Displaying publications 1 - 20 of 46 in total

Abstract:
Sort:
  1. First Report of Pantoea anthophila Causing Soft Rot Disease in Clausena lansium (Wampee) in China
    Zhou JN, Liu SY, Chen YF, Liao LS
    Plant Dis, 2015 Mar;99(3):416.
    PMID: 30699721 DOI: 10.1094/PDIS-10-14-1025-PDN
    Clausena lansium, also known as wampee (Clausena wampi), is a plant species native to China, Vietnam, the Philippines, Malaysia, and Indonesia, where it is widely cultivated, and also grown in India, Sri Lanka, Queensland, Florida, and Hawaii, but less frequently (3). The fruit can be consumed fresh or made into juice, jam, or succade. In summer to fall 2014, a soft rot disease was found in a wampee planting region in Yunan County, Guangdong Province, China. On Sept. 18, we collected diseased samples from a wampee orchard with about 20% disease incidence. The infected fruit initially showed pinpoint spots on the peel, water-soaked lesions, and light to dark brown discoloration. Spots expanded in 2 days, and tissues collapsed after 5 days. Severely affected fruit showed cracking or nonodorous decay. Five diseased samples were collected, and causal agents were isolated from symptomatic tissues 1 cm under the peel after surface sterilization in 0.3% NaOCl for 10 min and rinsing in sterile water three times. Tissues were placed on a Luria Bertani (LB) plate for culture. Ten representative isolates were selected for further characterization. No colony was isolated from healthy tissues. Colonies were round, smooth, with irregular edges, and produced a yellow pigment in culture. Biolog identification (Version 4.20.05) showed that all strains were gram negative, negative for indole production, and utilized glucose, maltose, trehalose, sucrose, D-lactose, and pectin but not sorbitol or gelatin. The isolates were identified as Pantoea agglomerans (SIM 0.69). Multilocus sequence analysis (MLSA) was conducted for rapid classification of the strains. Sequences of atpD, gyrB, infB, and rpoB were amplified using corresponding primers (2). All sequences of the 10 isolates were identical in each gene. BLASTn was performed, and maximum likelihood trees based on the concatenated nucleotide sequences of the four genes were constructed using MEGA6. Bootstrap values after 1,000 replicates were expressed as percentages. Results showed that the tested strain named CL1 was most homologous to P. anthophila, with 98% identity for atpD (KM521543), 100% for gyrB (KM521544), infB (KM521545), and rpoB (KM521546). The 16S rRNA sequence (KM521542) amplified by primers 27f and 1492r shared 99% identity with that of P. anthophila M19_2C (JN644500). P. anthophila was previously reclassified from P. agglomerans (3); therefore, we suggest naming this wampee pathogen P. anthophila. Subsequently, 10 wampee fruits were injected with 20 μl of bacterial suspension (1 × 108 CFU/ml) of strains CL1 and CL2, respectively, and another 10 were injected with 20 μl of LB medium as controls, all kept at 28°C for 4 days. Symptoms similar to those of natural infections were observed on inoculated fruits but not on the negative controls. Bacteria were isolated from diseased tissues and further identified as P. anthophila by gyrB sequencing. P. anthophila was reported to naturally infect balsam and marigold (1,2). To our knowledge, this is the first report of P. anthophila naturally causing soft rot disease and cracking on C. lansium (wampee). References: (1) C. Brady et al. Syst. Appl. Microbiol. 31:447, 2008. (2) C. Brady et al. Int. J. Syst. Evol. Microbiol. 59:2339, 2009. (3) J. Morton. Fruits of Warm Climates. Echo Point Books & Media, Miami, FL, 1987.
    Matched MeSH terms: Lactose
  2. Kinetic behaviour of free lipase and mica-based immobilized lipase catalyzing the synthesis of sugar esters
    Zaidan UH, Abdul Rahman MB, Othman SS, Basri M, Abdulmalek E, Rahman RN, et al.
    Biosci Biotechnol Biochem, 2011;75(8):1446-50.
    PMID: 21821960
    The utilization of natural mica as a biocatalyst support in kinetic investigations is first described in this study. The formation of lactose caprate from lactose sugar and capric acid, using free lipase (free-CRL) and lipase immobilized on nanoporous mica (NER-CRL) as a biocatalyst, was evaluated through a kinetic study. The apparent kinetic parameters, K(m) and V(max), were determined by means of the Michaelis-Menten kinetic model. The Ping-Pong Bi-Bi mechanism with single substrate inhibition was adopted as it best explains the experimental findings. The kinetic results show lower K(m) values with NER-CRL than with free-CRL, indicating the higher affinity of NER-CRL towards both substrates at the maximum reaction velocity (V(max,app)>V(max)). The kinetic parameters deduced from this model were used to simulate reaction rate data which were in close agreement with the experimental values.
    Matched MeSH terms: Lactose/metabolism*
  3. Fulltext The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer
    Yeow ST, Shahar A, Abdul Aziz N, Anuar MS, Yusof YA, Taip FS
    Drug Des Devel Ther, 2011;5:465-9.
    PMID: 22162640 DOI: 10.2147/DDDT.S25047
    To investigate the effect of feed preparation characteristics and operational parameters on mixing homogeneity in a convective batch ribbon mixer.
    Matched MeSH terms: Lactose/chemistry
  4. Centrifugal air-assisted melt agglomeration for fast-release "granulet" design
    Wong TW, Musa N
    Int J Pharm, 2012 Jul 1;430(1-2):184-96.
    PMID: 22531845 DOI: 10.1016/j.ijpharm.2012.04.026
    Conventional melt pelletization and granulation processes produce round and dense, and irregularly shaped but porous agglomerates respectively. This study aimed to design centrifugal air-assisted melt agglomeration technology for manufacture of spherical and yet porous "granulets" for ease of downstream manufacturing and enhancing drug release. A bladeless agglomerator, which utilized shear-free air stream to mass the powder mixture of lactose filler, polyethylene glycol binder and poorly water-soluble tolbutamide drug into "granulets", was developed. The inclination angle and number of vane, air-impermeable surface area of air guide, processing temperature, binder content and molecular weight were investigated with reference to "granulet" size, shape, texture and drug release properties. Unlike fluid-bed melt agglomeration with vertical processing air flow, the air stream in the present technology moved centrifugally to roll the processing mass into spherical but porous "granulets" with a drug release propensity higher than physical powder mixture, unprocessed drug and dense pellets prepared using high shear mixer. The fast-release attribute of "granulets" was ascribed to porous matrix formed with a high level of polyethylene glycol as solubilizer. The agglomeration and drug release outcomes of centrifugal air-assisted technology are unmet by the existing high shear and fluid-bed melt agglomeration techniques.
    Matched MeSH terms: Lactose/chemistry
  5. Formulation and evaluation of controlled release Eudragit buccal patches
    Wong CF, Yuen KH, Peh KK
    Int J Pharm, 1999 Feb 01;178(1):11-22.
    PMID: 10205621
    Controlled release buccal patches were fabricated using Eudragit NE40D and studied. Various bioadhesive polymers, namely hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose and Carbopol of different grades, were incorporated into the patches, to modify their bioadhesive properties as well as the rate of drug release, using metoprolol tartrate as the model drug. The in-vitro drug release was determined using the USP 23 dissolution test apparatus 5 with slight modification, while the bioadhesive properties were evaluated using texture analyzer equipment with chicken pouch as the model tissue. The incorporation of hydrophilic polymers was found to affect the drug release as well as enhance the bioadhesiveness. Although high viscosity polymers can enhance the bioadhesiveness of the patches, they also tend to cause non-homogeneous distribution of the polymers and drug, resulting in non-predictable drug-release rates. Of the various bioadhesive polymers studied, Cekol 700 appeared to be most satisfactory in terms of modifying the drug release and enhancement of the bioadhesive properties.
    Matched MeSH terms: Lactose/analogs & derivatives; Lactose/chemistry
  6. Relative Humidity Cycling: Implications on the Stability of Moisture-Sensitive Drugs in Solid Pharmaceutical Products
    Veronica N, Heng PWS, Liew CV
    Mol Pharm, 2023 Feb 06;20(2):1072-1085.
    PMID: 36480246 DOI: 10.1021/acs.molpharmaceut.2c00812
    The stability of a moisture-sensitive drug in tablet formulations depends particularly on the environment's relative humidity (RH) and the products' prior exposure to moisture. This study was designed to understand drug stability in relation to the moisture interaction of the excipients, moisture history of the tablets, and RH of the environment. The stability study was performed on tablets containing acetylsalicylic acid (ASA), formulated with common pharmaceutical excipients like native maize starch, microcrystalline cellulose (MCC), partially pregelatinized maize starch (PGS), dicalcium phosphate dihydrate (DCP), lactose, and mannitol. The tablets were subjected to storage conditions with RH cycling alternating between 53% and 75%. Results were also compared to tablets stored at a constant RH of 53% or 75%. The excipients demonstrated marked differences in their interactions with moisture. They could be broadly grouped as excipients with RH-dependent moisture content (native maize starch, MCC, and PGS) and RH-independent moisture content (DCP, lactose, and mannitol). As each excipient interacted differently with moisture, degradation of ASA in the tablets depended on the excipients' ability to modulate the moisture availability for degradation. The lowest ASA degradation was observed in tablets formulated with low moisture content water-soluble excipients, such as lactose and mannitol. The impact of RH cycling on ASA stability was apparent in tablets containing native maize starch, MCC, PGS, or DCP. These findings suggested that the choice of excipients influences the effect of moisture history on drug stability. The results from studies investigating moisture interaction of excipients and drug stability are valuable to understanding the inter-relationship between excipients, moisture history, and drug stability.
    Matched MeSH terms: Lactose*
  7. Fulltext Optimization of culture conditions for flexirubin production by Chryseobacterium artocarpi CECT 8497 using response surface methodology
    Venil CK, Zakaria ZA, Ahmad WA
    Acta Biochim. Pol., 2015;62(2):185-90.
    PMID: 25979288 DOI: 10.18388/abp.2014_870
    Flexirubins are the unique type of bacterial pigments produced by the bacteria from the genus Chryseobacterium, which are used in the treatment of chronic skin disease, eczema etc. and may serve as a chemotaxonomic marker. Chryseobacterium artocarpi CECT 8497, an yellowish-orange pigment producing strain was investigated for maximum production of pigment by optimizing medium composition employing response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Lactose, l-tryptophan and KH2PO4 were the most significant variables affecting pigment production. Box Behnken design (BBD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (521.64 mg/L) in 50 L bioreactor were lactose 11.25 g/L, l-tryptophan 6 g/L and KH2PO4 650 ppm. Production under optimized conditions increased to 7.23 fold comparing to its production prior to optimization. Results of this study showed that statistical optimization of medium composition and their interaction effects enable short listing of the significant factors influencing maximum pigment production from Chryseobacterium artocarpi CECT 8497. In addition, this is the first report optimizing the process parameters for flexirubin type pigment production from Chryseobacterium artocarpi CECT 8497.
    Matched MeSH terms: Lactose/metabolism
  8. Mixed polymer coating for modified release from coated spheroids
    Tan YT, Heng PW, Wan LS
    Pharm Dev Technol, 1999;4(4):561-70.
    PMID: 10578511
    Modified-release drug spheroids coated with an aqueous mixture of high-viscosity hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were formulated. The preparation of core drug spheroids and the coating procedures were performed using the rotary processor and a bottom-spray fluidized bed, respectively. Dissolution studies indicated that incorporation of suitable additives, such as poly(vinylpyrrolidone) (PVP) and poly(ethylene glycol) 400 (PEG) improved the flexibility and integrity of the coat layer by retarding the drug release. An increase in coating levels applied generally retarded the release rate of the drug. However, the ratio of HPMC to NaCMC in the mixed, plasticized polymeric coat played a more dominant role in determining the dissolution T50% values. The optimal ratio of HPMC to NaCMC for prolonged drug release was found to be 3:1, whereas an increase in the amount of NaCMC in the mixed polymer coat only increased drug release. The synergistic viscosity effect of HPMC and NaCMC in retarding drug release rate was greater in distilled water than in dissolution media of pH 1 and 7.2. Cross-sectional view of the scanning electron micrograph showed that all of the coated spheroids exhibited a well-fused, continuous, and distinct layer of coating film. The drug release kinetics followed a biexponential first-order kinetic model.
    Matched MeSH terms: Lactose/analogs & derivatives*
  9. In vitro evaluation of chitosan coated- and uncoated-calcium alginate beads containing methyl salicylate-lactose physical mixture
    Tamilvanan S, Karmegam S
    Pharm Dev Technol, 2012 Jul-Aug;17(4):494-501.
    PMID: 21609308 DOI: 10.3109/10837450.2010.550622
    Methyl salicylate-lactose physical mixture (1:1 and 1:1.5 ratios) was incorporated into calcium alginate beads by a coacervation method involving an ionotropic gelation/polyelectrolyte complexation approach.
    Matched MeSH terms: Lactose/administration & dosage
  10. The effect of high lactose-isomaltulose on cognitive performance of young children. A double blind cross-over design study
    Taib MN, Shariff ZM, Wesnes KA, Saad HA, Sariman S
    Appetite, 2012 Feb;58(1):81-7.
    PMID: 21986189 DOI: 10.1016/j.appet.2011.09.004
    Changes in blood glucose are hypothesized to influence cognitive performance and these changes can be affected by certain nutrients. This double-blind 4-period cross-over study evaluated the effects of a slow-release modified sucrose (isomaltulose) in combination with a high concentration of lactose on cognitive performance of 5-6 year old children. Thirty children received a standard growing upmilk (Std GUM), reformulated growing up milk (Reform GUM), standard growing up milk with lactose-isomaltulose (Iso GUM), and a standard glucose drink (Glucose). The CDR System, a computerised cognitive assessment system, was used to assess various measures of attention and memory of the children at baseline (T=0), 60 (T=1), 120 (T=2), and 180 (T=3) minutes following the intake of test products. Overall, there was a decline in performance over the morning on almost every cognitive task. Children showed better attention following consumption of Iso GUM compared to Std GUM but attention was not significantly different than Reform GUM and glucose. Also, Iso GUM conferred a beneficial effect over both Reform GUM and glucose on sensitivity index of numeric working memory with no difference observed between Iso GUM and Std GUM. Surprisingly, glucose group showed lowest decline in the sensitivity index of spatial working memory and highest speed in picture recognition, although the latter was significantly better than Reform GUM only. For speed of spatial working memory, Reform GUM had the lowest decline but was significantly different only with Std GUM. There was, however, no significant difference among conditions for continuity of attention, speed of numeric working memory and picture recognition sensitivity. Despite the small sample size, the findings are intriguing as carbohydrate composition seems to influence some aspects of cognitive performance such as attention and memory. However, further studies are needed to confirm these findings.
    Matched MeSH terms: Lactose/administration & dosage*
  11. Fulltext Beneficial Properties of Probiotics
    Shi LH, Balakrishnan K, Thiagarajah K, Mohd Ismail NI, Yin OS
    Trop Life Sci Res, 2016 Aug;27(2):73-90.
    PMID: 27688852 MyJurnal DOI: 10.21315/tlsr2016.27.2.6
    Probiotics are live microorganisms that can be found in fermented foods and cultured milk, and are widely used for the preparation of infant food. They are well-known as "health friendly bacteria", which exhibit various health beneficial properties such as prevention of bowel diseases, improving the immune system, for lactose intolerance and intestinal microbial balance, exhibiting antihypercholesterolemic and antihypertensive effects, alleviation of postmenopausal disorders, and reducing traveller's diarrhoea. Recent studies have also been focused on their uses in treating skin and oral diseases. In addition to that, modulation of the gut-brain by probiotics has been suggested as a novel therapeutic solution for anxiety and depression. Thus, this review discusses on the current probiotics-based products in Malaysia, criteria for selection of probiotics, and evidences obtained from past studies on how probiotics have been used in preventing intestinal disorders via improving the immune system, acting as an antihypercholesterolemic factor, improving oral and dermal health, and performing as anti-anxiety and anti-depressive agents.
    Matched MeSH terms: Lactose Intolerance
  12. Fulltext Amount and types of sugars in selected commercial and traditional kuih in Klang Valley, Malaysia
    Sharifah Azizah, T.N., Nik Shanita, S., Hasnah, H.
    International Food Research Journal, 2015;22(6):2642-2649.
    MyJurnal
    The aim of this study was to determine the specific content and type of sugars in selected commercial and traditional kuih in Klang Valley. The selection of the kuih was based on the validated Food Frequency Questionnaire (FFQ) for sugar. The selected commercial kuih was doughnut coated with sugar (Big Apple) while the ten traditional kuih samples consisted of kuih bingka ubi, kuih kasui, kuih keria, kuih koci, kuih lapis, kuih lopes, kuih onde-onde, kuih sagu, kuih seri muka and kuih talam. The doughnut coated with sugar (Big Apple) was purchased from Big Apple Donuts and Coffee franchise at two different locations, while the traditional kuih were randomly bought from stalls, cafeterias and restaurants around Kuala Lumpur and Rawang. The types and amount of sugar were determined using High Performance High Chromatography (HPLC) with a refractive index (RI) detector. Results showed that doughnut coated with sugar (Big Apple) has the highest starch content (22.6±0.3 g/100g) and kuih keria contained the highest available carbohydrate (41.5±1.7 g/100g), comprising of 24.2±2.4 g/100g total sugar and 17.3±0.7 g/100g of starch. The least available carbohydrate content was found in kuih talam (20.0±0.5 g/100g), which was 50% lower than the one in kuih keria. Major individual sugars detected in all kuih samples were consisted of sucrose (60.0%), glucose (16.2%), fructose (14.0%), maltose (9.5%) and lactose (0.3%). Majority of the kuih samples (90.9%) in this study can be categorized as medium sugar while only kuih keria was categorized as high sugar. Based on the two main ingredients (sugar and flour) used in the preparation of kuih, results showed that all kuih samples can be categorized as medium sugarmedium starch. In conclusion, this study served as a guideline by locals in selecting kuih of
    different sugar levels.
    Matched MeSH terms: Lactose
  13. Application of similarity factor in development of controlled-release diltiazem tablet
    Peh KK, Wong CF
    Drug Dev Ind Pharm, 2000 Jul;26(7):723-30.
    PMID: 10872090
    Controlled-release grade hydroxypropylmethylcellulose (HPMC) or xanthan gum (XG) and microcrystalline cellulose (MCC) were employed to prepare controlled-release diltiazem hydrochloride tablets. The similarity factor f2 was used for dissolution profile comparison using Herbesser 90 SR as a reference product. Drug release could be sustained in a predictable manner by modifying the content of HPMC or XG. Moreover, the drug release profiles of tablets prepared using these matrix materials were not affected by pH and agitation rate. The f2 values showed that only one batch of tablets (of diltiazem HCl, HPMC or XG, and MCC in proportions of 3.0:3.0:4.0) was considered similar to that of the reference product, with values above 50. The unbiased similarity factor f2* values were not much different from the f2 values, ascribing to a small dissolution variance of the test and reference products. The amount of HPMC or XG incorporated to produce tablets with the desired dissolution profile could be determined from the curves of f2 versus polymer content. Hence, the f2 values can be applied as screening and optimization tools during development of controlled-release preparations.
    Matched MeSH terms: Lactose/analogs & derivatives; Lactose/chemistry
  14. Occurrence of Blastocystis sp. in water catchments at Malay villages and Aboriginal settlement during wet and dry seasons in Peninsular Malaysia
    Noradilah SA, Lee IL, Anuar TS, Salleh FM, Abdul Manap SN, Mohd Mohtar NS, et al.
    PeerJ, 2016;4:e2541.
    PMID: 27761331
    In the tropics, there are too few studies on isolation of Blastocystis sp. subtypes from water sources; in addition, there is also an absence of reported studies on the occurrence of Blastocystis sp. subtypes in water during different seasons. Therefore, this study was aimed to determine the occurrence of Blastocystis sp. subtypes in river water and other water sources that drained aboriginal vicinity of highly endemic intestinal parasitic infections during wet and dry seasons. Water samples were collected from six sampling points of Sungai Krau (K1-K6) and a point at Sungai Lompat (K7) and other water sources around the aboriginal villages. The water samples were collected during both seasons, wet and dry seasons. Filtration of the water samples were carried out using a flatbed membrane filtration system. The extracted DNA from concentrated water sediment was subjected to single round polymerase chain reaction and positive PCR products were subjected to sequencing. All samples were also subjected to filtration and cultured on membrane lactose glucuronide agar for the detection of faecal coliforms. During wet season, Blastocystis sp. ST1, ST2 and ST3 were detected in river water samples. Blastocystis sp. ST3 occurrence was sustained in the river water samples during dry season. However Blastocystis sp. ST1 and ST2 were absent during dry season. Water samples collected from various water sources showed contaminations of Blastocystis sp. ST1, ST2, ST3 and ST4, during wet season and Blastocystis sp. ST1, ST3, ST8 and ST10 during dry season. Water collected from all river sampling points during both seasons showed growth of Escherichia coli and Enterobacter aerogenes, indicating faecal contamination. In this study, Blastocystis sp. ST3 is suggested as the most robust and resistant subtype able to survive in any adverse environmental condition. Restriction and control of human and animal faecal contaminations to the river and other water sources shall prevent the transmission of Blastocystis sp. to humans and animals in this aboriginal community.
    Matched MeSH terms: Lactose
  15. Fulltext Optimization of Protective Agents for The Freeze-Drying of Paenibacillus polymyxa Kp10 as a Potential Biofungicide
    Nasran HS, Mohd Yusof H, Halim M, Abdul Rahman N
    Molecules, 2020 Jun 04;25(11).
    PMID: 32512825 DOI: 10.3390/molecules25112618
    Anthracnose is a fungal disease causing major losses in crop production. Chemical fungicides widely used in crop plantations to combat fungal infections can be a threat to the environment and humans in the long term. Recently, biofungicides have gained much interest as an alternative to chemical fungicides due to their environmentally friendly nature. Biofungicide products in powder form can be formulated using the freeze-drying technique to provide convenient storage. Protective agent formulation is needed in maintaining the optimal viable cells of biofungicide products. In this study, 8.10 log colony-forming unit (CFU)/mL was the highest cell viability of Paenibacillus polymyxa Kp10 at 22 h during incubation. The effects of several selected protective agents on the viability of P. polymyxa Kp10 after freeze-drying were studied. Response surface methodology (RSM) was used for optimizing formulation for the protective agents. The combination of lactose (10% w/v), skim milk (20% w/v), and sucrose (27.5% w/v) was found to be suitable for preserving P. polymyxa Kp10 during freeze-drying. Further, P. polymyxa Kp10 demonstrated the ability to inhibit fungal pathogens, Colletotrichum truncatum and C. gloeosporioides, at 60.18% and 66.52% of inhibition of radial growth, respectively.
    Matched MeSH terms: Lactose/pharmacology
  16. Evaluating the Potential of Oleaginous Yeasts as Feedstock for Biodiesel Production
    Mukhtar H, Suliman SM, Shabbir A, Mumtaz MW, Rashid U, Rahimuddin SA
    Protein Pept Lett, 2018;25(2):195-201.
    PMID: 29359654 DOI: 10.2174/0929866525666180122112805
    BACKGROUND: Lipid-producing microorganisms, said to be oleaginous have been recognized since several years. We had investigated the effects of medium components and culturing situations on cell growth and lipid accumulation of oleaginous yeasts which were analytically examined so as to enhance lipid yield for biodiesel production.

    OBJECTIVE: The main objective of this study was to explore oleaginous yeast, Yarrowia lipolytica isolated from soil and optimization of culture conditions and medium components to obtained better quality microbial oil for biodiesel production.

    METHODS: Fifty yeast strains were isolated from soil from different regions of Lahore and eleven of them were selected for oil production. The isolated yeast colonies were screened to further check their lipid producing capabilities by the qualitative analysis. Five yeast strains were designated as oleaginous because they produced more than 16% of oil based on their biomass. To estimate the total lipid content of yeast cells, the extraction of lipids was done by performing the procedure proposed by Bligh and Dyer. The transesterification of yeast oils was performed by using different methods. There were three different strategies customized to transesterifying microbial oil using base catalyzed transesterification, acid catalyzed transesterification and enzyme-based transesterification. After completion of transesterification, sample was used for fatty acid methyl esters (FAMEs) were analyzed by gas-chromatograph with ionization detector type MS.

    RESULTS: The isolate IIB-10 identified as Yarrowia lipolytica produced maximum amount of lipids i.e. 22.8%. More amount of biomass was obtained when cane molasses was utilized as carbon source where it produced 29.4 g/L of biomass while sucrose and lactose were not utilized by IIB-10 and no biomass was obtained. Similarly, meat extracts showed best results when it was used as nitrogen source because it resulted in 35.8 g/L biomass of Yarrowia lipolytica IIB-10. The culturing conditions like size of inoculum, effect of pH and time of incubation were also studied. The 10% of inoculum size produced 25.4 g/L biomass at 120 h incubation time, while the pH 7 was the optimum pH at which 24.8 g/L biomass was produced by Yarrowia lipolytica IIB-10. GC-MS analysis showed that biodiesel produced by transesterification contained similar fatty acids as found in vegetable oil for this reason it is widely accepted feedstock for biodiesel production.

    CONCLUSION: The analysis of fatty acids methyl esters showed the similar composition of microbial oil as in vegetable oils and high amount of methyl esters were obtained after transesterification. Therefore, potentially oleaginous yeast could be used to generate a large amount of lipids for biodiesel production that will be the better substitute of petroleum-based diesel and will also control the environmental pollution.

    Matched MeSH terms: Lactose
  17. Manipulation of nanofiber-based β-galactosidase nanoenvironment for enhancement of galacto-oligosaccharide production
    Misson M, Dai S, Jin B, Chen BH, Zhang H
    J Biotechnol, 2016 Mar 20;222:56-64.
    PMID: 26876609 DOI: 10.1016/j.jbiotec.2016.02.014
    The nanoenvironment of nanobiocatalysts, such as local hydrophobicity, pH and charge density, plays a significant role in optimizing the enzymatic selectivity and specificity. In this study, Kluyveromyces lactis β-galactosidase (Gal) was assembled onto polystyrene nanofibers (PSNFs) to form PSNF-Gal nanobiocatalysts. We proposed that local hydrophobicity on the nanofiber surface could expel water molecules so that the transgalactosylation would be preferable over hydrolysis during the bioconversion of lactose, thus improve the galacto-oligosaccharides (GOS) yield. PSNFs were fabricated by electro-spinning and the operational parameters were optimized to obtain the nanofibers with uniform size and ordered alignment. The resulting nanofibers were functionalized for enzyme immobilization through a chemical oxidation method. The functionalized PSNF improved the enzyme adsorption capacity up to 3100mg/g nanofiber as well as enhanced the enzyme stability with 80% of its original activity. Importantly, the functionalized PSNF-Gal significantly improved the GOS yield and the production rate was up to 110g/l/h in comparison with 37g/l/h by free β-galactosidase. Our research findings demonstrate that the localized nanoenvironment of the PSNF-Gal nanobiocatalysts favour transgalactosylation over hydrolysis in lactose bioconversion.
    Matched MeSH terms: Lactose
  18. Dendrimer-like nanoparticles based β-galactosidase assembly for enhancing its selectivity toward transgalactosylation
    Misson M, Du X, Jin B, Zhang H
    Enzyme Microb Technol, 2016 Mar;84:68-77.
    PMID: 26827776 DOI: 10.1016/j.enzmictec.2015.12.008
    Functional nanomaterials have been pursued to assemble nanobiocatalysts since they can provide unique hierarchical nanostructures and localized nanoenvironments for enhancing enzyme specificity, stability and selectivity. Functionalized dendrimer-like hierarchically porous silica nanoparticles (HPSNs) was fabricated for assembling β-galactosidase nanobiocatalysts for bioconversion of lactose to galacto-oligosaccharides (GOS). The nanocarrier was functionalized with amino (NH2) and carboxyl (COOH) groups to facilitate enzyme binding, benchmarking with non-functionalized HPSNs. Successful conjugation of the functional groups was confirmed by FTIR, TGA and zeta potential analysis. HPSNs-NH2 showed 1.8-fold and 1.1-fold higher β-galactosidase adsorption than HPSNs-COOH and HPSNs carriers, respectively, with the highest enzyme adsorption capacity of 328mg/g nanocarrier at an initial enzyme concentration of 8mg/ml. The HPSNs-NH2 and β-galactosidase assembly (HPSNs-NH2-Gal) demonstrated to maintain the highest activity at all tested enzyme concentrations and exhibited activity up to 10 continuous cycles. Importantly, HPSNs-NH2-Gal was simply recycled through centrifugation, overcoming the challenging problems of separating the nanocarrier from the reaction medium. HPSNs-NH2-Gal had distinguished catalytic reaction profiles by favoring transgalactosylation, enhancing GOS production of up to 122g/l in comparison with 56g/l by free β-galactosidase. Furthermore, it generated up to 46g/l GOS at a lower initial lactose concentration while the free counterpart had negligible GOS production as hydrolysis was overwhelmingly dominant in the reaction system. Our research findings show the amino-functionalized HPSNs can selectively promote the enzyme activity of β-galactosidase for transgalactosylation, which is beneficial for GOS production.
    Matched MeSH terms: Lactose/metabolism
  19. Unilateral rampant caries: an unusual presentation
    Meon R
    J Clin Pediatr Dent, 1991;16(1):10-2.
    PMID: 1815737
    An unusual presentation of rampant caries in a child was described. Lactose from bovine milk, bad feeding habits and poor oral hygiene appear to play a major role in its aetiology.
    Matched MeSH terms: Lactose/adverse effects
  20. The Potential Source of B. licheniformis Contamination During Whey Protein Concentrate 80 Manufacture
    Md Zain SN, Bennett R, Flint S
    J Food Sci, 2017 Mar;82(3):751-756.
    PMID: 28135405 DOI: 10.1111/1750-3841.13633
    The objective of this study was to determine the possible source of predominant Bacillus licheniformis contamination in a whey protein concentrate (WPC) 80 manufacturing plant. Traditionally, microbial contaminants of WPC were believed to grow on the membrane surfaces of the ultrafiltration plant as this represents the largest surface area in the plant. Changes from hot to cold ultrafiltration have reduced the growth potential for bacteria on the membrane surfaces. Our recent studies of WPCs have shown the predominant microflora B. licheniformis would not grow in the membrane plant because of the low temperature (10 °C) and must be growing elsewhere. Contamination of dairy products is mostly due to bacteria being released from biofilm in the processing plant rather from the farm itself. Three different reconstituted WPC media at 1%, 5%, and 20% were used for biofilm growth and our results showed that B. licheniformis formed the best biofilm at 1% (low solids). Further investigations were done using 3 different media; tryptic soy broth, 1% reconstituted WPC80, and 1% reconstituted WPC80 enriched with lactose and minerals to examine biofilm growth of B. licheniformis on stainless steel. Thirty-three B. licheniformis isolates varied in their ability to form biofilm on stainless steel with stronger biofilm in the presence of minerals. The source of biofilms of thermo-resistant bacteria such as B. licheniformis is believed to be before the ultrafiltration zone represented by the 1% WPC with lactose and minerals where the whey protein concentration is about 0.6%.
    Matched MeSH terms: Lactose
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links