Displaying publications 61 - 80 of 115 in total

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  1. Fulltext The Binding Efficiency and Interaction of Lactobacillus casei Shirota Toward Aflatoxin B1
    Liew WP, Nurul-Adilah Z, Than LTL, Mohd-Redzwan S
    Front Microbiol, 2018;9:1503.
    PMID: 30042748 DOI: 10.3389/fmicb.2018.01503
    The use of probiotic as dietary approach to prevent exposure to food contaminant, aflatoxin B1 (AFB1) has greatly increased. Several studies found that AFB1 binding to the bacterial cell wall is strain-specific. Moreover, the interaction between AFB1 and bacterial cell wall is not well-understood, thus warrants further investigation. This research was conducted to assess the ability of Lactobacillus casei Shirota (Lcs) to bind AFB1 at different concentrations and to determine AFB1 binding efficiency of different Lcs cell components including live cell, heat-treated, and cell wall. In addition, the interaction between AFB1 and Lcs was also evaluated via scanning electron microscopy (SEM) and through an animal study. The binding of AFB1 by all Lcs cell components depends on the concentration of available AFB1. Among all Lcs cell components, the live Lcs cells exhibited the highest binding efficiency (98%) toward AFB1. Besides, the SEM micrographs showed that AFB1 induced structural changes on the bacterial cell surface and morphology including rough and irregular surface along with a curve rod-shaped. In vivo experiment revealed that Lcs is capable to neutralize the toxicity of AFB1 on body weight and intestine through the binding process. The animal's growth was stunted due to AFB1 exposure, however, such effect was significantly (p < 0.05) alleviated by Lcs. This phenomenon can be explained by a significant (p < 0.05) decreased level of blood serum AFB1 by Lcs (49.6 ± 8.05 ng/mL) compared to AFB1-exposed rats without treatment (88.12 ± 10.65 ng/mL). Taken together, this study highlights the potential use of Lcs as a preventive agent against aflatoxicosis via its strong binding capability.
    Matched MeSH terms: Cell Wall
  2. Improved nucleic acid extraction protocols for Ganoderma boninense, G. miniatocinctum and G. tornatum
    Nagappan J, Chin CF, Angel LPL, Cooper RM, May ST, Low EL
    Biotechnol Lett, 2018 Dec;40(11-12):1541-1550.
    PMID: 30203158 DOI: 10.1007/s10529-018-2603-7
    The first and most crucial step of all molecular techniques is to isolate high quality and intact nucleic acids. However, DNA and RNA isolation from fungal samples are usually difficult due to the cell walls that are relatively unsusceptible to lysis and often resistant to traditional extraction procedures. Although there are many extraction protocols for Ganoderma species, different extraction protocols have been applied to different species to obtain high yields of good quality nucleic acids, especially for genome and transcriptome sequencing. Ganoderma species, mainly G. boninense causes the basal stem rot disease, a devastating disease that plagues the oil palm industry. Here, we describe modified DNA extraction protocols for G. boninense, G. miniatocinctum and G. tornatum, and an RNA extraction protocol for G. boninense. The modified salting out DNA extraction protocol is suitable for G. boninense and G. miniatocinctum while the modified high salt and low pH protocol is suitable for G. tornatum. The modified DNA and RNA extraction protocols were able to produce high quality genomic DNA and total RNA of ~ 140 to 160 µg/g and ~ 80 µg/g of mycelia respectively, for Single Molecule Real Time (PacBio Sequel® System) and Illumina sequencing. These protocols will benefit those studying the oil palm pathogens at nucleotide level.
    Matched MeSH terms: Cell Wall
  3. Fulltext Mechanism of biosorption of Pb (ii) and Cu (ii) ions using dead biomass of Fusarium equiseti strain UMAS and Penicillium citrinum strain UMAS B2
    Wahab Abideen Akinkunmi, Awang Ahmad Sallehin Awang Husaini, Azham Zulkharnain, Tay, Meng Guan, Hairul Azman Roslan
    Journal of Biochemistry, Microbiology and Biotechnology, 2016;4(2):1-6.
    MyJurnal
    Filamentous fungi such as Fusarium equiseti KR706303 and Penicillium citrinum KR706304
    are capable of sequestering heavy metals from aqueous solutions. In the present study, the role
    play by various functional groups present in the cell wall of F. equiseti KR706303 and P.
    citrinum KR706304 during lead and copper ions biosorption was investigated. The fungal
    biomass was chemically treated to modify the functional groups present in their cell wall. These
    modifications were studied through biosorption experiments. It was found that an esterification
    of the carboxyl and phosphate groups, methylation of the amine groups and extraction of lipids
    significantly decrease the biosorption of both lead and copper ions studied. Therefore, the
    carbonyl, hydroxyl and amide groups were recognized as important in the biosorption of metal
    ions by the tested fungi. The study showed that there was no release of any metal ions from the
    biomass after biosorption, indicating that ion exchange may not be a key mechanism in the
    biosorption of lead and copper ions by these fungi but complexation of metal ions within the
    fungal cell wall.
    Matched MeSH terms: Cell Wall
  4. Fulltext Cytotoxicity and antifungal properties of hydroxychavicol against trichophyton rubrum
    Ridzuan, P.M., Nasir Mohamad, Salwani Ismail, Nor Iza A. Rahman, Hairul Aini H., Zunariah, B., et al.
    International Medical Journal Malaysia, 2018;17(1):31-36.
    MyJurnal
    Hydroxychavicol (HC) is a phenolic compound of betel leaf (Piper betle). It has been reported to have antifungal properties against dermatophytes including T. rubrum. The aim of this study was to identify the effects of the HC against T. rubrum. Broth dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the HC. Microscopic study of the treated fungus was done by transmission electron microscope (TEM). Cytotoxicity study using pre-adipocyte (3T3-L1) cell line was performed by means of MTT cell proliferation assay. The MIC and MFC results of the HC were both 0.49 µg/ml. Microscopic study revealed the destruction of the fungal cell wall and organelles. Cytotoxicity study showed HC to be non-toxic to the tested human cell line. In conclusion, HC may potentially be used as an alternative therapeutic agent against T. rubrum infections.
    Matched MeSH terms: Cell Wall
  5. Fulltext Cell surface proteins of cryptococcus neoformans mediate adherence and internalisation into mammalian cells
    Choo, K.K., Chin, V.K., Chong, P.P., Ho, S.H., Yong, V.C.
    JUMMEC, 2019;22(2):24-30.
    MyJurnal
    Cryptococcus neoformans is an encapsulated fungal pathogen that causes severe disease primarily in
    immunocompromised patients. Adherence and internalisation of microbial pathogens into host cells often
    begin with engagement of microbes to the surface receptors of host. However, the mechanisms involved
    remain poorly understood. In this study, we investigated the association of cell surface determinants of C.
    neoformans with mammalian cells. Our results showed that treatment with trypsin, but not paraformaldehyde
    or heat killing, could reduce host-cryptococci interaction, suggesting the involvement of cell surface proteins
    (CSPs) of C. neoformans in the interaction. We extended our investigations to determine the roles of CSPs
    during cryptococci-host cells interaction by extracting and conjugating CSPs of C. neoformans to latex beads.
    Conjugation of CSPs with both encapsulated and acapsular C. neoformans increased the association of latex
    beads with mammalian alveolar epithelial cells, alveolar macrophages and monocyte-derived macrophages.
    Further examination on the actin organisation of the host cells implied the involvement of actin-dependent
    phagocytosis in the internalisation of C. neoformans in CSP-conjugated latex beads. We hypothesised that
    CSPs present on the cell wall of C. neoformans mediate the adherence and actin-dependent phagocytosis
    of cryptococci by mammalian cells. Our results warrant further studies on the exact role of CSPs in the
    pathogenesis of cryptococcosis.
    Matched MeSH terms: Cell Wall
  6. Fulltext Current Pretreatment/Cell Disruption and Extraction Methods Used to Improve Intracellular Lipid Recovery from Oleaginous Yeasts
    Zainuddin MF, Fai CK, Ariff AB, Rios-Solis L, Halim M
    Microorganisms, 2021 Jan 27;9(2).
    PMID: 33513696 DOI: 10.3390/microorganisms9020251
    The production of lipids from oleaginous yeasts involves several stages starting from cultivation and lipid accumulation, biomass harvesting and finally lipids extraction. However, the complex and relatively resistant cell wall of yeasts limits the full recovery of intracellular lipids and usually solvent extraction is not sufficient to effectively extract the lipid bodies. A pretreatment or cell disruption method is hence a prerequisite prior to solvent extraction. In general, there are no recovery methods that are equally efficient for different species of oleaginous yeasts. Each method adopts different mechanisms to disrupt cells and extract the lipids, thus a systematic evaluation is essential before choosing a particular method. In this review, mechanical (bead mill, ultrasonication, homogenization and microwave) and nonmechanical (enzyme, acid, base digestions and osmotic shock) methods that are currently used for the disruption or permeabilization of oleaginous yeasts are discussed based on their principle, application and feasibility, including their effects on the lipid yield. The attempts of using conventional and "green" solvents to selectively extract lipids are compared. Other emerging methods such as automated pressurized liquid extraction, supercritical fluid extraction and simultaneous in situ lipid recovery using capturing agents are also reviewed to facilitate the choice of more effective lipid recovery methods.
    Matched MeSH terms: Cell Wall
  7. Control of Basal Stem Rot Disease in Oil Palm by Supplementation of Calcium, Copper, and Salicylic Acid
    Bivi MS, Paiko AS, Khairulmazmi A, Akhtar MS, Idris AS
    Plant Pathol J, 2016 Oct;32(5):396-406.
    PMID: 27721689
    Continuous supplementation of mineral nutrients and salicylic acid (SA) as foliar application could improve efficacy in controlling basal stem rot (BSR) disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3%) was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA]) (5.0%) followed by T1 (5.5%), T5 (5.8%), T3 (8.3%), T6 (8.3%), T4 (13.3%), and T2 (15.8%) treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease.
    Matched MeSH terms: Cell Wall
  8. In vitro assessment on effect of duodenal contents on the lead (Pb(2+)) binding capacity of two probiotic bacterial strains
    Xing S, Song Y, Liang JB, Faseleh Jahromi M, Shokryazda P, Mi J, et al.
    Ecotoxicol Environ Saf, 2017 May;139:78-82.
    PMID: 28113114 DOI: 10.1016/j.ecoenv.2017.01.016
    In vitro Lead (Pb(2+)) binding capacity of two probiotic bacteria strains, namely Bifidobacterium longumBB79 and Lactobacillus pentosusITA23, was assessed following incubation with the intestinal contents (IC) of laying hens. Results of this study demonstrated that IC treatment significantly enhanced (P<0.01) Pb(2+) binding capacity of both bacterial strains. Fourier transform infrared analysis indicated that several functional groups (O-H or N-H, C-H, C˭O, C-O, and C-O-C) on the bacteria cell wall involved in metal ion binding were altered after IC incubation, and new groups appeared between the 3700cm(-1) and 4000cm(-1)bands. Transmission electron microscopy demonstrated that after incubation with IC, unidentified IC components created new binding sites on the bacterial cell surface. These particles also changed the mechanism of Pb(2+) binding of the two strains from intracellular accumulation to extracellular adsorption.
    Matched MeSH terms: Cell Wall
  9. Fulltext Nano-structural study of microfibrils in Acacia Mangium wood using small- angle x-ray scattering (SAXS)
    Tabet, Tamer A., Fauziah Abdul Aziz, Shahidan Radiman
    Journal of Nuclear and Related Technologies, 2007;2007(1):209-216.
    MyJurnal
    Small-angle X-ray scattering (SAXS) was used to investigate the nanostructure of the microfibrils of cell wall in Acacia Mangium wood. Parameters, such as the fibre length (L), surface area of the single fibre (S), the correspondence distance from the center of the fibre to the center of its neighbor and the shape of the fibre were determined as a function to the distance from pith towards the bark. The results indicate that the fibre length ranged from 53.44 nm to 13.72 nm from pith to bark. Surface area of the single fibre varied from 0.65 nm 2 to 4.36 nm 2 , the highest being found at the end of bark region. The mean value of the correspondence distance is 13.95 nm. Surface structure analysis from scattering graph showed a rod shape of fibre in the pith region of Acacia Mangium wood. The use of SAXS technique and scanning electron microscope (SEM) micrographs gives the most reliable dimensions values.
    Matched MeSH terms: Cell Wall
  10. Fulltext Protective effects of defatted dabai peel extracts in hypercholesterolemic rabbits based on histopathological methods
    Hock, Eng Khoo, Azrina Azlan, Amin Ismail, Al-Sheraji, Sadek Hassan
    Malaysian Journal of Medicine and Health Sciences, 2015;11(2):59-68.
    MyJurnal
    Defatted dabai peel contains a high amount of anthocyanin. Anthocyanins are known to prevent several
    types of disease, including cardiovascular-related complications. This study aimed to describe the
    effects of different doses of defatted dabai peel extract by histopathological analyses on lesions in the
    liver, kidney, heart and aorta. Histopathology methods were applied to determine the protective effects
    of defatted dabai peel extracts against hypercholesterolemia-induced oxidative damages to animal
    organs. Haematoxylin and eosin staining was applied for histopathology examination for liver, kidney,
    heart and aorta. Data showed that a high dose of defatted dabai extract (3000 mg per day) applied to
    hypercholesterolemic rabbits for eight weeks had mild protective effect, especially reducing the severity
    of hepatic fibrosis and steatosis of the renal medulla. The high dose of extract supplementation also
    reduced inflammation of aorta and formation of atherosclerosis plaque in the cell wall of right ventricle
    of the heart. The high dose of defatted dabai peel extract could be a protective agent against oxidative
    stress.
    Matched MeSH terms: Cell Wall
  11. Fulltext Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta)
    Lee WK, Namasivayam P, Ong Abdullah J, Ho CL
    Sci Rep, 2017 04 24;7:46563.
    PMID: 28436444 DOI: 10.1038/srep46563
    Seaweeds survive in marine waters with high sulfate concentration compared to those living at freshwater habitats. The cell wall polymer of Gracilaria spp. which supplies more than 50% of the world agar is heavily sulfated. Since sulfation reduces the agar quality, it is interesting to investigate the effects of sulfate deprivation on the sulfate contents of seaweed and agar, as well as the metabolic pathways of these seaweeds. In this study, two agarophytes G. changii and G. salicornia were treated under sulfate deprivation for 5 days. The sulfate contents in the seaweed/agar were generally lower in sulfate-deprivated samples compared to those in the controls, but the differences were only statistically significant for seaweed sample of G. changii and agar sample of G. salicornia. RNA sequencing (RNA-Seq) of sulfate-deprivated and untreated seaweed samples revealed 1,292 and 3,439 differentially expressed genes (DEGs; ≥1.5-fold) in sulfate-deprivated G. changii and G. salicornia, respectively, compared to their respective controls. Among the annotated DEGs were genes involved in putative agar biosynthesis, sulfur metabolism, metabolism of sulfur-containing amino acids, carbon metabolism and oxidative stress. These findings shed light on the sulfate deprivation responses in agarophytes and help to identify candidate genes involved in agar biosynthesis.
    Matched MeSH terms: Cell Wall
  12. Fulltext Novel Mangosteen-Leaves-Based Marker Ink: Color Lightness, Viscosity, Optimized Composition, and Microstructural Analysis
    Mohd Basri MS, Liew Min Ren B, A Talib R, Zakaria R, Kamarudin SH
    Polymers (Basel), 2021 May 14;13(10).
    PMID: 34069259 DOI: 10.3390/polym13101581
    Dry mangosteen leaves are one of the raw materials used to produce marker ink. However, research using this free and abundant resource is rather limited. The less efficient one-factor-at-a-time (OFAT) approach was mostly used in past studies on plant-based marker ink. The use of statistical analysis and the regression coefficient model (mathematical model) was considered essential in predicting the best combination of factors in formulating mangosteen leaf-based marker ink. Ideally, ink should have maximum color lightness, minimum viscosity, and fast-drying speed. The objective of this study to study the effect of glycerol and carboxymethyl cellulose (CMC) on the color lightness and viscosity of mangosteen-leaves-based marker ink. The viscosity, color lightness, and drying properties of the ink were tested, the significant effect of glycerol and CMC (responses) on ink properties was identified and the prediction model on the optimum value of the responses was developed by using response surface methodology (RSM). The microstructure of mangosteen leaves was analyzed to study the surface morphology and cell structure during dye extraction. A low amount of glycerol used was found to increase the value of color lightness. A decrease in CMC amounts resulted in low viscosity of marker ink. The optimum formulation for the ink can be achieved when the weight percents of glycerol, benzalkonium chloride, ferrous sulphate, and CMC are set at 5, 5, 1, and 3, respectively. SEM micrographs showed the greatest amount of cell wall structure collapse on samples boiled with the lowest amount of glycerol.
    Matched MeSH terms: Cell Wall
  13. Fulltext Identification and analysis of expressed sequence tags present in xylem tissues of kelampayan (Neolamarckia cadamba (Roxb.) Bosser)
    Ho WS, Pang SL, Abdullah J
    Physiol Mol Biol Plants, 2014 Jul;20(3):393-7.
    PMID: 25049467 DOI: 10.1007/s12298-014-0230-x
    The large-scale genomic resource for kelampayan was generated from a developing xylem cDNA library. A total of 6,622 high quality expressed sequence tags (ESTs) were generated through high-throughput 5' EST sequencing of cDNA clones. The ESTs were analyzed and assembled to generate 4,728 xylogenesis unigenes distributed in 2,100 contigs and 2,628 singletons. About 59.3 % of the ESTs were assigned with putative identifications whereas 40.7 % of the sequences showed no significant similarity to any sequences in GenBank. Interestingly, most genes involved in lignin biosynthesis and several other cell wall biosynthesis genes were identified in the kelampayan EST database. The identified genes in this study will be candidates for functional genomics and association genetic studies in kelampayan aiming at the production of high value forests.
    Matched MeSH terms: Cell Wall
  14. The Genus Cladophora Kützing (Ulvophyceae) as a Globally Distributed Ecological Engineer
    Zulkifly SB, Graham JM, Young EB, Mayer RJ, Piotrowski MJ, Smith I, et al.
    J Phycol, 2013 Feb;49(1):1-17.
    PMID: 27008383 DOI: 10.1111/jpy.12025
    The green algal genus Cladophora forms conspicuous nearshore populations in marine and freshwaters worldwide, commonly dominating peri-phyton communities. As the result of human activities, including the nutrient pollution of nearshore waters, Cladophora-dominated periphyton can form nuisance blooms. On the other hand, Cladophora has ecological functions that are beneficial, but less well appreciated. For example, Cladophora has previously been characterized as an ecological engineer because its complex structure fosters functional and taxonomic diversity of benthic microfauna. Here, we review classic and recent literature concerning taxonomy, cell biology, morphology, reproductive biology, and ecology of the genus Cladophora, to examine how this alga functions to modify habitats and influence littoral biogeochemistry. We review the evidence that Cladophora supports large, diverse populations of microalgal and bacterial epiphytes that influence the cycling of carbon and other key elements, and that the high production of cellulose and hydrocarbons by Cladophora-dominated periphyton has the potential for diverse technological applications, including wastewater remediation coupled to renewable biofuel production. We postulate that well-known aspects of Cladophora morphology, hydrodynamically stable and perennial holdfasts, distinctively branched architecture, unusually large cell and sporangial size and robust cell wall construction, are major factors contributing to the multiple roles of this organism as an ecological engineer.
    Matched MeSH terms: Cell Wall
  15. Fulltext Endophytic filamentous fungi from a Catharanthus roseus: Identification and its hydrolytic enzymes
    Ayob FW, Simarani K
    Saudi Pharm J, 2016 May;24(3):273-8.
    PMID: 27275114 DOI: 10.1016/j.jsps.2016.04.019
    This paper reported on the various filamentous fungi strains that were isolated from a wild grown Catharanthus roseus. Based on the morphological characteristics and molecular technique through a Polymerase Chain Reaction and DNA sequencing method using internal transcribed spacer (ITS), these fungi had been identified as a Colletotrichum sp., Macrophomina phaseolina, Nigrospora sphaerica and Fusarium solani. The ultrastructures of spores and hyphae were observed under a Scanning Electron Microscope. The hydrolytic enzyme test showed that all strains were positive in secreting cellulase. Colletotrichum sp. and F. solani strains also gave a positive result for amylase while only F. solani was capable to secrete protease. These fungi were putatively classified as endophytic fungi since they produced extracellular enzymes that allow them to penetrate plant cell walls and colonize with symbiotic properties.
    Matched MeSH terms: Cell Wall
  16. Fulltext Identification and Partial Characterization of a Novel UDP-N-Acetylenolpyruvoylglucosamine Reductase/UDP-N-Acetylmuramate:l-Alanine Ligase Fusion Enzyme from Verrucomicrobium spinosum DSM 4136(T)
    Naqvi KF, Patin D, Wheatley MS, Savka MA, Dobson RC, Gan HM, et al.
    Front Microbiol, 2016;7:362.
    PMID: 27047475 DOI: 10.3389/fmicb.2016.00362
    The enzymes involved in synthesizing the bacterial cell wall are attractive targets for the design of antibacterial compounds, since this pathway is essential for bacteria and is absent in animals, particularly humans. A survey of the genome of a bacterium that belongs to the phylum Verrucomicrobia, the closest free-living relative to bacteria from the Chlamydiales phylum, shows genetic evidence that Verrucomicrobium spinosum possesses a novel fusion open reading frame (ORF) annotated by the locus tag (VspiD_010100018130). The ORF, which is predicted to encode the enzymes UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and UDP-N-acetylmuramate:l-alanine ligase (MurC) that are involved in the cytoplasmic steps of peptidoglycan biosynthesis, was cloned. In vivo analyses using functional complementation showed that the fusion gene was able to complement Escherichia coli murB and murC temperature sensitive mutants. The purified recombinant fusion enzyme (MurB/C Vs ) was shown to be endowed with UDP-N-acetylmuramate:l-alanine ligase activity. In vitro analyses demonstrated that the latter enzyme had a pH optimum of 9.0, a magnesium optimum of 10 mM and a temperature optimum of 44-46°C. Its apparent K m values for ATP, UDP-MurNAc, and l-alanine were 470, 90, and 25 μM, respectively. However, all attempts to demonstrate an in vitro UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) activity were unsuccessful. Lastly, Hidden Markov Model-based similarity search and phylogenetic analysis revealed that this fusion enzyme could only be identified in specific lineages within the Verrucomicrobia phylum.
    Matched MeSH terms: Cell Wall
  17. Global Transcriptome Analysis of Gracilaria changii (Rhodophyta) in Response to Agarolytic Enzyme and Bacterium
    Lim EL, Siow RS, Abdul Rahim R, Ho CL
    Mar Biotechnol (NY), 2016 Apr;18(2):189-200.
    PMID: 26631182 DOI: 10.1007/s10126-015-9680-6
    Many bacterial epiphytes of agar-producing seaweeds secrete agarase that degrade algal cell wall matrix into oligoagars which elicit defense-related responses in the hosts. The molecular defense responses of red seaweeds are largely unknown. In this study, we surveyed the defense-related transcripts of an agarophyte, Gracilaria changii, treated with β-agarase through next generation sequencing (NGS). We also compared the defense responses of seaweed elicited by agarase with those elicited by an agarolytic bacterium isolated from seaweed, by profiling the expression of defense-related genes using quantitative reverse transcription real-time PCR (qRT-PCR). NGS detected a total of 391 differentially expressed genes (DEGs) with a higher abundance (>2-fold change with a p value <0.001) in the agarase-treated transcriptome compared to that of the non-treated G. changii. Among these DEGs were genes related to signaling, bromoperoxidation, heme peroxidation, production of aromatic amino acids, chorismate, and jasmonic acid. On the other hand, the genes encoding a superoxide-generating NADPH oxidase and related to photosynthesis were downregulated. The expression of these DEGs was further corroborated by qRT-PCR results which showed more than 90 % accuracy. A comprehensive analysis of their gene expression profiles between 1 and 24 h post treatments (hpt) revealed that most of the genes analyzed were consistently upregulated or downregulated by both agarase and agarolytic bacterial treatments, indicating that the defense responses induced by both treatments are highly similar except for genes encoding vanadium bromoperoxidase and animal heme peroxidase. Our study has provided the first glimpse of the molecular defense responses of G. changii to agarase and agarolytic bacterial treatments.
    Matched MeSH terms: Cell Wall
  18. Fulltext Recovery of recombinant Mycobacterium tuberculosis antigens fused with cell wall-anchoring motif (LysM) from inclusion bodies using non-denaturing reagent (N-laurylsarcosine)
    Mustafa AD, Kalyanasundram J, Sabidi S, Song AA, Abdullah M, Abdul Rahim R, et al.
    BMC Biotechnol, 2019 05 14;19(1):27.
    PMID: 31088425 DOI: 10.1186/s12896-019-0522-x
    BACKGROUND: The current limitations of conventional BCG vaccines highlights the importance in developing novel and effective vaccines against tuberculosis (TB). The utilization of probiotics such as Lactobacillus plantarum for the delivery of TB antigens through in-trans surface display provides an effective and safe vaccine approach against TB. Such non-recombinant probiotic surface display strategy involves the fusion of candidate proteins with cell wall binding domain such as LysM, which enables the fusion protein to anchor the L. plantarum cell wall externally, without the need for vector genetic modification. This approach requires sufficient production of these recombinant fusion proteins in cell factory such as Escherichia coli which has been shown to be effective in heterologous protein production for decades. However, overexpression in E. coli expression system resulted in limited amount of soluble heterologous TB-LysM fusion protein, since most of it are accumulated as insoluble aggregates in inclusion bodies (IBs). Conventional methods of denaturation and renaturation for solubilizing IBs are costly, time-consuming and tedious. Thus, in this study, an alternative method for TB antigen-LysM protein solubilization from IBs based on the use of non-denaturating reagent N-lauroylsarcosine (NLS) was investigated.

    RESULTS: Expression of TB antigen-LysM fusion genes was conducted in Escherichia coli, but this resulted in IBs deposition in contrast to the expression of TB antigens only. This suggested that LysM fusion significantly altered solubility of the TB antigens produced in E. coli. The non-denaturing NLS technique was used and optimized to successfully solubilize and purify ~ 55% of the recombinant cell wall-anchoring TB antigen from the IBs. Functionality of the recovered protein was analyzed via immunofluorescence microscopy and whole cell ELISA which showed successful and stable cell wall binding to L. plantarum (up to 5 days).

    CONCLUSION: The presented NLS purification strategy enables an efficient and rapid method for obtaining higher yields of soluble cell wall-anchoring Mycobacterium tuberculosis antigens-LysM fusion proteins from IBs in E. coli.

    Matched MeSH terms: Cell Wall/metabolism*
  19. Functional and structural analyses of an expansin-like protein from the antarctic yeast Glaciozyma antarctica PI12 reveal strategies of nutrient scavenging in the sea ice environment
    Mohamad Nor N, Hashim NHF, Quay DHX, Mahadi NM, Illias RM, Abu Bakar FD, et al.
    Int J Biol Macromol, 2020 Feb 01;144:231-241.
    PMID: 31843615 DOI: 10.1016/j.ijbiomac.2019.12.099
    Genome data mining of the Antarctic yeast, Glaciozyma antarctica PI12 revealed an expansin-like protein encoding sequence (GaEXLX1). The GaEXLX1 protein is 24.8 kDa with a high alkaline pI of 9.81. Homology modeling of GaEXLX1 showed complete D1 and D2 domains of a conventional expansin. The protein exhibited 36% sequence similarity to Clavibacter michiganensis EXLX1 (PDB: 4JCW). Subsequently, a recombinant GaEXLX1 protein was produced using Escherichia coli expression system. Incubation with Avicel, filter paper and cotton fiber showed that the protein can disrupt the surface of crystalline and pure cellulose, suggesting a cell wall modification activity usually exhibited by expansin-like proteins. Binding assays displayed that GaEXLX1 can bind to polymeric substrates, including those postulated to be present in the sea ice ecosystem such as crab chitin and moss lichenan. GaEXLX1 may assist in the recognition and loosening of these substrates in the sea ice prior to hydrolysis by other extracellular enzymes. Similar loosening mechanism to classical expansin-like protein has been postulated for this psychrophilic protein based on several conserved residues of GaEXLX1 involved in binding interaction identified by docking analyses.
    Matched MeSH terms: Cell Wall/metabolism
  20. Fulltext Role of Fimbriae, Flagella and Cellulose on the Attachment of Salmonella Typhimurium ATCC 14028 to Plant Cell Wall Models
    Tan MS, White AP, Rahman S, Dykes GA
    PLoS One, 2016;11(6):e0158311.
    PMID: 27355584 DOI: 10.1371/journal.pone.0158311
    Cases of foodborne disease caused by Salmonella are frequently associated with the consumption of minimally processed produce. Bacterial cell surface components are known to be important for the attachment of bacterial pathogens to fresh produce. The role of these extracellular structures in Salmonella attachment to plant cell walls has not been investigated in detail. We investigated the role of flagella, fimbriae and cellulose on the attachment of Salmonella Typhimurium ATCC 14028 and a range of isogenic deletion mutants (ΔfliC fljB, ΔbcsA, ΔcsgA, ΔcsgA bcsA and ΔcsgD) to bacterial cellulose (BC)-based plant cell wall models [BC-Pectin (BCP), BC-Xyloglucan (BCX) and BC-Pectin-Xyloglucan (BCPX)] after growth at different temperatures (28°C and 37°C). We found that all three cell surface components were produced at 28°C but only the flagella was produced at 37°C. Flagella appeared to be most important for attachment (reduction of up to 1.5 log CFU/cm2) although both cellulose and fimbriae also aided in attachment. The csgD deletion mutant, which lacks both cellulose and fimbriae, showed significantly higher attachment as compared to wild type cells at 37°C. This may be due to the increased expression of flagella-related genes which are also indirectly regulated by the csgD gene. Our study suggests that bacterial attachment to plant cell walls is a complex process involving many factors. Although flagella, cellulose and fimbriae all aid in attachment, these structures are not the only mechanism as no strain was completely defective in its attachment.
    Matched MeSH terms: Cell Wall/microbiology
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