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Shankar R.,University of Technology Malaysia | Madihah M.S.,University of Technology Malaysia | Shaza E.M.,University of Technology Malaysia | Nur Aswati K.O.,University of Technology Malaysia | And 2 more authors.
Carbohydrate Polymers | Year: 2014

The production of pullulanase by Bacillus flavothermus KWF-1 in batch and fed batch culture were compared using 2 L 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. © 2013 Elsevier Ltd. Source


Ujang Z.,Industrial Biotechnology Research Center | Rashid A.H.A.,Industrial Biotechnology Research Center | Suboh S.K.,Industrial Biotechnology Research Center | Halim A.S.,Universiti Sains Malaysia | Lim C.K.,Skin Research and Innovation Center
Journal of Applied Biomaterials and Functional Materials | Year: 2014

Background: The physical and biological characteristics of oligochitosan (O-C) film, including its barrier and mechanical properties, in vitro cytotoxicity and in vivo biocompatibility, were studied to assess its potential use as a wound dressing. Methods: Membrane films were prepared from water-soluble O-C solution blended with various concentrations of glycerol to modify the physical properties of the films. In vitro and in vivo biocompatibility evaluations were performed using primary human skin fibroblast cultures and subcutaneous implantation in a rat model, respectively. Results: Addition of glycerol significantly influenced the barrier and mechanical properties of the films. Water absorption capacity was in the range of 80%-160%, whereas water vapor transmission rate varied from 1,180 to 1,618 g/m2 per day. Both properties increased with increasing glycerol concentration. Tensile strength decreased while elongation at break increased with the addition of glycerol. O-C films were found to be noncytotoxic to human fibroblast cultures and histological examination proved that films are biocompatible. Conclusion: These results indicate that the membrane film from O-C has potential application as a wound-dressing material. © 2014 Società Italiana Biomateriali. Source


Lim S.-H.,Industrial Biotechnology Research Center | Lim S.-H.,Chungnam National University | Ryu J.-M.,Biotechnology Process Engineering Center | Lee H.,Biotechnology Process Engineering Center | And 3 more authors.
Bioresource Technology | Year: 2011

A strain of Saccharomyces cerevisiae, KCCM50549, was found to efficiently ferment the inulin-containing carbohydrates in Jerusalem artichoke without acidic or enzymatic pretreatment prior to fermentation. S. cerevisiae KCCM50549 could utilize almost completely the fructo-oligosaccharides present in Jerusalem artichoke (up to degree of polymerization (DP) of 15), in contrast to the other S. cerevisiae strain such as NCYC625 that fermented the fructo-oligosaccharides with DP of up to around six. Inulin-fermenting S. cerevisiae KCCM50549 produced c.a. 1.6 times more ethanol from Jerusalem artichoke compared with S. cerevisiae NCYC625. Direct ethanol fermentation of Jerusalem artichoke flour at 180. g/L without any supplements or pretreatments by S. cerevisiae KCCM50549 in a 5. L jar fermentor yielded 36.2. g/L of ethanol within 36. h. The conversion efficiency of inulin-type sugars to ethanol was 70% of the theoretical ethanol yield. © 2010 Elsevier Ltd. Source


Periayah M.H.,Universiti Sains Malaysia | Halim A.S.,Universiti Sains Malaysia | Yaacob N.S.,Universiti Sains Malaysia | Mat Saad A.Z.,Universiti Sains Malaysia | And 3 more authors.
BioMed Research International | Year: 2014

Platelet membrane receptor glycoprotein IIb/IIIa (gpiibiiia) is a receptor detected on platelets. Adenosine diphosphate (ADP) activates gpiibiiia and P2Y causing platelet aggregation and thrombus stabilization during blood loss. Chitosan biomaterials were found to promote surface induced hemostasis and were capable of activating blood coagulation cascades by enhancing platelet aggregation. Our current findings show that the activation of the gpiibiiia complex and the major ADP receptor P2Yis required for platelet aggregation to reach hemostasis following the adherence of various concentrations of chitosan biomaterials [7% N,O-carboxymethylchitosan (NO-CMC) with 0.45 mL collagen, 8% NO-CMC, oligochitosan (O-C), and oligochitosan 53 (O-C 53)]. We studied gpiibiiia and P2Ythrough flow cytometric analysis and western blotting techniques. The highest expression of gpiibiiia was observed with Lyostypt (74.3 ± 7.82%), followed by O-C (65.5 ± 7.17%). Lyostypt and O-C resulted in gpiibiiia expression increases of 29.2% and 13.9%, respectively, compared with blood alone. Western blot analysis revealed that only O-C 53 upregulated the expression of P2Y(1.12 ± 0.03-fold) compared with blood alone. Our findings suggest that the regulation of gpiibiiia and P2Ylevels could be clinically useful to activate platelets to reach hemostasis. Further, we show that the novel oligochitosan is able to induce the increased expression of gpiibiiia and P2Y thus accelerating platelet aggregation in vitro. © 2014 Mercy Halleluyah Periayah et al. Source


Lim S.J.,National University of Malaysia | Wan Aida W.M.,National University of Malaysia | Maskat M.Y.,National University of Malaysia | Mamot S.,National University of Malaysia | And 2 more authors.
Food Hydrocolloids | Year: 2014

The objective of this research was to screen and isolate fucoidan from Malaysian seaweeds and subsequently determine its antioxidant capacity. A screening test employing a colorimetric method was conducted on five types of Malaysian brown and red seaweeds. It was found that Sargassum binderi contained the highest fucoidan content (6.16±0.08%). Thus, fucoidan was isolated from S. binderi (yield 7.5%, purity 89.63%) for the determination of its antioxidant capacity. The isolated fucoidan was identified using high performance anion exchange chromatography (HPAEC) and attenuated total reflectance Fourier transform infra-red (ATR-FTIR) spectroscopy. The antioxidant assays performed were total phenolic content (TPC), free-radical scavenging activity (DPPH), reducing power, superoxide anion scavenging activity (SOA) and hydroxyl radical scavenging activity (OH). The antioxidant capacity of the extracted fucoidan (Fsar) was compared with those of a commercial food-grade fucoidan (Fysk) and of BHA, BHT and ascorbic acid. All the antioxidant assays performed showed either Fsar has significantly higher (p<0.05) or do not differ significantly (p>0.05) in activities compared to that of Fysk. At the same time, both Fsar and Fysk showed significant (p<0.05) antioxidant capacity in terms of superoxide anion and hydroxyl radical scavenging activities compared to those of the synthetic antioxidants. This shows that Fsar has the potential to be commercialised as a functional food product or as bioingredients with high antioxidative properties. © 2014 Elsevier Ltd. Source

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