• Title/Summary/Keyword: BIOENGINEERING AND TECHNOLOGY

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Overexpression of Mutant Galactose Permease (ScGal2_N376F) Effective for Utilization of Glucose/Xylose or Glucose/Galactose Mixture by Engineered Kluyveromyces marxianus

  • Kwon, Deok-Ho;Kim, Saet-Byeol;Park, Jae-Bum;Ha, Suk-Jin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1944-1949
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    • 2020
  • Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.

Anthocyanins from Clitoria ternatea Attenuate Food-Borne Penicillium expansum and its Potential Application as Food Biopreservative

  • Leong, Chean-Ring;Azizi, Muhammad Afif Kamarul;Taher, Md Abu;Wahidin, Suzana;Lee, Kok-Chang;Tan, Wen-Nee;Tong, Woei-Yenn
    • Natural Product Sciences
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    • v.23 no.2
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    • pp.125-131
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    • 2017
  • Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.

Enhanced Antioxidant Activity of Berry Juice through Acetic Acid Bacteria Fermentation (초산균 발효에 의한 베리 농축액의 항산화 활성 증진 효과)

  • Park, Joong-Hee;Kwon, Hun-Joo;Kwon, Deok-Ho;Park, Jae-Bum;Nam, Hee-Sop;Lee, Do Yup;Kim, Myoung-Dong;Ha, Suk-Jin
    • KSBB Journal
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    • v.32 no.3
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    • pp.238-244
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    • 2017
  • Antioxidant activities of blackberry juice and aronia juice were enhanced when fermentation was performed by acetic acid bacteria. Acetobacter pasteurianus exhibited 19.84% improvement of antioxidant activity (from $198.12{\pm}2.03$ to $237.42{\pm}7.32{\mu}mol\;TE/g$) after 12 h fermentation of blackberry juice among four acetic acid bacteria. And A. pasteurianus sub sp. Pasteurianus exhibited 9.62% improvement of antioxidant activity (from $204.25{\pm}3.98$ to $223.89{\pm}5.52{\mu}mol\;TE/g$) after 12 h fermentation of aronia juice. Metabolites of blackberry juice were analyzed to investigate the enhancement of antioxidant activity before and after fermentation. As results, Quercetin 7-(rhamnosylglucoside), nicotinic acid adenine dinucleotide, and quercetin 3-O-(6"-acetyl-glucoside) were significantly increased after fermentation by A. pasteurianus.

Chemical Composition and Antimicrobial Efficacy of Helminthostachys zeylanica against Foodborne Bacillus cereus

  • Yenn, Tong Woei;Ring, Leong Chean;Zahan, Khairul Azly;Rahman, Muhammad Sharir Abdul;Tan, Wen-Nee;Alaudin, Bintul Jauza' Shaik
    • Natural Product Sciences
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    • v.24 no.1
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    • pp.66-70
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    • 2018
  • Helminthostachys zeylanica is a rare plant grows in lightly shaded areas. The fern was traditionally used as antipyretic and antiphlogistic agents. This study was aimed to evaluate the antibacterial potential of H. zeylanica on foodborne Bacillus cereus. The chemical composition of its ethanolic extract was also determined. The plant samples were collected at Kampung Kebun Relong, Kedah, Malaysia. The ethanolic extract showed significant inhibitory activity on B. cereus with a sizeable clear zone detected on disc diffusion assay. On broth microdilution assay, the MIC of the extract on B. cereus was 6.25 mg/ml and the MBC was 12.5 mg/ml. The inhibitory activity of the extract on B. cereus was bactericidal. In the growth dynamic study, the antibacterial efficacy of the extract was concentration dependent, where a lower colony forming unit count was obtained with increased extract concentration. The SEM micrograph of extract treated B. cereus cells showed invaginations of cell wall. The bacterial cell structure collapsed after 24 h exposure to the extract. The GCMS analysis of the extract showed that the major constituents of the extract were phenol (36.26%) and quercetin (29.70%). This study is important as it shows the potential use of H. zeylanica as an effective agent to control B. cereus related infections.

Characteristics of a Lettuce mosaic virus Isolate Infecting Lettuce in Korea

  • Lim, Seungmo;Zhao, Fumei;Yoo, Ran Hee;Igori, Davaajargal;Lee, Su-Heon;Lim, Hyoun-Sub;Moon, Jae Sun
    • The Plant Pathology Journal
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    • v.30 no.2
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    • pp.183-187
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    • 2014
  • Lettuce mosaic virus (LMV) causes disease of plants in the family Asteraceae, especially lettuce crops. LMV isolates have previously been clustered in three main groups, LMV-Yar, LMV-Greek and LMV-RoW. The first two groups, LMV-Yar and LMV-Greek, have similar characteristics such as no seed-borne transmission and non-resistance-breaking. The latter one, LMV-RoW, comprising a large percentage of the LMV isolates contains two large subgroups, LMV-Common and LMV-Most. To date, however, no Korean LMV isolate has been classified and characterized. In this study, LMV-Muju, the Korean LMV isolate, was isolated from lettuce showing pale green and mottle symptoms, and its complete genome sequence was determined. Classification method of LMV isolates based on nucleotide sequence divergence of the NIb-CP junction showed that LMV-Muju was categorized as LMV-Common. LMV-Muju was more similar to LMV-O (LMV-Common subgroup) than to LMV-E (LMV-RoW group but not LMV-Common subgroup) even in the amino acid domains of HC-Pro associated with pathogenicity, and in the CI and VPg regions related to ability to overcome resistance. Taken together, LMV-Muju belongs to the LMV-Common subgroup, and is expected to be a seed-borne, non-resistance-breaking isolate. According to our analysis, all other LMV isolates not previously assigned to a subgroup were also included in the LMV-RoW group.

Antimicrobial Efficacy of Penicillium amestolkiae elv609 Extract Treated Cotton Fabric for Diabetic Wound Care

  • Rozman, Nur Amiera Syuhada Binti;Hamin, Nurhanis Syafiqah Binti Mohd Nor;Ring, Leong Chean;Nee, Tan Wen;Mustapha, Mahfuzah Binti;Yenn, Tong Woei
    • Mycobiology
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    • v.45 no.3
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    • pp.178-183
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    • 2017
  • Diabetes mellitus is a chronic disorder which affects millions of population worldwide. Global estimates published in 2010 reported the world diabetic prevalence as 6.4%, affecting 285 million adults. Foot ulceration and wound infection are major forms of disabilities arising from diabetic diseases. This study was aimed to develop a natural antimicrobial finishing on medical grade textile that meets American Association of Textiles Chemists and Colorists (AATCC) standard. The textile samples were finished with the ethanolic extract of Penicillium amestolkiae elv609, an endophytic fungus isolated from Orthosiphon stamineus Benth (common name: cat's whiskers). Endophyte is defined as microorganism that reside in the living plant tissue, without causing apparent disease symptom to the host. The antimicrobial efficacy of the ethanolic extract of P. minioluteum was tested on clinical pathogens isolated from diabetic wound. The extract exhibited significant inhibitory activity against 4 bacteria and 1 yeast with the minimal inhibitory concentration ranged from 6.25 to 12.5 mg/mL. The results indicate different susceptibility levels of the test microorganism to the ethanolic extract. However, the killing activity of the extract was concentration-dependent. The finished medical textile showed excellent antimicrobial efficacy on AATCC test assays. All the microbial cultures treated with the textile sample displayed a growth reduction of 99.9% on Hoheinstein Challenge Test. The wash durability of the finished textile was found good even after 50 washes with commercial detergent. Besides, the gas chromatography mass spectrometry analysis showed that 6-octadecenoic acid and diethyl phthalate were the main bioactive constituents of the extract. In conclusion, the developed medical textile showed good antimicrobial efficacy on laboratory tests. This work can be extended to in vivo trials for developing healthcare textile products for antimicrobial applications.

Production of Tween 80-inducing Esterase by Acinetobacter sp. B1 Using Response Surface Methodology

  • Ma, Peiyu;Li, Yuqi;Miao, Chensi;Sun, Yunpeng;Liu, Chunhui;Li, Huijuan
    • Microbiology and Biotechnology Letters
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    • v.47 no.1
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    • pp.87-95
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    • 2019
  • Esterase produced by Acinetobacter sp. B1 (strain B1) was optimized by means of one-variable-at-a-time and response surface methodologies. Results of the one-variable-at-a-time experiment showed that Tween 80 significantly increased esterase production of strain B1. The addition of Tween 80 to the culture medium increased the biomass and esterase activity of strain B1, stimulated content of total extracellular protein, and enhanced the oleic acid (C18:1) composition in the cell membrane of strain B1. The influence of eight culture variables on esterase production was evaluated by Plackett-Burman design. Results showed that Tween 80, pH, and $K_2HPO_4$ significantly affected the esterase production of strain B1. Tween 80, pH, and $K_2HPO_4$ were further optimized by central composite design. Under the optimized conditions (w/v, soluble starch 2.5%, tryptone 1.5%, Tween 80 0.8%, $K_2HPO_4$ 0.5%, NaCl 0.5%, pH 8.0, inoculum size 1%, and inoculum age 24 h), the maximum esterase activity of strain B1 was 152.13 U/ml, which was 10-fold higher than that of non-optimization after 36 h cultivation.

COVID-19 progression towards ARDS: a genome wide study reveals host factors underlying critical COVID-19

  • Shama Mujawar;Gayatri Patil;Srushti Suthar;Tanuja Shendkar;Vaishnavi Gangadhar
    • Genomics & Informatics
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    • v.21 no.2
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    • pp.16.1-16.14
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    • 2023
  • Coronavirus disease 2019 (COVID-19) is a viral infection produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus epidemic, which was declared a global pandemic in March 2020. The World Health Organization has recorded around 43.3 billion cases and 59.4 million casualties to date, posing a severe threat to global health. Severe COVID-19 indicates viral pneumonia caused by the SARS-CoV-2 infections, which can induce fatal consequences, including acute respiratory distress syndrome (ARDS). The purpose of this research is to better understand the COVID-19 and ARDS pathways, as well as to find targeted single nucleotide polymorphism. To accomplish this, we retrieved over 100 patients' samples from the Sequence Read Archive, National Center for Biotechnology Information. These sequences were processed through the Galaxy server next generation sequencing pipeline for variant analysis and then visualized in the Integrative Genomics Viewer, and performed statistical analysis using t-tests and Bonferroni correction, where six major genes were identified as DNAH7, CLUAP1, PPA2, PAPSS1, TLR4, and IFITM3. Furthermore, a complete understanding of the genomes of COVID-19-related ARDS will aid in the early identification and treatment of target proteins. Finally, the discovery of novel therapeutics based on discovered proteins can assist to slow the progression of ARDS and lower fatality rates.