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Ramli N.,University Putra Malaysia | Abd-Aziz S.,University Putra Malaysia | Hassan M.A.,University Putra Malaysia | Alitheen N.,University Putra Malaysia | Kamaruddin K.,Environment and Bioprocess Technology Center
African Journal of Biotechnology

Cyclodextrin glycosyltransferase (CGTase) is one of the most important groups of microbial amylolytic enzymes that have been used for degradation of starch to yield cyclodextrin (CD) via cyclization reaction. The increasing demand for CD in industrial application has led to an extensive study about CGTase which begin with screening, isolation and characterization of CGTase-producing bacteria. The identification of CGTase producer involves the use of solid media containing phenolphthalein and methyl orange as indicators that was detected by the colour changes. The formations of clearance zone around the bacterial colony in the starch-containing medium were observed and the diameters were measured to gauge the hydrolytic efficiency of the bacteria. Out of 65 soil bacterial samples screened, Bacillus sp. NR5 UPM was identified as the most prolific CGTase producer, which produced highest CGTase activity (11.709 U/ml) and highest β-CD concentration (2.504 mg/ml) with α-CD:β-CD:γ-CD ratio was 0.5:91.1:8.4 when using raw soluble starch as a substrate. It also showed as the best CGTase producer when using sago starch as a substrate (15.514 U/ml). This isolate was known as a raw starchdegrading enzyme producer since it has the capability to use raw starch as a substrate. Thus, in the future, this new isolate perhaps can share the biggest market in industrial application. © 2010 Academic Journals. Source

Siwayanan P.,University of Technology Malaysia | Aziz R.,University of Technology Malaysia | Bakar N.A.,Malaysia Japan International Institute of Technology | Ya H.,Product Design and Engineering Center | And 2 more authors.
Journal of Surfactants and Detergents

Laboratory and pilot scale investigations were carried out on phosphate-free detergent (PFD) formulations comprising binary anionic surfactants of C16 palm methyl ester sulfonates (C16MES) and linear alkyl benzene sulfonic acid (LABSA) with the aim of maximizing the incorporation of C16MES into low density detergent powders without compromising the detergency and other significant properties. Initial laboratory experiments revealed that the detergent powder resulting from C16MES/LABSA with a 50:50 ratio and pH 7-8 has acceptable detergency stability over 1 week of accelerated ageing test at 50 °C and 85 % relative humidity. Subsequent experiments were carried out in a 5-kg/h-capacity pilot spray dryer using PFD formulations of C16MES/LABSA over the whole range of weight ratios under the same pH of 7-8. The concentration of the detergent slurry and cleaning performance (detergency, foaming ability and wetting power) of the resulting spray dried detergent powder (SDDP) were evaluated. C16MES/LABSA in a 40:60 ratio was selected as the ideal formulation based on its optimum detergent slurry concentration and comparable cleaning performance against the control formulation. Further environmental tests have confirmed that SDDP obtained from the ideal formulation is readily biodegradable (60 % in 13 days) and exhibits low eco-toxicity properties (LC50 of 11.3 mg/L). © 2014 AOCS. Source

Siwayanan P.,University of Technology Malaysia | Aziz R.,University of Technology Malaysia | Bakar N.A.,Malaysia Japan International Institute of Technology | Ya H.,Product Design and Engineering Center | And 2 more authors.
Journal of Oleo Science

Phosphate-free spray dried detergent powders (SDDP) comprising binary anionic surfactants of palm C16 methyl ester sulfonate (C16MES) and linear alkyl benzene sulfonic acid (LABSA) were produced using a 5 kg/h-capacity co-current pilot spray dryer (CSD). Six phosphate-free detergent (PFD) formulations comprising C16MES/LABSA in various ratios under pH 7 - 8 were studied. Three PFD formulations having C16MES/LABSA in respective ratios of 0:100 (control), 20:80 and 40:60 ratios were selected for further evaluation based on their optimum detergent slurry concentrations. The resulting SDDP from these formulations were analysed for its detergency stability (over nine months of storage period) and particle characteristics. C16MES/LABSA of 40:60 ratio was selected as the ideal PFD formulation since its resulting SDDP has consistent detergency stability (variation of 2.3% in detergency/active over nine months storage period), excellent bulk density (0.37 kg/L), fine particle size at 50% cumulative volume percentage (D50 of 60.48 μm), high coefficient of particle size uniformity (D60/D10 of 3.86) and large spread of equivalent particle diameters. In terms of surface morphology, the SDDP of the ideal formulation were found to have regular hollow particles with smooth spherical surfaces. Although SDDP of the ideal formulation have excellent characteristics, but in terms of flowability, these powders were classified as slightly less free flowing (Hausner ratio of 1.27 and Carr's index of 21.3). © 2014 by Japan Oil Chemists' Society. Source

Sirat H.M.,University of Technology Malaysia | Rezali M.F.,University of Technology Malaysia | Rezali M.F.,National Metrology Laboratory | Ujang Z.,Environment and Bioprocess Technology Center
Journal of Agricultural and Food Chemistry

Phytochemical and bioactivity studies of the leaves and stem barks of Tibouchina semidecandra L. have been carried out. The ethyl acetate extract of the leaves yielded four flavonoid compounds, identified as quercetin, quercetin 3-O-α-L-(2'-O-acetyl) arabinofuranoside, avicularin, and quercitrin, while the stem barks gave one ellagitannin, identified as 3,3'-O-dimethyl ellagic acid 4-O-α-Lrhamnopyranoside. Evaluation of the antioxidative activity on the crude extracts and pure compounds by electron spin resonance (ESR) and ultraviolet-visible (UV-vis) spectrophotometric assays showed that the pure isolated polyphenols and the EtOAc extract possessed strong antioxidative capabilities. Quercetin was found to be the most active radical scavenger in DPPHUV and ESR methods with SC50 values of 0.7 μM ± 1.4 and 0.7 μM ± 0.6 μM, respectively, in the antioxidant assay. A combination of quercetin and quercitrin was tested for synergistic antioxidative capacity;, however, there was no significant improvement observed. Quercetin also exhibited strong antityrosinase activity with a percent inhibition of 95.0% equivalent to the positive control, kojic acid, in the tyrosinase inhibition assay. © 2010 American Chemical Society. Source

Ramli N.,University Putra Malaysia | Abd-Aziz S.,University Putra Malaysia | Hassan M.A.,University Putra Malaysia | Alitheen N.B.,University Putra Malaysia | And 2 more authors.
African Journal of Microbiology Research

The cloning of a polymerase chain reaction (PCR) gene fragment from Bacillus sp. NR5 UPM isolated from the soil in Malaysia into an Escherichia coli expression vector was successfully carried out. Analysis of the nucleotide sequences revealed the presence of an open reading frame of 2112 bp which encoded a protein containing 704 amino acids with a putative molecular weight of 78.6 kDa. The deduced amino acids sequence showed about 98% homology with the CGTase from Bacillus sp. KC201. Compared to the wild type, the CGTase that was produced in E. coli cells only required one- fourth of culture time and neutral pH to produce CGTase. After 12 h of cultivation, the CGTase activity in the culture medium reached 29.6 U/ml, which was approximately 2.5-fold higher than the CGTase from the parental strain. The CGTase was produced extracellularly by E. coli (94%) indicating the signal peptide was functional in E. coli. © 2011 Academic Journals. Source

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