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  1. Application of different feeding strategies in fed batch culture for pullulanase production using sago starch
    R S, M S M, E M S, K O NA, A A S, K K
    Carbohydr Polym, 2014 Feb 15;102:962-9.
    PMID: 24507370 DOI: 10.1016/j.carbpol.2013.10.031
    The production of pullulanase by Bacillus flavothermus KWF-1 in batch and fed batch culture were compared using 2L bioreactor. In batch culture, 0.0803 U/mL of pullulanase activity with specific activity of 0.0213 U/mg was produced by controlling the agitation speed and temperature at 200 rpm and 50 °C, respectively. Fed batch production was studied by feeding the culture with different sago starch concentrations in various feeding modes for enhanced pullulanase production. Exponential feeding mode at dilution rate of 0.01/h was the preeminent strategy for enhanced pullulanase production of 0.1710 U/mL with specific activity of 0.066 U/mg. It had shown an increment of pullulanase production and specific activity by 2.1 and 3.1-fold, respectively when compared to batch culture. Increment of pullulanase activity in exponential feeding mode improved hydrolyzation of sago starch into maltotriose and panose by 4.5 and 2.5-fold respectively compared to batch system.
    Matched MeSH terms: Glycoside Hydrolases/biosynthesis*
  2. Whole genome strategies and bioremediation insight into dehalogenase-producing bacteria
    Oyewusi HA, Wahab RA, Huyop F
    Mol Biol Rep, 2021 Mar;48(3):2687-2701.
    PMID: 33650078 DOI: 10.1007/s11033-021-06239-7
    An integral approach to decoding both culturable and uncultured microorganisms' metabolic activity involves the whole genome sequencing (WGS) of individual/complex microbial communities. WGS of culturable microbes, amplicon sequencing, metagenomics, and single-cell genome analysis are selective techniques integrating genetic information and biochemical mechanisms. These approaches transform microbial biotechnology into a quick and high-throughput culture-independent evaluation and exploit pollutant-degrading microbes. They are windows into enzyme regulatory bioremediation pathways (i.e., dehalogenase) and the complete bioremediation process of organohalide pollutants. While the genome sequencing technique is gaining the scientific community's interest, it is still in its infancy in the field of pollutant bioremediation. The techniques are becoming increasingly helpful in unraveling and predicting the enzyme structure and explore metabolic and biodegradation capabilities.
    Matched MeSH terms: Hydrolases/biosynthesis*
  3. Tannase enzyme production by entrapped cells of Aspergillus niger FETL FT3 in submerged culture system
    Darah I, Sumathi G, Jain K, Lim SH
    Bioprocess Biosyst Eng, 2011 Sep;34(7):795-801.
    PMID: 21347668 DOI: 10.1007/s00449-011-0529-8
    The ability of immobilized cell cultures of Aspergillus niger FETL FT3 to produce extracellular tannase was investigated. The production of enzyme was increased by entrapping the fungus in scouring mesh cubes compared to free cells. Using optimized parameters of six scouring mesh cubes and inoculum size of 1 × 10(6) spores/mL, the tannase production of 3.98 U/mL was obtained from the immobilized cells compared to free cells (2.81 U/mL). It was about 41.64% increment. The immobilized cultures exhibited significant tannase production stability of two repeated runs.
    Matched MeSH terms: Carboxylic Ester Hydrolases/biosynthesis*
  4. Fulltext Induction of epoxide hydrolase, glucuronosyl transferase, and sulfotransferase by phenethyl isothiocyanate in male Wistar albino rats
    Abdull Razis AF, Mohd Noor N, Konsue N
    Biomed Res Int, 2014;2014:391528.
    PMID: 24592387 DOI: 10.1155/2014/391528
    Phenethyl isothiocyanate (PEITC) is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin). The isothiocyanate is converted from the glucosinolate by intestinal microflora or when contacted with myrosinase during the chopping and mastication of the vegetable. PEITC manifested protection against chemically-induced cancers in various tissues. A potential mechanism of chemoprevention is by modulating the metabolism of carcinogens so as to promote deactivation. The principal objective of this study was to investigate in rats the effect of PEITC on carcinogen-metabolising enzyme systems such as sulfotransferase (SULT), N-acetyltransferase (NAT), glucuronosyl transferase (UDP), and epoxide hydrolase (EH) following exposure to low doses that simulate human dietary intake. Rats were fed for 2 weeks diets supplemented with PEITC at 0.06 µmol/g (low dose, i.e., dietary intake), 0.6 µmol/g (medium dose), and 6.0 µmol/g (high dose), and the enzymes were monitored in rat liver. At the Low dose, no induction of the SULT, NAT, and EH was noted, whereas UDP level was elevated. At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed. It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.
    Matched MeSH terms: Epoxide Hydrolases/biosynthesis*
  5. Expression and biochemical characterization of a novel thermostable alkaline β-1,3-1,4-glucanase (lichenase) from an alkaliphilic Bacillus lehensis G1
    Mat Yajit NL, Fazlin Hashim NH, Illias RM, Abdul Murad AM
    Protein Expr Purif, 2024 Jul;219:106486.
    PMID: 38642864 DOI: 10.1016/j.pep.2024.106486
    New thermostable β-1,3-1,4-glucanase (lichenase) designated as Blg29 was expressed and purified from a locally isolated alkaliphilic bacteria Bacillus lehensis G1. The genome sequence of B. lehensis predicted an open reading frame of Blg29 with a deduced of 249 amino acids and a molecular weight of 28.99 kDa. The gene encoding for Blg29 was successfully amplified via PCR and subsequently expressed as a recombinant protein using the E. coli expression system. Recombinant Blg29 was produced as a soluble form and further purified via immobilized metal ion affinity chromatography (IMAC). Based on biochemical characterization, recombinant Blg29 showed optimal activity at pH9 and temperature 60 °C respectively. This enzyme was stable for more than 2 h, incubated at 50 °C, and could withstand ∼50 % of its activity at 70 °C for an hour and a half. No significant effect on Blg29 was observed when incubated with metal ions except for a small increase with ion Ca2+. Blg29 showed high substrate activity towards lichenan where Vm, Km, Kcat, and kcat/Km values were 2040.82 μmolmin‾1mg‾1, 4.69 mg/mL, and 986.39 s‾1 and 210.32 mLs‾1mg‾1 respectively. The high thermostability and activity make this enzyme useable for a broad prospect in industry applications.
    Matched MeSH terms: Glycoside Hydrolases/biosynthesis
  6. Physical factors affecting the production of organic solvent-tolerant protease by Pseudomonas aeruginosa strain K
    Rahman RN, Geok LP, Basri M, Salleh AB
    Bioresour Technol, 2005 Mar;96(4):429-36.
    PMID: 15491823
    The physical factors affecting the production of an organic solvent-tolerant protease from Pseudomonas aeruginosa strain K was investigated. Growth and protease production were detected from 37 to 45 degrees C with 37 degrees C being the optimum temperature for P. aeruginosa. Maximum enzyme activity was achieved at static conditions with 4.0% (v/v) inoculum. Shifting the culture from stationary to shaking condition decreased the protease production (6.0-10.0% v/v). Extracellular organic solvent-tolerant protease was detected over a broad pH range from 6.0 to 9.0. However, the highest yield of protease was observed at pH 7.0. Neutral media increased the protease production compared to acidic or alkaline media.
    Matched MeSH terms: Peptide Hydrolases/biosynthesis*
  7. Proteinase, phospholipase, biofilm forming abilities and antifungal susceptibilities of Malaysian Candida isolates from blood cultures
    Tay ST, Abidin IA, Hassan H, Ng KP
    Med Mycol, 2011 Jul;49(5):556-60.
    PMID: 21254967 DOI: 10.3109/13693786.2010.551424
    This study was conducted to determine the proteinase, phospholipase, and biofilm forming abilities of Candida isolates in blood cultures of specimens from patients at the University Malaya Medical Center, Kuala Lumpur, Malaysia. Proteinase and phospholipase activities were detected in 93.7% and 73.3%, respectively, of 15 Candida albicans isolates. Amongst the 26 non-C. albicans Candida isolates, proteinase and phospholipase activities were detected in 88.5% and 7.7% of the isolates, respectively. There was no significant difference in the expression levels of proteinase amongst the Candida isolates studied (P = 0.272), but the phospholipase activity of C. albicans was significantly higher than that of the non-C. albicans Candida isolates (P = 0.003). There was no significant difference in the biofilm forming abilities of C. albicans and non-C. albicans Candida isolates on the polystyrene microtiter wells (P = 0.379). In addition, the findings of this study demonstrate increased resistance of Candida isolates in biofilms to amphotericin and fluconazole, as compared to their planktonic counterparts.
    Matched MeSH terms: Peptide Hydrolases/biosynthesis*
  8. Fulltext Optimizing culture conditions for production of intra and extracellular inulinase and invertase from Aspergillus niger ATCC 20611 by response surface methodology (RSM)
    Dinarvand M, Rezaee M, Foroughi M
    Braz J Microbiol, 2017 Jul-Sep;48(3):427-441.
    PMID: 28359854 DOI: 10.1016/j.bjm.2016.10.026
    The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R2) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30°C, 6% (v/v), inoculum size and 150rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications.
    Matched MeSH terms: Glycoside Hydrolases/biosynthesis*
  9. Rapid degradation of N-3-oxo-acylhomoserine lactones by a Bacillus cereus isolate from Malaysian rainforest soil
    Chan KG, Wong CS, Yin WF, Sam CK, Koh CL
    Antonie Van Leeuwenhoek, 2010 Oct;98(3):299-305.
    PMID: 20376561 DOI: 10.1007/s10482-010-9438-0
    A bacterial strain, KM1S, was isolated from a Malaysian rainforest soil sample by using a defined enrichment medium that specifically facilitates selection of quorum quenching bacteria. KM1S was clustered closely to Bacillus cereus by 16S ribosomal DNA sequence analysis. It degraded N-3-oxo-hexanoyl homoserine lactone and N-3-oxo-octanoyl homoserine lactone in vitro rapidly at 4.98 and 6.56 microg AHL h(-1) per 10(9) CFU/ml, respectively, as determined by the Rapid Resolution Liquid Chromatography. The aiiA homologue, encoding an autoinducer inactivation enzyme catalyzing the degradation of N-acylhomoserine lactones, of KM1S was amplified and cloned. Sequence analysis indicated the presence of the motif (106)HXDH-59 amino acids-H(169)-21 amino acids-D(191) for N-acylhomoserine lactone lactonases.
    Matched MeSH terms: Carboxylic Ester Hydrolases/biosynthesis*
  10. Fulltext Discovery of a new class of inhibitors for the protein arginine deiminase type 4 (PAD4) by structure-based virtual screening
    Teo CY, Shave S, Chor AL, Salleh AB, Rahman MB, Walkinshaw MD, et al.
    BMC Bioinformatics, 2012;13 Suppl 17:S4.
    PMID: 23282142 DOI: 10.1186/1471-2105-13-S17-S4
    BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease with unknown etiology. Anticitrullinated protein autoantibody has been documented as a highly specific autoantibody associated with RA. Protein arginine deiminase type 4 (PAD4) is the enzyme responsible for catalyzing the conversion of peptidylarginine into peptidylcitrulline. PAD4 is a new therapeutic target for RA treatment. In order to search for inhibitors of PAD4, structure-based virtual screening was performed using LIDAEUS (Ligand discovery at Edinburgh university). Potential inhibitors were screened experimentally by inhibition assays.

    RESULTS: Twenty two of the top-ranked water-soluble compounds were selected for inhibitory screening against PAD4. Three compounds showed significant inhibition of PAD4 and their IC50 values were investigated. The structures of the three compounds show no resemblance with previously discovered PAD4 inhibitors, nor with existing drugs for RA treatment.

    CONCLUSION: Three compounds were discovered as potential inhibitors of PAD4 by virtual screening. The compounds are commercially available and can be used as scaffolds to design more potent inhibitors against PAD4.

    Matched MeSH terms: Hydrolases/biosynthesis
  11. High level expression of Glomerella cingulata cutinase in dense cultures of Pichia pastoris grown under fed-batch conditions
    Seman WM, Bakar SA, Bukhari NA, Gaspar SM, Othman R, Nathan S, et al.
    J Biotechnol, 2014 Aug 20;184:219-28.
    PMID: 24910973 DOI: 10.1016/j.jbiotec.2014.05.034
    A Pichia pastoris transformant carrying the cutinase cDNA of Glomerella cingulata was over-expressed in a 5L bioreactor (2.0L working volume) under fed-batch conditions. Bioreactor experiments rely on varying selected parameters in repeated rounds of optimisation: here these included duration of induction, pH and temperature. Highest cell densities (320gL(-1) wet cell weight) with a cutinase production of 3800mgL(-1) and an activity of 434UmL(-1) were achieved 24h after induction with methanol in basal salt medium (at pH 5 and 28°C). Characterisation of the cutinase showed that it was stable between pH 6 and pH 11, had an optimum pH of 8.0 and retained activity for 30min at 50°C (optimum temperature 25°C).The preferred substrates of G. cingulata cutinase were the medium- to long-chain ρ-nitrophenyl esters of ρ-nitrophenylcaprylate (C8), ρ-nitrophenyllaurate (C12) and ρ-nitrophenylmyristate (C14), with the highest catalytic efficiency, kcat/Km of 7.7±0.7mM(-1)s(-1) for ρ-nitrophenylcaprylate. Microscopic analyses showed that the G. cingulata cutinase was also capable of depolymerising the high molecular weight synthetic polyester, polyethylene terephthalate.
    Matched MeSH terms: Carboxylic Ester Hydrolases/biosynthesis*
  12. Fulltext Production, purification and evaluation of biodegradation potential of PHB depolymerase of Stenotrophomonas sp. RZS7
    Sayyed RZ, Wani SJ, Alarfaj AA, Syed A, El-Enshasy HA
    PLoS One, 2020;15(1):e0220095.
    PMID: 31910206 DOI: 10.1371/journal.pone.0220095
    There are numerous reports on poly-β-hydroxybutyrate (PHB) depolymerases produced by various microorganisms isolated from various habitats, however, reports on PHB depolymerase production by an isolate from plastic rich sites scares. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase from Stenotrophomonas sp. RZS7 isolated from a dumping yard rich in plastic waste. The isolate produced extracellular PHB depolymerase in the mineral salt medium (MSM) at 30°C during 4 days of incubation under shaking. The enzyme was purified by three methods namely ammonium salt precipitation, column chromatography, and solvent purification. Among these purification methods, the enzyme was best purified by column chromatography on the Octyl-Sepharose CL-4B column giving optimum yield (0.7993 Umg-1mL-1). The molecular weight of purified PHB depolymerase was 40 kDa. Studies on the assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential of Stenotrophomonas sp. RZS7. The results obtained in Fourier-Transform Infrared (FTIR) analysis, High-Performance Liquid Chromatography (HPLC) study and Gas Chromatography Mass-Spectrometry (GC-MS) analysis confirmed the biodegradation of PHB in liquid medium by Stenotrophomonas sp. RZS7. Changes in surface morphology of PHB film in soil burial as observed in Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the biodegradation of PHB under natural soil environment. The isolate was capable of degrading PHB and it resulted in 87.74% biodegradation. A higher rate of degradation under the natural soil condition is the result of the activity of soil microbes that complemented the biodegradation of PHB by Stenotrophomonas sp. RZS7.
    Matched MeSH terms: Carboxylic Ester Hydrolases/biosynthesis
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