Abstract:
:Pseudomonas sp. BGI-2 is a psychrotrophic bacterium isolated from the ice sample collected from Batura glacier, Pakistan. This strain produces highly viscous colonies on agar media supplemented with glucose. In this study, we have optimized growth and production of exopolysaccharide (EPS) by the cold-adapted Pseudomonas sp. BGI-2 using different nutritional and environmental conditions. Pseudomonas sp. BGI-2 is able to grow in a wide range of temperatures (4-35°C), pH (5-11), and salt concentrations (1-5%). Carbon utilization for growth and EPS production was extensively studied and we found that glucose, galactose, mannose, mannitol, and glycerol are the preferable carbon sources. The strain is also able to use sugar waste molasses as a growth substrate, an alternative for the relatively expensive sugars for large scale EPS production. Maximum EPS production was observed at 15°C, pH 6, NaCl (10 g L-1), glucose as carbon source (100 g L-1), yeast extract as nitrogen source (10 g L-1), and glucose/yeast extract ratio (10/1). Under optimized conditions, EPS production was 2.01 g L-1, which is relatively high for a Pseudomonas species compared to previous studies using the same method for quantification. High-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) analysis of EPS revealed glucose, galactose, and glucosamine as the main sugar monomers. Membrane protection assay using human RBCs revealed significant reduction in cell lysis (∼50%) in the presence of EPS, suggesting its role in membrane protection. The EPS (5%) also conferred significant cryoprotection for a mesophilic Escherichia coli k12 which was comparable to glycerol (20%). Also, improvement in lipid peroxidation inhibition (in vitro) resulted when lipids from the E. coli was pretreated with EPS. Increased EPS production at low temperatures, freeze thaw tolerance of the EPS producing strain, and increased survivability of E. coli in the presence of EPS as cryoprotective agent supports the hypothesis that EPS production is a strategy for survival in extremely cold environments such as the glacier ice.
journal_name
Front Microbioljournal_title
Frontiers in microbiologyauthors
Ali P,Shah AA,Hasan F,Hertkorn N,Gonsior M,Sajjad W,Chen Fdoi
10.3389/fmicb.2019.03096subject
Has Abstractpub_date
2020-02-11 00:00:00pages
3096issn
1664-302Xjournal_volume
10pub_type
杂志文章abstract::Ralstonia solanacearum is a soil and water-borne pathogen that can infect a wide range of plants and cause the devastating bacterial wilt disease. To successfully colonize a host, R. solanacearum requires the type III secretion system (T3SS), which delivers bacterial effector proteins inside the plant cells. HrpG is a...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2013.00349
更新日期:2013-11-20 00:00:00
abstract::Paraquat is a non-selective fast-acting herbicide used to control weeds in agricultural crops. Many years of extensive use has caused environmental pollution and food toxicity. This agrochemical degrades slowly in nature, adsorbs onto clay lattices, and may require environmental remediation. Studies have shown that bi...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.575361
更新日期:2020-09-15 00:00:00
abstract::Incompatibility group C (IncC) plasmids have received attention due to their broad host range and because they harbor key antibiotic resistance genes. Because these resistance genes can spread from food-producing animals to human, the proliferation of these plasmids represents a public health risk. In this study, a to...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.580960
更新日期:2020-10-27 00:00:00
abstract::Methylketones are broadly distributed in nature and perform a variety of functions. Most microorganisms are thought to produce methylketone by abortive β-oxidation of fatty acid catalytic metabolism. However, two methylketone synthetase genes in wild tomatoes are reported to synthesize methylketone using intermediates...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.01489
更新日期:2019-07-02 00:00:00
abstract::Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2017.01882
更新日期:2017-09-29 00:00:00
abstract::The human immune response that controls Plasmodium infection in the liver and blood stages of the parasite life cycle is composed by both pro- and anti-inflammatory programs. Pro-inflammatory responses primarily mediated by IFN-γ controls the infection, but also induce tolerogenic mechanisms to limit host damage, incl...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00400
更新日期:2020-03-17 00:00:00
abstract::Manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment during infection. Kaposi's sarcoma-associated herpesvirus (KSHV), the primary etiological agent of several human malignancies including Kaposi's sarcoma, and primary effusion lymphoma, encodes several o...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2016.00334
更新日期:2016-03-30 00:00:00
abstract::Heterotrophic bacterioplankton communities play an important role in organic matter processing in the oceans worldwide. In order to investigate the significance of distinct phylogenetic bacterial groups it is not only important to assess their quantitative abundance but also their growth dynamics in relation to the en...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2017.01771
更新日期:2017-09-13 00:00:00
abstract::The present study aimed to understand the biofilm formation mechanism of Propionibacterium acnes by analyzing the components and structure of the biofilms. P. acnes strains were isolated from the surface of explanted cardiac pacemaker devices that exhibited no clinical signs of infection. Culture tests using a simple ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.00182
更新日期:2018-02-14 00:00:00
abstract::The polymyxin antibiotic colistin shows in vitro activity against Stenotrophomonas maltophilia. However, an increased incidence of colistin-resistant isolates has been recently observed. In addition, in vitro evaluation of colistin susceptibility for this organism has been problematic. The aims of this study were to i...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.02871
更新日期:2018-11-22 00:00:00
abstract::In Agrobacterium-mediated transformation (AMT) of plants, a single-strand (ss) T-DNA covalently linked with a VirD2 protein moves through a bacterial type IV secretion channel called VirB/D4. This transport system originates from conjugal plasmid transfer systems of bacteria. The relaxase VirD2 and its equivalent prot...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.00895
更新日期:2018-05-28 00:00:00
abstract::In this article we compare the efficacy of different pharmacological agents (ranitidine, and omeprazole) to support phage transit from stomach to distal portions of the gastrointestinal tract in rats. We show that a temporal modification of environment in the animal stomach may protect Twort-like therapeutic antistaph...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2017.00467
更新日期:2017-03-23 00:00:00
abstract::Two-component systems (TCS) are modular signal transduction pathways that allow cells to adapt to prevailing environmental conditions by modifying cellular physiology. Staphylococcus aureus has 16 TCSs to adapt to the diverse microenvironments encountered during its life cycle, including host tissues and implanted med...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.00342
更新日期:2018-03-07 00:00:00
abstract::The use of excess conventional Phosphorus (P) fertilizers to improve agricultural productivity, in order to meet constantly increasing global food demand, potentially causes surface and ground water pollution, waterway eutrophication, soil fertility depletion, and accumulation of toxic elements such as high concentrat...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2017.00971
更新日期:2017-06-02 00:00:00
abstract::Bacterial species differ greatly in the number and location of the rRNA operons which may be present in the bacterial chromosomes and plasmids. Most bacterial species contain more than one ribosomal RNA operon copy in their genomes, with some species containing up to 15 such copies. We review the number and location o...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01232
更新日期:2018-06-08 00:00:00
abstract::Recent evidence has shown that antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are ubiquitous in natural environments, including sites considered pristine. To understand the origin of ARGs and their dynamics, we must first define their actual presence in the natural bacterial assemblage. Her...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2013.00102
更新日期:2013-04-30 00:00:00
abstract::Salmonellosis is one of the most common causes of foodborne infection and a leading cause of human gastroenteritis. Throughout the last decade, Salmonella enterica serotype Typhimurium (ST) has shown an increase report with the simultaneous emergence of multidrug-resistant isolates, as phage type DT104. Therefore, to ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2017.02587
更新日期:2017-12-22 00:00:00
abstract::Background: The gut microbiota is increasingly recognized as playing an important role in the development of obesity, but the influence of gender remains elusive. Using a large cohort of Chinese adults, our study aimed to identify differences in gut microbiota as a function of body mass index (BMI) and investigate gen...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01250
更新日期:2018-06-22 00:00:00
abstract::Two entomopathogenic bacteria, Xenorhabdus and Photorhabdus, are known to be able to synthesize and secrete eicosanoid biosynthesis inhibitors (EIBs) that can enhance pathogenicity of Bacillus thuringiensis (Bt) against different target insects. Such enhancements can be explained by the suppression of immune responses...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00528
更新日期:2020-03-27 00:00:00
abstract::Porcine strains of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) have been recognized in many countries and have been shown to be able to cause human infection. Resistance to non-beta lactam antibiotics has been reported but non-susceptibility to vancomycin, which is known to occur in huma...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2013.00316
更新日期:2013-10-25 00:00:00
abstract::Omeprazole was shown to improve the anti-cancer effects of the nucleoside analogue 5-fluorouracil. Here, we combined omeprazole with the antiviral nucleoside analogues ribavirin and acyclovir. Omeprazole did not affect the antiviral effects of ribavirin in non-toxic concentrations up to 80 μg/mL but increased the acyc...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.02790
更新日期:2019-12-03 00:00:00
abstract::Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is an adaptive immune system that resists foreign genes through nuclease targeting in bacteria and archaea. In this study, we analyzed 68 strains of Lactobacillus casei group from the NCBI GenBank database, and bioinformatic tools were used to investig...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00624
更新日期:2020-04-08 00:00:00
abstract::[This corrects the article DOI: 10.3389/fmicb.2019.00159.]. ...
journal_title:Frontiers in microbiology
pub_type: 已发布勘误
doi:10.3389/fmicb.2019.00518
更新日期:2019-03-26 00:00:00
abstract::The Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is a notorious Rutaceae plant pest. Frequent and extensive use of pesticides has resulted in severe insecticide resistance in ACP populations. Fully understanding the mechanism of ACP resistance to pesticides is vital for us to control ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.522164
更新日期:2020-12-16 00:00:00
abstract::Bacteriocins are proteinaceous antibacterial compounds, produced by diverse bacteria, which have been successfully used as: (i) food biopreservative; (ii) anti-biofilm agents; and (iii) additives or alternatives to the currently existing antibiotics, to minimize the risk of emergence of resistant strains. However, the...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2016.01385
更新日期:2016-09-16 00:00:00
abstract::Symbioses in marine sponges involve diverse consortia of microorganisms that contribute to the health and ecology of their hosts. The microbial communities of 13 taxonomically diverse Great Barrier Reef (GBR) sponge species were assessed by DGGE and 16S rRNA gene sequencing to determine intra and inter species variati...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2012.00444
更新日期:2013-01-18 00:00:00
abstract::Streptomyces clavuligerus F613-1 produces a clinically important β-lactamase inhibitor, clavulanic acid (CA). Although the biosynthesis pathway of CA has essentially been elucidated, the global regulatory mechanisms of CA biosynthesis remain unclear. The paired genes cagS and cagR, which are annotated, respectively, a...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.00244
更新日期:2019-02-14 00:00:00
abstract::Coinfection by bovine respiratory syncytial virus (BRSV) and Pasteurella multocida (PM) frequently has been observed in cattle that develop severe pneumonia. We recently reported that BRSV infection significantly increased PM adherence to bovine lower respiratory tract epithelial cells. However, the molecular mechanis...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.01676
更新日期:2020-07-31 00:00:00
abstract::The alarming spread of bacterial resistance to traditional antibiotics has warranted the study of alternative antimicrobial agents. Quorum sensing (QS) is a chemical cell-to-cell communication mechanism utilized by bacteria to coordinate group behaviors and establish infections. QS is integral to bacterial survival, a...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.00189
更新日期:2015-03-10 00:00:00
abstract::Six aerobic alkanotrophs (organism that can metabolize alkanes as their sole carbon source) isolated from deep-sea hydrothermal vents were characterized using the radical clock substrate norcarane to determine the metalloenzyme and reaction mechanism used to oxidize alkanes. The organisms studied were Alcanivorax sp. ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2013.00109
更新日期:2013-05-10 00:00:00