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Journal of Materials Science. Materials... Nov 2018This study validated the utilization of triacylglycerides (TAGs) by Pseudomonas mendocina CH50, a wild type strain, resulting in the production of novel mcl-PHAs with...
This study validated the utilization of triacylglycerides (TAGs) by Pseudomonas mendocina CH50, a wild type strain, resulting in the production of novel mcl-PHAs with unique physical properties. A PHA yield of 58% dcw was obtained using 20 g/L of coconut oil. Chemical and structural characterisation confirmed that the mcl-PHA produced was a terpolymer comprising of three different repeating monomer units, 3-hydroxyoctanoate, 3-hydroxydecanoate and 3-hydroxydodecanoate or P(3HO-3HD-3HDD). Bearing in mind the potential of P(3HO-3HD-3HDD) in biomedical research, especially in neural tissue engineering, in vitro biocompatibility studies were carried out using NG108-15 (neuronal) cells. Cell viability data confirmed that P(3HO-3HD-3HDD) supported the attachment and proliferation of NG108-15 and was therefore confirmed to be biocompatible in nature and suitable for neural regeneration.
Topics: Animals; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Cell Survival; Coconut Oil; Materials Testing; Mice; Polyhydroxyalkanoates; Pseudomonas mendocina; Rats
PubMed: 30506294
DOI: 10.1007/s10856-018-6183-9 -
RSC Advances Aug 2018Immobilisation of bacteria on or into a polymer support is a common method for the utilisation of bacteria as biocatalysts for many biotechnological, medical and...
One-step formation of three-dimensional macroporous bacterial sponges as a novel approach for the preparation of bioreactors for bioremediation and green treatment of water.
Immobilisation of bacteria on or into a polymer support is a common method for the utilisation of bacteria as biocatalysts for many biotechnological, medical and environmental applications. The main challenge in this approach is the time taken for the formation of stable biofilms, and the typically low percentage of bacterial cells present on or in the polymer matrix. In this work we propose a novel method for producing a porous bacteria based structure with the properties of a sponge (bacterial sponge) that we then use as a bioreactor for water treatment. Cryogelation has been used as a tool to create macroporous ( with pores in the range 10-100 μm), highly permeable systems with low diffusion constraints and high bacterial content (more than 98% to total material content). A novel crosslinking system was used to form stable bacterial sponges with a high percentage of live bacteria organized in a 3D porous structure. The bacterial sponge was produced in a one step process and can be made from one or several bacterial strains (in this case, two bacterial strains and (and a mixture of both) were used). Reduction of the total polymer content to 2% makes the system more sustainable and environmentally friendly under disposal as it can be simply composted. The bacterial sponges have good mechanical stability and cell viability, which enables repeated use of the materials for phenol degradation for up to five weeks. The material can be stored and transported in cryogenic conditions (-80 °C) for prolonged periods of time, retaining its bioremediation activity following 4-6 weeks of frozen storage. The proposed method of producing bioreactors with a high number of live immobilised bacteria, low polymer content and controlled 3D structure is a promising tool for developing novel materials based on active bacterial cells for various environmental, biotechnological, biological and medical applications.
PubMed: 35548719
DOI: 10.1039/c8ra04219e -
Metabolic Engineering Sep 2018Liquid fuels sourced from fossil sources are the dominant energy form for mobile transport today. The consumption of fossil fuels is still increasing, resulting in a...
Liquid fuels sourced from fossil sources are the dominant energy form for mobile transport today. The consumption of fossil fuels is still increasing, resulting in a continued search for more sustainable methods to renew our supply of liquid fuel. Photosynthetic microorganisms naturally accumulate hydrocarbons that could serve as a replacement for fossil fuel, however productivities remain low. We report successful introduction of five synthetic metabolic pathways in two green cell factories, prokaryotic cyanobacteria and eukaryotic algae. Heterologous thioesterase expression enabled high-yield conversion of native fatty acyl-acyl carrier protein (ACP) into free fatty acids (FFA) in Synechocystis sp. PCC 6803 but not in Chlamydomonas reinhardtii where the polar lipid fraction instead was enhanced. Despite no increase in measurable FFA in Chlamydomonas, genetic recoding and over-production of the native fatty acid photodecarboxylase (FAP) resulted in increased accumulation of 7-heptadecene. Implementation of a carboxylic acid reductase (CAR) and aldehyde deformylating oxygenase (ADO) dependent synthetic pathway in Synechocystis resulted in the accumulation of fatty alcohols and a decrease in the native saturated alkanes. In contrast, the replacement of CAR and ADO with Pseudomonas mendocina UndB (so named as it is responsible for 1-undecene biosynthesis in Pseudomonas) or Chlorella variabilis FAP resulted in high-yield conversion of thioesterase-liberated FFAs into corresponding alkenes and alkanes, respectively. At best, the engineering resulted in an increase in hydrocarbon accumulation of 8- (from 1 to 8.5 mg/g cell dry weight) and 19-fold (from 4 to 77 mg/g cell dry weight) for Chlamydomonas and Synechocystis, respectively. In conclusion, reconstitution of the eukaryotic algae pathway in the prokaryotic cyanobacteria host generated the most effective system, highlighting opportunities for mix-and-match synthetic metabolism. These studies describe functioning synthetic metabolic pathways for hydrocarbon fuel synthesis in photosynthetic microorganisms for the first time, moving us closer to the commercial implementation of photobiocatalytic systems that directly convert CO into infrastructure-compatible fuels.
Topics: Biofuels; Carbon Dioxide; Chlamydomonas reinhardtii; Fatty Acids; Microorganisms, Genetically-Modified; Synechocystis
PubMed: 30144559
DOI: 10.1016/j.ymben.2018.08.008 -
Journal of Global Antimicrobial... Sep 2018
Topics: Adult; Burns; Colistin; Fatal Outcome; Humans; Male; Middle Aged; Multiple Organ Failure; Pseudomonas Infections; Pseudomonas mendocina; Skin Transplantation; Treatment Outcome; beta-Lactamases
PubMed: 30118765
DOI: 10.1016/j.jgar.2018.08.002 -
Journal of Basic Microbiology Nov 2018Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But,...
Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But, at industrial level, the successful commercialization of PHAs is limited by the high production cost due to the expensive carbon source and recovery processes. Pseudomonas mendocina PSU cultured for 72 h in mineral salts medium (MSM) containing 2% (v/v) biodiesel liquid waste (BLW) produced 79.7 wt% poly(3-hydroxybutyrate) (PHB) at 72 h. In addition, this strain produced 43.6 wt% poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 8.6 HV mol% at 60 h when added with 0.3% sodium propionate. The synthesized intracellular PHA granules were recovered and purified by the recently reported biological method using mealworms. The weight average molecular weight (M ) and number average molecular weight (M ) of the biologically extracted PHA were higher than that from the chloroform extraction with comparable melting temperature (T ) and high purity. This study has successfully established a low-cost process to synthesize PHAs from BLW and subsequently confirmed the ability of mealworms to extract PHAs from various kinds of bacterial cells.
Topics: 3-Hydroxybutyric Acid; Animals; Biofuels; Biotransformation; Conservation of Natural Resources; Nitrogen; Polyesters; Polyhydroxyalkanoates; Pseudomonas mendocina; Reproducibility of Results; Tenebrio; Waste Disposal, Fluid
PubMed: 30095175
DOI: 10.1002/jobm.201800279 -
Archives of Microbiology Sep 2018Mine tailings and wastewater generate man-made environments with several selective pressures, including the presence of heavy metals, arsenic and high cyanide...
Mine tailings and wastewater generate man-made environments with several selective pressures, including the presence of heavy metals, arsenic and high cyanide concentrations, but severe nutritional limitations. Some oligotrophic and pioneer bacteria can colonise and grow in mine wastes containing a low concentration of organic matter and combined nitrogen sources. In this study, Pseudomonas mendocina P6115 was isolated from mine tailings in Durango, Mexico, and identified through a phylogenetic approach of 16S rRNA, gyrB, rpoB, and rpoD genes. Cell growth, cyanide consumption, and ammonia production kinetics in a medium with cyanide as sole nitrogen source showed that at the beginning, the strain grew assimilating cyanide, when cyanide was removed, ammonium was produced and accumulated in the culture medium. However, no clear stoichiometric relationship between both nitrogen sources was observed. Also, cyanide complexes were assimilated as nitrogen sources. Other phenotypic tasks that contribute to the strain's adaptation to a mine tailing environment included siderophores production in media with moderate amounts of heavy metals, arsenite and arsenate tolerance, and the capacity of oxidizing arsenite. P. mendocina P6115 harbours cioA/cioB and aoxB genes encoding for a cyanide-insensitive oxidase and an arsenite oxidase, respectively. This is the first report where P. mendocina is described as a cyanotrophic and arsenic oxidizing species. Genotypic and phenotypic tasks of P. mendocina P6115 autochthonous from mine wastes are potentially relevant for biological treatment of residues contaminated with cyanide and arsenic.
Topics: Ammonia; Arsenic; Arsenites; Bacterial Proteins; Cyanides; Mexico; Mining; Oxidoreductases; Phylogeny; Pseudomonas mendocina; RNA, Ribosomal, 16S; Soil Microbiology
PubMed: 29644379
DOI: 10.1007/s00203-018-1514-2 -
BMC Medical Genomics Feb 2018Cell-free circulating DNA (cfDNA) is becoming a useful biopsy for noninvasive diagnosis of diseases. Microbial sequences in plasma cfDNA may provide important...
BACKGROUND
Cell-free circulating DNA (cfDNA) is becoming a useful biopsy for noninvasive diagnosis of diseases. Microbial sequences in plasma cfDNA may provide important information to improve prognosis and treatment. We have developed a stringent method to identify microbial species via microbial cfDNA in the blood plasma of early-onset breast cancer (EOBC) patients and healthy females. Empirically, microbe-originated sequence reads were identified by mapping non-human PE reads in cfDNA libraries to microbial databases. Those mapped concordantly to unique microbial species were assembled into contigs, which were subsequently aligned to the same databases. Microbial species uniquely aligned were identified and compared across all individuals on MCRPM (Microbial CfDNA Reads Per Million quality PE reads) basis.
RESULTS
The predominant microbial cfDNAs in all plasma samples examined are originated from bacteria and these bacteria were limited to only a few genera. Among those, Acinetobacter johnsonii XBB1 and low levels of Mycobacterium spp. were commonly found in all healthy females, but also present in an EOBC patient. Compared to those in healthy counterparts, bacterial species in EOBC patients are more diverse and more likely to present at high levels. Among these three EOBC patients tested, a patient who has record high titer (2,724 MCRPM) of Pseudomonas mendocina together with 8.82 MCRPM of Pannonibacter phragmitetus has passed away; another patient infected by multiple Sphingomonas species remains alive; while the third patient who has similar microbial species (Acinetobacter johnsonii XBB1) commonly seen in normal controls is having a normal life.
CONCLUSIONS
Our preliminary data on the profiles of microbial cfDNA sequences suggested that it may have some prognostic value in cancer patients. Validation in larger number of patients is warranted.
Topics: Adult; Age of Onset; Biomarkers; Breast Neoplasms; Case-Control Studies; Cell-Free Nucleic Acids; DNA, Bacterial; Female; Humans; Prognosis
PubMed: 29504912
DOI: 10.1186/s12920-018-0329-y -
Bioresource Technology Apr 2018In this study, we report the ability of Stenotrophomonas maltophilia, Ochrobactrum anthropi, Pseudomonas mendocina, Microbacterium esteraromaticum and Pseudomonas...
In this study, we report the ability of Stenotrophomonas maltophilia, Ochrobactrum anthropi, Pseudomonas mendocina, Microbacterium esteraromaticum and Pseudomonas aeruginosa to degrade multiple polycyclic aromatic hydrocarbons (PAHs) present in crude oil. The PAHs in the crude oil sample obtained from Digboi oil refinery, India were estimated to be naphthalene (10.0 mg L), fluorene (1.9 mg L), phenanthrene (3.5 mg L) and benzo(b)fluoranthene (6.5 mg L). Exposure of individual bacteria to crude oil showed high rate of biodegradation of specific PAHs by M. esteraromaticum, 81.4%-naphthalene; P. aeruginosa, 67.1%-phenanthrene and 61.0%-benzo(b)fluoranthene; S. maltophilia, 47.9%-fluorene in 45 days. However, consortium of these bacteria showed enhanced biodegradation of 89.1%-naphthalene, 63.8%-fluorene, 81% of phenanthrene and 72.8% benzo(b)fluoranthene in the crude oil. The degradation was further improved up to 10% by consortium on addition of 40 μg mL rhamnolipid JBR-425 biosurfactant. These results suggest that the developed bacterial consortium has significant potential in PAH remediation.
Topics: Bacteria; Biodegradation, Environmental; India; Petroleum; Polycyclic Aromatic Hydrocarbons
PubMed: 29413920
DOI: 10.1016/j.biortech.2018.01.075 -
The Kaohsiung Journal of Medical... Jan 2018Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics... (Comparative Study)
Comparative Study
The clinical characteristics of adult bacterial meningitis caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas species: A clinical comparison with Ps. aeruginosa meningitis.
Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics of 52 cases of Pseudomonas ABM (11 NPAP- and 41 Ps. aeruginosa-related meningitis) collected during a 30-year study period (1986-2015) were included. Eleven cases of NPAP ABM were identified in the literature, and their clinical data were also collected. Therefore, a total of 22 NPAP ABM cases were enrolled. The clinical characteristics of the NPAP ABM and Ps. aeruginosa ABM groups were compared. Of the implicated NPAP strains, Ps. putida and Ps. stutzeri were the most common (7 cases each), followed by Ps. mendocina in 4, Ps. fluorescens in 1, Ps. fulva in 1, Ps. alcaligenes in 1, and Ps. mosselii in 1. Of the 22 cases, 50% (11/22) had an underlying postneurosurgical state. Fever (77.3%, 17/22) and altered consciousness (45.5%, 10/22) were the most common clinical presentations. Antibiotic non-susceptibility was found in 3 strains of Ps. putida and 1 Ps. mosselii strain. Compared to the patients with Ps. aeruginosa ABM, those with NPAP ABM had a higher incidence of spontaneous infections and a better survival rate. In conclusion, although Ps. putida, Ps. stutzeri and Ps. mendocina were the major implicated strains of NPAP ABM, the clinical characteristics of this specific group of ABM demonstrated marked heterogeneity. Even though the cases with NPAP ABM had better therapeutic results than those with Ps. aeruginosa ABM, further large-scale studies are needed to better delineate this specific group of ABM.
Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Confusion; Female; Fever; Humans; Male; Meningitis, Bacterial; Middle Aged; Pseudomonas; Pseudomonas Infections; Pseudomonas aeruginosa; Retrospective Studies; Survival Analysis; Treatment Outcome
PubMed: 29310816
DOI: 10.1016/j.kjms.2017.08.007 -
Water Environment Research : a Research... Dec 2017The goals of this study were to assess the effectiveness of (1) enhancing octachlorinated dibenzo-p-dioxin (OCDD) biodegradation under aerobic conditions by...
The goals of this study were to assess the effectiveness of (1) enhancing octachlorinated dibenzo-p-dioxin (OCDD) biodegradation under aerobic conditions by Pseudomonas mendocina NSYSU (P. Mendocina NSYSU) with the addition of lecithin, and (2) inducing OCDD ring-cleavage genes by pentachlorophenol (PCP) and OCDD addition. P. Mendocina NSYSU could biodegrade OCDD via aerobic cometabolism and lecithin was used as a primary substrate. Approximately 74 and 67% of OCDD biodegradation was observed after 60 days of incubation with lecithin and glucose supplement, respectively. Lecithin was also used as the solubilization additive resulting in OCDD solubilization and enhanced bioavailability of OCDD to P. Mendocina NSYSU. Two intradiol and extradiol ring-cleavage dioxygenase genes (Pmen_0474 and Pmen_2526) were identified from gene analyses. Gene concentration was significantly enhanced after the inducement by PCP and OCDD. Higher gene inducement efficiency was obtained using PCP as the inducer, and Pmen_2526 played a more important role in OCDD biodegradation.
Topics: Anaerobiosis; Biodegradation, Environmental; Dioxins; Environmental Restoration and Remediation; Pentachlorophenol; Pseudomonas mendocina; Soil Pollutants
PubMed: 29166993
DOI: 10.2175/106143017X15054988926415