Displaying publications 1 - 20 of 25 in total

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  1. Cha TS, Yee W, Phua PSP, Loh SH, Aziz A
    Biotechnol Lett, 2021 Apr;43(4):803-812.
    PMID: 33438120 DOI: 10.1007/s10529-021-03077-2
    OBJECTIVE: The effects of a brief (3 days) and prolonged (6 days) period of incubation in darkness and light on the biomass content, lipid content and fatty acid profile in Chlorella vulgaris UMT-M1 were determined.

    RESULTS: Three days of incubation in darkness increased saturated fatty acid (SFA) content from 34.0 to 41.4% but decreased monounsaturated fatty acid (MUFA) content from 36.7 to 29.8%. Palmitic acid (C16:0) content was increased from 23.2 to 28.9%, whereas oleic acid (C18:1) content was reduced from 35.4 to 28.8%. Total oil content was slightly decreased from 20.4 to 18.7% after 3 days of darkness, without a significant reduction in biomass compared to 3 days of incubation in light. Biomass and oil content was highest in cultures incubated for 6 days in light, however the stimulatory and inhibitory effects of darkness (or light) on SFA and MUFA content was no longer present at 6 days of incubation.

    CONCLUSIONS: Findings from this study suggests that fatty acid composition in C. vulgaris could be modulated to favor either C16:0 or C18:1 by a brief period of either darkness or light incubation, prior to harvesting.

  2. Ismail NF, Hamdan S, Mahadi NM, Murad AM, Rabu A, Bakar FD, et al.
    Biotechnol Lett, 2011 May;33(5):999-1005.
    PMID: 21234789 DOI: 10.1007/s10529-011-0517-8
    L-Asparaginase II signal peptide was used for the secretion of recombinant cyclodextrin glucanotransferase (CGTase) into the periplasmic space of E. coli. Despite its predominant localisation in the periplasm, CGTase activity was also detected in the extracellular medium, followed by cell lysis. Five mutant signal peptides were constructed to improve the periplasmic levels of CGTase. N1R3 is a mutated signal peptide with the number of positively charged amino acid residues in the n-region increased to a net charge of +5. This mutant peptide produced a 1.7-fold enhancement of CGTase activity in the periplasm and significantly decreased cell lysis to 7.8% of the wild-type level. The formation of intracellular inclusion bodies was also reduced when this mutated signal peptide was used as judged by SDS-PAGE. Therefore, these results provide evidence of a cost-effective means of expression of recombinant proteins in E. coli.
  3. Wan Dagang WR, Bowen J, O'Keeffe J, Robbins PT, Zhang Z
    Biotechnol Lett, 2016 May;38(5):787-92.
    PMID: 26892223 DOI: 10.1007/s10529-016-2047-x
    The adhesion of colloidal probes of stainless steel, glass and cellulose to Pseudomonas fluorescens biofilms was examined using atomic force microscopy (AFM) to allow comparisons between surfaces to which biofilms might adhere.
  4. Futane A, Jadhav P, Mustafa AH, Srinivasan A, Narayanamurthy V
    Biotechnol Lett, 2024 Feb;46(1):1-17.
    PMID: 38155321 DOI: 10.1007/s10529-023-03454-z
    Metal-Organic Frameworks (MOFs) have exceptional inherent properties that make them highly suitable for diverse applications, such as catalysis, storage, optics, chemo sensing, and biomedical science and technology. Over the past decades, researchers have utilized various techniques, including solvothermal, hydrothermal, mechanochemical, electrochemical, and ultrasonic, to synthesize MOFs with tailored properties. Post-synthetic modification of linkers, nodal components, and crystallite domain size and morphology can functionalize MOFs to improve their aptamer applications. Advancements in AI and machine learning led to the development of nonporous MOFs and nanoscale MOFs for medical purposes. MOFs have exhibited promise in cancer therapy, with the successful accumulation of a photosensitizer in cancer cells representing a significant breakthrough. This perspective is focused on MOFs' use as advanced materials and systems for cancer therapy, exploring the challenging aspects and promising features of MOF-based cancer diagnosis and treatment. The paper concludes by emphasizing the potential of MOFs as a transformative technology for cancer treatment and diagnosis.
  5. Loo CY, Lee WH, Tsuge T, Doi Y, Sudesh K
    Biotechnol Lett, 2005 Sep;27(18):1405-10.
    PMID: 16215858
    Palm kernel oil, palm olein, crude palm oil and palm acid oil were used for the synthesis of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by a mutant strain of Wautersia eutropha (formerly Ralstonia eutropha) harboring the Aeromonas caviae polyhydroxyalkanoate (PHA) synthase gene. Palm kernel oil was an excellent carbon source for the production of cell biomass and P(3HB-co-3HHx). About 87% (w/w) of the cell dry weight as P(3HB-co-3HHx) was obtained using 5 g palm kernel oil/l. Gravimetric and microscopic analyses further confirmed the high PHA content in the recombinant cells. The molar fraction of 3HHx remained constant at 5 mol % regardless of the type and concentration of palm oil products used. The small amount of 3HHx units was confirmed by 13C NMR analysis. The number average molecular weight (M(n)) of the PHA copolymer produced from the various palm oil products ranged from 27 0000 to 46 0000 Da. The polydispersity was in the range of 2.6-3.9.
  6. Azman AR, Mahat NA, Wahab RA, Ahmad WA, Puspanadan JK, Huri MAM, et al.
    Biotechnol Lett, 2021 Apr;43(4):881-898.
    PMID: 33389272 DOI: 10.1007/s10529-020-03052-3
    OBJECTIVE: Optimisation of the green novel nanobio-based reagent (NBR) for rapid visualisation of groomed fingerprints on wet non-porous substrates using response surface methodology and assessment of its stability and sensitivity were attempted for forensic applications.

    RESULTS: Scanning electron microscopy images demonstrated successful attachments of NBR onto the constituents of fingerprints on the substrates. The highest average quality of visualised fingerprints was attained at the optimum condition (100 mg of CRL; 75 mg of acid-functionalised multi-walled carbon nanotubes; 5 h of immobilisation). The NBR produced comparable average quality of fingerprints with the commercially available small particle reagent, even after 4 weeks of storage (without any preservatives) in both chilled and sultry conditions. The NBR was sensitive enough to visualise the increasingly weaker fingerprints, particularly on glass slides.

    CONCLUSION: The optimised novel NBR could be the relatively greener option for visualising latent fingerprints on wet, non-porous substrates for forensic applications.

  7. Fong MY, Lau YL, Zulqarnain M
    Biotechnol Lett, 2008 Apr;30(4):611-8.
    PMID: 18043869
    The surface antigen 2 (SAG2) gene of the protozoan parasite, Toxoplasma gondii, was cloned and extracellularly expressed in the yeast Pichia pastoris. The effectiveness of the secreted recombinant SAG2 (rSAG2-S) as a serodiagnosis reagent was assessed by western blots and ELISA. In the western blot assay, rSAG2-S reacted with all Toxoplasma-antibody positive human serum samples but not with Toxoplasma-negative samples. In the ELISA, rSAG2-S yielded sensitivity rates ranging from 80% (IgG negative, IgM positive) to 100% (IgG positive, IgM negative). In vivo experiments showed that serum from mice immunized with rSAG2-S reacted specifically with the native SAG2 of T. gondii. These mice were protected when challenged with live cells of T. gondii.
  8. Baradaran A, Sieo CC, Foo HL, Illias RM, Yusoff K, Rahim RA
    Biotechnol Lett, 2013 Feb;35(2):233-8.
    PMID: 23076361 DOI: 10.1007/s10529-012-1059-4
    Fifty signal peptides of Pediococcus pentosaceus were characterized by in silico analysis and, based on the physicochemical analysis, (two potential signal peptides Spk1 and Spk3 were identified). The coding sequences of SP were amplified and fused to the gene coding for green fluorescent protein (GFP) and cloned into Lactococcus lactis pNZ8048 and pMG36e vectors, respectively. Western blot analysis indicated that the GFP proteins were secreted using both heterologous SPs. ELISA showed that the secretion efficiency of GFP using Spk1 (0.64 μg/ml) was similar to using Usp45 (0.62 μg/ml) and Spk3 (0.58 μg/ml).
  9. Saik AY, Lim YY, Stanslas J, Choo WS
    Biotechnol Lett, 2017 Feb;39(2):297-304.
    PMID: 27812823 DOI: 10.1007/s10529-016-2246-5
    OBJECTIVES: To investigate the lipase-catalyzed acylation of quercetin with oleic acid using Candida antarctica lipase B.

    RESULTS: Three acylated analogues were produced: quercetin 4'-oleate (C33H42O8), quercetin 3',4'-dioleate (C51H74O9) and quercetin 7,3',4'-trioleate (C69H106O10). Their identities were confirmed with UPLC-ESI-MS and (1)H NMR analyses. The effects of temperature, duration and molar ratio of substrates on the bioconversion yields varied across conditions. The regioselectivity of the acylated quercetin analogues was affected by the molar ratio of substrates. TLC showed the acylated analogues had higher lipophilicity (152% increase) compared to quercetin. Partition coefficient (log P) of quercetin 4'-oleate was higher than those of quercetin and oleic acid. Quercetin 4'-oleate was also stable over 28 days of storage.

    CONCLUSIONS: Quercetin oleate esters with enhanced lipophilicity can be produced via lipase-catalyzed reaction using C. antarctica lipase B to be used in topical applications.

  10. 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.
  11. Rafiqul IS, Sakinah AM, Zularisam AW
    Biotechnol Lett, 2015 Jan;37(1):191-6.
    PMID: 25214231 DOI: 10.1007/s10529-014-1672-5
    Xylose reductase (XR) is an oxidoreductase having potential applications in the production of various specialty products, mainly xylitol. It is important to screen for compounds that can decrease XR activity and consequently can decrease xylitol production. We have identified the byproducts in the hemicellulosic hydrolysate that inhibit XR from Candida tropicalis and measured their effects. XR inhibitory activities of byproducts, glucose, acetic acid, arabinose, lignin-degradation products (LDPs), furfural and hydroxymethylfurfural (HMF), were evaluated by measuring the MIC and IC50 values. XR activity was 11.2 U/ml. Acetic acid, LDPs, furfural and HMF significantly inhibited XR with IC50 values of 11, 6.4, 2.3 and 0.4 g/l, respectively. This is the first report on the inhibitory activities of several byproducts for XR.
  12. Bayat O, Baradaran A, Ariff A, Mohamad R, Rahim RA
    Biotechnol Lett, 2014 Mar;36(3):581-5.
    PMID: 24185903 DOI: 10.1007/s10529-013-1390-4
    Human interferon alpha (IFN-α) was expressed in two strains of Lactococcus lactis by aid of two promoters (P32 and Pnis) giving rise to two recombinant strains: MG:IFN and NZ:IFN, respectively. The expression of IFN was confirmed by ELISA and western blotting. Highest production was achieved using glucose for growth of both recombinant strains with nisin, used for induction of the recombinant strain with Pnis promoter, at 30 ng/ml. The optimum time for MG:IFN was 9 h and for NZ:IFN was 4.5 h. The highest productions by MG:IFN and NZ:IFN were 1.9 and 2.4 μg IFN/l, respectively. Both of the expressed IFNs showed bioactivities of 1.9 × 10(6) IU/mg that were acceptable for further clinical studies.
  13. Guan L, Zhu S, Han Y, Yang C, Liu Y, Qiao L, et al.
    Biotechnol Lett, 2018 Mar;40(3):501-508.
    PMID: 29249062 DOI: 10.1007/s10529-017-2491-2
    OBJECTIVE: To study the effects of CTNNB1 gene knockout by CRISPR-Cas9 technology on cell adhesion, proliferation, apoptosis, and Wnt/β-catenin signaling pathway.

    RESULTS: CTNNB1 gene of HEK 293T cells was knocked out by CRISPR-Cas9. This was confirmed by sequencing and western blotting. Methylthiazolyl-tetrazolium bromide assays indicated that deletion of β-catenin significantly weakened adhesion ability and inhibited proliferation rate (P 

  14. Awang R, Basri M, Ahmad S, Salleh AB
    Biotechnol Lett, 2004 Jan;26(1):11-4.
    PMID: 15005144
    The esterification of palm-based 9,10-dihydroxystearic acid (DHSA) and 1-octanol in hexane as catalyzed by lipase from Rhizomucor meihei (Lipozyme IM) followed Michaelis-Menten kinetics. The esterification reaction follows a Ping-Pong, Bi-Bi mechanism. The maximum rate was estimated to be 1 micromol min(-1) mg(-1) catalyst in hexane at 50 degrees C, and the Michaelis-Menten constants for DHSA and 1-octanol were 1.3 M and 0.7 M, respectively.
  15. Ashkani S, Rafii MY, Rahim HA, Latif MA
    Biotechnol Lett, 2013 May;35(5):799-810.
    PMID: 23315158 DOI: 10.1007/s10529-012-1130-1
    Malaysian rice, Pongsu Seribu 2, has wide-spectrum resistance against blast disease. Chromosomal locations conferring quantitative resistance were detected by linkage mapping with SSRs and quantitative trait locus (QTL) analysis. For the mapping population, 188 F3 families were derived from a cross between the susceptible cultivar, Mahsuri, and a resistant variety, Pongsu Seribu 2. Partial resistance to leaf blast in the mapping population was assessed. A linkage map covering ten chromosomes and consisting of 63 SSR markers was constructed. 13 QTLs, including 6 putative and 7 putative QTLs, were detected on chromosomes 1, 2, 3, 5, 6, 10, 11 and 12. The resulting phenotypic variation due to a single QTL ranged from 2 to 13 %. These QTLs accounted for approx. 80 % of the total phenotypic variation within the F3 population. Therefore, partial resistance to blast in Pongsu Seribu 2 is due to combined effects of multiple loci with major and minor effects.
  16. Joan SS, Pui-Fong J, Song AA, Chang LY, Yusoff K, AbuBakar S, et al.
    Biotechnol Lett, 2016 May;38(5):793-9.
    PMID: 26758876 DOI: 10.1007/s10529-016-2034-2
    An oral lactococcal-based vaccine which haboured the haemagglutinin1 (HA1) antigen fused to nisP anchor protein for the purpose of surface displaying the HA1 antigen was developed against H1N1 virus.
  17. Khor CY, Khoo BY
    Biotechnol Lett, 2020 Aug;42(8):1581-1595.
    PMID: 32385743 DOI: 10.1007/s10529-020-02904-2
    OBJECTIVE: This study aimed to examine the metabolising effect of chrysin by investigating the mRNA expression levels of PPARα and its related cellular mechanisms in HCT116 cells.

    RESULTS: The mRNA expression of PPARα was significantly induced in HCT116 cells following treatment with chrysin for 36 h, but the mRNA expression of PPARα was inhibited, when the cells were treated with a combination of chrysin and MK886 (PPARα inhibitor). This phenomenon proved that the incorporation of MK886 lowers the expression levels of PPARα, thus enabling us to study the function of PPARα. The cell population of the G0/G1 phase significantly increased in chrysin-treated cells, which was accompanied by a decrease in the percentage of S phase cell population after 12 h of treatment. However, treatments of HCT116 cells with chrysin only or a combination of chrysin and MK886 did not show the opposite situation in the G0/G1 and S phase cell populations, indicating that the expression of PPARα may not be associated with the cell cycle in the treated cells. The migration rate in chrysin-treated HCT116 cells was reduced significantly after 24 and 36 h of treatments. However, the activity was revived, when the expression of PPARα was inhibited, indicating that the migration activity of chrysin-treated cells is likely correlated with the expression of PPARα. Comparison of the CYP2S1 and CYP1B1 mRNA expression in chrysin only treated, and a combination of chrysin and MK886-treated HCT116 cells for 24 and 36 h showed a significant difference in the expression levels, indicating that PPARα inhibitor could also modify the expression of CYP2S1 and CYP1B1.

    CONCLUSION: The study indicates that PPARα may play an essential role in regulating the migration activity, and the expression of CYP2S1 and CYP1B1 in chrysin-treated colorectal cancer cells.

  18. Lim BN, Tye GJ, Choong YS, Ong EB, Ismail A, Lim TS
    Biotechnol Lett, 2014 Dec;36(12):2381-92.
    PMID: 25214212 DOI: 10.1007/s10529-014-1635-x
    Antibodies have been used efficiently for the treatment and diagnosis of many diseases. Recombinant antibody technology allows the generation of fully human antibodies. Phage display is the gold standard for the production of human antibodies in vitro. To generate monoclonal antibodies by phage display, the generation of antibody libraries is crucial. Antibody libraries are classified according to the source where the antibody gene sequences were obtained. The most useful library for infectious diseases is the immunized library. Immunized libraries would allow better and selective enrichment of antibodies against disease antigens. The antibodies generated from these libraries can be translated for both diagnostic and therapeutic applications. This review focuses on the generation of immunized antibody libraries and the potential applications of the antibodies derived from these libraries.
  19. Woon JS, Mackeen MM, Sudin AH, Mahadi NM, Illias RM, Murad AM, et al.
    Biotechnol Lett, 2016 May;38(5):825-32.
    PMID: 26830095 DOI: 10.1007/s10529-016-2045-z
    To express and determine the hydrolytic activity of a cellobiohydrolase (TTCBH6B) from the thermophilic fungus Thielavia terrestris in Pichia pastoris.
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