Displaying publications 1 - 20 of 63 in total

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  1. 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: Yeast, Dried
  2. Fulltext EFFECT OF ENRICHED COPEPODS ON THE GROWTH, SURVIVAL AND COLOURATION OF ANGELFISH (Pterophyllum scalare)
    NIZALMIE AZANI, NADIAH W RASDI, NADIAH W RASDI
    UMT Journal of Undergraduate Research, 2021;3(2):25-36.
    MyJurnal
    Cyclopoid copepod has a potential as live feed that can provide ornamental fish larvae with energy and essential nutrients, and promote their growth and survival, as well as affect their colouration. However, the nutrition, growth and nutritional requirements of this species are poorly understood. This research focuses on comparing the efficacy of enrichment types on copepods towards the growth rate, survival rate and colouration of Pterophyllum scalare larvae. The enrichment of copepods consists of four enrichment procedures (rice bran, palm kernel cake (PKC),Chlorella and yeast). This study was carried out over 50 days and the growth rate, survival rate and colouration (growth rate, survival rate, SGR and colouration) were used to evaluate the responses of P. scalare larvae towards different enrichment methods. Specific growth rates (8.0161 ± 1.4928 %; P = 0.775) and survival rates (66.667 ± 5.337%; P = 0.815) of fish larvae were found to not be significantly different (P = 0.775, P = 0.815; P >0.05). However, the colouration of the fish larvae was affected by the types of enrichment used (P
    Matched MeSH terms: Yeast, Dried
  3. Fulltext Antifreeze Proteins and Their Practical Utilization in Industry, Medicine, and Agriculture
    Eskandari A, Leow TC, Rahman MBA, Oslan SN
    Biomolecules, 2020 12 09;10(12).
    PMID: 33317024 DOI: 10.3390/biom10121649
    Antifreeze proteins (AFPs) are specific proteins, glycopeptides, and peptides made by different organisms to allow cells to survive in sub-zero conditions. AFPs function by reducing the water's freezing point and avoiding ice crystals' growth in the frozen stage. Their capability in modifying ice growth leads to the stabilization of ice crystals within a given temperature range and the inhibition of ice recrystallization that decreases the drip loss during thawing. This review presents the potential applications of AFPs from different sources and types. AFPs can be found in diverse sources such as fish, yeast, plants, bacteria, and insects. Various sources reveal different α-helices and β-sheets structures. Recently, analysis of AFPs has been conducted through bioinformatics tools to analyze their functions within proper time. AFPs can be used widely in various aspects of application and have significant industrial functions, encompassing the enhancement of foods' freezing and liquefying properties, protection of frost plants, enhancement of ice cream's texture, cryosurgery, and cryopreservation of cells and tissues. In conclusion, these applications and physical properties of AFPs can be further explored to meet other industrial players. Designing the peptide-based AFP can also be done to subsequently improve its function.
    Matched MeSH terms: Yeast, Dried
  4. Phomopsidione-Loaded Chitosan Polyethylene Glycol (PEG) Nanocomposite Dressing for Pressure Ulcers
    Chin IBI, Yenn TW, Ring LC, Lazim Y, Tan WN, Rashid SA, et al.
    J Pharm Sci, 2020 09;109(9):2884-2890.
    PMID: 32534882 DOI: 10.1016/j.xphs.2020.06.005
    Pressure ulcers are commonly associated with microbial infections on the wounds which require an effective wound dressing for treatment. Thus far, the available silver dressing has shown tremendous result, however, it may cause argyria and complicate the internal organ function. Hence, our study aims to develop and characterize phomopsidione-loaded chitosan-polyethylene glycol nanocomposite hydrogel (C/PEG/Ph) as an antimicrobial dressing. Physically, the C/PEG/Ph hydrogel demonstrated a uniform light blue color, soft, flexible, and elastic, with no aggregation form. The evaluation via Fourier Transform Infrared (FTIR) exposed the C/PEG/Ph hydrogel has a notable shift towards lower frequency at 1600 and 1554 cm-1. For drug release test, the phomopsidione attained plateau at 24 h, with a total release of 67.9 ± 6.4% from the C/PEG/Ph hydrogel. There was a null burst release effect discovered throughout the experimental period. The C/PEG/Ph hydrogel showed significant results against all 4 Gram-negative bacteria and 1 yeast, with 99.99-100% reduction of microbial growth. The findings revealed that the C/PEG/Ph hydrogel can potentially act as an antimicrobial dressing for pressure ulcers.
    Matched MeSH terms: Yeast, Dried
  5. Structural insight into tanapoxvirus mediated inhibition of apoptosis
    Suraweera CD, Anasir MI, Chugh S, Javorsky A, Impey RE, Hasan Zadeh M, et al.
    FEBS J, 2020 May 15.
    PMID: 32412687 DOI: 10.1111/febs.15365
    Premature programmed cell death or apoptosis of cells is a strategy utilized by multicellular organisms to counter microbial threats. Tanapoxvirus (TANV) is a large double-stranded DNA virus belonging to the poxviridae that causes mild Monkeypox-like infections in humans and primates. TANV encodes for a putative apoptosis inhibitory protein 16L. We show that TANV16L is able to bind to a range of peptides spanning the BH3 motif of human pro-apoptotic Bcl-2 proteins, and is able to counter growth arrest of yeast induced by human Bak and Bax. We then determined the crystal structures of TANV16L bound to three identified interactors, Bax, Bim and Puma BH3. TANV16L adopts a globular Bcl-2 fold comprising 7 a-helices, and utilizes the canonical Bcl-2 binding groove to engage pro-apoptotic host cell Bcl-2 proteins. Unexpectedly, TANV16L is able to adopt both a monomeric as well as a domain-swapped dimeric topology where the a1 helix from one protomer is swapped into a neighbouring unit. Despite adopting two different oligomeric forms, the canonical ligand binding groove in TANV16L remains unchanged from monomer to domain-swapped dimer. Our results provide a structural and mechanistic basis for tanapoxvirus mediated inhibition of host cell apoptosis, and reveal the capacity of Bcl-2 proteins to adopt differential oligomeric states whilst maintaining the canonical ligand binding groove in an unchanged state.
    Matched MeSH terms: Yeast, Dried
  6. Fulltext Pre-grafting histological studies of skin grafts cryopreserved in α helix antarctic yeast oriented antifreeze peptide (Afp1m)
    Khan MS, Ibrahim SM, Adamu AA, Rahman MBA, Bakar MZA, Noordin MM, et al.
    Cryobiology, 2020 02 01;92:26-33.
    PMID: 31580830 DOI: 10.1016/j.cryobiol.2019.09.012
    A number of living creatures in the Antarctic region have developed characteristic adaptation of cold weather by producing antifreeze proteins (AFP). Antifreeze peptide (Afp1m) fragment have been designed in the sequence of strings from native proteins. The objectives of this study were to assess the properties of Afp1m to cryopreserve skin graft at the temperature of -10 °C and -20 °C and to assess sub-zero injuries in Afp1m cryopreserved skin graft using light microscopic techniques. In the present study, a process was developed to cryopreserve Sprague-Dawley (SD) rat skin grafts with antifreeze peptide, Afp1m, α-helix peptide fragment derived from Glaciozyma antractica yeast. Its viability assessed by different microscopic techniques. This study also described the damages caused by subzero temperatures (-10 and -20 °C) on tissue cryopreserved in different concentrations of Afp1m (0.5, 1, 2, 5 and 10 mg/mL) for 72 h. Histological scores of epidermis, dermis and hypodermis of cryopreserved skin grafts showed highly significant difference (p 
    Matched MeSH terms: Yeast, Dried
  7. Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi
    Sorribes-Dauden R, Peris D, Martínez-Pastor MT, Puig S
    Comput Struct Biotechnol J, 2020;18:3712-3722.
    PMID: 33304466 DOI: 10.1016/j.csbj.2020.10.044
    Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/VIT1 iron transporter. New sequenced genomes and bioinformatic tools are facilitating the functional characterization, evolution and ecological relevance of metabolic pathways and homeostatic networks across the Tree of Life. Sequence analysis shows that Ccc1/VIT1 homologs are widely distributed among organisms with the exception of animals. The recent elucidation of the crystal structure of a Ccc1/VIT1 plant ortholog has enabled the identification of both conserved and species-specific motifs required for its metal transport mechanism. Moreover, recent studies in the yeast Saccharomyces cerevisiae have also revealed that multiple transcription factors including Yap5 and Msn2/Msn4 contribute to the expression of CCC1 in high-iron conditions. Interestingly, Malaysian S. cerevisiae strains express a partially functional Ccc1 protein that renders them sensitive to iron. Different regulatory mechanisms have been described for non-Saccharomycetaceae Ccc1 homologs. The characterization of Ccc1/VIT1 proteins is of high interest in the development of biofortified crops and the protection against microbial-derived diseases.
    Matched MeSH terms: Yeast, Dried
  8. Fulltext Application of supercritical carbon dioxide (SC-CO2 ) on the microbial and physicochemical quality of fresh chicken meat stored at chilling temperature
    Ismail Fitry Mohammad Rashedi, Safiullah Jauhar, Chong, ?Gun Hean, Nor Khaizura Mahmud @ Ab Rashid, Wan Zunairah Wan Ibadullah
    International Food Research Journal, 2020;27(1):103-110.
    MyJurnal
    Supercritical carbon dioxide (SC-CO2 ) is a non-thermal technique implemented by food, pharmaceutical, and similar industries with the aim of inhibiting the microorganisms and apply effective sterilisation. Presently, limited number of studies has reported the application of SC-CO2 on fresh chicken meat. The present work therefore aimed to reveal the microbial and physicochemical quality of the SC-CO2 -treated fresh chicken meat. The fresh chicken meat was subjected to the SC-CO2 at 14 MPa and 45°C for 40 min and was stored at 4°C for 0, 3, and 7 days. The obtained results indicated that the treatment with SC-CO2 significantly decreased the total plate count and, yeast and mould count from log10 5.90 to 2.00 CFU/g and from log10 5.02 to 2.00 CFU/g at day 7 of storage, respectively. The values of pH, cooking loss, and water holding capacity were not affected by the treatment. The results revealed that the SC-CO2 -treated samples displayed harder texture, higher lightness and yellowness, and lower redness. In addition, lipid peroxidation of SC-CO2 and control samples resulted in values of 1.9 and 0.5 MDA/mg of meat at day 7 of storage time and did not significantly change in the rest of the evaluation days. In summary, the application of SC-CO2 was capable of enhancing the microbial quality and certain physicochemical attributes. However, alteration of certain parameters of SC-CO2 might enhance the overall meat quality.
    Matched MeSH terms: Yeast, Dried
  9. Fulltext Proline Homeostasis in Saccharomyces cerevisiae: How Does the Stress-Responsive Transcription Factor Msn2 Play a Role?
    Mat Nanyan NSB, Takagi H
    Front Genet, 2020;11:438.
    PMID: 32411186 DOI: 10.3389/fgene.2020.00438
    Overexpression of MSN2, which is the transcription factor gene in response to stress, is well-known to increase the tolerance of the yeast Saccharomyces cerevisiae cells to a wide variety of environmental stresses. Recent studies have found that the Msn2 is a feasible potential mediator of proline homeostasis in yeast. This result is based on the finding that overexpression of the MSN2 gene exacerbates the cytotoxicity of yeast to various amino acid analogs whose uptake is increased by the active amino acid permeases localized on the plasma membrane as a result of a dysfunctional deubiquitination process. Increased understanding of the cellular responses induced by the Msn2-mediated proline incorporation will provide better comprehension of how cells respond to and counteract to different kinds of stimuli and will also contribute to the breeding of industrial yeast strains with increased productivity.
    Matched MeSH terms: Yeast, Dried
  10. Fulltext Disinfectant of pummelo (Citrus Grandis L. Osbeck) fruit juice using gaseous ozone
    Shah NNAK, Supian NAM, Hussein NA
    J Food Sci Technol, 2019 Jan;56(1):262-272.
    PMID: 30728568 DOI: 10.1007/s13197-018-3486-2
    This work studied the effectiveness of gaseous ozone disinfection on pummelo (Citrus Grandis L. Osbeck) fruit juice components. Unfiltered and filtered pummelo fruit juices were treated with gaseous ozone for up to 50 min with ozone concentration fixed at 600 mg/h. A microbiological and physicochemical properties analysis were conducted on the ozone-treated fruit juices samples. It was found that the survival rate of aerobic bacteria, yeast and mold in unfiltered pummelo fruit juice were higher compared to filtered juice, as the juice components acted as protective barriers to the microorganisms. The microorganisms' inactivation in pummelo fruit juices was also observed to have increased as the ozone treatment time increased. Significant effects on total colour difference, ascorbic acid content, and total phenolic content were also observed over increased ozone-treatment time. However, ozone was shown to be ineffective in activating PME activity in both types of juice. The experimental results of this study indicated that pummelo fruit juice components had significant effects on the effectiveness of gaseous ozone, however, the degree of the effects depends on the different fruit components (total soluble solids, total phenolic content). As a conclusion, filtered juice showed better quality characteristics in comparison to unfiltered juice post-ozone treatment.
    Matched MeSH terms: Yeast, Dried
  11. Fulltext The effect of synbiotic Streptococcus salivarius K12 and Musa acuminata on Candida albicans biofilm formation
    Nurul Alia Risma Rismayuddin, Munirah Mokhtar, Noratikah Othman, Ahmad Faisal Ismail, Mohd Hafiz Arzmi
    Malaysian Journal of Medicine and Health Sciences, 2019;15(108):37-37.
    MyJurnal
    Introduction:Candida albicans is an opportunistic fungus that is associated with oral carcinogenesis. In addition, biofilm formation has been one of the important virulence factors of the yeast. Streptococcus salivarius K12 is an oral probiotic while Musa acuminata is a well-known prebiotic. The objective of this study is to investigate the effect of S. salivarius K12 and M. acuminata skin aqueous extract (synbiotic) on C. albicans with the hypothesis that S. salivariusK12 and M. acuminata inhibit C. albicans biofilm formation. Methods: To develop mono-species biofilm, C. albicans(ATCC MYA-4901 and cancer isolates, ALC2 and ALC3 strains) and S. salivarius K12 were standardised to 105 cells and 106 cells, respectively and grown in 96-well plate in nutrient broth (NB) or RPMI at 37 °C for 72 h. Polymicro-bial biofilms were developed by inoculating both microorganisms in the same well with similar cell number as in mono-species. To determine the effect of synbiotic, similar protocol was repeated by mixing with 800 mg mL-1 of M. acuminata skin extract and incubated at 37 °C for 72 h. The medium was replenished at every 24 h, aseptically. Finally, the biofilms were assessed using crystal violet assay and the optical density was measured at OD620nm. Results:C. albicans strain MYA-4901 and ALC3, when grown in polymicrobial with S. salivarius K12 in NB that is predominated by yeast-form C. albicans, exhibited decreased biofilms by 71.40±11.7% and 49.40±3.9%, respec-tively when compared to the expected biofilms. Meanwhile in RPMI, which C. albicans strain ATCC MYA-4901, ALC2 and ALC3 were predominated by hyphal-form showed decreased biofilms by 72.0±26.7%, 53.4±14.4% and 65.7±6.7%, respectively when compared to the expected biofilms. Conclusion:S. salivarius K12 and M. acuminata skin extract synbiotic inhibit biofilm formation of C. albicans yeast and hyphal forms thus supported the hypothesis of the present study.
    Matched MeSH terms: Yeast, Dried
  12. 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: Yeast, Dried
  13. Multiobjective optimization to reconstruct biological networks
    Naef A, Abdullah R, Abdul Rashid N
    Biosystems, 2018 Sep 17;174:22-36.
    PMID: 30236951 DOI: 10.1016/j.biosystems.2018.09.003
    Automated methods for reconstructing biological networks are becoming increasingly important in computational systems biology. Public databases containing information on biological processes for hundreds of organisms are assisting in the inference of such networks. This paper proposes a multiobjective genetic algorithm method to reconstruct networks related to metabolism and protein interaction. Such a method utilizes structural properties of scale-free networks and known biological information about individual genes and proteins to reconstruct metabolic networks represented as enzyme graph and protein interaction networks. We test our method on four commonly-used protein networks in yeast. Two are networks related to the metabolism of the yeast: KEGG and BioCyc. The other two datasets are networks from protein-protein interaction: Krogan and BioGrid. Experimental results show that the proposed method is capable of reconstructing biological networks by combining different omics data and structural characteristics of scale-free networks. However, the proposed method to reconstruct the network is time-consuming because several evaluations must be performed. We parallelized this method on GPU to overcome this limitation by parallelizing the objective functions of the presented method. The parallel method shows a significant reduction in the execution time over the GPU card which yields a 492-fold speedup.
    Matched MeSH terms: Yeast, Dried
  14. Fulltext Potential of Zeolite and Algae in Biomass Immobilization
    Emami Moghaddam SA, Harun R, Mokhtar MN, Zakaria R
    Biomed Res Int, 2018;2018:6563196.
    PMID: 30643814 DOI: 10.1155/2018/6563196
    The interest in utilizing algae for wastewater treatment has been increased due to many advantages. Algae-wastewater treatment system offers a cost-efficient and environmentally friendly alternative to conventional treatment processes such as electrocoagulation and flocculation. In this biosystem, algae can assimilate nutrients in the wastewater for their growth and simultaneously capture the carbon dioxide from the atmosphere during photosynthesis resulting in a decrease in the greenhouse gaseousness. Furthermore, the algal biomass obtained from the treatment process could be further converted to produce high value-added products. However, the recovery of free suspended algae from the treated effluent is one of the most important challenges during the treatment process as the current methods such as centrifugation and filtration are faced with the high cost. Immobilization of algae is a suitable approach to overcome the harvesting issue. However, there are some drawbacks with the common immobilization carriers such as alginate and polyacrylamide related to low stability and toxicity, respectively. Hence, it is necessary to apply a new carrier without the mentioned problems. One of the carriers that can be a suitable candidate for the immobilization is zeolite. To date, various types of zeolite have been used for the immobilization of cells of bacteria and yeast. If there is any possibility to apply them for the immobilization of algae, it needs to be considered in further studies. This article reviews cell immobilization technique, biomass immobilization onto zeolites, and algal immobilization with their applications. Furthermore, the potential application of zeolite as an ideal carrier for algal immobilization has been discussed.
    Matched MeSH terms: Yeast, Dried
  15. Fulltext A catheter-related bloodstream infection caused by the yeast Kodamaea ohmeri
    Ding, C.H., Tzar M.N., Biswas S., Muttaqillah N.A.S., Wahab A.A.
    International Medical Journal Malaysia, 2018;17(2):135-138.
    MyJurnal
    Catheter-related bloodstream infections caused by Kodamaea ohmeri are generally not considered due to the relative scarcity of reported cases. This is a case of an 85-year-old man with poorly controlled diabetes mellitus who was initially admitted to our hospital for diabetic ketoacidosis. An internal jugular catheter was inserted as part of the initial management. A week later the patient developed a temperature spike and a yeast identified as Kodamaea ohmeri by ID 32 C (bioMérieux, France) was isolated from both his central and peripheral blood cultures. The catheter was removed and the patient was treated with fluconazole despite the organism’s relatively high minimum inhibitory concentration (2 μg/mL) to this antifungal. The fungemia resolved following a 2-weeks course of fluconazole.
    Matched MeSH terms: Yeast, Dried
  16. Fulltext Growth kinetics of ethidium bromide mutagenized Lipomyces starkeyi strains
    Micky Vincent, Latifah Suali, Afizul Safwan Azahari, Patricia Rowena Mark Baran, Elexson Nillian, Lesley Maurice Bilung
    Journal of Advanced Research in Applied Sciences and Engineering Technology, 2018;11(1):47-54.
    MyJurnal
    Yeast growth and biomass production are greatly influenced by the length of the
    incubation period during cultivation. Therefore, this study was conducted to
    investigate the growth kinetics of five Lipomyces starkeyi strains as determined by
    biomass production. The five L. starkeyi strains, namely L. starkeyi ATCC 12659, L.
    starkeyi MV-1, L. starkeyi MV-4, L. starkeyi MV-5 and L. starkeyi MV-8, were inoculated
    in sterilized Yeast Malt broth, and, incubated for 192 hr at ambient temperature.
    Biomass yields were assessed and calculated gravimetrically every 24 hr. Results
    indicated that the optimal biomass production of L. starkeyi ATCC 12659, L. starkeyi
    MV-1, L. starkeyi MV-4, L. starkeyi MV-5 and L. starkeyi MV-8 were at 120, 168, 144,
    168 and 120 hr, with the concentrations of 6.64, 6.43, 9.78, 11.23 and 8.56 g/L,
    respectively. These results indicate that each L. starkeyi strain requires specific
    incubation period for the optimum production of fungal biomass. Therefore, by
    cultivating each L. starkeyi strain at the predetermined incubation period, biomass
    yields could significantly be improved for further downstream applications such as
    single cell protein and lipid production.
    Matched MeSH terms: Yeast, Dried
  17. Antimicrobial activity of fungal endophytes from vaccinium dunalianum var. Urophyllum
    Xin Tong, Xiao-ye Shen, Cheng-lin Hou
    Sains Malaysiana, 2018;47:1685-1692.
    Fungi associated with Vaccinium species play important roles in plant growth and disease control, especially in the final
    blueberry production. Vaccinium dunalianum var. urophyllum (Ericaceae) is a well-known medicinal plant in Southern
    China used to treat inflammation and microbial infections. The endophytic fungi from these plants are therefore anticipated
    as potential new sources of antimicrobials. In this report, the inhibitory effects of endophytes against clinical bacteria
    and yeast were comprehensively screened and 11 isolates indicated high bioactivity by the agar diffusion method. The
    corresponding crude extracts of these fungi under submerged fermentation also demonstrated distinct differences and
    n-butyl alcohol displayed the lowest extraction efficiency among the extracts. The ethyl acetate and dichloromethane
    extracts of filtrates from the Colletotrichum sp. VD001, Epicoccum nigrum VD021 and E. nigrum VD022 strains
    displayed good properties against pathogenic microorganisms according to disc diffusion assays and minimal inhibitory
    concentration (MIC). This study is the first indicating that cultivable endophytic fungi associated with blueberry plants
    produce potential compounds against clinical pathogens.
    Matched MeSH terms: Yeast, Dried
  18. Physicochemical, antioxidant and microbial properties of fresh black stem sugarcane juice with addition of calamansi juice
    Noor Afiqah Md Noor, Maizura Murad, Effarizah Mohd Esah
    Sains Malaysiana, 2018;47:2047-2054.
    This study was designed to determine the physicochemical, antioxidant and microbial properties of fresh sugarcane juice
    with calamansi juice addition. The sugarcane that was used in the experiments was the black cane variety (Saccharum
    officinarum). Sugarcane pressed with and without their peel was juiced and added with calamansi juice before analysis
    was carried out. Standard method was used to analyse physicochemical properties such as pH, total soluble solids,
    acidity and colour of sugarcane juice. Total phenolic content (TPC), DPPH and FRAP assay were conducted for antioxidant
    properties. Total plate count and yeast and mould count were carried out for the microbiological analyses. Two way
    analysis of variance (ANOVA) shows significant (p<0.05) difference on colour of sugarcane juiced after extraction with and
    without peel. There were no significant (p>0.05) difference shown for pH, acidity and total soluble solids of sugarcane
    juice pressed with and without peel. Sugarcane juice pressed with peel produced higher antioxidant value compared
    to sugarcane pressed without peel. However, sugarcane juice pressed without peeled showed a lower microbial count
    compared to sugarcane juice pressed with peel. The addition of calamansi juice proved to have significant (p<0.05)
    effect on colour, antioxidant and microbial count of the sugarcane juices.
    Matched MeSH terms: Yeast, Dried
  19. 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: Yeast, Dried
  20. Fulltext The Glaciozyma antarctica genome reveals an array of systems that provide sustained responses towards temperature variations in a persistently cold habitat
    Firdaus-Raih M, Hashim NHF, Bharudin I, Abu Bakar MF, Huang KK, Alias H, et al.
    PLoS One, 2018;13(1):e0189947.
    PMID: 29385175 DOI: 10.1371/journal.pone.0189947
    Extremely low temperatures present various challenges to life that include ice formation and effects on metabolic capacity. Psyhcrophilic microorganisms typically have an array of mechanisms to enable survival in cold temperatures. In this study, we sequenced and analysed the genome of a psychrophilic yeast isolated in the Antarctic region, Glaciozyma antarctica. The genome annotation identified 7857 protein coding sequences. From the genome sequence analysis we were able to identify genes that encoded for proteins known to be associated with cold survival, in addition to annotating genes that are unique to G. antarctica. For genes that are known to be involved in cold adaptation such as anti-freeze proteins (AFPs), our gene expression analysis revealed that they were differentially transcribed over time and in response to different temperatures. This indicated the presence of an array of adaptation systems that can respond to a changing but persistent cold environment. We were also able to validate the activity of all the AFPs annotated where the recombinant AFPs demonstrated anti-freeze capacity. This work is an important foundation for further collective exploration into psychrophilic microbiology where among other potential, the genes unique to this species may represent a pool of novel mechanisms for cold survival.
    Matched MeSH terms: Yeast, Dried
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