Pseudomonas Koreensis Research Articles

Genome variations between rhizosphere and bulk soil ecotypes of a Pseudomonas koreensis population.

Bulk soil and rhizosphere are soil compartments selecting different microbial communities. However, it is unknown whether this selection also can change the genome content of specific bacterial taxa, splitting a population in distinct ecotypes. To answer this question we compared the genome sequences of 53 isolates obtained from sugarcane rhizosphere (28) and bulk soil (25). These isolates were previously classified in the Pseudomonas koreensis subgroup of the P. fluorescens complex. Phylogenomics showed a trend of separation between bulk soil and rhizosphere isolates. Discriminant analysis of principal components (DAPC) identified differences in the accessory genome of rhizosphere and bulk soil sub-populations. We found significant changes in gene frequencies distinguishing rhizosphere from bulk soil ecotypes, for example, enrichment of phosphatases and xylose utilization (xut) genes, respectively. Phenotypic assays and deletion of xutA gene indicated that accumulation of xut genes in the bulk soil sub-population provided a higher growth capacity in a d-xylose medium, supporting the corresponding genomic differences. Despite the clear differences distinguishing the two ecotypes, all 53 isolates were classified in a single 16S rRNA gene OTU. Collectively, our results revealed that the gene pool and ecological behavior of a bacterial population can be different for ecotypes living in neighbouring soil habitats.

Polyfunctional Biopreparations-Crude Oil Destructors: The Effect on Plants and the Content of Oil in the Soil

The results of an experiment on cleaning oil-contaminated soil and accelerating the restoration of its fertility with the aid of combined biopreparations containing bacteria that degrade oil and microorganisms that can stimulate the growth and development of plants. It is shown that the introduction of bacterial mixtures reduced the oil content by 3.1–3.6 times and increased by 2-3 orders the number of basic physiological groups of soil microorganisms participating in its transformation, and also accelerated the germination of seeds (for 2 days) and the beginning (for 6–7 days) of all stages of oat development, used as a phytomeliorant. The most effective was a biopreparation consisting of a consortium of microorganisms Acinetobacter calcoaceticus IB DT-5.1/ 1 and Ochrobactrum intermedium IB DT-5.3/2 and strains of Pseudomonas koreensis IB-4 and Paenibacillus ehimensis IB 739, which, among other things, increased the mass of oat shoots in 2.3–2.6 times and their length is 54.0–77.8% compared to plants in the soil untreated with bacteria with oil.

A serological approach for the identification of the effector hopz5 of Pseudomonas syringae pv. actinidiae: a tool for the rapid immunodetection of kiwifruit bacterial canker

Pseudomonas syringae pv. actinidiae (Psa) is responsible for outbreaks of kiwifruit canker over the world, and the cause of heavy economic losses. Although molecular detection methods for this bacterium are well-established, its serological detection is much less advanced. A polyclonal antiserum to the bacterial effector-hopz5 was raised (PAb:hopz5) and its specificity tested. No cross-reaction was observed with other bacteria, including Pseudomonas syringae pv. tomato, Pseudomonas syringae pv. theae, Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas koreensis, Bacillus subtilis, Bacillus megaterium, Ralstonia solanacearum, Erwinia rhapontica, Pseudomonas syringae pv. syringae. PAb:hopz5 was able to detect Psa from culture and infected plant samples, thus representing a suitable tool for the immunodetection of the agent of kiwifruit bacterial canker in field samples. The detection sensitivity of a colloidal gold immunochromatographic strip was high, up to 2.2 × 103 CFU/ml. Thus PAb:hopz5 constitutes a suitable and accurate tool for detection of Psa and haplotype distribution.

Investigation of a Contaminated, Nationally Distributed, Organ Transplant Preservation Solution — United States, 2016–2017

BackgroundIn December 2016, bacterial contamination of an organ preservation solution (OPS) was reported by Transplant Center A in Iowa. Annually, >20,000 abdominal organs are transplanted in the United States; OPS is used for organ storage. We investigated the scope of OPS contamination and its association with adverse events in patients.MethodsWe assessed infection control practices related to OPS at Transplant Centers A and B in Iowa and the local organ procurement organization (OPO). We issued national notifications about OPS contamination and requested transplant centers to report product-related concerns or potential patient harm. Among transplant recipients at Center A, we compared adverse events (fever, bacteremia, surgical site infection, peritonitis, or pyelonephritis within 14 days of transplantation) during October–December 2015 with October–December 2016, the presumed window of exposure to contaminated OPS. Isolates from OPS were characterized.ResultsNo infection control deficiencies were identified at Transplant Centers A, B, or the OPO. In January 2017, contaminated OPS from the same manufacturer was reported by Transplant Center C in Texas. Nationally, there were no reports of patient harm definitively linked to OPS. Post-transplant adverse events at Center A did not increase between fourth quarter 2015 (5/12 [42%]) and 2016 (2/15 [13%]). Organisms recovered from OPS included Pantoea agglomerans and Enterococcus gallinarum (Center A) and Pseudomonas koreensis (Center C). Five Pantoea isolates from ≥3 opened OPS bags were indistinguishable by pulsed-field gel electrophoresis. The OPS distributor issued recalls and suspended production. The US Food and Drug Administration identified deficiencies in current good manufacturing practices at manufacturing and distribution facilities, including inadequate validation of OPS sterility.ConclusionBacterial contamination of a nationally distributed product was identified by astute clinicians. The investigation found no illnesses were directly linked to the product. Prompt reporting of concerns about potentially contaminated healthcare products, which might put patients at risk, is critical for swift public health action.Disclosures All authors: No reported disclosures.

Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species Isolated from Sugarcane Rhizosphere.

The study was designed to isolate and characterize Pseudomonas spp. from sugarcane rhizosphere, and to evaluate their plant- growth- promoting (PGP) traits and nitrogenase activity. A biological nitrogen-fixing microbe has great potential to replace chemical fertilizers and be used as a targeted biofertilizer in a plant. A total of 100 isolates from sugarcane rhizosphere, belonging to different species, were isolated; from these, 30 isolates were selected on the basis of preliminary screening, for in vitro antagonistic activities against sugarcane pathogens and for various PGP traits, as well as nitrogenase activity. The production of IAA varied from 312.07 to 13.12 μg mL−1 in tryptophan supplemented medium, with higher production in AN15 and lower in CN20 strain. The estimation of ACC deaminase activity, strains CY4 and BA2 produced maximum and minimum activity of 77.0 and 15.13 μmoL mg−1 h−1. For nitrogenase activity among the studied strains, CoA6 fixed higher and AY1 fixed lower in amounts (108.30 and 6.16 μmoL C2H2 h−1 mL−1). All the strains were identified on the basis of 16S rRNA gene sequencing, and the phylogenetic diversity of the strains was analyzed. The results identified all strains as being similar to Pseudomonas spp. Polymerase chain reaction (PCR) amplification of nifH and antibiotic genes was suggestive that the amplified strains had the capability to fix nitrogen and possessed biocontrol activities. Genotypic comparisons of the strains were determined by BOX, ERIC, and REP PCR profile analysis. Out of all the screened isolates, CY4 (Pseudomonas koreensis) and CN11 (Pseudomonas entomophila) showed the most prominent PGP traits, as well as nitrogenase activity. Therefore, only these two strains were selected for further studies; Biolog profiling; colonization through green fluorescent protein (GFP)-tagged bacteria; and nifH gene expression using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The Biolog phenotypic profiling, which comprised utilization of C and N sources, and tolerance to osmolytes and pH, revealed the metabolic versatility of the selected strains. The colonization ability of the selected strains was evaluated by genetically tagging them with a constitutively expressing GFP-pPROBE-pTetr-OT plasmid. qRT-PCR results showed that both strains had the ability to express the nifH gene at 90 and 120 days, as compared to a control, in both sugarcane varieties GT11 and GXB9. Therefore, our isolated strains, P. koreensis and P. entomophila may be used as inoculums or in biofertilizer production for enhancing growth and nutrients, as well as for improving nitrogen levels, in sugarcane and other crops. The present study, to the best of our knowledge, is the first report on the diversity of Pseudomonas spp. associated with sugarcane in Guangxi, China.

Insights into the fecal microbiota of captive Iberian lynx (Lynx pardinus).

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

Effectiveness of Co-inoculation with Pseudomonas koreensis and Rhizobia on Growth, Nodulation and Yield of Common Bean (Phaseolus vulgaris L.)

Effectiveness of Co-inoculation with Pseudomonas koreensis and Rhizobia on Growth, Nodulation and Yield of Common Bean (Phaseolus vulgaris L.)

Genome Sequence of Pseudomonas koreensis CRS05-R5, an Antagonistic Bacterium Isolated from Rice Paddy Field.

Pseudomonas koreensis, a new nominated Gram-negative bacterium was first reported and isolated from Korean agricultural soil (Kwon et al., 2003). CRS05-R5 (first reported as Pseudomonas sp.), which showed biocontrol ability against Sitophilus oryzae and Acidovorax avenae subsp. avenae (Liu et al., 2014), was first isolated from the rice rhizosphere in Heilongjiang province and reported in 2003 (Xie et al., 2003). Except for that, this species has been reported to produce the biosurfactant, which has biocontrol ability against Phytophthora infestans and Pythium ultimum (Hultberg et al., 2010a,b). These interesting features raise our attention on CRS05-R5. Recently, we sequenced the 16S rRNA sequence from CRS05-R5 and built the phylogenetic tree (Figure S1). Based on that, we confirmed that CRS05-R5 should be classified as P. koreensis. However, only one genome was sequenced (D26) and no detailed analysis was performed on this species. In this case, we did whole-genome sequencing on CRS05-R5, and tried to reveal the possible mechanism behind its antagonistic ability.

Pseudomonas kribbensis sp. nov., isolated from garden soils in Daejeon, Korea.

Two bacterial strains, 46-1 and 46-2T, were isolated from garden soil. These strains were observed to be aerobic, Gram-stain negative, rod-shaped, non-spore-forming, motile and catalase and oxidase positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains shared 100% sequence similarity with each other and belong to the genus Pseudomonas in the class Gammaproteobacteria. The concatenated 16S rRNA, gyrB, rpoB and rpoD gene sequences further confirmed that the isolates belong to the Pseudomonas koreensis subgroup (SG), with P. koreensis Ps 9-14T, Pseudomonas moraviensis 1B4T and Pseudomonas granadensis F-278,770T as their close relatives (>96% pairwise similarity). DNA-DNA hybridization with the closely related type strain P. koreensis SG revealed a low level of relatedness (<50%). A cladogram constructed using whole-cell matrix-assisted laser desorption/ionization time-of-flight (WC-MALDI-TOF) MS analysis showed the isolates formed a completely separate monophyletic group. The isolates were negative for utilization of glycogen, D-psicose, α-keto butyric acid, α-keto valeric acid, succinamic acid and D, L-α-glycerol phosphate. In contrast, all these reactions were positive in P. koreensis JCM 14769T and P. moraviensis DSM 16007T. The fatty acid C17:0 cyclo was detected as one of the major cellular fatty acids (>15%) in the isolates but it was a minor component (<4%) in both reference type strains. In contrast, the fatty acid, C12:0 was not observed in the isolates but was present in both reference strains. Based on differences such as phylogenetic position, low-level DNA-DNA hybridization, WC-MALDI-TOF MS analysis, fluorescence pigmentation, fatty acid profiles, and substrate utilization, we propose that the isolates 46-1 and 46-2T represent a novel species of the genus Pseudomonas, for which the name Pseudomonas kribbensis sp. nov. is proposed; the type strain is 46-2T (=KCTC 32541T=DSM 100278T).

Spore associated bacteria of arbuscular mycorrhizal fungi improve maize tolerance to salinity by reducing ethylene stress level

The role of spore associated bacteria of arbuscular mycorrhizal fungi (AMF) in improving plant growth and alleviating salt stress is a potential area to explore. In the present study, 22 bacteria isolated from the spore walls of AMF were identified to contain 1-aminocyclopropane-1-carboxylate deaminase. These were tested for their ability to improve seed germination and alleviate salt stress in the early growth of maize. Among the isolates, 19 bacteria that were able to grow at 4 % NaCl were used for germination assay. Two bacteria and seven bacteria significantly improved maize seed germination at 100 mM NaCl and 200 mM NaCl, respectively. Based on the presence of plant growth promoting (PGP) characters and the ability to improve seed germination, five strains were chosen for further experiments. At 0 mM NaCl, all the strains were able to increase maize shoot and root growth significantly. At 25 mM NaCl, except for Bacillus aryabhattai S210B15, all the strains were able to increase shoot and root growth significantly. At 50 mM NaCl, Bacillus aryabhattai S110B3 and B. aryabhattai S210B15 significantly improved shoot length, whereas, Pseudomonas koreensis S2CB35 and B. aryabhattai S210B15 significantly increased root length. Although salinity increased ethylene production in maize, bacterial inoculation significantly reduced the ethylene level at 0, 25 and 50 mM NaCl. Among the five strains, only P. koreensis S2CB35 showed the presence of PGP functional traits of nifH, acdS and nodA genes.

A new bacterial strain, Pseudomonas koreensis IB-4, as a promising agent for plant pathogen biological control

A bacterial strain IB-4, antagonistic to plant pathogenic fungi of the genera Fusarium, Bipolaris, and Alternaria, was isolated from arable soils of the Mechetlinskii district, Bashkortostan. Physiological, biochemical, and culture morphological properties of strain IB-4 supported its classification within the genus Pseudomonas. In spite of some discrepancies in the results of phenotypic and chemotaxonomic research, analysis of the 16S rRNA gene sequence, DNA–DNA hybridization, GC-content, and MALDI mass spectral data provide considerable evidence supporting its identification as a Pseudomonas koreensis strain. P. koreensis strain IB-4 was shown to possess the valuable features characteristic of PGPR microorganisms: antifungal and nitrogenase activities and ability to synthesize indole-3-acetic acid (IAA) and cytokinin-like compounds. Field test, in which potato plants were treated with the culture liquid of P. koreensis strain IB-4 revealed a positive effect on potato yield and resistance to plant pathogens.

Microbial Colonization of Tomato Phylloplane is Influenced by Leaf Age

Nutrient status on the leaf alters as it matures, which often restructures the microbial population. To understand the effect of age on phylloplane colonization, two varieties of tomato (Pusa early dwarf and F1-Priya-6636) were sampled. Various stages of leaf development and microbial colonization was studied by leaf imprint culture method. The bacterial species were identified by 16S rRNA sequencing, and fungal species by microscopic methods. The dominant bacterial species were Pseudomonas koreensis, P. stutzeri, P. jesseni, Sphingobacterium daejonense, Klebsiella pneumoneae, Serratia fonticola and fungal species were Alternaria alternata, A. citrifolia, Aspergillus niger, A. flavus, A. candidus, A. nidulans, Penicillium expansum, Curvlaria lunata, Cladosporium cladosporioides, C. herbarum, Fusarium oxysporum, Trichoderma harzianum and Rhizoctonia solani. Leaf surfaces were investigated by assessment of microbial colonization patterns. Adaxial surface was found to be densely populated with age.

Efficacy of lactoferricin B in controlling ready-to-eat vegetable spoilage caused by Pseudomonas spp.

The microbial content of plant tissues has been reported to cause the spoilage of ca. 30% of chlorine-disinfected fresh vegetables during cold storage. The aim of this work was to evaluate the efficacy of antimicrobial peptides in controlling microbial vegetable spoilage under cold storage conditions. A total of 48 bacterial isolates were collected from ready-to-eat (RTE) vegetables and identified as belonging to Acinetobacter calcoaceticus, Aeromonas media, Pseudomonas cichorii, Pseudomonas fluorescens, Pseudomonas jessenii, Pseudomonas koreensis, Pseudomonas putida, Pseudomonas simiae and Pseudomonas viridiflava species. Reddish or brownish pigmentation was found when Pseudomonas strains were inoculated in wounds on leaves of Iceberg and Trocadero lettuce and escarole chicory throughout cold storage. Bovine lactoferrin (BLF) and its hydrolysates (LFHs) produced by pepsin, papain and rennin, were assayed in vitro against four Pseudomonas spp. strains selected for their heavy spoiling ability. As the pepsin-LFH showed the strongest antimicrobial effect, subsequent experiments were carried out using the peptide lactoferricin B (LfcinB), well known to be responsible for its antimicrobial activity. LfcinB significantly reduced (P≤0.05) spoilage by a mean of 36% caused by three out of four inoculated spoiler pseudomonads on RTE lettuce leaves after six days of cold storage. The reduction in the extent of spoilage was unrelated to viable cell density in the inoculated wounds. This is the first paper providing direct evidence regarding the application of an antimicrobial peptide to control microbial spoilage affecting RTE leafy vegetables during cold storage.

Epiphytic marine pigmented bacteria: A prospective source of natural antioxidants.

Awareness on antioxidants and its significance in human healthcare has increased many folds in recent time. Increased demand requisite on welcoming newer and alternative resources for natural antioxidants. Seaweed associated pigmented bacteria screened for its antioxidant potentials reveals 55.5% of the organisms were able to synthesize antioxidant compounds. DPPH assay showed 20% of the organisms to reach a antioxidant zone of 1 cm and 8.3% of the strains more than 3 cm. Pseudomonas koreensis (JX915782) a Sargassum associated yellowish brown pigmented bacteria have better activity than known commercial antioxidant butylated hydroxytoluene (BHT) against DPPH scavenging. Serratia rubidaea (JX915783), an associate of Ulva sp. and Pseudomonas argentinensis (JX915781) an epiphyte of Chaetomorpha media , were also contributed significantly towards ABTS (7.2% ± 0.03 to 15.2 ± 0.09%; 1.8% ± 0.01 to 15.7 ± 0.22%) and FRAP (1.81 ± 0.01 to 9.35 ± 0.98; 7.97 ± 0.12 to 18.70 ± 1.84 μg/mL of AsA Eq.) respectively. 16S rRNA gene sequence analysis revealed bacteria that have higher antioxidant activity belongs to a bacterial class Gammaproteobacteria. Statistical analysis of phenolic contents in relation with other parameters like DPPH, ABTS, reducing power and FRAP are well correlated (p < 0.05). Results obtained from the current study inferred that the seaweed associated pigmented bacteria have enormous potential on antioxidant compounds and need to be extracted in a larger way for clinical applications.

Biosurfactants Have the Potential to Induce Defence Against Phytophthora infestans in Potato

Potato late blight caused by Phytophthora infestans is one of the most destructive plant diseases worldwide. Currently, its management mainly relies on the frequent use of synthetic chemicals, and there is a need to develop more sustainable strategies. Biosurfactants produced by fluorescent pseudomonads have been shown to rapidly, within 1 min, cause zoospore lyses. This study investigated if the biosurfactant-producing strain Pseudomonas koreensis 2.74 and its biosurfactants have the potential to induce resistance in potato to late blight. The experiments were performed with treatments of whole plants of the susceptible potato cultivar Bintje and the partially resistant cultivar Ovatio. A significant disease reduction and an induced secretion of proteins such as pathogenesis-related (PR) protein 1, within the leaf apoplast, were observed in the potato cultivar Ovatio after treatment with the biosurfactant at a concentration of 1 mg ml �1 . No significant effects on disease development were observed after treatment with the bacterial suspension of Pseudomonas koreensis 2.74.

Pseudomonas-Mediated Mitigation of Salt Stress and Growth Promotion in Glycine max

In the present investigation we emphasized the role of plant growth-promoting bacterium to characterize activities of stress-associated enzymes, proline accumulation, chlorophyll estimation, and Na+/K+ ratio in Glycine max L. Merrill under salt stress. The results showed that inoculation of plants with Pseudomonas koreensis strain AK-1 (MTCC no. 12058) grown under salt treatment induced growth promotion, reduced Na+ levels but increased K+ levels in leaves and roots in comparison with the non-inoculated salt-treated plants. Correspondingly, inoculation of soil with bacterium treated with NaCl plants maintained a lower ratio of [Na+]/[K+] in NaCl-stressed plants. The experiment designed in a completely randomized manner which consisted of four treatments comprising of bacterial inoculation with and without salt treatment including one absolute control (without inoculation and salt treatment). Inoculation of bacterial strains together with salt treatment showed significant increase in activity of stress enzymes along with proline content as compared to salt-treated plants. Application of 200 mM NaCl at 0 day after seeding results inadequate number of lateral roots in uninoculated plants as compared to strain AK-1-inoculated plants. Soybean plants not inoculated with strain AK-1 showed 33 % seed germination in salt-treated plants, and the plant growth was also significantly decreased compared to the strain AK-1-treated plants.

Potential use of Pseudomonas koreensis AGB-1 in association with Miscanthus sinensis to remediate heavy metal(loid)-contaminated mining site soil

Endophytic bacteria have the potential to promote plant growth and heavy metal(loid) (HM) removal from contaminated soil. Pseudomonas koreensis AGB-1, isolated from roots of Miscanthus sinensis growing in mine-tailing soil, exhibited high tolerance to HMs and plant growth promoting traits. Transmission electron microscope (TEM) analysis revealed that AGB-1 sequestered HMs extracellularly and their accumulation was visible as dark metal complexes on bacterial surfaces and outside of the cells. DNA sequencing of HM resistance marker genes indicated high homology to the appropriate regions of the arsB, ACR3(1), aoxB, and bmtA determinants. Inoculating mining site soil with AGB-1 increased M. sinensis biomass by 54%, chlorophyll by 27%, and protein content by 28%. High superoxide dismutase and catalase activities, and the lower malondialdehyde content of plants growing in AGB-1-inoculated soil indicate reduced oxidative stress. Metal(loid) concentrations in roots and shoots of plants grown in inoculated soil were higher than those of the controls in pot trials with mine tailing soil. Results suggest that AGB-1 can be used in association with M. sinensis to promote phytostabilization and remediation of HM-contaminated sites.

Antifungal Activity of Bacteria on Phylloplane of Tomato

A wide array of bacterial and microfungal species possess features, like secretion of metabolic compounds or toxins that help them in interaction with each other or suppression of their growth. In the present study, bacteria were isolated from the phylloplane of Lycopersicum esculentum, to evaluate their antifungal properties tested against microfungal species isolated from the same habitat. Bacterial and fungal isolates were obtained by the leaf imprint technique and pure cultures were made on nutrient agar and potato dextrose agar at 35±1°C and 25±1°C, respectively. The antagonistic activity was tested by dual culture assay. It was found that the growth of Rhizoctonia solani, Alternaria alternata, A. citrifolia, Penicillium expansum, Fusarium oxysporum, Cladosporium herbarum, C. cladosporioides, Curvularia lunata, Aspergillus flavus and A. candidus was inhibited by Pseudomonas koreensis, P. stutzeri, Sphingobacterium daejeonense and Klebsiella pneumonea.

Distribution of Pseudomonas Species in a Dairy Plant Affected by Occasional Blue Discoloration.

During 2010 many cases of discoloration in mozzarella, popularly termed as blue mozzarella, have been reported to the attention of public opinion. Causes of the alteration were bacteria belonging to the genus Pseudomonas. The strong media impact of such cases has created confusion, not only among consumers, but also among experts. In order to help improving the knowledge on microbial ecology of this microorganism a study has been set up with the collaboration of a medium-sized dairy plant producing fresh mozzarella cheese, with occasional blue discoloration, conducting surveys and sampling in the pre-operational, operational and post-operational process phase, milk before and after pasteurization, water (n=12), environmental surfaces (n=22) and the air (n=27). A shelf life test was conducted on finished products stored at different temperatures (4-8°C). Among the isolates obtained from the microbiological analysis of the samples, 60 were subjected to biomolecular tests in order to confirm the belonging to Pseudomonas genus and to get an identification at species level by the amplification and sequencing of the gyrB gene. The results of microbiological tests demonstrated the presence of microorganisms belonging to the genus Pseudomonas along the entire production lane; molecular tests showed 7 different species among the 40 isolates identified. One particular species (Pseudomonas koreensis) was isolated from blue discolored mozzarella cheese and was indicated as the most relevant for the production plant, both for the distribution along the processing chain and for the consequences on the finished product.

Pseudomonas granadensis sp. nov., a new bacterial species isolated from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain.

During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770(T) was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770(T) belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis, P. koreensis, P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770(T) in the genus Pseudomonas. DNA-DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas, for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770(T) ( = DSM 28040(T) = LMG 27940(T)).