Displaying publications 181 - 200 of 366 in total

Abstract:
Sort:
  1. Norizan SN, Yin WF, Chan KG
    Sensors (Basel), 2013;13(4):5117-29.
    PMID: 23598500 DOI: 10.3390/s130405117
    Quorum sensing enables bacteria to control the gene expression in response to the cell density. It regulates a variety of bacterial physiological functions such as biofilm formation, bioluminescence, virulence factors and swarming which has been shown contribute to bacterial pathogenesis. The use of quorum sensing inhibitor would be of particular interest in treating bacterial pathogenicity and infections. In this work, we have tested caffeine as quorum sensing inhibitor by using Chromobacterium violaceum CV026 as a biosensor. We verified that caffeine did not degrade the N-acyl homoserine lactones tested. In this work, it is shown that caffeine could inhibit N-acyl homoserine lactone production and swarming of a human opportunistic pathogen, namely Pseudomonas aeruginosa PA01. To the best of our knowledge, this is the first documentation providing evidence on the presence of anti-quorum sensing activity in caffeine. Our work will allow caffeine to be explored as anti-infective drugs.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*
  2. Tan LY, Yin WF, Chan KG
    Sensors (Basel), 2013;13(3):3975-85.
    PMID: 23519352 DOI: 10.3390/s130303975
    Various parts of Piper nigrum, Piper betle and Gnetum gnemon are used as food sources by Malaysians. The purpose of this study is to examine the anti-quorum sensing (anti-QS) properties of P. nigrum, P. betle and G. gnemon extracts. The hexane, chloroform and methanol extracts of these plants were assessed in bioassays involving Pseudomonas aeruginosa PA01, Escherichia coli [pSB401], E. coli [pSB1075] and Chromobacterium violaceum CV026. It was found that the extracts of these three plants have anti-QS ability. Interestingly, the hexane, chloroform and methanol extracts from P. betle showed the most potent anti-QS activity as judged by the bioassays. Since there is a variety of plants that serve as food sources in Malaysia that have yet to be tested for anti-QS activity, future work should focus on identification of these plants and isolation of the anti-QS compounds.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects
  3. See Too WC, Few LL
    World J Microbiol Biotechnol, 2010 Jul;26(7):1251-9.
    PMID: 24026930 DOI: 10.1007/s11274-009-0295-9
    Psychrophiles are organisms that thrive in cold environments. One of the strategies for their cold adaptation is the ability to synthesize cold-adapted enzymes. These enzymes usually display higher catalytic efficiency and thermolability at lower temperatures compared to their mesophilic and thermophilic counterparts. In this work, a psychrophilic bacterial isolate codenamed π9 was selected for the cloning of the gene encoding triose phosphate isomerase (TIM), an enzyme in the glycolytic pathway. Based on 16S rRNA gene sequence analysis, this isolate was identified as a species of the genus Pseudomonas under the P. fluorescens group. The cloning of a 816 bp fragment of TIM gene which covers the 756 bp open reading frame was achieved by a combination of degenerate and splinkerette PCRs. The partial sequence of this gene was first PCR amplified by using degenerate primers and the flanking sequences were subsequently amplified by splinkerette PCR technique. Amino acid sequence of the cloned TIM was 97% identical to TIM from Pseudomonas fluorescens and shared 51% identity with the TIM from psychrophilic Vibrio sp. This work demonstrated the use of multiple PCR techniques to clone a gene without prior knowledge of its sequence. The cloning of the TIM gene by PCR was more rapid and cost effective compared to the traditional genomic library construction and screening method. Homology model of the TIM protein in this study was generated based on Escherichia coli TIM crystal structure. The model could serve as a hypothetical TIM structure from a psychrophilic microorganism for further investigation into areas that showed deviations from the known mesophilic TIM structures.
    Matched MeSH terms: Pseudomonas; Pseudomonas fluorescens
  4. Rahman RN, Ghaza FM, Salleh AB, Basri M
    J Microbiol, 2006 Jun;44(3):354-9.
    PMID: 16820766
    This study examined the capacity of immobilized bacteria to degrade petroleum hydrocarbons. A mixture of hydrocarbon-degrading bacterial strains was immobilized in alginate and incubated in crude oil-contaminated artificial seawater (ASW). Analysis of hydrocarbon residues following a 30-day incubation period demonstrated that the biodegradation capacity of the microorganisms was not compromised by the immobilization. Removal of n-alkanes was similar in immobilized cells and control cells. To test reusability, the immobilized bacteria were incubated for sequential increments of 30 days. No decline in biodegradation capacity of the immobilized consortium of bacterial cells was noted over its repeated use. We conclude that immobilized hydrocarbon-degrading bacteria represent a promising application in the bioremediation of hydrocarbon-contaminated areas.
    Matched MeSH terms: Pseudomonas aeruginosa/metabolism
  5. Wahab HA, Ahmad Khairudin NB, Samian MR, Najimudin N
    BMC Struct Biol, 2006;6:23.
    PMID: 17076907
    Polyhydroxyalkanoates (PHA), are biodegradable polyesters derived from many microorganisms such as the pseudomonads. These polyesters are in great demand especially in the packaging industries, the medical line as well as the paint industries. The enzyme responsible in catalyzing the formation of PHA is PHA synthase. Due to the limited structural information, its functional properties including catalysis are lacking. Therefore, this study seeks to investigate the structural properties as well as its catalytic mechanism by predicting the three-dimensional (3D) model of the Type II Pseudomonas sp. USM 4-55 PHA synthase 1 (PhaC1P.sp USM 4-55).
    Matched MeSH terms: Pseudomonas/enzymology*
  6. Yoga R, Khairul A, Sunita K, Suresh C
    Med J Malaysia, 2006 Feb;61 Suppl A:14-6.
    PMID: 17042222
    Infection plays a pivotal role in enhancing a diabetic foot at risk toward amputation. Effective antibiotic therapy against the offending pathogens is an important component of treatment of diabetic foot infections. Recognition of the pathogen is always difficult as the representative deep tissue sample for culture is surrounded by ulcer surface harbouring colonies of organisms frequently labelled as skin commensals. The emergent of resistant strains represents a compounding problem standing against efforts to prevent amputation. This study was undertaken to identify the pathogens associated with diabetic foot infection in terms of their frequency and sensitivity against certain commonly used antibiotics. Forty-four consecutive patients with open diabetic foot infections had wound swab taken for culture and sensitivity testing. Cultures positive were observed in 89% of the cases with Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeroginosa encountered in 20%, 14% and 14% of cases respectively. Mixed growths were isolated in 6% of cultures. All Staphylcoccus aureus isolates were resistant to Penicillin but 80% were sensitive to Erythromycin and Co-trimoxazole. Klebsiella pneumoniae isolates were sensitive to Methicillin and Gentamycin in 80% and 60% of cases respectively, and resistant to Ampicillin and Ceftazidime in 83% and 50% respectively. All Pseudomonas aeroginosa isolates were sensitive to Amikacin and Ciprofloxacin but 50% were resistant to Gentamycin. There was no single antibiotic possessing good coverage for all common organisms isolated from diabetic foot lesions. Staphylococcus aureus remains the predominant cause of diabetic foot infections followed by Klebsiela pneumonia and Pseudomonas aeroginosa. Most infections are monomicrobial. The emergence of multiresistant organisms is a worrying feature in diabetic foot infections.
    Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification*
  7. Rahman RN, Baharum SN, Basri M, Salleh AB
    Anal Biochem, 2005 Jun 15;341(2):267-74.
    PMID: 15907872
    An organic solvent-tolerant S5 lipase was purified by affinity chromatography and anion exchange chromatography. The molecular mass of the lipase was estimated to be 60 kDa with 387 purification fold. The optimal temperature and pH were 45 degrees C and 9.0, respectively. The purified lipase was stable at 45 degrees C and pH 6-9. It exhibited the highest stability in the presence of various organic solvents such as n-dodecane, 1-pentanol, and toluene. Ca2+ and Mg2+ stimulated lipase activity, whereas EDTA had no effect on its activity. The S5 lipase exhibited the highest activity in the presence of palm oil as a natural oil and triolein as a synthetic triglyceride. It showed random positional specificity on the thin-layer chromatography.
    Matched MeSH terms: Pseudomonas/enzymology*
  8. Lim SP, Gan SN, Tan IK
    Appl Biochem Biotechnol, 2005 Jul;126(1):23-33.
    PMID: 16014996
    Bacterial polyhydroxyalkanoates (PHAs) are perceived to be a suitable alternative to petrochemical plastics because they have similar material properties, are environmentally degradable, and are produced from renewable resources. In this study, the in situ degradation of medium-chain-length PHA (PHAMCL) films in tropical forest and mangrove soils was assessed. The PHAMCL was produced by Pseudomonas putida PGA1 using saponified palm kernel oil (SPKO) as the carbon source. After 112 d of burial, there was 16.7% reduction in gross weight of the films buried in acidic forest soil (FS), 3.0% in the ones buried in alkaline forest soil by the side of a stream (FSst) and 4.5% in those buried in mangrove soil (MS). There was a slight decrease in molecular weight for the films buried in FS but not for the films buried in FSst and in MS. However, no changes were observed for the melting temperature, glass transition temperature, monomer compositions, structure, and functional group analyses of the films from any of the burial sites during the test period. This means that the integral properties of the films were maintained during that period and degradation was by surface erosion. Scanning electron microscopy of the films from the three sites revealed holes on the film surfaces which could be attributed to attack by microorganisms and bigger organisms such as detritivores. For comparison purposes, films of polyhydroxybutyrate (PHB), a short-chain-length PHA, and polyethylene (PE) were buried together with the PHAMCL films in all three sites. The PHB films disintegrated completely in MS and lost 73.5% of their initial weight in FSst, but only 4.6% in FS suggesting that water movement played a major role in breaking up the brittle PHB films. The PE films did not register any weight loss in any of the test sites.
    Matched MeSH terms: Pseudomonas putida/metabolism*
  9. Agamuthu P, Faizura PN
    Waste Manag Res, 2005 Apr;23(2):95-100.
    PMID: 15864950
    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.
    Matched MeSH terms: Pseudomonas aeruginosa/metabolism*
  10. Chan XY, Chua KO, How KY, Yin WF, Chan KG
    ScientificWorldJournal, 2014;2014:930727.
    PMID: 25436236 DOI: 10.1155/2014/930727
    Most Pseudomonas putida strains are environmental microorganisms exhibiting a wide range of metabolic capability but certain strains have been reported as rare opportunistic pathogens and some emerged as multidrug resistant P. putida. This study aimed to assess the drug resistance profile of, via whole genome analysis, P. putida strain T2-2 isolated from oral cavity. At the same time, we also compared the nonenvironmental strain with environmentally isolated P. putida. In silico comparative genome analysis with available reference strains of P. putida shows that T2-2 has lesser gene counts on carbohydrate and aromatic compounds metabolisms, which suggested its little versatility. The detection of its edd gene also suggested T2-2's catabolism of glucose via ED pathway instead of EMP pathway. On the other hand, its drug resistance profile was observed via in silico gene prediction and most of the genes found were in agreement with drug-susceptibility testing in laboratory by automated VITEK 2. In addition, the finding of putative genes of multidrug resistance efflux pump and ATP-binding cassette transporters in this strain suggests a multidrug resistant phenotype. In summary, it is believed that multiple metabolic characteristics and drug resistance in P. putida strain T2-2 helped in its survival in human oral cavity.
    Matched MeSH terms: Pseudomonas putida/genetics*
  11. Nik Zuraina NMN, Mohamad S, Hasan H, Goni MD, Suraiya S
    Pathog Glob Health, 2023 Feb;117(1):63-75.
    PMID: 35331083 DOI: 10.1080/20477724.2022.2028378
    Respiratory tract infections (RTIs), including pneumonia and pulmonary tuberculosis, are among the leading causes of death worldwide. The use of accurate diagnostic tests is crucial to initiate proper treatment and therapy to reduce the mortality rates for RTIs. A PCR assay for simultaneous detection of six respiratory bacteria: Haemophilus influenzae, Klebsiella pneumoniae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae, was developed in our lab. The current study aimed to evaluate the performance of this assay along with the retrospective surveillance of respiratory pathogens at a teaching hospital in Kelantan, Malaysia. Leftover sputa (n = 200) from clinical laboratories were collected and undergone DNA template preparation for PCR analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the PCR assay were determined in comparison with the gold standard sputum culture. Overall, the accuracy performance of this assay was 94.67% (95% CI: 90.87% to 97.21%) with sensitivity, specificity, PPV and NPV of 100%, 91.67%, 87.1% and 100%, respectively. Based on the organisms detected from sputa, K. pneumoniae ranked as the top isolate (n = 48), followed by P. aeruginosa (n = 13) and H. influenzae (n = 10). Surveillance among the patients showed that the associations of bacterial positive with gender and means of acquisition were found significant (p values = 0.049 and 0.001, respectively). Besides the promising performance of this ready-to-use molecular-based assay for the rapid detection of selected bacteria pathogens, this study also highlighted significant spread of K. pneumoniae RTIs in the community.
    Matched MeSH terms: Pseudomonas aeruginosa/genetics
  12. Prathiksha D, Rajeshkumar S, Lingaraj J, Pradeep M
    Med J Malaysia, 2025 Jan;80(Suppl 1):1-6.
    PMID: 39773934
    INTRODUCTION: Silver nanoparticles (AgNPs) are effective against almost all kinds of pathogenic organisms. The green synthesis of AgNPs utilizing extracts from medicinal plants is being researched to examine the therapeutic advantages of AgNPs because the chemical production of AgNPs is more toxic. In this study, the stem extract of Ocimum Gratissimum (OG) also known as Karunthulasi or wild basil for green synthesis of AgNPs and evaluating their antiinflammatory and antimicrobial effects.

    MATERIALS AND METHODS: The produced nanoparticles were characterized using UV-visible spectroscopy. The Bovine Serum Assay (BSA) and Egg Albumin (EA) assays were used to assess the anti-inflammatory effects. The protein denaturation of AgNPs was calculated and compared to a standard to determine the anti-inflammatory activity of green synthesized AgNPs. Using varying concentrations of OGmediated AgNPs in Mueller Hinton Agar (MHA), the antimicrobial effects of OG have been investigated against E. coli, S. aureus, and Pseudomonas sp. Additionally, by measuring optical density, the time-kill curve analysis for E. Coli and S. Aureus has been examined from one hour for up to five hours.

    RESULTS: The green synthesized AgNPs were developed successfully using a plant Ocimum gratissimum. The synthesized AgNPs exhibited a maximum absorption peak at 440 nm and SEM analysis revealed that the synthesized AgNPs were spherical and oval. The result findings of the anti-inflammatory activity reveal that AgNPs have great potential when compared to the standard. At the concentration of 50 μg/mL, AgNPs exhibit 76% in BSA assay and 74% in EA assay, where the standard shows 80% inhibition. The antimicrobial activity showed a zone of inhibition around 19mm for E. coli and a 20mm zone of inhibition for S. aureus and Pseudomonas sp., which shows the efficacy of AgNPs. The time-kill assay shows that the optical density of E. coli and S. aureus was reduced to 0.1 after 5 hours of incubation, which shows the potential of green synthesized AgNPs.

    CONCLUSION: OG-mediated AgNPs have both antiinflammatory and antimicrobial effects. Anti-inflammatory effects are better when compared to standard drugs. Antimicrobial effects are better for Gram-negative bacteria.

    Matched MeSH terms: Pseudomonas/drug effects
  13. Goh SM, Dassanayake MK, Foan CC, Wiart C, Symonds R, Khoo TJ, et al.
    Microb Pathog, 2025 Jan;198:107134.
    PMID: 39566830 DOI: 10.1016/j.micpath.2024.107134
    BACKGROUND AND OBJECTIVES: Plants contain a wide variety of bioactive compounds, which have attracted the interest of researchers in finding novel sources of natural medicine. In the following paper, we aim to evaluate the antibacterial potential of extract fractions associated with Parkia speciosa pods and beans against human pathogenic bacteria.

    METHODS: Antimicrobial activity was determined with disc diffusion and broth microdilution assays against eight skin colonising microorganisms including Staphylococcus aureus, Staphylococcus epidermidis, Salmonella enterica, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia followed by further fractionation of the pods ethyl acetate fraction by column chromatography along with preparative thin-layer chromatography. Quantification of bacterial death mechanism was elucidated by the measurement of hole size in cell wall that has been induced by extract constituents via field-emission scanning electron microscopy (FESEM).

    RESULTS: Four fractions showed significant antimicrobial activity against the six microorganisms tested (p 

    Matched MeSH terms: Pseudomonas aeruginosa/drug effects
  14. Faris Taufeq FY, Nordin ML, Katas H
    PLoS One, 2025;20(9):e0327375.
    PMID: 40911569 DOI: 10.1371/journal.pone.0327375
    Poor vascularization and infections hinder diabetic wound healing, posing challenges in therapy development. A multi-action approach incorporating Dicer-substrate small interfering RNA (DsiRNA) against the prostaglandin transporter (PGT) gene and gold nanoparticles (AuNPs) into a Pluronic F-127 (PF127) gel was developed. This study aimed to upscale AuNP biosynthesis using Lignosus rhinocerotis (tiger milk mushroom, TMM) extract and chitosan as stabilizers. Response Surface Methodology (RSM) optimized the synthesis with 0.6 mL chloroauric acid (HAuCl₄) and 4.4 mL TMM extract, producing upscaled AuNPs (152.93 ± 1.56 nm, + 30 mV) with a Surface Plasmon Resonance peak at 538 nm. Both lab-scale and upscaled AuNPs exhibited antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa (MIC: 250 μg/mL). The gel formulation demonstrated favourable gelling properties for wound dressing. A 28-day toxicity study confirmed no adverse effects on haematology, biochemistry, or organ morphology. In diabetic Wistar rats, only the wounds treated with Pluronic gels containing AuNPs-DsiRNA showed no signs of infection, while the other groups exhibited infection and pustules in the wounded areas. These findings highlight the potential of AuNP-DsiRNA thermoresponsive gels as an innovative, safe, and effective therapy for diabetic wound healing.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects
  15. Al-Ameryeen HA, Tarawneh MAA, Garalleh HA, Yu LJ
    ScientificWorldJournal, 2026;2026(1).
    PMID: 42952129 DOI: 10.1155/tswj/7155762
    In this work, the silver nanoparticles (AgNPs) were synthesized by an eco-friendly biosynthesis using Bougainvillea spectabilis leaf extract, which acts as reducing and capping agent. The AgNPs were analyzed using UV spectroscopy, FTIR spectroscopy, XRD, and scanning electron SEM. From the UV-visible spectral analysis we recorded an SPR peak at 415 nm, which is characteristic of spherical AgNPs. The results obtained from FTIR suggest the potential role of biomolecules in reducing Ag+ and the capping of AgNPs. The XRD pattern demonstrated the FCC crystalline of metallic silver, showing average crystallite size ranging from 30 to 50 nm. Results obtained from the SEM revealed the morphology and size distribution of synthesized AgNPs. From the images obtained, we determined a spherical morphology with an estimated size distribution measuring 50-200 nm. Furthermore, the AgNPs exhibited strong antibacterial behavior against tested bacterial strains, namely Staphylococcus aureus and Pseudomonas aeruginosa. These results highlight that the silver NPs are sustainable for potential biomedical and environmental applications.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects
  16. Harun SN, Holford NHG, Grimwood K, Wainwright CE, Hennig S, Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) study group
    Thorax, 2019 08;74(8):740-748.
    PMID: 31203197 DOI: 10.1136/thoraxjnl-2018-211548
    BACKGROUND: While Aspergillus detection rates in adults, adolescents and older children with cystic fibrosis (CF) have increased, the risk of acquiring this fungal pathogen in young children is unknown.

    AIM: To determine the risk and explanatory factors of acquiring Aspergillus in children with CF by age 5 years.

    METHODS: Cross-sectional analysis of clinical, bronchoalveolar lavage and treatment data from the Australasian Cystic Fibrosis Bronchoalveolar Lavage study was used to identify predictive factors for detecting Aspergillus at age 5 years. A parametric repeated time-to-event model quantitatively described the risk and factors associated with acquiring Aspergillus and Pseudomonas aeruginosa from birth until age 5 years.

    RESULTS: Cross-sectional analysis found that the number of P. aeruginosa eradication courses increased the odds of detecting Aspergillus at age 5 years (OR 1.61, 95% CI 1.23 to 2.12). The median (IQR) age for the first P. aeruginosa positive culture was 2.38 (1.32-3.79) years and 3.69 (1.68-4.74) years for the first Aspergillus positive culture. The risk of P. aeruginosa and Aspergillus events changes with time after the first year of study entry. It also decreases for P. aeruginosa after completing P. aeruginosa eradication (HR 0.15, 95% CI 0.00 to 0.79), but increases for Aspergillus events (HR 2.75, 95% CI 1.45 to 5.41). The risk of acquiring both types of events increases after having had a previous event.

    CONCLUSION: In young children with CF, completing P. aeruginosa eradication therapy and previous Aspergillus events are associated with increased risk of acquiring Aspergillus.

    Matched MeSH terms: Pseudomonas aeruginosa*; Pseudomonas Infections/drug therapy*; Pseudomonas Infections/epidemiology*
  17. Ganasen M, Yaacob N, Rahman RN, Leow AT, Basri M, Salleh AB, et al.
    Int J Biol Macromol, 2016 Nov;92:1266-1276.
    PMID: 27506122 DOI: 10.1016/j.ijbiomac.2016.06.095
    Lipolytic enzymes with cold adaptation are gaining increasing interest due to their biotechnological prospective. Previously, a cold adapted family I.3 lipase (AMS8 lipase) was isolated from an Antarctic Pseudomonas. AMS8 lipase was largely expressed in insoluble form. The refolded His-tagged recombinant AMS8 lipase was purified with 23.0% total recovery and purification factor of 9.7. The purified AMS8 lipase migrated as a single band with a molecular weight approximately 65kDa via electrophoresis. AMS8 lipase was highly active at 30°C at pH 10. The half-life of AMS8 lipase was reported at 4 and 2h under the incubation of 30 and 40°C, respectively. The lipase was stable over a broad range of pH. It showed enhancement effect in its relative activity under the presence of Li(+), Na(+), K(+), Rb(+) and Cs(+) after 30min treatment. Heavy metal ions such as Cu(2+), Fe(3+) and Zn(2+) inhibited AMS8 activity. This cold adapted alkalophilic AMS lipase was also active in various organic solvent of different polarity. These unique properties of this biological macromolecule will provide considerable potential for many biotechnological applications and organic synthesis at low temperature.
    Matched MeSH terms: Pseudomonas/classification; Pseudomonas/enzymology*; Pseudomonas/growth & development; Pseudomonas/chemistry
  18. Rahman RN, Baharum SN, Salleh AB, Basri M
    J Microbiol, 2006 Dec;44(6):583-90.
    PMID: 17205035
    In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of production were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions (Mg2+) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, Na+, was found to stimulate the production of S5 lipase.
    Matched MeSH terms: Pseudomonas/classification; Pseudomonas/enzymology*; Pseudomonas/genetics; Pseudomonas/growth & development
  19. Romero M, Silistre H, Lovelock L, Wright VJ, Chan KG, Hong KW, et al.
    Nucleic Acids Res, 2018 Jul 27;46(13):6823-6840.
    PMID: 29718466 DOI: 10.1093/nar/gky324
    Pseudomonads typically carry multiple non-identical alleles of the post-transcriptional regulator rsmA. In Pseudomonas aeruginosa, RsmN is notable in that its structural rearrangement confers distinct and overlapping functions with RsmA. However, little is known about the specificities of RsmN for its target RNAs and overall impact on the biology of this pathogen. We purified and mapped 503 transcripts directly bound by RsmN in P. aeruginosa. About 200 of the mRNAs identified encode proteins of demonstrated function including some determining acute and chronic virulence traits. For example, RsmN reduces biofilm development both directly and indirectly via multiple pathways, involving control of Pel exopolysaccharide biosynthesis and c-di-GMP levels. The RsmN targets identified are also shared with RsmA, although deletion of rsmN generally results in less pronounced phenotypes than those observed for ΔrsmA or ΔrsmArsmNind mutants, probably as a consequence of different binding affinities. Targets newly identified for the Rsm system include the small non-coding RNA CrcZ involved in carbon catabolite repression, for which differential binding of RsmN and RsmA to specific CrcZ regions is demonstrated. The results presented here provide new insights into the intricacy of riboregulatory networks involving multiple but distinct RsmA homologues.
    Matched MeSH terms: Pseudomonas aeruginosa/genetics*; Pseudomonas aeruginosa/metabolism
  20. Martla M, Umsakul K, Sudesh K
    J Basic Microbiol, 2018 Nov;58(11):977-986.
    PMID: 30095175 DOI: 10.1002/jobm.201800279
    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 (Mw ) and number average molecular weight (Mn ) of the biologically extracted PHA were higher than that from the chloroform extraction with comparable melting temperature (Tm ) 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.
    Matched MeSH terms: Pseudomonas mendocina/growth & development; Pseudomonas mendocina/metabolism*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links