scholarly journals Enhanced 2-phenylethanol production by newly isolated Meyerozyma sp. strain YLG18 and characterization of its synthetic pathways

2020 ◽  
Author(s):  
Wei Yan ◽  
Xiujuan Qian ◽  
Wenming Zhang ◽  
Jie Zhou ◽  
Weiliang Dong ◽  
...  
Keyword(s):  
Acid Methyl Ester ◽  
Shikimate Pathway ◽  
Transcriptional Analysis ◽  
Scale Production ◽  
Ehrlich Pathway ◽  
Food Industries ◽  
Meyerozyma Guilliermondii ◽  
In Situ Product Recovery ◽  
Optimized Conditions

Abstract Background2-Phenylethanol (2-PE) is an aromatic alcohol which has been widely used in cosmetics, perfume and food industries owning to its delicate rose scent. The newly isolated yeast Meyerozyma guilliermondii YLG18 was able to tolerate high exogenous 2-PE and produce 2-PE with two different pathways.ResultsA unique Meyerozyma sp. strain YLG18 was obtained in this study, which was capable of tolerating 4.0 g/L exogenous 2-PE. Response surface methodology (RSM) was implemented to improve the maximum 2-PE production. At optimized conditions: temperature, 24.7℃; initial glucose, 63.54 g/L; initial L-phe, 10.70 g/L, 2-PE production was increased to 2.55 g/L, leading to 104% increase compared to the pre-optimized one. In situ product recovery (ISPR) could further help improve the final 2-PE production to 3.20 g/L with fatty acid methyl ester as the extractant, representing the highest 2-PE production by using Meyerozyma sp.. Furthermore, genes involved in 2-PE synthesis were identified and their expression levels between Shikimate pathway and Ehrlich pathway were compared. Based on the genomic and transcriptional analysis, a penta-functional enzyme AroM in Shikimate pathway and an aspartate aminotransferase (AAT) with the potential to convert phenylalanine into phenylpyruvate in Ehrlich pathway were identified.ConclusionsThese findings would help broaden our knowledge and add to the pool of known 2-PE generating microbes and genes. Moreover, this study describes a potential, new 2-PE producer that lays foundation for the industrial-scale production of 2-PE and its derivatives in the future. Key words: 2-phenylethanol; Meyerozyma guilliermondii; RSM; ISPR; gene analysis

Optimization on Influencing Factors of Fracture Toughness of Corundum-Mullite Toughened by In Situ Synthesized Mullite Whiskers by Response Surface Methodology

2012 ◽  
Vol 581-582 ◽  
pp. 819-822 ◽  
Author(s):  
Bin Meng ◽  
Jin Hui Peng
Keyword(s):  
Fracture Toughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Response Surface Method ◽  
Sintering Temperature ◽  
Surface Method ◽  
Mullite Whiskers ◽  
Optimized Conditions ◽  
Addition Amount

The corundum-mullite was toughened by in-situ synthesized mullite whiskers and the process parameters influencing the fracture toughness of corundum-mullite, such as sintering temperature, addition amount of AlF3 and V2O5, were optimized by means of response surface method. Corundum-mullite with fracture toughness of 9.44 MPa.m-1/2 could be obtained under the optimized conditions, i.e. sintering temperature of 1400°C, 4.8 wt.% of AlF3 and 5.8 wt.% of V2O5. The results showed that it was feasible to prepare corundum-mullite toughened by in-situ synthesized mullite whiskers by the optimized parameters. In addition, an accurate model based on response surface method was proposed to predict the experimental results.

scholarly journals Ionic Liquid-modified NiTi Composite Nanosheets Coating for Efficient Solid Phase Microextraction of Octadecylamine in Brine

2019 ◽  
pp. 1-8
Author(s):  
Huiju Wang
Keyword(s):  
Ionic Liquid ◽  
Solid Phase Microextraction ◽  
Extraction Efficiency ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Fiber Coating ◽  
Relative Standard ◽  
Optimized Conditions ◽  
As Solid Phase

Ionic     liquid (IL), 1-dodecyl-3-methylimidazolium-3-hydroxy-2-naphthoate (C12mimHNC) was synthesized and coated on the surface of NiTi as solid phase microextractiom fiber coating for determination the octadecylamine in brine. Prior to modification with IL, the NiTi was hydrothermally treated for in-situ growth of titanium and nickel oxide composite nanosheets (TiO2/NiOCNSs). The TiO2/NiOCNSs fibers coating was oriented  around the NiTi  substrate and  presented  double-faced  open  access  sites,  which provided a desired support framework for the further modification with IL. The extraction performance of C12mimHNC-TiO2/NiOCNSs fiber coating was evaluated for       detection of octadecylamine (ODA) coupled to HPLC with UV detection. As a result, the C12mimHNC-TiO2/NiOCNSs fiber coating illustrated excellent adsorption and extraction capability for ODA. The main factors affected extraction efficiency were optimized. Under the optimized  conditions,  good  linearity was  obtained  in  the  range of  1-150  µg/L with correlation  coefficients  (r2)  above  0.985.  Limits of detection (LODs) for  the  developed method was 0.280 µg/L. The proposed method was first applied to extract the ODA in brine samples. Relative recoveries varied from 78.3% to 96.5% at spiking level of 15µg/L and 30 µg/L with the relative standard deviations (RSDs) less than 8.7%.

scholarly journals A comparison of the energy use of in situ product recovery techniques for the Acetone Butanol Ethanol fermentation

2016 ◽  
Vol 220 ◽  
pp. 590-600 ◽  
Author(s):  
Victoria Outram ◽  
Carl-Axel Lalander ◽  
Jonathan G.M. Lee ◽  
E. Timothy Davis ◽  
Adam P. Harvey
Keyword(s):  
Ethanol Fermentation ◽  
Energy Use ◽  
Product Recovery ◽  
In Situ Product Recovery ◽  
Recovery Techniques ◽  
Acetone Butanol Ethanol

scholarly journals Rheological Characterization of Hydrogels from Alginate-Based Nanodispersion

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
Francesca Cuomo ◽  
Martina Cofelice ◽  
Francesco Lopez
Keyword(s):  
Essential Oil ◽  
Tween 80 ◽  
Creep Recovery ◽  
Ion Release ◽  
Rheological Characterization ◽  
Burger Model ◽  
Food Industries ◽  
Hydrogel Network

The interest toward alginate and nanoemulsion-based hydrogels is driven by the wide potential of application. These systems have been noticed in several areas, ranging from pharmaceutical, medical, coating, and food industries. In this investigation, hydrogels prepared through in situ calcium ion release, starting from lemongrass essential oil nanodispersions stabilized in alginate aqueous suspensions in the presence of the nonionic surfactant Tween 80, were evaluated. The hydrogels prepared at different concentrations of oil, alginate, and calcium were characterized through rheological tests. Flow curves demonstrate that the hydrogels share shear thinning behavior. Oscillatory tests showed that the strength of the hydrogel network increases with the crosslinker increase, and decreases at low polymer concentrations. The hydrogels were thixotropic materials with a slow time of structural restoration after breakage. Finally, by analyzing the creep recovery data, the hydrogel responses were all fitted to the Burger model. Overall, it was demonstrated that the presence of essential oil in the proposed hydrogels does not affect the mechanical characteristics of the materials, which are mainly influenced by the concentration of polymer and calcium as a crosslinker.

scholarly journals Improved Production and In Situ Recovery of Sesquiterpene (+)-Zizaene from Metabolically-Engineered E. coli

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3356 ◽  
Author(s):  
Francisco Aguilar ◽  
Thomas Scheper ◽  
Sascha Beutel
Keyword(s):  
Liquid Phase ◽  
Product Recovery ◽  
Expanded Bed Adsorption ◽  
Biotechnological Production ◽  
Promising Alternative ◽  
Phase Partitioning ◽  
In Situ Product Recovery ◽  
Solid Liquid ◽  
In Situ Recovery

The sesquiterpene (+)-zizaene is the direct precursor of khusimol, the main fragrant compound of the vetiver essential oil from Chrysopogon zizanioides and used in nearly 20% of men’s fine perfumery. The biotechnological production of such fragrant sesquiterpenes is a promising alternative towards sustainability; nevertheless, product recovery from fermentation is one of the main constraints. In an effort to improve the (+)-zizaene recovery from a metabolically-engineered Escherichia coli, we developed an integrated bioprocess by coupling fermentation and (+)-zizaene recovery using adsorber extractants. Initially, (+)-zizaene volatilization was confirmed from cultivations with no extractants but application of liquid–liquid phase partitioning cultivation (LLPPC) improved (+)-zizaene recovery nearly 4-fold. Furthermore, solid–liquid phase partitioning cultivation (SLPPC) was evaluated by screening polymeric adsorbers, where Diaion HP20 reached the highest recovery. Bioprocess was scaled up to 2 L bioreactors and in situ recovery configurations integrated to fermentation were evaluated. External recovery configuration was performed with an expanded bed adsorption column and improved (+)-zizaene titers 2.5-fold higher than LLPPC. Moreover, internal recovery configuration (IRC) further enhanced the (+)-zizaene titers 2.2-fold, whereas adsorption velocity was determined as critical parameter for recovery efficiency. Consequently, IRC improved the (+)-zizaene titer 8.4-fold and productivity 3-fold from our last report, achieving a (+)-zizaene titer of 211.13 mg L−1 and productivity of 3.2 mg L−1 h−1. This study provides further knowledge for integration of terpene bioprocesses by in situ product recovery, which could be applied for many terpene studies towards the industrialization of fragrant molecules.

In situ lipase-catalyzed transesterification in rice bran for synthesis of fatty acid methyl ester

2018 ◽  
Vol 120 ◽  
pp. 140-146 ◽  
Author(s):  
Nakyung Choi ◽  
Da Som No ◽  
Heejin Kim ◽  
Byung Hee Kim ◽  
Jieun Kwak ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Methyl Ester ◽  
Fatty Acid Methyl Ester ◽  
Rice Bran ◽  
Acid Methyl Ester ◽  
Acid Methyl

scholarly journals A Facile Synthesis of ZrOx-MnCO3/Graphene Oxide (GRO) Nanocomposites for the Oxidation of Alcohols using Molecular Oxygen under Base Free Conditions

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 759 ◽  
Author(s):  
Syed Farooq Adil ◽  
Mohamed E. Assal ◽  
Mohammed Rafi Shaik ◽  
Mufsir Kuniyil ◽  
Nawaf M. AlOtaibi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Activity ◽  
Oxidation Catalyst ◽  
Facile Synthesis ◽  
Reduced Graphene ◽  
Short Period ◽  
Oxidation Of Alcohols ◽  
Lower Temperature ◽  
Optimized Conditions

Graphene and its nanocomposites are showing excellent potential in improving the catalytic performances of different materials. However, the synthetic protocol and its form, such as graphene oxide (GRO) or highly reduced graphene oxide (HRG), influence the catalytic efficiencies. Here, we present, a facile synthesis of graphene oxide (GRO) and ZrOx-MnCO3-based nanocomposites [(1%)ZrOx–MnCO3/(x%)GRO] and their outcome as an oxidation catalyst for alcohol oxidation under mild conditions using O2 as a clean oxidant. The ZrOx–MnCO3/GRO catalyst prepared by incorporating GRO to pre-calcined ZrOx-MnCO3 using ball milling showed remarkable enhancement in the catalytic activities as compared to pristine ZrOx–MnCO3, ZrOx–MnCO3 supported on HRG or ZrOx–MnCO3/GRO prepared by in-situ growth of ZrOx–MnCO3 onto GRO followed by calcination. The catalyst with composition (1%)ZrOx–MnCO3/(1%)GRO exhibited superior specific activity (57.1 mmol/g·h) with complete conversion and >99% selectivity of the product within a short period of time (7 min) and at a relatively lower temperature (100 °C). The catalyst could be recycled at least five times with a negligible decrease in efficiency and selectivity. The catalytic study was extended to different aromatic as well as aliphatic alcohols under optimized conditions, which confirmed the efficiency and selectivity of the catalyst.

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