed by the C degradation and the denitrification genes, and S genes (especially cys genes) were the main genes linked to the co-occurrence network of the C-N-S-related genes. In summary, this study strengthened our knowledge regarding the C-N-S-related coal microbial communities, which is of great significance in understanding the microbial ecology and geochemical cycle of coals.

Differential exopolysaccharide production and composition by Herbaspirillum strains from diverse ecological environments

Bacteria belonging to the genus Herbaspirillum are found in many different ecological niches. Some species are typically endophytic, while others were reported as free-living organisms that occupy various environments. Also, opportunistic herbaspirilli have been found infecting humans affected by several diseases. We have analyzed the production of exopolysaccharides (EPS) by Herbaspirillum strains isolated from different sources and with distinct ecological characteristics. The monosaccharide composition was determined for the EPS obtained for selected strains including free-living, plant-associated and clinical isolates, and the relationship with the ecological niches occupied by Herbaspirillum spp. is proposed.

Environmental and clinical isolates of Herbaspirillum induce pulmonary infection in mice and its secretome is cytotoxic to human lung cells

Introduction. In recent years, the Herbaspirillum genus has emerged as a pathogen in healthcare-related infections and has became stablished as an opportunistic pathogen.Hypothesis/Gap Statement. Little is known about the pathogenesis induced by Herbaspirillum genus.Aim. To evaluate the cytotoxic effects of genus Herbaspirillum, its ability to adhere to lung human cells and the ability of environmental and clinical strains of Herbaspirillum to induce pneumonia in mice.Methodology. Environmental and clinical isolates of Herbaspirillum were examined for their cytotoxic effects on the Calu-3 cell lineage. Cytotoxic activity of secretome was tested using MTT/neutral red assays and cell morphology analysis. Herbaspirillum adhesion on Calu-3 cells was assessed using bright-field microscopy and cell-associated bacteria were counted. A mouse model of acute lung infection was done using a clinical and an environmental strain. Adult male mice were used, and the pneumonia was inducted by intra-tracheal inoculation of 10⁸ or 10⁹ bacteria. Mice weight variations were evaluated at the end of the experiment. Bronchoalveolar lavage was collected and evaluated for total and differential cytology. A histological examination of lungs was performed giving a histological score.Results. The secretomes of all the strains induced morphological alterations in cells, but only H. seropedicae SmR1 were cytotoxic in MTT and neutral red assays. Clinical strains of H. frisingense AU14459 and H. hutttiense subsp. huttiense AU11883 exhibited low adherence to lung cells, while SmR1 was non-adhesive. Following intratracheal inoculation, mice treated with 10⁹ c.f.u. of the SmR1 and AU11883 strains lost 18 and 6% of their weight over 7 days, respectively, and presented moderate clinical signs. Infected mice showed inflammatory cell infiltration in the perivascular and peribroncheal/peribronchiolar spaces. Bronchoalveolar fluid of mice inoculated with SmR1 10⁹ c.f.u. presented an increase in total leucocyte cells and in neutrophils population.Conclusion. These in vivo and in vitro results provide insights into how some Herbaspirillum strains cause infection in humans, providing a basis for the characterization of pathogenesis studies on this emerging infectious agent.

Challenges and opportunities for the biodegradation of chlorophenols: Aerobic, anaerobic and bioelectrochemical processes

Chlorophenols (CPs) are highly toxic and refractory contaminants which widely exist in various environments and cause serious harm to human and environment health and safety. This review provides comprehensive information on typical CPs biodegradation technologies, the most green and benign ones for CPs removal. The known aerobic and anaerobic degradative bacteria, functional enzymes, and metabolic pathways of CPs as well as several improving methods and critical parameters affecting the overall degradation efficiency are systematically summarized and clarified. The challenges for CPs mineralization are also discussed, mainly including the dechlorination of polychlorophenols (poly-CPs) under aerobic condition and the ring-cleavage of monochlorophenols (MCPs) under anaerobic condition. The coupling of functional materials and degraders as well as the operation of sequential anaerobic-aerobic bioreactors and bioelectrochemical system (BES) are promising strategies to overcome some current limitations. Future perspective and research gaps in this field are also proposed, including the further understanding of microbial information and the specific role of materials in CPs biodegradation, the potential application of innovative biotechnologies and new operating modes to optimize and maximize the function of the system, and the scale-up of bioreactors towards the efficient biodegradation of CPs.

Noviherbaspirillum galbum sp. nov., a bacterium isolated from soil

A Gram-stain-negative, aerobic, non-motile and yellow-colored bacterium, strain 17J57-3 ^T, was isolated from soil collected in Pyeongchang city, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 17J57-3 ^T formed a distinct lineage within the family Oxalobacteraceae (order Burkholderiales, class Betaproteobacteria). Strain 17J57-3 ^T was the most closely related to Noviherbaspirillum humi U15^T (96.4% 16S rRNA gene sequence similarity) and Noviherbaspirillum massiliense JC206^T (96.2%). The draft genome size of strain 17J57-3 ^T was 6,117,206 bp. Optimal growth occurred at 30 °C, pH 7.0 without NaCl. The predominant cellular fatty acids were summed feature 3 (C_16:1 ω6c/C_16:1 ω7c) and C_16:0. The major respiratory quinone was Q-8. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strain 17J57-3 ^T represents a novel bacterial species within the genus Noviherbaspirillum, for which the name Noviherbaspirillum galbum is proposed. The type strain of Noviherbaspirillum galbum is 17J57-3 ^T (= KCTC 62213 ^T = NBRC 114384 ^T).

Three chlorotoluene-degrading bacterial strains: Differences in biodegradation potential and cell surface properties

Pollution of the environment with chlorinated aromatic compounds is a problem of increasing importance, which has stimulated the search for efficient methods for the remediation of contaminated soil and water. Additionally, for better understanding of the significance of bioavailability to biodegradation, investigation of the cell surface properties is necessary. Hence, this study concerns the properties and possible application, in chlorotoluene removal, of three newly isolated environmental bacterial strains from the genera Pseudomonas, Raoultella and Rahnella. The results show the differences in the biochemical profiles of the isolated strains, their cellular fatty acid composition and their hemolytic properties. However, all three strains exhibit high biodegradation potential, degrading not less than 60% of each monochlorotoluene isomer in 21-day experiments. What is more, observations of changes in the cell surface properties indicate the possible adaptation mechanisms of the strains that enable efficient biodegradation of hydrophobic pollutants such as monochlorotoluenes.

Bacterial Small RNAs in the Genus Herbaspirillum spp

The genus Herbaspirillum includes several strains isolated from different grasses. The identification of non-coding RNAs (ncRNAs) in the genus Herbaspirillum is an important stage studying the interaction of these molecules and the way they modulate physiological responses of different mechanisms, through RNA⁻RNA interaction or RNA⁻protein interaction. This interaction with their target occurs through the perfect pairing of short sequences (cis-encoded ncRNAs) or by the partial pairing of short sequences (trans-encoded ncRNAs). However, the companion Hfq can stabilize interactions in the trans-acting class. In addition, there are Riboswitches, located at the 5' end of mRNA and less often at the 3' end, which respond to environmental signals, high temperatures, or small binder molecules. Recently, CRISPR (clustered regularly interspaced palindromic repeats), in prokaryotes, have been described that consist of serial repeats of base sequences (spacer DNA) resulting from a previous exposure to exogenous plasmids or bacteriophages. We identified 285 ncRNAs in Herbaspirillum seropedicae (H. seropedicae) SmR1, expressed in different experimental conditions of RNA-seq material, classified as cis-encoded ncRNAs or trans-encoded ncRNAs and detected RNA riboswitch domains and CRISPR sequences. The results provide a better understanding of the participation of this type of RNA in the regulation of the metabolism of bacteria of the genus Herbaspirillum spp.

Herbaspirillum piri sp. nov., isolated from bark of a pear tree

A Gram-stain-negative, aerobic, motile bacterial strain, shQ-4^T, was isolated from a pear tree in Henan Province, China. The strain grew at 10-41 °C, at pH 4.0-8.0 and in the presence of 1-3 % (w/v) NaCl. It shared highest 16S rRNA gene sequence similarity (96.66 %) with Herbaspirillum chlorophenolicum CPW301^T. The phylogenetic tree based on 16S rRNA gene sequences showed that strain shQ-4^T formed a distinct branch next to reference species in the genus Herbaspirillum. The profile of major polar lipids of strain shQ-4^T contained phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and an unidentified aminophospholipid (APL). The major respiratory quinone was Q-8. The major fatty acids of this strain were C16 : 0, summed feature 3 (C16 : 1ω6c/C16 : 1ω7c), C17 : 0 cyclo and C18 : 0. Strain shQ-4^T is considered to represent a novel species of the genus Herbaspirillum, with the proposed name Herbaspirillum piri sp. nov. The type strain is shQ-4^T (=CFCC 14641^T=KCTC 52804^T).

Parvibium lacunae gen. nov., sp. nov., a new member of the family Alcaligenaceae isolated from a freshwater pond

A bacterial strain designated KMB9^T was isolated from a freshwater pond in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain KMB9^T were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a monopolar flagellum, non-spore-forming and rods surrounded by a thick capsule and forming white-coloured colonies. Growth occurred at 20-40 °C (optimum, 25-37 °C), at pH 6.5-7.5 (optimum, pH 7.0) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene and four housekeeping gene sequences (recA, rpoA, rpoB and atpD) showed that strain KMB9^T forms a distinct phyletic line within the family Alcaligenaceae, and the levels of 16S rRNA gene sequence similarity to its closest relatives with validly published names were less than 93.3 %. The predominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8. The major polyamine was putrescine. The polar lipid profile revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and several uncharacterized aminophospholipids, aminolipids, phospholipids and lipids. The genomic DNA G+C content of strain KMB9^T was 54.5 mol%. On the basis of the genotypic and phenotypic data, strain KMB9^T represents a novel species of a new genus in the family Alcaligenaceae, for which the name Parvibium lacunae gen. nov., sp. nov. is proposed. The type strain is KMB9^T (=BCRC 81053^T=LMG 30055^T=KCTC 52814^T).

Herbaspirillum robiniae sp. nov., isolated from root nodules of Robinia pseudoacacia in a lead-zinc mine

A novel endophytic bacterium, designated strain HZ10^T, was isolated from root nodules of Robinia pseudoacacia growing in a lead-zinc mine in Mianxian County, Shaanxi Province, China. The bacterium was Gram-stain-negative, aerobic, motile, slightly curved- and rod-shaped, methyl red-negative, catalase-positive, and did not produce H2S. Strain HZ10^T grew at 4-45 °C (optimum, 25-30 °C), pH 5-9 (optimum, pH 7-8) and 0-1 % (w/v) NaCl. The major fatty acids were identified as C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), and the quinone type was Q-8. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of the genomic DNA was 64.9 mol% based on the whole genome sequence. According to the 16S rRNA gene sequence analysis, the closest phylogenetic relative to strain HZ10^T is Herbaspirillum chlorophenolicum CPW301^T (98.72 % sequence identity). Genome relatedness of the type strains H. chlorophenolicum CPW301^T, Herbaspirillum seropedicae Z67^T and Herbaspirillum aquaticum IEH 4430^T, was quantified by using the average nucleotide identity (86.9-88.0 %) and a genome-to-genome distance analysis (26.6 %-29.3 %), with both strongly supporting the notion that strain HZ10^T belongs to the genus Herbaspirillum as a novel species. Based on the results from phylogenetic, chemotaxonomic and physiological analyses, strain HZ10^T represents a novel Herbaspirillum species, for which the name Herbaspirillum robiniae sp. nov. is proposed. The type strain is HZ10^T (=JCM 31754^T=CCTCC AB 2014352^T).

Piscinibacterium candidicorallinum gen. nov., sp. nov., a member of the order Burkholderiales isolated from a fish pond

A bacterial strain designated LYH-15T was isolated from a freshwater fish pond in Taiwan and characterized using a polyphasic taxonomy approach. Cells of LYH-15T were Gram-staining-negative, aerobic, motile by means of a single polar flagellum, poly-β-hydroxybutyrate-containing, non-spore forming, straight rods and formed light-coral-colored colonies. Growth occurred at 15-40 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that LYH-15T forms a distinct phyletic line within the order Burkholderiales, with less than 94 % sequence similarity to its closest relatives with validly published names. The predominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8 and the DNA G+C content was 63.8 mol%. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized lipids. The major polyamines were 2-hydroxyputrescine and putrescine. On the basis of the genotypic and phenotypic data, LYH-15T represents a novel species of a new genus in the order Burkholderiales, for which the name Piscinibacterium candidicorallinum gen. nov., sp. nov. is proposed. The type strain is LYH-15T (=BCRC 80969T=LMG 29480T=KCTC 52168T).

Microbial diversity, community composition and metabolic potential in hydrocarbon contaminated oily sludge: prospects for in situ bioremediation

Microbial community composition and metabolic potential have been explored in petroleum-hydrocarbon-contaminated sludge of an oil storage facility. Culture-independent clone library-based 16S rRNA gene analyses revealed that the bacterial community within the sludge was dominated by the members of β-Proteobacteria (35%), followed by Firmicutes (13%), δ-Proteobacteria (11%), Bacteroidetes (10%), Acidobacteria (6%), α-Proteobacteria (3%), Lentisphaerae (2%), Spirochaetes (2%), and unclassified bacteria (5%), whereas the archaeal community was composed of Thermoprotei (54%), Methanocellales (33%), Methanosarcinales/Methanosaeta (8%) and Methanoculleus (1%) members. Methyl coenzyme M reductase A (mcrA) gene (a functional biomarker) analyses also revealed predominance of hydrogenotrophic, methanogenic Archaea (Methanocellales, Methanobacteriales and Methanoculleus members) over acetoclastic methanogens (Methanosarcinales members). In order to explore the cultivable bacterial population, a total of 28 resident strains were identified and characterized in terms of their physiological and metabolic capabilities. Most of these could be taxonomically affiliated to the members of the genera Bacillus, Paenibacillus, Micrococcus, Brachybacterium, Aerococcus, and Zimmermannella, while two strains were identified as Pseudomonas and Pseudoxanthomonas. Metabolic profiling exhibited that majority of these isolates were capable of growing in presence of a variety of petroleum hydrocarbons as sole source of carbon, tolerating different heavy metals at higher concentrations (≥1 mM) and producing biosurfactant during growth. Many strains could grow under a wide range of pH, temperature, or salinity as well as under anaerobic conditions in the presence of different electron acceptors and donors in the growth medium. Correlation between the isolates and their metabolic properties was estimated by the unweighted pair group method with arithmetic mean (UPGMA) analysis. Overall observation indicated the presence of diverse groups of microorganisms including hydrocarbonoclastic, nitrate reducing, sulphate reducing, fermentative, syntrophic, methanogenic and methane-oxidizing bacteria and Archaea within the sludge community, which can be exploited for in situ bioremediation of the oily sludge.

Survival of prokaryotes in a polluted waste dump during remediation by alkaline hydrolysis

A combination of culture-dependent and culture-independent techniques was used to characterize bacterial and archaeal communities in a highly polluted waste dump and to assess the effect of remediation by alkaline hydrolysis on these communities. This waste dump (Breakwater 42), located in Denmark, contains approximately 100 different toxic compounds including large amounts of organophosphorous pesticides such as parathions. The alkaline hydrolysis (12 months at pH >12) decimated bacterial and archaeal abundances, as estimated by 16S rRNA gene-based qPCR, from 2.1 × 10(4) and 2.9 × 10(3) gene copies per gram wet soil respectively to below the detection limit of the qPCR assay. Clone libraries constructed from PCR-amplified 16S rRNA gene fragments showed a significant reduction in bacterial diversity as a result of the alkaline hydrolysis, with preferential survival of Betaproteobacteria, which increased in relative abundance from 0 to 48 %. Many of the bacterial clone sequences and the 27 isolates were related to known xenobiotic degraders. An archaeal clone library from a non-hydrolyzed sample showed the presence of three main clusters, two representing methanogens and one representing marine aerobic ammonia oxidizers. Isolation of alkalitolerant bacterial pure cultures from the hydrolyzed soil confirmed that although alkaline hydrolysis severely reduces microbial community diversity and size certain bacteria survive a prolonged alkaline hydrolysis process. Some of the isolates from the hydrolyzed soil were capable of growing at high pH (pH 10.0) in synthetic media indicating that they could become active in in situ biodegradation upon hydrolysis.

Draft Genome Sequence of the Naphthalene Degrader Herbaspirillum sp. Strain RV1423

Herbaspirillum sp. strain RV1423 was isolated from a site contaminated with alkanes and aromatic compounds and harbors the complete pathway for naphthalene degradation. The new features found in RV1423 increase considerably the versatility and the catabolic potential of a genus of bacteria previously considered mainly to be diazotrophic endophytes to plants.

Bacterial degradation of chlorophenols and their derivatives

Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives.

Noviherbaspirillum suwonense sp. nov., isolated from an air sample

A Gram-stain-negative bacterium, strain 5410S-62T, was isolated from an air sample collected in Suwon, Republic of Korea. It was aerobic, motile, mesophilic and formed rod-shaped cells. Colonies on R2A agar were convex, circular and pale orange with entire margins. Growth occurred at pH 5-9 (optimally at pH 7) and at 10-40 °C (optimally at 28 °C). It did not grow in the presence of 1% NaCl. Comparative analyses of 16S rRNA gene sequences demonstrated that the novel strain was closely related to members of the genus Noviherbaspirillum. Strain 5410S-62T showed the highest sequence similarity (98.2%) to Glaciimonas singularis A2-57T. It also showed high 16S rRNA gene sequence similarity (98.1-95.6%) to members of the genus Noviherbaspirillum (98.1% to Noviherbaspirillum aurantiacum SUEMI08T, 97.8% to Noviherbaspirillum soli SUEMI10T and Noviherbaspirillum canariense SUEMI03T, 97.6% to Noviherbaspirillum psychrotolerans PB1T and 95.6% to Noviherbaspirillum malthae CC-AFH3T). The strain contained summed feature 3 (C16:1ω6c and/or C16:1ω7c), C16:0 and summed feature 8 (C18:1ω6c and/or C18:1ω7c) as major fatty acids, Q-8 as the only ubiquinone and large amounts of phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. Strain 5410S-62T revealed less than 70% DNA-DNA relatedness with the type strains of closely related species of the genera Noviherbaspirillum and Herbaspirillum and Glaciimonas singularis. Based on the physiological, biochemical and chemotaxonomic data obtained in this study, it is proposed that strain 5410S-62T represents a novel species, Noviherbaspirillum suwonense sp. nov., with 5410S-62T (=KACC 16657T= NBRC 108944T) as the type strain.

Description of Noviherbaspirillum malthae gen. nov., sp. nov., isolated from an oil-contaminated soil, and proposal to reclassify Herbaspirillum soli, Herbaspirillum aurantiacum, Herbaspirillum canariense and Herbaspirillum psychrotolerans as Noviherbaspirillum soli comb. nov., Noviherbaspirillum aurantiacum comb. nov., Noviherbaspirillum canariense comb. nov. and Noviherbaspirillum psychrotolerans comb. nov. based on polyphasic analysis

An aerobic, Gram-negative, rod-shaped bacterium with polar flagella, strain CC-AFH3(T), was isolated from an oil-contaminated site located in Kaohsiung county, Taiwan. Strain CC-AFH3(T) grew at 20-40 °C, pH 5.0-10.0 and <2 % (w/v) NaCl. 16S rRNA gene sequence analysis indicated that strain CC-AFH3(T) showed the greatest degree of similarity to Herbaspirillum soli SUEMI10(T) (96.5 %), H. aurantiacum SUEMI08(T) (96.3 %), H. canariense SUEMI03(T) (96.0 %), H. psychrotolerans PB1(T) (95.4 %) and members of other Herbaspirillum species (94.1-95.2 %), and lower similarity to members of other genera (<94 %). Phylogenetic analyses also positioned the novel strain in the genus Herbaspirillum as an independent lineage. The major fatty acids in strain CC-AFH3(T) were C10 : 0 3-OH, C12 : 0, C14 : 0 2-OH, C16 : 0, iso-C15 : 0 3-OH, C17 : 0 cyclo, C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. The major polar lipids of strain CC-AFH3(T) were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The predominant quinone was ubiquinone 8 (Q-8) and the DNA G+C content was 63.4 mol%. On the basis of 16S rRNA gene sequence analysis in combination with physiological and chemotaxonomic data, strain CC-AFH3(T) represents a novel species in a new genus, for which we propose the name Noviherbaspirillum malthae gen. nov., sp. nov.; the type strain of Noviherbaspirillum malthae is CC-AFH3(T) ( = BCRC 80516(T) = JCM 18414(T)). We also propose the reclassification of Herbaspirillum soli, Herbaspirillum aurantiacum, Herbaspirillum canariense and 'Herbaspirillum psychrotolerans' as Noviherbaspirillum soli comb. nov. (type strain SUEMI10(T) = LMG 26149(T) = CECT 7840(T)), Noviherbaspirillum aurantiacum comb. nov. (type strain SUEMI08(T) = LMG 26150(T) = CECT 7839(T)), Noviherbaspirillum canariense comb. nov. (type strain SUEMI03(T) = LMG 26151(T) = CECT 7838(T)) and Noviherbaspirillum psychrotolerans comb. nov. (type strain PB1(T) = DSM 26001(T) = LMG 27282(T)), respectively. An emended description of Herbaspirillum seropedicae is also presented.

Paraherbaspirillum soli gen. nov., sp. nov. isolated from soil

A bacterial strain, designated JS5-2(T), was isolated from soil collected from Jeju Island, Republic of Korea. The cells of the strain were Gram-negative, nonspore forming, catalase- and oxidase-positive, aerobic, nonmotile and rod-shaped. Strain JS5-2(T) exhibited 96.2-97.2, 95.1-96.3, and 95.4-95.8% 16S rRNA gene sequence similarities to the genera Herbaspirillum, Oxalicibacterium, and Herminiimonas, respectively. The highest sequence similarities were with Herbaspirillum autotrophicum IAM 14942(T) (97.2%) and Herbaspirillum frisingense GSF30(T) (97.1%). The major fatty acids of strain JS5-2(T) were C16:0 (35.0%), C17:0 cyclo (19.9%), C18:1 ω7c (11.4%), and summed feature 3 (C16:1 ω7c/C15:0 iso 2-OH) (15.2%), and the major polar lipids of strain JS5-2(T) were diphosphatidylglycerol and an unknown aminophospholipid. The strain contained Q-8 as the predominant ubiquinone. DNA-DNA relatedness values between strain JS5-2(T) and H. autotrophicum IAM 14942(T), and H. frisingense GSF30(T) were 32 and 35%, respectively. The DNA G+C content of strain JS5-2(T) was 59.0 mol%. On the basis of phenotypic, genotypic, and physiological evidence, strain JS5-2(T) represents a novel species of a new genus, for which the name Paraherbaspirillum soli gen. nov., sp. nov. is proposed. The type strain JS5-2(T) (=KACC 12633(T) =NBRC 106496(T)) is proposed.

Herbaspirillum psychrotolerans sp. nov., a member of the family Oxalobacteraceae from a glacier forefield

A novel psychrotolerant, Gram-negative, shiny white, curved-rod-shaped, facultatively anaerobic bacterium PB1(T) was isolated from a soil sample collected from a glacier forefield of the Larsemann Hills, East Antarctica. Isolate PB1(T) has catalase and low urease activity and hydrolyses gelatin and starch. Strain PB1(T) is able to grow between -5 °C and 30 °C with optimum growth at 14-20 °C. Glycerol, dl-arabinose, d-xylose, d-galactose, d-fructose, d-lyxose, d-fucose and potassium gluconate are used as sole carbon sources. The major quinone is ubiquinone Q-8. The major fatty acids (>10%) for PB1(T) are C(16:0) (19.1%), C(16:1)ω7cis (44.6%) and C(18:1)ω7cis (16.2%). The major polyamines are putrescine [54.9 µmol (g dry weight)(-1)] and 2-hydroxy putrescine [18.5 µmol (g dry weight)(-1)]. DNA G+C content is 62.5 mol%. Strain PB1(T) is phylogenetically related to species of the genus Herbaspirillum, with highest 16S rRNA gene sequence similarities to Herbaspirillum canariense (97.3%), Herbaspirillum aurantiacum (97.2%), Herbaspirillum soli (97.2%) and Herbaspirillum frisingense (97.0%). The DNA-DNA relatedness values were below 30% between PB1(T) and the type strains of Herbaspirillum canariense, Herbaspirillum aurantiacum and Herbaspirillum soli. The different geographical origin of strain PB1(T) from its closest phylogenetic relatives resulted in different phenotypic and genotypic specifications, whereby strain PB(T) represents a novel species of the genus Herbaspirillum, for which the name Herbaspirillum psychrotolerans is proposed. The type strain is PB1(T) (DSM 26001(T) =LMG 27282(T)).

Non-contiguous finished genome sequence and description of Herbaspirillum massiliense sp. nov

Herbaspirillum massiliense strain JC206^T sp. nov. is the type strain of H. massiliense sp. nov., a new species within the genus Herbaspirillum. This strain, whose genome is described here, was isolated from the fecal flora of a healthy Senegalese patient. H. massiliense is an aerobic rod. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 4,186,486 bp long genome (one chromosome but no plasmid) contains 3,847 protein-coding and 54 RNA genes, including 3 rRNA genes.

Herbaspirillum canariense sp. nov., Herbaspirillum aurantiacum sp. nov. and Herbaspirillum soli sp. nov., isolated from volcanic mountain soil, and emended description of the genus Herbaspirillum

Three Gram-negative, motile and slightly curved rod-shaped bacteria, strains SUEMI03T, SUEMI08T and SUEMI10T, were isolated from an old volcanic mountain soil on Tenerife (Canary Islands). The three strains were related phylogenetically to Herbaspirillum seropedicae . 16S rRNA gene sequence similarity was 99.2–99.6 % among strains SUEMI03T, SUEMI08T and SUEMI10T, which presented 97.5, 97.8 and 97.7 % identity, respectively, with respect to H. seropedicae DSM 6445T. The three strains grew optimally in TSB at 28 °C and contained summed features 3 (C16 : 1ω6c and/or C16 : 1ω7c) and 8 (C18 : 1ω6c and/or C18 : 1ω7c) and C16 : 0 as major cellular fatty acids. The DNA G+C contents of strains SUEMI03T, SUEMI08T and SUEMI10T were 61.6, 60.4 and 61.9 mol%, respectively. Strains SUEMI03T, SUEMI08T and SUEMI10T presented less than 60 % interstrain DNA relatedness and less than 30 % relatedness with respect to H. seropedicae DSM 6445T. In spite of their common geographical origin, the three strains isolated in this study presented several phenotypic differences, presenting phenotypic profiles highly divergent from that of H. seropedicae . Therefore, we propose that the strains isolated in this study represent three novel species of the genus Herbaspirillum , named Herbaspirillum canariense sp. nov. (type strain SUEMI03T  = LMG 26151T  = CECT 7838T), Herbaspirillum aurantiacum sp. nov. (type strain SUEMI08T  = LMG 26150T  = CECT 7839T) and Herbaspirillum soli sp. nov. (type strain SUEMI10T  = LMG 26149T  = CECT 7840T).

Microbial community changes in aquifer sediment microcosm for anaerobic anthracene biodegradation under methanogenic condition

The widespread distribution of polycyclic aromatic hydrocarbons (PAHs) in groundwater has become an important environmental issue. Knowledge of microbial community changes could aid in identification of particular microorganisms that are capable of degrading PAHs in contaminated aquifers. Therefore, 16S rRNA gene clone library analysis was used to identify the archaeal and bacterial communities in an aquifer sediment microcosm used for anaerobic anthracene degradation under methanogenic conditions. A remarkable shift of the archaeal community structure occurred after anaerobic anthracene degradation, but the types of the abundant bacterial phyla did not change. However, a decrease of both archaeal and bacterial diversity was observed. Bacterial genera Bacillus, Rhodococcus and Herbaspirillum might have links with anaerobic anthracene degradation, suggesting a role of microbial consortia. This work might add some new information for understanding the mechanism of PAH degradation under methanogenic conditions.

Shinella daejeonensis sp. nov., a nitrate-reducing bacterium isolated from sludge of a leachate treatment plant

A Gram-negative-staining, motile, rod-shaped, aerobic bacterial strain, designated MJ02T, was isolated from sludge of a leachate treatment plant in Daejeon (South Korea) and was characterized to determine its taxonomic position by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain MJ02T belonged to the family Rhizobiaceae, class Alphaproteobacteria, and was most closely related to Shinella yambaruensis MS4T (97.6 % sequence similarity) and Shinella fusca DC-196T (97.5 %). The G+C content of the genomic DNA of strain MJ02T was 64.3 mol%. The detection of a quinone system with ubiquinone Q-10 as the predominant respiratory lipoquinone and a fatty acid profile with C18 : 1ω7c (45.8 %) and C16 : 0 (21.8 %) as the major components supported the affiliation of strain MJ02T to the genus Shinella. However, strain MJ02T exhibited relatively low levels of DNA–DNA relatedness with respect to S. fusca DSM 21319T (17±7 %) and S. yambaruensis KACC 14483T (12±6 %), showing clearly that the isolate constituted a new genospecies. Strain MJ02T could be clearly differentiated from its phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, strain MJ02T is considered to represent a novel species of the genus Shinella, for which the name Shinella daejeonensis sp. nov. is proposed. The type strain is MJ02T ( = KCTC 22450T = JCM 16236T).

Ochrobactrum daejeonense sp. nov., a nitrate-reducing bacterium isolated from sludge of a leachate treatment plant

A Gram-reaction-negative, non-spore-forming, rod-shaped, aerobic bacterial strain, designated MJ11(T), was isolated from sludge of a leachate treatment plant in Daejeon, South Korea, and was characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain MJ11(T) belonged to the family Brucellaceae, class Alphaproteobacteria, and was most closely related to Ochrobactrum ciceri Ca-34(T) (97.9 % sequence similarity) and Ochrobactrum pituitosum CCUG 50899(T) (96.4 %). Comparative sequence analyses of the additional phylogenetic marker genes dnaK, groEL and gyrB confirmed the affiliation of strain MJ11(T) to the genus Ochrobactrum. The G+C content of the genomic DNA of strain MJ11(T) was 59.3 mol%. The detection of a quinone system with ubiquinone Q-10 as the predominant respiratory lipoquinone, a fatty acid profile with C(18 : 1)ω7c (62.6 %) and C(19 : 0) cyclo ω8c (14.2 %) as the major components, a polar lipid profile with phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol and unknown aminolipids AL1 and AL2 as major polar lipids and spermidine and putrescine as the predominant polyamines also supported the affiliation of strain MJ11(T) to the genus Ochrobactrum. The DNA-DNA relatedness between strain MJ11(T) and Ochrobactrum ciceri DSM 22292(T) was 29 ± 7 %, clearly showing that the isolate constitutes a new genospecies. Strain MJ11(T) could be clearly differentiated from its closest neighbours on the basis of its phenotypic, genotypic and chemotaxonomic features. Therefore, strain MJ11(T) represents a novel species of the genus Ochrobactrum, for which the name Ochrobactrum daejeonense sp. nov. is proposed. The type strain is MJ11(T) ( = KCTC 22458(T) = JCM 16234(T)).

Shinella fusca sp. nov., isolated from domestic waste compost

A bacterium, designated strain DC-196(T), isolated from kitchen refuse compost was analysed by using a polyphasic approach. Strain DC-196(T) was characterized as a Gram-negative short rod that was catalase- and oxidase-positive, and able to grow at 10-40 degrees C, pH 6-9 and in NaCl concentrations as high as 3 %. Chemotaxonomically, C(18 : 1) was observed to be the predominant cellular fatty acid and ubiquinone 10 (Q10) was the predominant respiratory quinone. The G+C content of the genomic DNA was determined to be 66 mol%. On the basis of the genotypic, phenotypic and chemotaxonomic characteristics, strain DC-196(T) was assigned to the genus Shinella, although with distinctive features. At the time of writing, 16S rRNA gene sequence similarities of 97.6-96.8 % and the low DNA-DNA hybridization values of 38.2-32.2 % with the type strains of the three recognized Shinella species confirmed that strain DC-196(T) represents a novel species of the genus, for which the name Shinella fusca sp. nov. is proposed (type strain DC-196(T)=CCUG 55808(T)=LMG 24714(T)).

Herbaspirillum rhizosphaerae sp. nov., isolated from rhizosphere soil of Allium victorialis var. platyphyllum

Two Gram-negative, milky-white-pigmented, motile, slightly curved rod-shaped bacterial isolates, UMS-37T and UMS-40, were isolated from rhizosphere soil of wild edible greens cultivated on Ulleung island, Korea, and their taxonomic positions were investigated by a polyphasic approach. They grew optimally at 25–30 °C and contained Q-8 as the predominant ubiquinone. The major cellular fatty acids (>10 % of total fatty acids) were C16 : 0, cyclo C17 : 0 and C16 : 1 ω7c and/oriso-C15 : 0 2-OH. The DNA G+C contents of the two isolates were 59.8 and 60.0 mol%. Isolates UMS-37T and UMS-40 exhibited no difference in their 16S rRNA gene sequences and possessed a mean DNA–DNA relatedness level of 94 %; they exhibited 16S rRNA gene sequence similarity levels of 96.8–98.2 % to the type strains of recognized Herbaspirillum species. Phylogenetic analyses based on 16S rRNA gene sequences showed that isolates UMS-37T and UMS-40 formed a distinct phylogenetic lineage within the genus Herbaspirillum. DNA–DNA relatedness levels between isolates UMS-37T and UMS-40 and the type strains of some phylogenetically related Herbaspirillum species were in the range 3–56 %. On the basis of differences in phenotypic properties and phylogenetic distinctiveness and genomic data, isolates UMS-37T and UMS-40 were classified in the genus Herbaspirillum within a novel species, for which the name Herbaspirillum rhizosphaerae sp. nov. is proposed, with the type strain UMS-37T (=KCTC 12558T =CIP 108917T).

Burkholderia ginsengisoli sp. nov., a β-glucosidase-producing bacterium isolated from soil of a ginseng field

A bacterial strain (designated KMY03T) that possesses β-glucosidase activity was isolated from soil from a ginseng field in South Korea and was characterized in order to determine its taxonomic position. The bacterium was found to comprise Gram-negative, rod-shaped, motile cells with unipolar polytrichous flagella. On the basis of 16S rRNA gene sequence similarity, strain KMY03T was shown to belong to the family Burkholderiaceae of the Betaproteobacteria, being most closely related to Burkholderia caledonica LMG 19076T (97.8 %), Burkholderia terricola LMG 20594T (97.5 %), Burkholderia xenovorans LMG 21463T (97.4 %) and Burkholderia phytofirmans LMG 22146T (97.3 %). Chemotaxonomic data (major ubiquinone, Q-8; major fatty acids, C17 : 0 cyclo, C16 : 0, C19 : 0 cyclo ω8c and summed feature 2) supported the affiliation of the novel strain with the genus Burkholderia. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed the strain to be differentiated genotypically and phenotypically from Burkholderia species with validly published names. On the basis of these data, strain KMY03T represents a novel species of the genus Burkholderia, for which the name Burkholderia ginsengisoli sp. nov. is proposed. The type strain is KMY03T (=KCTC 12389T=NBRC 100965T).

Herbaspirillum hiltneri sp. nov., isolated from surface-sterilized wheat roots

The genus Herbaspirillum of the Betaproteobacteria mainly comprises diazotrophic bacteria with a potential for endophytic and systemic colonization of a variety of plants. The plant-associated bacterial isolates N3T, N5 and N9 were derived from surface-sterilized wheat roots. After phylogenetic analysis of 16S rRNA gene sequence data the isolates could be allocated to the genus Herbaspirillum, and 99.9 % similarity to the sequence of Herbaspirillum lusitanum P6-12T was found. A set of 16S rRNA gene-targeted oligonucleotide probes was developed for the identification of the three novel isolates and H. lusitanum (Hhilu446), and for the specific detection of several other Herbaspirillum species described recently. For higher phylogenetic resolution, the 23S rRNA gene sequences of all members of the genus was sequenced and used to construct a phylogenetic tree. Isolates N3T, N5 and N9 formed a group that was distinct from all other Herbaspirillum species. In addition, isolate N3T and H. lusitanum P6-12T exhibited a DNA–DNA hybridization value of only 25 %. The value for DNA–DNA hybridization between N3T and other members of the genus Herbaspirillum was between 14 and 32 %; DNA–DNA hybridization between strain N3T and isolates N5 and N9 produced values above 95 %. This places the three isolates as representatives of a novel species within the genus Herbaspirillum. A Biolog GN2 assay supported this conclusion. The major fatty acids were C16 : 1 ω7c, C16 : 0 and C18 : 1 ω7c, and the DNA G+C content ranged from 60.9 to 61.5 mol%. Therefore these three isolates should be classified within a novel species, for which the name Herbaspirillum hiltneri sp. nov. is proposed. The type strain is N3T (=DSM 17495T=LMG 23131T).

Azonexus caeni sp. nov., a denitrifying bacterium isolated from sludge of a wastewater treatment plant

A polyphasic taxonomic study was carried out to determine the taxonomic position of a newly isolated denitrifying bacterium, designated Slu-05T, which had been isolated from sludge from the main aerobic treatment tanks of a municipal sewage treatment plant. Phylogenetic analysis based on comparative 16S rRNA gene sequencing indicated that strain Slu-05T was closely related to Azonexus fungiphilus LMG 19178T (96.4 % sequence similarity), the sole species in the genus Azonexus. Strain Slu-05T comprised Gram-negative, motile, non-spore-forming and slightly curved rods. The predominant respiratory lipoquinone was Q-8. The major fatty acids were C16 : 1 ω7c, C16 : 0, C18 : 1 isomers and C10 : 0 3-OH. The G+C content of the genomic DNA was 65.6 mol%. The results of DNA–DNA hybridization (15.6 %) together with phenotypic determination showed that strain Slu-5T could be distinguished from A. fungiphilus. Moreover, some phenotypic properties concerning enzyme activity, the substrates utilized as carbon sources and growth conditions distinguish strain Slu-5T from A. fungiphilus. On the basis of the results obtained in this study, Slu-05T (=DSM 17719T=KCTC 12530T=CCBAU 10199T) is the type strain of a novel species of Azonexus, for which the name Azonexus caeni sp. nov. is proposed.

Shinella granuli gen. nov., sp. nov., and proposal of the reclassification of Zoogloea ramigera ATCC 19623 as Shinella zoogloeoides sp. nov

The taxonomic position of a novel bacterial strain, Ch06T, isolated from an upflow anaerobic sludge blanket reactor was determined. Strain Ch06T was Gram-negative, aerobic, motile and oxidase- and catalase-positive. A comparative 16S rRNA gene sequence analysis showed a clear affiliation of strain Ch06T to the Alphaproteobacteria and it was most closely related to Zoogloea ramigera ATCC 19623 and Mycoplana dimorpha IAM 13154T (97.9 and 96.3% sequence similarity, respectively). The major respiratory quinone was Q-10 and the predominant fatty acids were C16:0, 3-OH C16:0, C18:0, C19:0 cyclo omega8c and summed feature 7 (C18:1omega7c/omega9t/omega12t, C18:1omega7c/omega9c/omega12t). On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, the novel isolate was assigned to a new genus, Shinella gen. nov., as Shinella granuli gen. nov., sp. nov. (type strain Ch06T=KCTC 12237T=JCM 13254T). It is proposed that Zoogloea ramigera ATCC 19623 is reclassified into the novel genus Shinella as Shinella zoogloeoides sp. nov. (type strain ATCC 19623T=IAM 12669T=I-16-MT).

Burkholderia terrae sp. nov., isolated from a forest soil

A Gram-negative, slightly curved rod-shaped bacterium, designated strain KMY02T, was isolated from a forest soil in Daejeon, South Korea. On the basis of 16S rRNA gene sequence similarity, strain KMY02T was shown to belong to the family Burkholderiaceae of the Betaproteobacteria, and to be related most closely to Burkholderia hospita LMG 20598T (98·7 %), Burkholderia caribensis LMG 18531T (98·0 %) and Burkholderia phymatum LMG 21445T (97·4 %). Its phylogenetic distance from all recognized species within the genus Burkholderia was less than 97 %. Chemotaxonomic data [Q-8 as the major ubiquinone; C16 : 0, C17 : 0 cyclo, summed feature 7 (C18 : 1 ω7c/ω9t/ω12t) and C15 : 0 as the major fatty acids] supported the affiliation of strain KMY02T to the genus Burkholderia. The results of DNA–DNA hybridization experiments and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the strain from recognized Burkholderia species. Therefore, KMY02T (=KCTC 12388T=NBRC 100964T) represents the type strain of a novel species, for which the name Burkholderia terrae sp. nov. is proposed.

An Investigation of Chlorophenol Proton Affinities and Their Influence on the Biological Activity of Microorganisms

The proton affinities of 15 chlorophenols are calculated by ab initio methods. Straight correlation between proton affinities and changes in the electronic structure is observed. The proton affinities decrease linearly with the electronic density gain on the chlorine atoms, as the liberation of the proton increases. To confirm the importance of the proton affinities on the toxicity of chlorophenols, calorimetric responses of these molecules and related ones where the acid proton is changed to a methyl group (anisol and its chlorinated derivatives) were used to verify their effects on Chromobacterium violaceum. The results confirmed that the chlorophenols are more toxic than the respective chloroanisols and suggest that high proton affinities are associated with low toxic activity. The toxicity of the chlorophenols can be associated with the respiratory mechanism in some microorganisms.

Three stages of a biofilm community developing at the liquid-liquid interface between polychlorinated biphenyls and water

Soil contaminated with polychlorinated biphenyls (PCB) was used as an inoculum to grow a complex biofilm community on PCB oil (Aroclor 1242) on a substratum (Permanox). The biofilm was monitored for 31 days by confocal laser scanning microscopy, community fingerprinting using single-strand conformational polymorphism (SSCP), amplicons of the 16S rRNA genes, and chemical analyses of the PCB congeners. SSCP analysis of the young biofilm revealed a rather diverse microbial community with species of the genera Herbaspirillum and Bradyrhizobium as dominant members. The biofilm developing on the PCB droplets displayed pronounced stages of PCB degradation and biofilm development not described before from pure-culture experiments. The first step was the colonization of the substratum while the PCB oil was hardly populated. When a certain density of bacteria was reached on the Permanox, the PCB was colonized, but soon the degradation of the congeners was markedly reduced and many cells were damaged, as seen by LIVE/DEAD staining. Finally, the biofilm formed aggregates and invaded the PCB oil, showing lower numbers of damaged cells than before and a dramatic increase in PCB degradation. This sequence of biofilm formation is understood as a maturation process prior to PCB oil colonization. This is followed by a thin biofilm on the PCB droplet, an aggregation process forming pockets in the PCB, and finally an invasion of the biofilm into the PCB oil. Only the mature biofilm showed degradation of pentachlorinated PCB congeners, which may be reductively dechlorinated and the resulting trichlorobiphenyls then aerobically metabolized.

Paracoccus koreensis sp. nov., isolated from anaerobic granules in an upflow anaerobic sludge blanket (UASB) reactor

A Gram-negative, short rod- to coccus-shaped, non-spore-forming bacterium (Ch05(T)) was isolated from granules in an upflow anaerobic sludge blanket (UASB) reactor. On the basis of 16S rRNA gene sequence similarity, strain Ch05(T) was shown to belong to the subclass alpha-Proteobacteria, being related to Paracoccus solventivorans (97.5%), Paracoccus alkenifer (96.9%) and Paracoccus kocurii (96.4%). The phylogenetic distance from Paracoccus species with validly published names was always less than 96%. Physiological and chemotaxonomic data (major ubiquinone, Q-10; major fatty acids, C(18:1) and C(18:0)) supported the affiliation of strain Ch05(T) to the genus Paracoccus. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Ch05(T) from the 17 Paracoccus species with validly published names. Ch05(T) therefore represents a novel species, for which the name Paracoccus koreensis sp. nov. is proposed. The type strain is Ch05(T) (=KCTC 12238(T)=IAM 15216(T)).

Cellulomonas terrae sp. nov., a cellulolytic and xylanolytic bacterium isolated from soil

A bacterial strain (DB5(T)), with polysaccharide-degrading activities, was isolated from garden soil in Daejeon, Republic of Korea. The cells were Gram-positive, aerobic or facultatively anaerobic, non-motile straight rods. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belongs to the genus Cellulomonas and that it is most closely related to Cellulomonas xylanilytica LMG 21723(T) and Cellulomonas humilata ATCC 25174(T) (98.0 and 97.9% similarity, respectively). Chemotaxonomic data also supported the classification of strain DB5(T) in the genus Cellulomonas, i.e. L-ornithine as the cell-wall diamino acid, anteiso-C(15:0) and iso-C(15:0) as the major fatty acids, MK-9(H(4)) as the predominant menaquinone and the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol mannosides in the polar lipid profile. The results of DNA-DNA hybridization in combination with chemotaxonomic and physiological data demonstrated that strain DB5(T) (=KCTC 19081(T)=NBRC 100819(T)) should be classified as the type strain of a novel species within the genus Cellulomonas, for which the name Cellulomonas terrae sp. nov. is proposed.

Phenylobacterium koreense sp. nov., isolated from South Korea

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterium, Slu-01T, was isolated from activated sludge from a wastewater treatment plant in Daejeon, South Korea. After 3 days on R2A medium, strain Slu-01T developed colourless colonies (0·7–1·2 mm). The non-motile rods (0·7–1·0×1·0–2·0 μm) were slightly curved and occurred singly and in pairs. No filamentous cells were found. On the basis of 16S rRNA gene sequence similarity, strain Slu-01T was shown to belong to the family Caulobacteraceae and was most closely related to Phenylobacterium immobile (96·6 %) and Phenylobacterium lituiforme (96·5 %). The genomic DNA G+C content of strain Slu-01T was 68·1 mol%, within the range of 67·3–68·4 mol% for the genus Phenylobacterium. Chemotaxonomic data (major ubiquinone, Q-10; major fatty acids C18 : 1 ω7c, C16 : 0, C15 : 0 and C17 : 0) and 16S rRNA gene sequence analysis supported the affiliation of strain Slu-01T to the genus Phenylobacterium. However, DNA–DNA hybridization data and phenotypic properties showed that strain Slu-01T could be distinguished from the two other Phenylobacterium species with validly published names. Thus, it is suggested that strain Slu-01T represents a novel species of the genus Phenylobacterium, for which the name Phenylobacterium koreense is proposed. The type strain is Slu-01T (=KCTC 12206T=IAM 15119T).

Herminiimonas fonticola gen. nov., sp. nov., a Betaproteobacterium isolated from a source of bottled mineral water

Several yellowish-pigmented bacteria with an optimum growth temperature of about 30 degrees C, were recovered from the source (borehole) of bottled mineral water in the Serra da Estrela in Eastern Portugal. Phylogenetic analyses of the 16S rRNA gene sequence of strains S-94T , S-97, S-99 and S-92 indicated that these organisms represent a new species of the Betaproteobacteria that is not closely related to any other known species. The major fatty acids of the strains are 16:1 omega7c and 16:0. Ubiquinone 8 is the major respiratory quinone. The new isolates are strictly organotrophic and aerobic. The new strains only assimilated organic acids, glycine and alanine. Casamino acids and a mixture of all natural amino acids are not used as sole carbon and nitrogen sources; these are used as nitrogen source in the presence of organic acids. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we are of the opinion that strains S-94T, S-97, S-99 and S-92 represent a new species of a novel genus for which we propose the name Herminiimonas fonticola gen. nov., sp. nov.

Flavobacterium granuli sp. nov., isolated from granules used in a wastewater treatment plant

A Gram-negative, rod-shaped, non-spore-forming bacterium (designated strain Kw05T) was isolated from granules used in the wastewater treatment plant of a beer-brewing factory in Kwang-Ju, Republic of Korea. On the basis of 16S rRNA gene sequence similarity, strain Kw05T was shown to belong to the family Flavobacteriaceae, and was most closely related to Flavobacterium limicola (96·6 %), Flavobacterium hibernum (96·3 %), Flavobacterium hydatis (96·1 %) and Flavobacterium xinjiangense (96·1 %). The G+C content of the genomic DNA of strain Kw05T was 36·2 mol%, within the range of 32–37 mol% for the genus Flavobacterium. Chemotaxonomic data (major menaquinone MK-6; major fatty acids iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and iso-C17 : 1 ω9c) supported the classification of strain Kw05T within the genus Flavobacterium. Kw05T therefore represents a novel species, for which the name Flavobacterium granuli sp. nov. is proposed. The type strain is Kw05T (=KCTC 12201T=IAM 15099T).