Displaying publications 1 - 20 of 85 in total

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  1. Li Y, Wen H, Chen L, Yin T
    PLoS One, 2014;9(12):e115024.
    PMID: 25502754 DOI: 10.1371/journal.pone.0115024
    The growing concern about the effectiveness of reclamation strategies has motivated the evaluation of soil properties following reclamation. Recovery of belowground microbial community is important for reclamation success, however, the response of soil bacterial communities to reclamation has not been well understood. In this study, PCR-based 454 pyrosequencing was applied to compare bacterial communities in undisturbed soils with those in reclaimed soils using chronosequences ranging in time following reclamation from 1 to 20 year. Bacteria from the Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, Planctomycetes and Bacteroidetes were abundant in all soils, while the composition of predominant phyla differed greatly across all sites. Long-term reclamation strongly affected microbial community structure and diversity. Initial effects of reclamation resulted in significant declines in bacterial diversity indices in younger reclaimed sites (1, 8-year-old) compared to the undisturbed site. However, bacterial diversity indices tended to be higher in older reclaimed sites (15, 20-year-old) as recovery time increased, and were more similar to predisturbance levels nearly 20 years after reclamation. Bacterial communities are highly responsive to soil physicochemical properties (pH, soil organic matter, Total N and P), in terms of both their diversity and community composition. Our results suggest that the response of soil microorganisms to reclamation is likely governed by soil characteristics and, indirectly, by the effects of vegetation restoration. Mixture sowing of gramineae and leguminosae herbage largely promoted soil geochemical conditions and bacterial diversity that recovered to those of undisturbed soil, representing an adequate solution for soil remediation and sustainable utilization for agriculture. These results confirm the positive impacts of reclamation and vegetation restoration on soil microbial diversity and suggest that the most important phase of microbial community recovery occurs between 15 and 20 years after reclamation.
  2. Zin CS, Chen LC, Knaggs RD
    Eur J Pain, 2014 Oct;18(9):1343-51.
    PMID: 24756859 DOI: 10.1002/j.1532-2149.2014.496.x
    BACKGROUND: This study evaluated the prescribing trends of four commonly prescribed strong opioids in primary care and explored utilization in non-cancer and cancer users.
    METHODS: This cross-sectional study was conducted from 2000 to 2010 using the UK Clinical Practice Research Datalink. Prescriptions of buprenorphine, fentanyl, morphine and oxycodone issued to adult patients were included in this study. Opioid prescriptions issued after patients had cancer medical codes were defined as cancer-related use; otherwise, they were considered non-cancer use. Annual number of prescriptions and patients, defined daily dose (DDD/1000 inhabitants/day) and oral morphine equivalent (OMEQ) dose were measured in repeat cross-sectional estimates.
    RESULTS: In total, there were 2,672,022 prescriptions (87.8% for non-cancer) of strong opioids for 178,692 users (59.9% female, 83.9% non-cancer, mean age 67.1 ± 17.0 years) during the study period. The mean annual (DDD/1000 inhabitants/day) was higher in the non-cancer group than in the cancer group for all four opioids; morphine (0.73 ± 0.28 vs. 0.12 ± 0.04), fentanyl (0.46 ± 0.29 vs. 0.06 ± 0.24), oxycodone (0.24 ± 0.19 vs. 0.038 ± 0.028) and buprenorphine (0.23 ± 0.15 vs. 0.008 ± 0.006). The highest proportion of patients were prescribed low opioid doses (OMEQ ≤ 50 mg/day) in both non-cancer (50.3%) and cancer (39.9%) groups, followed by the dose ranks of 51-100 mg/day (26.2% vs. 28.7%), 101-200 mg/day (15.1% vs. 19.2%) and >200 mg/day (8.25% vs. 12.1%).
    CONCLUSIONS: There has been a huge increase in strong opioid prescribing in the United Kingdom, with the majority of prescriptions for non-cancer pain. Morphine was the most frequently prescribed, but the utilization of oxycodone, buprenorphine and fentanyl increased markedly over time.
  3. Chen L, Kumar S, Wu H
    Arch Microbiol, 2023 Oct 20;205(11):356.
    PMID: 37863957 DOI: 10.1007/s00203-023-03699-2
    The emergence and transmission of antibiotic resistance is a global public health crisis with significant burden on healthcare systems, resulting in high mortality and economic costs. In 2019, almost five million deaths were associated with drug-resistant infections, and if left unchecked, the global economy could lose $100 trillion by 2050. To effectively combat this crisis, it is essential for all countries to understand the current situation of antibiotic resistance. In this review, we examine the current driving factors leading to the crisis, impact of critical superbugs in three regions, and identify novel mechanisms of antibiotic resistance. It is crucial to monitor the phenotypic characteristics of drug-resistant pathogens and describe the mechanisms involved in preventing the emergence of cross-resistance to novel antimicrobials. Additionally, maintaining an active pipeline of new antibiotics is essential for fighting against diverse antibiotic-resistant pathogens. Developing antibacterial agents with novel mechanisms of action is a promising way to combat increasing antibiotic-resistant pathogens.
  4. Bavanandan S, Ahmad G, Teo AH, Chen L, Liu FX
    Value Health Reg Issues, 2016 May;9:8-14.
    PMID: 27881266 DOI: 10.1016/j.vhri.2015.06.003
    OBJECTIVES: To investigate the 5-year health care budget impact of variable distribution of adult patients treated with peritoneal dialysis (PD) and in-center hemodialysis (ICHD) on government funding in Malaysia.

    METHODS: An Excel-based budget impact model was constructed to assess dialysis-associated costs when changing dialysis modalities between PD and ICHD. The model incorporates the current modality distribution and accounts for Malaysian government dialysis payments and erythropoiesis-stimulating agent costs. Epidemiological data including dialysis prevalence, incidence, mortality, and transplant rates from the Malaysian renal registry reports were used to estimate the dialysis patient population for the next 5 years. The baseline scenario assumed a stable distribution of PD (8%) and ICHD (92%) over 5 years. Alternative scenarios included the prevalence of PD increasing by 2.5%, 5.0%, and 7.5% or decreasing 1% yearly over 5 years. All four scenarios were accompanied with commensurate changes in ICHD.

    RESULTS: Under the current best available cost information, an increase in the prevalent PD population from 8% in 2014 to 18%, 28%, or 38% in 2018 is predicted to result in 5-year cumulative savings of Ringgit Malaysia (RM) 7.98 million, RM15.96 million, and RM23.93 million, respectively, for the Malaysian government. If the prevalent PD population were to decrease from 8% in 2014 to 4.0% by 2018, the total expenditure for dialysis treatments would increase by RM3.19 million over the next 5 years.

    CONCLUSIONS: Under the current cost information associated with PD and HD paid by the Malaysian government, increasing the proportion of patients on PD could potentially reduce dialysis-associated costs in Malaysia.

  5. Hatti-Kaul R, Chen L, Dishisha T, Enshasy HE
    FEMS Microbiol Lett, 2018 10 01;365(20).
    PMID: 30169778 DOI: 10.1093/femsle/fny213
    Lactic acid bacteria constitute a diverse group of industrially significant, safe microorganisms that are primarily used as starter cultures and probiotics, and are also being developed as production systems in industrial biotechnology for biocatalysis and transformation of renewable feedstocks to commodity- and high-value chemicals, and health products. Development of strains, which was initially based mainly on natural approaches, is also achieved by metabolic engineering that has been facilitated by the availability of genome sequences and genetic tools for transformation of some of the bacterial strains. The aim of this paper is to provide a brief overview of the potential of lactic acid bacteria as biological catalysts for production of different organic compounds for food and non-food sectors based on their diversity, metabolic- and stress tolerance features, as well as the use of genetic/metabolic engineering tools for enhancing their capabilities.
  6. Li C, Chen L, Ma C, Zhang S, Huang H
    Front Psychol, 2021;12:752084.
    PMID: 34721232 DOI: 10.3389/fpsyg.2021.752084
    This paper reports a mixed-methods study that explored the strategy use of a cohort of Chinese as second language learners in mainland China from the perspective of mediation theory. Data sources include a questionnaire survey (N = 189) and a semi-structured interview (N = 12). The findings revealed that the participants orchestrated a repertoire of language learning strategies and frequently used social and meta-cognitive strategies. Analysis of the qualitative data suggested that the participants' strategy use was shaped by the learners' self agentic power (their beliefs and Ideal L2 self), and the socio-cultural environment. Specifically, their strategy use was mediated by a host of socio-cultural factors, including learner beliefs, social agents, cultural artifacts, and learning environment. Considered together, the findings illuminate the socially situated nature of the use of language learning strategy. That is, strategy use of the participants stems from the interplay of learner agency and socio-cultural factors. The findings also imply the necessity of strategy-based instruction and highlight the importance of a Chinese-speaking environment for Chinese learning.
  7. Zhou J, Chen L, Foo HL, Cao Z, Lin Q
    Food Chem, 2024 Nov 15;458:140293.
    PMID: 38970959 DOI: 10.1016/j.foodchem.2024.140293
    The present study aimed to determine microbial community, short-chain fatty acids (SCFAs), and volatilome of Bulang pickled tea during fermentation. Sequencing of 16S rRNA and ITS revealed that Bualng pickled tea was dominated by Lactobacillus plantarum, unclassified Enterobacteriaceae, unclassified Debaryomyces, Candida metapsilosis, Cladosporium sphaerospermum, and unclassified Aspergillus. The overall contents of SCFAs increased, with acetic acid showing the highest content. A total of 398 differential volatile metabolites were detected using differential metabolomics analysis. Out of these different volatile compounds, ten key volatile compounds including (Z)-4-heptenal, 1-(2-thienyl)-ethanone, 5-methyl-(E)-2-hepten-4-one, 2-ethoxy-3-methylpyrazine, p-cresol, 2-methoxy-phenol, ethy-4-methylvalerate, 3-ethyl-phenol, p-menthene-8-thiol, and 2-s-butyl-3-methoxypyrazinewere were screened based on odor activity value (OAV). The Spearman correlation analysis showed a high correlation of SCFAs and volatile compounds with microorganisms, especially L. plantarum and C. sphaerospermum. This study provided a theoretical basis for elucidating the flavor quality formation mechanism of Bulang pickled tea.
  8. Teng H, Chen Y, Lin X, Lv Q, Chai TT, Wong FC, et al.
    Food Chem Toxicol, 2019 Jul;129:138-143.
    PMID: 31034934 DOI: 10.1016/j.fct.2019.04.043
    The aim of this study was to assess the inhibitory effects of Sonchus olearleu extract on the generation of heterocyclic amines in roasted pork patties cooked by pan-frying. All samples were cooked for two different durations (45 min and 105 min) under 200 °C and 230 °C. 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-ami- no-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinox-aline (4,8-DiMeIQx), harman, and norharman were detected and quantified. In patties cooked at 230 °C for 105 min, S. olearleu extract (0.5%) significantly inhibited the formation of IQ, harman, and norharman by 39%, 67%, and 63%, respectively. In contrast to IQ, the levels of harman and norharman were significantly reduced by the extracts tested. However, no such effects were observed for MeIQx and 4, 8-DiMeIQx. Notably, the inhibitory effect on heterocyclic amines is significantly correlated with the antioxidant potential and total phenolic content of S. olearleu extract.
  9. Liu S, Dang M, Lei Y, Ahmad SS, Khalid M, Kamal MA, et al.
    Curr Pharm Des, 2020;26(37):4808-4814.
    PMID: 32264807 DOI: 10.2174/1381612826666200407161842
    BACKGROUND: Alzheimer's disease (AD) is the most well-known reason for disability in persons aged greater than 65 years worldwide. AD influences the part of the brain that controls cognitive and non-cognitive functions.

    OBJECTIVE: The study focuses on the screening of natural compounds for the inhibition of AChE and BuChE using a computational methodology.

    METHODS: We performed a docking-based virtual screening utilizing the 3D structure of AChE and BuChE to search for potential inhibitors for AD. In this work, a screened inhibitor Ajmalicine similarity search was carried out against a natural products database (Super Natural II). Lipinski rule of five was carried out and docking studies were performed between ligands and enzyme using 'Autodock4.2'.

    RESULTS: Two phytochemical compounds SN00288228 and SN00226692 were predicted for the inhibition of AChE and BuChE, respectively. The docking results revealed Ajmalicine, a prominent natural alkaloid, showing promising inhibitory potential against AChE and BuChE with the binding energy of -9.02 and -8.89 kcal/mole, respectively. However, SN00288228- AChE, and SN00226692-BuChE were found to have binding energy -9.88 and -9.54 kcal/mole, respectively. These selected phytochemical compounds showed better interactions in comparison to Ajmalicine with the target molecule.

    CONCLUSION: The current study verifies that SN00288228 and SN00226692 are more capable inhibitors of human AChE and BuChE as compared to Ajmalicine with reference to ΔG values.

  10. Ma X, Cai L, Chen L, Fei B, Lu J, Xia C, et al.
    J Environ Manage, 2021 May 15;286:112190.
    PMID: 33636623 DOI: 10.1016/j.jenvman.2021.112190
    As an abundant and fast-growing biomass, bamboo can be used as construction materials owing to its desirable physical and mechanical properties, environmentally friendly features, and alternative to replace toxic and hazardous wastes in industrial processing. In this study, grid material made from bamboo (termed 'bamboo grid') was developed and compared to commercially used polyvinyl chloride (PVC) as packing material in cooling towers; PVC packing has drawbacks such as fouling, deposit buildup, low durability, and is harmful to environments. The cooling capacity, energy efficiency and environmental impact of bamboo grid packing were evaluated via life cycle assessment (LCA), particularly the cumulative energy demand (CED) and the Building for Environmental and Economic Sustainability (BEES). Although the thermal performance of the PVC packing was found higher than that of the bamboo grid packing, the bamboo grid packing showed improved resistance characteristic, recording a total saving of 529.2 tons of standard coal during a six-month field test in a real thermal power generation plant. LCA results revealed that the utilization of bamboo-grid packing to replace PVC packing in cooling towers reduced total CED from 3420 MJ to 561 MJ per functional unit, achieving 6 times reduction. A desirable reduction ranging from 1.5 to 10.5 times was also recorded for the BEES indices. This LCA comparison analysis confirmed the improvement of energy efficiency and reduction of environmental impact by using the bamboo grid to replace PVC as packing material in cooling towers. The major environmental impact (BEES) indices (e.g., the total Global warming potential, Acidification, Eutrophication and Smog) were reduced by 1.5-10.5 times via the use of bamboo grid. The results demonstrate that bamboo grid packing is a good alternative to replace existing grid packing materials such as concrete and PVC that are harmful to human health and environments.
  11. Chen L, Xie W, Luo Y, Ding X, Fu B, Gopinath SCB, et al.
    PMID: 33786878 DOI: 10.1002/bab.2155
    A highly sensitive silica-alumina (Si-Al)-modified capacitive non-Faradaic glucose biosensor was introduced to monitor gestational diabetes. Glucose oxidase (GOx) was attached to the Si-Al electrode surface as the probe through amine-modification followed by glutaraldehyde premixed GOx as aldehyde-amine chemistry. This Si-Al (∼50 nm) modified electrode surface has increased the current flow upon binding of GOx with glucose. Capacitance values were increased by increasing the glucose concentrations. A mean capacitance value was plotted and the detection limit was found as 0.03 mg/mL with the regression coefficient value, R² = 0.9782 [y = 0.8391x + 1.338] on the linear range between 0.03 and 1 mg/mL. Further, a biofouling experiment with fructose and galactose did not increase the capacitance, indicating the specific glucose detection. This Si-Al-modified capacitance sensor detects a lower level of glucose presence and helps in monitoring gestational diabetes.
  12. Chen L, Ho CD, Jen LY, Lim JW, Chen YH
    Membranes (Basel), 2020 Oct 22;10(11).
    PMID: 33105658 DOI: 10.3390/membranes10110302
    We investigated the insertion of eddy promoters into a parallel-plate gas-liquid polytetrafluoroethylene (PTFE) membrane contactor to effectively enhance carbon dioxide absorption through aqueous amine solutions (monoethanolamide-MEA). In this study, a theoretical model was established and experimental work was performed to predict and to compare carbon dioxide absorption efficiency under concurrent- and countercurrent-flow operations for various MEA feed flow rates, inlet CO2 concentrations, and channel design conditions. A Sherwood number's correlated expression was formulated, incorporating experimental data to estimate the mass transfer coefficient of the CO2 absorption in MEA flowing through a PTFE membrane. Theoretical predictions were calculated and validated through experimental data for the augmented CO2 absorption efficiency by inserting carbon-fiber spacers as an eddy promoter to reduce the concentration polarization effect. The study determined that a higher MEA feed rate, a lower feed CO2 concentration, and wider carbon-fiber spacers resulted in a higher CO2 absorption rate for concurrent- and countercurrent-flow operations. A maximum of 80% CO2 absorption efficiency enhancement was found in the device by inserting carbon-fiber spacers, as compared to that in the empty channel device. The overall CO2 absorption rate was higher for countercurrent operation than that for concurrent operation. We evaluated the effectiveness of power utilization in augmenting the CO2 absorption rate by inserting carbon-fiber spacers in the MEA feed channel and concluded that the higher the flow rate, the lower the power utilization's effectiveness. Therefore, to increase the CO2 absorption flux, widening carbon-fiber spacers was determined to be more effective than increasing the MEA feed flow rate.
  13. Cai R, Yue X, Wang Y, Yang Y, Sun D, Li H, et al.
    J Ethnopharmacol, 2021 Dec 05;281:114563.
    PMID: 34438033 DOI: 10.1016/j.jep.2021.114563
    ETHNOPHARMACOLOGICAL RELEVANCE: The genus Amomum belonging to the family Zingiberaceae, is mainly distributed in tropical regions of Asia and Oceania. Their fruits and seeds are valuable traditional medicine and used extensively, particularly in South China, India, Malaysia, and Vietnam. The genus Amomum has long been used for treating gastric diseases, digestive disorder, cancer, hepatopathy, malaria, etc. AIMS OF THE REVIEW: The main purpose of this review is to provide the available information on the traditional medicinal uses, phytochemistry, and pharmacology aspects of the genus Amomum in order to explore the trends and perspectives for further studies on its non-volatile constituents.

    MATERIALS AND METHODS: The present review collected the literatures published prior to 2020 on the traditional medicinal uses, phytochemistry, and pharmacology of the genus Amomum. The available literatures were extracted from scientific databases, such as Sci-finder, PubMed, Web of Science, Google Scholar, Baidu Scholar, and CNKI, books, and others.

    RESULTS: Herein, we summarize all 166 naturally occurring non-volatile compounds from 16 plants of the genus Amomum reported in 171 references, including flavonoids, terpenoids, diarylheptanoids, coumarins, etc. Triterpenes and flavonoids are the main constituents among these compounds and maybe play an important role in the activities directly or indirectly. As traditional medicine, the plants from the genus Amomum have been usually used in some traditional herbal prescriptions, and pharmacological researches in vitro and in vivo revealed that the extracts possessed significant antioxidant, anti-inflammatory, anti-allergic activities, etc. CONCLUSION: The review systematically summarizes current studies on traditional medicinal uses, phytochemistry, pharmacological activity on the plants from the genus Amomum. To date, the majority of publications still focused on the research of volatile constituents. However, the promising preliminary data of non-volatile constituents indicated the research potential of this genus in phytochemical and pharmacological aspects. Furthermore, the further in-depth investigations on the safety, efficacy, as well as the stereo-chemistry and structure-activity relationships of pure compounds from this genus are essential in the future.

  14. Chen L, Wang Z, Zhang B, Ge M, Ng H, Niu Y, et al.
    Carbohydr Polym, 2019 Feb 01;205:271-278.
    PMID: 30446105 DOI: 10.1016/j.carbpol.2018.10.070
    Carbon and nitrogen sources in culture medium of Antrodia cinnamomea were optimized to eliminate the interference of exterior macromolecules on exopolysaccharide (EPS) yield by submerged fermentation. The results suggested that culture medium containing 50 g/L of glucose and 20 g/L of yeast extract as the optimal carbon and nitrogen sources could produce 1.03 g/L of exopolysaccharides. After purification, two heteropolysaccharides (AC-EPS1 and AC-EPS2) were obtained and characterized to provide the basic structure information. As the main component of the produced EPS, AC-EPS2 (accounting for 89.63%) was mainly composed of galactose (87.42%) with Mw (molecular weight) and R.M.S. (root-mean-square) radius of 1.18 × 105 g/mol and 25.3 nm, respectively. Furthermore, the spherical and flexible chain morphologies of EPS were observed in different solvents by TEM. The structural and morphological information of purified EPS were significant for further study on their structure-activity relationship and related applications.
  15. El-Seedi HR, Khalifa SAM, Yosri N, Khatib A, Chen L, Saeed A, et al.
    J Ethnopharmacol, 2019 Oct 28;243:112007.
    PMID: 31170516 DOI: 10.1016/j.jep.2019.112007
    ETHNOPHARMACOLOGICAL RELEVANCE: Over the past thousand years, Islamic physicians have collected cultural, philosophical, sociological and historical backgrounds for understanding diseases and medications. The Prophet Mohammed (Peace Be Upon Him (PBUH) said: "There is no disease that Allah has created, except that Allah also has created its cure." Therefore, Islamic scholars are encouraged to explore and use both traditional and modern forms of medicine.

    AIM OF THE STUDY: (1) To identify some of the medicinal plants mentioned in the Holy Qur'ân and Ahadith textbooks of the period 700-1500 AD; (2) to compare them with presently used traditional medicines; (3) to evaluate their value based on modern research; and (4) to investigate the contributions of Islamic scholars to the development of the scientific branches, particularly medicine.

    MATERIALS AND METHODS: A literature search was performed relating to 12 medicinal plants mentioned in the Holy Qur'ân and Ahadith using textbooks, Al-Azhar scholars, published articles, the plant list website (http://www.theplantlist.org/), the medicinal plant names services website (http://mpns.kew.org/mpns-portal/) and web databases (PubMed, Science Direct, and Google Scholar).

    RESULTS AND DISCUSSION: The Islamic Golden Age was a step towards modern medicine, with unique insights and multi-disciplinary aspects. Traditional Islamic Medicine has had a significant impact on the development of various medical, scientific and educational activities. Innumerable Muslim and non-Muslim physicians have built on the strong foundation of Traditional Islamic Medicine by translating the described natural remedies and effects. The influences of different ancient cultures on the traditional uses of natural products were also documented in Islamic Scriptures in the last part of the second millennium. The divine teachings of Islam combine natural and practical healing and incorporate inherited science and technology.

    CONCLUSION: In this review, we discuss Traditional Islamic Medicine with reference to both medical recommendations mentioned in the Holy Qur'ân and Prophetic Traditional Medicine (al-Tibb al-Nabawi). Although the molecular mechanisms and functions of some of the listed medicinal plants and their derivatives have been intensively studied, some traditional remedies have yet to be translated into clinical applications.

  16. Chen L, Jiang X, Gao S, Liu X, Gao Y, Kow ASF, et al.
    Front Pharmacol, 2022;13:1032069.
    PMID: 36386146 DOI: 10.3389/fphar.2022.1032069
    ABT-199 (venetoclax) is the first-in-class selective B-cell lymphoma 2 (BCL2) inhibitor, which is known to be ineffective towards liver cancer cells. Here, we investigated the efficacy and the underlying molecular processes of the sensitization effect of kaempferol isolated from persimmon leaves (KPL) on the ABT-199-resistant HepG2 cells. The effects of various doses of KPL coupled with ABT-199 on the proliferation of HepG2 cells and on the H22 liver tumor-bearing mouse model were examined, as well as the underlying mechanisms. Our findings showed that ABT-199 alone, in contrast to KPL, had no significant impact on hepatoma cell growth, both in vitro and in vivo. Interestingly, the combination therapy showed significantly higher anti-hepatoma efficacy. Mechanistic studies revealed that combining KPL and ABT-199 may promote both early and late apoptosis, as well as decrease the mitochondrial membrane potential in HepG2 cells. Western blot analysis showed that combination of KPL and ABT-199 significantly reduced the expression of the anti-apoptotic proteins Bcl-2, Bcl-xL, and Mcl-1, raised the expression of Bax and cleaved caspase 3, and enhanced cytochrome C release and Bax translocation. Therefore, KPL combined with ABT-199 has a potential application prospect in the treatment of hepatocellular carcinoma.
  17. Ng HS, Kee PE, Wu YC, Chen L, Wong SYW, Lan JC
    J Biosci Bioeng, 2021 Nov;132(5):513-518.
    PMID: 34479804 DOI: 10.1016/j.jbiosc.2021.07.004
    Microbial astaxanthin with strong antioxidant activity is greatly demanded for diverse applications. Extractive disruption in aqueous biphasic system (ABS) integrates the cells disruption and biomolecules recovery processes in one-step operation, allowing the direct recovery of intracellular biomolecules with biphasic system upon released from cells. In this study, astaxanthin was recovered from recombinant Kluyveromyces marxianus yeast cells via extractive disruption using alcohol/salt ABS. Recombinant K. marxianus yeast is engineered to produce high concentration of free form astaxanthin. Highest partition coefficient (K = 90.02 ± 2.25) and yield (Y = 96.80% ± 0.05) of astaxanthin were obtained with ABS composed of 20% (w/w) 1-propanol and 20% (w/w) sodium citrate of pH 5, 0.5% (w/w) yeast cells loading and additional of 1% (w/w) 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim)BF4 to improve the migration of astaxanthin to alcohol-rich top phase. The incorporation of 2.5 h of ultrasonication to the biphasic system further enhanced the astaxanthin recovery in ABS. The direct recovery of astaxanthin from recombinant K. marxianus cells was demonstrated with the ultrasonication-assisted alcohol/salt ABS which integrates the extraction and concentration of astaxanthin in a single-step operation.
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