Displaying publications 81 - 100 of 162 in total

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  1. Nanofork for single cells adhesion measurement via ESEM-nanomanipulator system
    Ahmad MR, Nakajima M, Kojima M, Kojima S, Homma M, Fukuda T
    IEEE Trans Nanobioscience, 2012 Mar;11(1):70-8.
    PMID: 22275723 DOI: 10.1109/TNB.2011.2179809
    In this paper, single cells adhesion force was measured using a nanofork. The nanofork was used to pick up a single cell on a line array substrate inside an environmental scanning electron microscope (ESEM). The line array substrate was used to provide small gaps between the single cells and the substrate. Therefore, the nanofork could be inserted through these gaps in order to successfully pick up a single cell. Adhesion force was measured during the cell pick-up process from the deflection of the cantilever beam. The nanofork was fabricated using focused ion beam (FIB) etching process while the line array substrate was fabricated using nanoimprinting technology. As to investigate the effect of contact area on the strength of the adhesion force, two sizes of gap distance of line array substrate were used, i.e., 1 μm and 2 μm. Results showed that cells attached on the 1 μm gap line array substrate required more force to be released as compared to the cells attached on the 1 μm gap line array substrate.
    Matched MeSH terms: Saccharomyces cerevisiae/cytology
  2. Membrane separations
    Walter JK, Jin Z, Jornitz MW, Gorrschalk U
    Methods Biochem Anal, 2011;54:281-317.
    PMID: 21954783
    Matched MeSH terms: Saccharomyces cerevisiae/isolation & purification
  3. Simultaneous saccharification and fermentation of ground corn stover for the production of fuel ethanol using Phanerochaete chrysosporium, Gloeophyllum trabeum, Saccharomyces cerevisiae, and Escherichia coli K011
    Vincent M, Pometto AL, van Leeuwen JH
    J Microbiol Biotechnol, 2011 Jul;21(7):703-10.
    PMID: 21791956
    Enzymatic saccharification of corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum and subsequent fermentation of the saccharification products to ethanol by Saccharomyces cerevisiae and Escherichia coli K011 were achieved. Prior to simultaneous saccharification and fermentation (SSF) for ethanol production, solid-state fermentation was performed for four days on ground corn stover using either P. chrysosporium or G. trabeum to induce in situ cellulase production. During SSF with S. cerevisiae or E. coli, ethanol production was the highest on day 4 for all samples. For corn stover treated with P. chrysosporium, the conversion to ethanol was 2.29 g/100 g corn stover with S. cerevisiae as the fermenting organism, whereas for the sample inoculated with E. coli K011, the ethanol production was 4.14 g/100 g corn stover. Corn stover treated with G. trabeum showed a conversion 1.90 and 4.79 g/100 g corn stover with S. cerevisiae and E. coli K011 as the fermenting organisms, respectively. Other fermentation co-products, such as acetic acid and lactic acid, were also monitored. Acetic acid production ranged between 0.45 and 0.78 g/100 g corn stover, while no lactic acid production was detected throughout the 5 days of SSF. The results of our experiment suggest that it is possible to perform SSF of corn stover using P. chrysosporium, G. trabeum, S. cerevisiae and E. coli K011 for the production of fuel ethanol.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  4. Optimization study of ethanolic fermentation from oil palm trunk, rubberwood and mixed hardwood hydrolysates using Saccharomyces cerevisiae
    Chin KL, H'ng PS, Wong LJ, Tey BT, Paridah MT
    Bioresour Technol, 2010 May;101(9):3287-91.
    PMID: 20056407 DOI: 10.1016/j.biortech.2009.12.036
    Ethanolic fermentation using Saccharomyces cerevisiae was carried out on three types of hydrolysates produced from lignocelulosic biomass which are commonly found in Malaysia such as oil palm trunk, rubberwood and mixed hardwood. The effect of fermentation temperature and pH of hydrolysate was evaluated to optimize the fermentation efficiency which defined as maximum ethanol yield in minimum fermentation time. The fermentation process using different temperature of 25 degrees Celsius, 30 degrees Celsius and 40 degrees Celsius were performed on the prepared fermentation medium adjusted to pH 4, pH 6 and pH 7, respectively. Results showed that the fermentation time was significantly reduced with the increase of temperature but an adverse reduction in ethanol yield was observed using temperature of 40 degrees Celsius. As the pH of hydrolysate became more acidic, the ethanol yield increased. Optimum fermentation efficiency for ethanolic fermentation of lignocellulosic hydrolysates using S. cerevisiae can be obtained using 33.2 degrees Celsius and pH 5.3.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  5. Fulltext Phylogenetic and Transcripts Profiling of Glucose Sensing Related Genes in Candida glabrata
    Ng TS, Mohd Desa MN, Sandai D, Chong PP, Than LT
    Jundishapur J Microbiol, 2015 Nov;8(11):e25177.
    PMID: 26855740 DOI: 10.5812/jjm.25177
    BACKGROUND: The sensing mechanism of glucose in Saccharomyces cerevisiae is well studied. However, such information is scarcely found in other yeast species such as Candida glabrata.

    OBJECTIVES: This study aimed to identify the glucose sensing pathway related genes of C. glabrata and to analyze the regulation pattern of these genes in response to different surrounding glucose concentrations through the quantitative real time polymerase chain reaction (qRT-PCR).

    MATERIALS AND METHODS: Phylogenetic analysis was carried out on predicted amino acid sequences of C. glabrata and S. cerevisiae to compare their degree of similarity. In addition, the growth of C. glabrata in response to different amounts of glucose (0%, 0.01%, 0.1%, 1% and 2%) was evaluated via the spot dilution assay on prepared agar medium. Besides, the SNF3 and RGT2, which act as putative glucose sensors, and the RGT1 and MIG1, which act as putative transcriptional regulators and selected downstream hexose transporters (HXTs), were analysed through qRT-PCR analysis for the gene expression level under different glucose concentrations.

    RESULTS: Comparative analysis of predicted amino acids in the phylogenetic tree showed high similarity between C. glabrata and S cerevisiae. Besides, C. glabrata demonstrated the capability to grow in glucose levels as low as 0.01% in the spot dilution assay. In qRT-PCR analysis, differential expressions were observed in selected genes when C. glabrata was subjected to different glucose concentrations.

    CONCLUSIONS: The constructed phylogenetic tree suggests the close evolutionary relationship between C. glabrata and S. cerevisiae. The capability of C. glabrata to grow in extremely low glucose environments and the differential expression of selected glucose-sensing related genes suggested the possible role of these genes in modulating the growth of C. glabrata in response to different glucose concentrations. This study helps deepen our understanding of the glucose sensing mechanism in C. glabrata and serves to provide fundamental data that may assist in unveiling this mechanism as a potential drug target.

    Matched MeSH terms: Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins
  6. Isatin based Schiff bases as inhibitors of α-glucosidase: Synthesis, characterization, in vitro evaluation and molecular docking studies
    Rahim F, Malik F, Ullah H, Wadood A, Khan F, Javid MT, et al.
    Bioorg Chem, 2015 Jun;60:42-8.
    PMID: 25955493 DOI: 10.1016/j.bioorg.2015.03.005
    Isatin base Schiff bases (1-20) were synthesized, characterized by (1)H NMR and EI/MS and evaluated for α-glucosidase inhibitory potential. Out of these twenty (20) compounds only six analogs showed potent α-glucosidase inhibitory potential with IC50 value ranging in between 2.2±0.25 and 83.5±1.0μM when compared with the standard acarbose (IC50=840±1.73μM). Among the series compound 2 having IC50 value (18.3±0.56μM), 9 (83.5±1.0μM), 11 (3.3±0.25μM), 12 (2.2±0.25μM), 14 (11.8±0.15μM), and 20 (3.0±0.15μM) showed excellent inhibitory potential many fold better than the standard acarbose. The binding interactions of these active analogs were confirmed through molecular docking.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  7. Fulltext A comparative study of adult mosquito trapping using dry ice and yeast generated carbon dioxide
    Oli K, Jeffery J, Vythilingam I
    Trop Biomed, 2005 Dec;22(2):249-51.
    PMID: 16883295 MyJurnal
    Adult mosquito collections were conducted for 12 weeks in two residential areas in Kuala Lumpur. The CDC light traps were compared using dry ice and yeast as sources of carbon dioxide attractants for mosquitoes. The efficacy of the dry ice baited trap was significant over yeast generated CO2 trap. The predominant species obtained were Culex quinquefasciatus, Stegomyia albopicta and Armigeres subalbatus.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  8. Strategies for humanizing glycosylation pathways and producing recombinant glycoproteins in microbial expression systems
    Khan AH, Noordin R
    Biotechnol Prog, 2019 03;35(2):e2752.
    PMID: 30457225 DOI: 10.1002/btpr.2752
    Homogeneously glycosylated proteins are essential for analyzing the structure of N-glycans, studying their consequences inside cells, and developing therapeutic glycoproteins. However, the isolation of glycoproteins with homogeneous glycans from human is difficult since glycoforms slightly differ from each other with respect to molecular weight and charge. Microbial expression systems have numerous benefits in expression technology and have gained great attention, because they are more adaptable to the biotechnology industry. While selecting an expression host, the glycosylation pattern must be taken into account, because glycosylation strongly depends on cellular production system and selected production clone. This review discussed the technological developments in glycoengineering of microbial expression systems for humanizing the glycosylation profile and highlighted the expression potential of Leishmania expression system. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2752, 2019.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  9. Alcoholic fermentation of soursop (Annona muricata) juice via an alternative fermentation technique
    Ho CW, Lazim A, Fazry S, Hussain Zaki UKH, Massa S, Lim SJ
    J Sci Food Agric, 2020 Feb;100(3):1012-1021.
    PMID: 31646636 DOI: 10.1002/jsfa.10103
    BACKGROUND: Wines are produced via the alcoholic fermentation of suitable substrates, usually sugar (sugar cane, grapes) and carbohydrates (wheat, grain). However, conventional alcoholic fermentation is limited by the inhibition of yeast by ethanol produced, usually at approximately 13-14%. Aside from that, soursop fruit is a very nutritious fruit, although it is highly perishable, and thus produces a lot of wastage. Therefore, the present study aimed to produce fermented soursop juice (soursop wine), using combination of two starter cultures, namely mushroom (Pleurotus pulmonarius) and yeast (Saccharomyces cerevisiae), as well as to determine the effects of fermentation on the physicochemical and antioxidant activities of fermented soursop juice. Optimisation of four factors (pH, temperature, time and culture ratio) using response surface methodology were performed to maximise ethanol production.

    RESULTS: The optimised values for alcoholic fermentation were pH 4.99, 28.29 °C, 131 h and a 0.42 culture ratio (42:58, P. pulmonarius mycelia:S. cerevisiae) with a predicted ethanol concentration of 22.25%. Through a verification test, soursop wine with 22.29 ± 0.52% ethanol was produced. The antioxidant activities (1,1-diphenyl-2-picrylhydrazyl and ferric reducing antioxidant power) showed a significant (P 

    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  10. Fulltext Separation and Detection of Escherichia coli and Saccharomyces cerevisiae Using a Microfluidic Device Integrated with an Optical Fibre
    Kamuri MF, Zainal Abidin Z, Yaacob MH, Hamidon MN, Md Yunus NA, Kamarudin S
    Biosensors (Basel), 2019 Mar 14;9(1).
    PMID: 30875829 DOI: 10.3390/bios9010040
    This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2⁻24 s and a flow rate range of 1.2⁻9.6 μ L min - 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min - 1 at a constant frequency, voltage, and a low conductivity.
    Matched MeSH terms: Saccharomyces cerevisiae/cytology*
  11. Fulltext Bi-allelic LETM1 variants perturb mitochondrial ion homeostasis leading to a clinical spectrum with predominant nervous system involvement
    Kaiyrzhanov R, Mohammed SEM, Maroofian R, Husain RA, Catania A, Torraco A, et al.
    Am J Hum Genet, 2022 Sep 01;109(9):1692-1712.
    PMID: 36055214 DOI: 10.1016/j.ajhg.2022.07.007
    Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) encodes an inner mitochondrial membrane protein with an osmoregulatory function controlling mitochondrial volume and ion homeostasis. The putative association of LETM1 with a human disease was initially suggested in Wolf-Hirschhorn syndrome, a disorder that results from de novo monoallelic deletion of chromosome 4p16.3, a region encompassing LETM1. Utilizing exome sequencing and international gene-matching efforts, we have identified 18 affected individuals from 11 unrelated families harboring ultra-rare bi-allelic missense and loss-of-function LETM1 variants and clinical presentations highly suggestive of mitochondrial disease. These manifested as a spectrum of predominantly infantile-onset (14/18, 78%) and variably progressive neurological, metabolic, and dysmorphic symptoms, plus multiple organ dysfunction associated with neurodegeneration. The common features included respiratory chain complex deficiencies (100%), global developmental delay (94%), optic atrophy (83%), sensorineural hearing loss (78%), and cerebellar ataxia (78%) followed by epilepsy (67%), spasticity (53%), and myopathy (50%). Other features included bilateral cataracts (42%), cardiomyopathy (36%), and diabetes (27%). To better understand the pathogenic mechanism of the identified LETM1 variants, we performed biochemical and morphological studies on mitochondrial K+/H+ exchange activity, proteins, and shape in proband-derived fibroblasts and muscles and in Saccharomyces cerevisiae, which is an important model organism for mitochondrial osmotic regulation. Our results demonstrate that bi-allelic LETM1 variants are associated with defective mitochondrial K+ efflux, swollen mitochondrial matrix structures, and loss of important mitochondrial oxidative phosphorylation protein components, thus highlighting the implication of perturbed mitochondrial osmoregulation caused by LETM1 variants in neurological and mitochondrial pathologies.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism
  12. Screening and characterization of microbial inhibitors against eukaryotic protein phosphatases (PP1 and PP2A)
    Ong SM, Voo LY, Lai NS, Stark MJ, Ho CC
    J Appl Microbiol, 2007 Mar;102(3):680-92.
    PMID: 17309617
    To identify novel microbial inhibitors of protein phosphatase 1 (PP1).
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology; Saccharomyces cerevisiae/genetics
  13. Fulltext Heterologous expression of cytotoxic sesquiterpenoids from the medicinal mushroom Lignosus rhinocerotis in yeast
    Yap HY, Muria-Gonzalez MJ, Kong BH, Stubbs KA, Tan CS, Ng ST, et al.
    Microb Cell Fact, 2017 Jun 12;16(1):103.
    PMID: 28606152 DOI: 10.1186/s12934-017-0713-x
    BACKGROUND: Genome mining facilitated by heterologous systems is an emerging approach to access the chemical diversity encoded in basidiomycete genomes. In this study, three sesquiterpene synthase genes, GME3634, GME3638, and GME9210, which were highly expressed in the sclerotium of the medicinal mushroom Lignosus rhinocerotis, were cloned and heterologously expressed in a yeast system.

    RESULTS: Metabolite profile analysis of the yeast culture extracts by GC-MS showed the production of several sesquiterpene alcohols (C15H26O), including cadinols and germacrene D-4-ol as major products. Other detected sesquiterpenes include selina-6-en-4-ol, β-elemene, β-cubebene, and cedrene. Two purified major compounds namely (+)-torreyol and α-cadinol synthesised by GME3638 and GME3634 respectively, are stereoisomers and their chemical structures were confirmed by 1H and 13C NMR. Phylogenetic analysis revealed that GME3638 and GME3634 are a pair of orthologues, and are grouped together with terpene synthases that synthesise cadinenes and related sesquiterpenes. (+)-Torreyol and α-cadinol were tested against a panel of human cancer cell lines and the latter was found to exhibit selective potent cytotoxicity in breast adenocarcinoma cells (MCF7) with IC50 value of 3.5 ± 0.58 μg/ml while α-cadinol is less active (IC50 = 18.0 ± 3.27 μg/ml).

    CONCLUSIONS: This demonstrates that yeast-based genome mining, guided by transcriptomics, is a promising approach for uncovering bioactive compounds from medicinal mushrooms.

    Matched MeSH terms: Saccharomyces cerevisiae/genetics; Saccharomyces cerevisiae/metabolism*
  14. Lipid biosynthesis in Cunninghamella bainieri 2A1 in N-limited and N-excess media
    Taha EM, Omar O, Yusoff WM, Hamid AA
    Annals of microbiology, 2010 Dec;60(4):615-622.
    PMID: 21125005
    Lipid biosynthesis and fatty acids composition of oleaginous zygomycetes, namely Cunninghamella bainieri 2A1, cultured in media with excess or limited nitrogen were quantitatively determined at different times of culture growth. Accumulation of lipids occurred even when the activity of NAD(+)-ICDH (β-Nicotinamide adenine dinucleotide-isocitrate dehydrogenase) was still detectable in both media. In C. bainieri 2A1, under nitrogen limitation, the ratio of lipids was around 35%, whereas in nitrogen excess medium (feeding media supplemented with ammonium tartarate), the lipid ratio decreased. The amount of this decrease depended on the level of ammonium tartarate in the media. The main findings in this paper were that C. bainieri 2A1 has the ability to accumulate lipid although nitrogen concentration detected inside the media and that NAD-ICDH was active in all culture periods. These results proved that the strain C. bainieri 2A1 has an alternative behavior in lipid biosynthesis that differs from yeast. According to the old hypotheses, yeasts could not accumulate lipid more than 10% when nitrogen was detected inside the media. Nitrogen-limited and excess media both contained the same fatty acids (palmitic acid, stearic acid, olic acid, linoleic acid and γ-linolenic acid), but at different concentrations. The C:N ratio was also studied and showed no effects on total lipid accumulation, but a significant effect on γ-linolenic acid concentration.
    Matched MeSH terms: Saccharomyces cerevisiae
  15. Sago starch and its utilisation
    Abd-Aziz S
    J Biosci Bioeng, 2002;94(6):526-9.
    PMID: 16233345
    The importance and development of industrial biotechnology processing has led to the utilisation of microbial enzymes in various applications. One of the important enzymes is amylase, which hydrolyses starch to glucose. In Malaysia, the use of sago starch has been increasing, and it is presently being used for the production of glucose. Sago starch represents an alternative cheap carbon source for fermentation processes that is attractive out of both economic and geographical considerations. Production of fermentable sugars from the hydrolysis of starches is normally carried out by an enzymatic processes that involves two reaction steps, liquefaction and saccharification, each of which has different temperature and pH optima with respect to the maximum reaction rate. This method of starch hydrolysis requires the use of an expensive temperature control system and a complex mixing device. Our laboratory has investigated the possibility of using amylolytic enzyme-producing microorganisms in the continuous single-step biological hydrolysis of sago flour for the production of a generic fermentation medium. The ability of a novel DNA-recombinated yeast, Saccharomyces cerevisiae strain YKU 107 (expressing alpha-amylase production) to hydrolyse gelatinised sago starch production has been studied with the aim of further utilizing sago starch to obtain value-added products.
    Matched MeSH terms: Saccharomyces cerevisiae
  16. Fulltext Numerical Analysis of Hydrodynamic Flow in Microfluidic Biochip for Single-Cell Trapping Application
    Khalili AA, Ahmad MR
    Int J Mol Sci, 2015;16(11):26770-85.
    PMID: 26569218 DOI: 10.3390/ijms161125987
    Single-cell analysis has become the interest of a wide range of biological and biomedical engineering research. It could provide precise information on individual cells, leading to important knowledge regarding human diseases. To perform single-cell analysis, it is crucial to isolate the individual cells before further manipulation is carried out. Recently, microfluidic biochips have been widely used for cell trapping and single cell analysis, such as mechanical and electrical detection. This work focuses on developing a finite element simulation model of single-cell trapping system for any types of cells or particles based on the hydrodynamic flow resistance (Rh) manipulations in the main channel and trap channel to achieve successful trapping. Analysis is carried out using finite element ABAQUS-FEA™ software. A guideline to design and optimize single-cell trapping model is proposed and the example of a thorough optimization analysis is carried out using a yeast cell model. The results show the finite element model is able to trap a single cell inside the fluidic environment. Fluid's velocity profile and streamline plots for successful and unsuccessful single yeast cell trapping are presented according to the hydrodynamic concept. The single-cell trapping model can be a significant important guideline in designing a new chip for biomedical applications.
    Matched MeSH terms: Saccharomyces cerevisiae
  17. Fulltext Effects of glucose, ethanol and acetic acid on regulation of ADH2 gene from Lachancea fermentati
    Yaacob N, Mohamad Ali MS, Salleh AB, Abdul Rahman NA
    PeerJ, 2016;4:e1751.
    PMID: 26989608 DOI: 10.7717/peerj.1751
    Background. Not all yeast alcohol dehydrogenase 2 (ADH2) are repressed by glucose, as reported in Saccharomyces cerevisiae. Pichia stipitis ADH2 is regulated by oxygen instead of glucose, whereas Kluyveromyces marxianus ADH2 is regulated by neither glucose nor ethanol. For this reason, ADH2 regulation of yeasts may be species dependent, leading to a different type of expression and fermentation efficiency. Lachancea fermentati is a highly efficient ethanol producer, fast-growing cells and adapted to fermentation-related stresses such as ethanol and organic acid, but the metabolic information regarding the regulation of glucose and ethanol production is still lacking. Methods. Our investigation started with the stimulation of ADH2 activity from S. cerevisiae and L. fermentati by glucose and ethanol induction in a glucose-repressed medium. The study also embarked on the retrospective analysis of ADH2 genomic and protein level through direct sequencing and sites identification. Based on the sequence generated, we demonstrated ADH2 gene expression highlighting the conserved NAD(P)-binding domain in the context of glucose fermentation and ethanol production. Results. An increase of ADH2 activity was observed in starved L. fermentati (LfeADH2) and S. cerevisiae (SceADH2) in response to 2% (w/v) glucose induction. These suggest that in the presence of glucose, ADH2 activity was activated instead of being repressed. An induction of 0.5% (v/v) ethanol also increased LfeADH2 activity, promoting ethanol resistance, whereas accumulating acetic acid at a later stage of fermentation stimulated ADH2 activity and enhanced glucose consumption rates. The lack in upper stream activating sequence (UAS) and TATA elements hindered the possibility of Adr1 binding to LfeADH2. Transcription factors such as SP1 and RAP1 observed in LfeADH2 sequence have been implicated in the regulation of many genes including ADH2. In glucose fermentation, L. fermentati exhibited a bell-shaped ADH2 expression, showing the highest expression when glucose was depleted and ethanol-acetic acid was increased. Meanwhile, S. cerevisiae showed a constitutive ADH2 expression throughout the fermentation process. Discussion. ADH2 expression in L. fermentati may be subjected to changes in the presence of non-fermentative carbon source. The nucleotide sequence showed that ADH2 transcription could be influenced by other transcription genes of glycolysis oriented due to the lack of specific activation sites for Adr1. Our study suggests that if Adr1 is not capable of promoting LfeADH2 activation, the transcription can be controlled by Rap1 and Sp1 due to their inherent roles. Therefore in future, it is interesting to observe ADH2 gene being highly regulated by these potential transcription factors and functioned as a promoter for yeast under high volume of ethanol and organic acids.
    Matched MeSH terms: Saccharomyces cerevisiae
  18. Fulltext Effect of fennel (Foeniculum vulgare Mill.) and coriander (Coriandrum sativum L.) on microbial quality and sensory acceptability of frozen paratha
    Rosli, N.A., Azilan, N A., Mahyudin, N.A., Mahmud Ab Rashid, N.K., Meon, F.N.S., Ismail, Z., et al.
    International Food Research Journal, 2019;26(3):945-952.
    MyJurnal
    Fennel (Foeniculum vulgare Mill.) and coriander (Coriandrum sativum L.) are known to possess good antimicrobial properties. In the present work, spice-infused frozen parathas were formulated to investigate the effect of fennel and coriander on microbial (aerobic mesophilic bacteria, yeast and mould, and Bacillus cereus) reduction and sensory acceptability of frozen paratha throughout the storage at -18°C. The present work was also aimed at determining the relationship between spice concentrations and storage durations on microbiological quality of the samples. Fennel and coriander seed powder were used at concentrations of 2, 4 and 6% of wheat flour (w/w). The microbiological analysis was performed by total plate count, yeast and mould count, and Bacillus cereus count after 9, 12 and 15 weeks of storage. Sensory evaluation was conducted using hedonic scales at the end of storage durations. Results showed that spice infusion in frozen paratha significantly delayed the growth of aerobic mesophilic bacteria, yeasts and moulds, and Bacillus cereus during storage. The lowest log count was demonstrated by coriander at 6% in total plate count (3.85, 3.90 and 3.91 log10 CFU/g), and yeast and mould count (2.54, 2.59 and 2.60 log10 CFU/g) after 9, 12 and 15 weeks, respectively. Bacillus cereus was not detected throughout the storage durations. Fennel exhibited minimum activity against Bacillus cereus with no significant difference on log count reduction when compared with control. Coriander showed the highest decrease in both total plate count and Bacillus cereus count during the storage duration. Sensory evaluation result indicated that control sample exhibited the highest preference over all attributes when compared with fennel and coriander. Coriander-infused paratha was slightly darker in colour due to high concentration of 6%. Fennel yielded the lowest score in terms of taste among all samples. Fennel and coriander showed no significant difference for sensory acceptability. Overall, all frozen parathas were in good quality after 15 weeks of frozen storage. It can thus be concluded that fennel and coriander can be used as potential natural preservatives to inhibit the growth of microorganisms in paratha during frozen storage. Nevertheless, the optimum spice concentration should be determined to minimise the effects on the sensory attributes.
    Matched MeSH terms: Saccharomyces cerevisiae
  19. Fulltext Safety and quality preservation of starfruit (Averrhoa carambola) at ambient shelf life using synergistic pectin-maltodextrin-sodium chloride edible coating
    Mohd Suhaimi NI, Mat Ropi AA, Shaharuddin S
    Heliyon, 2021 Feb;7(2):e06279.
    PMID: 33681497 DOI: 10.1016/j.heliyon.2021.e06279
    The demand for fresh, safe, and healthy fruits by consumers has increased, which concurrently occurs with an increase in initiatives on reducing food wastage. Starfruit consists of good nutrition and valuable sensory attributes, but its shelf life is short and can only be preseved for a few days at ambient storage. This research was conducted to determine the effectiveness of synergistic edible coatings (pectin [Pe] and maltodextrin [M] and 100, 200, and 300 ppm of sodium chloride [SC]) on the quality and safety criterion of starfruits throughout a shelf life analysis of 14 days at ambient temperature. Consumer acceptability of the edible-coated starfruit was also evaluated. The coating process was performed using a dipping method. The uncoated (control) and coated samples were evaluated for the characteristics of weight, pH, total soluble solids (TSS), water activity, color, texture, microbial growth, FTIR, and sensory evaluation. From the results, the starfruit coated with Pe + M + 100 ppm SC had a significantly lower weight-loss trend compared to the other samples. On day 14, pH of the coated starfruits were 3.02, 3.14, and 3.31 for 100, 200, and 300 ppm of SC, respectively, were found to be significantly different (p < 0.05) from the control (pH 3.49). The control had a significantly higher value of total soluble solids (6.00 ⁰Brix) compared to the coated starfruits (6.00, 5.47, and 5.33 ⁰Brix, respectively). The coated samples have significantly higher values of firmness than control especially in initial days of storage. It was observed that Pe + M + 100 ppm SC could minimize the spoilage of fruits by reducing the growth of yeast and mold, as well as bacteria, up to 0.86 and 2.02 log CFU/ml, respectively. FTIR results confirmed the presence of the coating on the starfruit. In the sensory evaluation, no significance different (p > 0.05) were obtained for all the sensory attributes and overall acceptability for day 0 and 3. In conclusion, starfruit coated with synergistic Pe + M + 100 ppm SC appeared to be the best sample in extending its shelf life and maintaining the physicochemical characteristics of starfruits up to more than 14 days.
    Matched MeSH terms: Saccharomyces cerevisiae
  20. Fulltext A New Model of Alcoholic Fermentation under a Byproduct Inhibitory Effect
    Zentou H, Zainal Abidin Z, Yunus R, Awang Biak DR, Abdullah Issa M, Yahaya Pudza M
    ACS Omega, 2021 Feb 16;6(6):4137-4146.
    PMID: 33644536 DOI: 10.1021/acsomega.0c04025
    Despite the advantages of continuous fermentation whereby ethanol is selectively removed from the fermenting broth to reduce the end-product inhibition, this process can concentrate minor secondary products to the point where they become toxic to the yeast. This study aims to develop a new mathematical model do describe the inhibitory effect of byproducts on alcoholic fermentation including glycerol, lactic acid, acetic acid, and succinic acid, which were reported as major byproducts during batch alcoholic fermentation. The accumulation of these byproducts during the different stages of batch fermentation has been quantified. The yields of total byproducts, glycerol, acetic acid, and succinic acid per gram of glucose were 0.0442, 0.023, 0.0155, and 0.0054, respectively. It was found that the concentration of these byproducts linearly increases with the increase in glucose concentration in the range of 25-250 g/L. The results have also showed that byproduct concentration has a significant inhibitory effect on specific growth coefficient (μ) whereas no effect was observed on the half-velocity constant (Ks). A new mathematical model of alcoholic fermentation was developed considering the byproduct inhibitory effect, which showed a good performance and more accuracy compared to the classical Monod model.
    Matched MeSH terms: Saccharomyces cerevisiae
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