scholarly journals New extraction techniques on bioseparations: 2. Pertraction, direct extraction

2004 ◽  
Vol 58 (12) ◽  
pp. 535-547
Author(s):  
Anca-Irina Galaction ◽  
Dan Cascaval

The second part of this review presents our original results on the separation of some biosynthetic products (antibiotics, carboxylic acids, alcohols) by pertraction and direct extraction from broths without biomass filtration. For the analyzed systems, the experimental conditions required for reaching maximum separation efficiency and the mathematical models describing the process have been established. For all the studied cases, these extraction techniques simplify the technologies and reduce the overall cost of the product.

2004 ◽  
Vol 58 (9) ◽  
pp. 375-386 ◽  
Author(s):  
Dan Cascaval ◽  
Anca-Irina Galaction

The complexity of downstream processes for biosynthetic products constitutes a particularity of industrial biotechnologies, especially because of the biosynthetic product high dilution in fermentation broth, their chemical and thermal liability and the presence of secondary products. For these reasons, new separation techniques have been developed and applied to bioseparations. Among them, reactive extraction, pertraction (extraction and transport through liquid membranes) and direct extraction from broths have considerable potential and are required for the further development of many biotechnologies. This review is structured on two parts and presents our original results of the studies on the separation of some biosynthetic products (antibiotics, carboxylic acids, amino acids, alcohols) by reactive extraction in the first part, and by pertraction and direct extraction from broths without biomass filtration in the second. For all the analyzed cases, these extraction techniques simplify the technologies by reducing material and energy consumption, by avoiding product inhibition, by increasing the separation selectivity, therefore decreasing the overall cost of the product.


2013 ◽  
Vol 864-867 ◽  
pp. 503-507
Author(s):  
Tao Wang

In this experiment, the main compounds of stilbene glucoside and anthraquinones from polygonum multiflorum extract were separated by HPLC gradient elution. SinoChrom ODS-BP C18 is selected as chromatographic column. The optimal experimental conditions under 254nm wavelength UV detector include the column temperature: 26°C, mobile phase: methanol/water, and flow rate: 1.0ml/mol. The gradient method can be optimized by changing the steepness and shape of gradient elution. Through optimizing gradient method, the separation efficiency is improved within a certain range of gradient elution strength. This article provides important reference for quality control and content determination of fleece-flower root.


2021 ◽  
Author(s):  
Anup Kumar Bairagi ◽  
Kollati Prudhvi Ravikumar ◽  
Abanti Sahoo ◽  
Soumya Sanjeeb Mohapatra ◽  
Sangam Agrawal

Abstract The large amount of wastewater generated from textile industries, petroleum industries, chemical industries contains heavy metals, suspended solids, hazardous waste, oils, fatty acids, dyes, pigment etc. It is very important to improve the quality of contaminated water before it discharges into the water sources or use. In the current work, an efficient methodology has been developed to separate emulsified oil from wastewater. The emulsified oil is tried to separate by using poly silicate Ferro aluminium sulphates, a flocculent. In addition to the above, the maximum separation efficiency for the devolved process is also revealed. Using PSFA, up to 93.5 % separation efficiency is achieved, and the discussed methodology can separate emulsified forms of the oil without altering the efficiency. The dissolved solid and metal content are also considered as the controlling parameters for the separation efficiency. The optimum TDS and the metal content must be maintained at 560 mg/L and 2 mg/L, respectively, to attain maximum separation efficiency.


2020 ◽  
Vol 83 (10) ◽  
pp. 1801-1811
Author(s):  
BALASUBRAHMANYAM KOTTAPALLI ◽  
DAVIDE QUARANTA ◽  
DEANN AKINS-LEWENTHAL ◽  
DONALD W. SCHAFFNER ◽  
JAIRUS R. D. DAVID

ABSTRACT High-moisture slurries used in the production of table spreads may permit growth of Staphylococcus aureus and Bacillus cereus and subsequent production of heat-stable enterotoxins. Compliance with the Food Safety Modernization Act (FSMA), specifically 21 CFR Part 117, subpart B and section 117.80 (c)(2) and (c)(3), requires a hazard analysis to determine whether preventive controls are needed. This study estimates the risk of potential growth of S. aureus and B. cereus in eight different dairy- and non-dairy–based slurries during extended storage and use. Mathematical models were used to screen which slurries might support the growth of S. aureus and B. cereus. Samples were individually inoculated with multiple strains of S. aureus and B. cereus to achieve a target level of 102 to 103 CFU/g. Inoculated and uninoculated slurry samples were incubated at typical holding temperatures of 35°C (95°F), 46.1°C (115°F), and 54.4°C (130°F). Samples were removed and tested following inoculation (time zero), after 4 and 12 h, and after 1, 2, 3, 4, 5, 6, 7, and 10 days of incubation at the target temperatures. All experiments were repeated in triplicate. Samples were analyzed for S. aureus and B. cereus using Baird-Parker agar and mannitol yolk polymyxin agar, respectively. Neither S. aureus nor B. cereus exceeded (P < 0.05) proposed food safety limits (105 CFU/g) at the evaluated experimental conditions. The study highlights the role of multiple hurdles (e.g., pH, potassium sorbate and sodium benzoate, salt, and other ingredients) in assuring microbiological safety of in-process dairy- and non-dairy–based slurries used in the production of table spreads. This study also found that mathematical models representative of product composition, intrinsic parameters, and experimental conditions can help risk managers make informed decisions during product development. Finally, the study findings indicate no significant risk of growth of the target pathogens associated with the dairy- and non-dairy–based aqueous slurries used in the routine manufacturing of table spreads. HIGHLIGHTS


1987 ◽  
Vol 62 (3-4) ◽  
pp. 307-319 ◽  
Author(s):  
Yery A. Mendoza ◽  
Fazil O. Gülaçar ◽  
Armand Buchs

1995 ◽  
Vol 03 (01) ◽  
pp. 105-113 ◽  
Author(s):  
MARTA CASCANTE ◽  
RAUL CURTO ◽  
ALBERT SORRIBAS

Mathematical models are useful for analyzing metabolic problems. To build up these models, we need: (1) A scheme of the target system, (2) Measurements of concentrations and fluxes in steady-state, (3) The rate law of each reaction and (4) The set of differential equations that reflects the model behaviour. Usually, the rate-laws are identified from in vitro data, which could result in unrealistic models when compared with the behavior of the intact system. Hence, mathematical models must be carefully validated before one can trust their behavior. We can use different features of a biological system as a reference for validating a model. The steady-state robustness to parameter changes can be used as an index for such an evaluation. In this sense, a realistic model should reflect a fundamental property of a living system: small perturbations are compatible with system performance. We present an example of such analysis in the case of the ethanolic fermentation pathway of Saccharomyces cerevisiae. The parameter sensitivities of the model are computed in two experimental conditions and a diagnostic is made on the validity of the corresponding model. Translation of the mechanistic model into an S-system model facilitates the analysis of parameter sensitivity. After the analysis, a high parameter sensitivity suggest the need for a careful estimation of the involved parameters.


2015 ◽  
Vol 73 (5) ◽  
pp. 1090-1097 ◽  
Author(s):  
T. Liu ◽  
Y. Sun ◽  
Z. L. Wang

Sediment contamination by heavy metals has become a widespread problem that can affect the normal behaviors of rivers and lakes. After chitosan/Fe0-nanoparticles (CS-NZVI) beads were cross-linked with glutaraldehyde (GLA), their mechanical strength, stability and separation efficiency from the sediment were obviously improved. Moreover, the average aperture size of GLA-CS-NZVI beads was 20.6 μm and NZVI particles were nearly spherical in shape with a mean diameter of 40.2 nm. In addition, the pH showed an insignificant effect on the removal rates from the sediment. Due to the dissolution of metals species into aqueous solutions as an introduction of the salt, the removal rates of all heavy metals from the sediment were increased with an increase of the salinity. The competitive adsorption of heavy metals between the sediment particles and GLA-CS-NZVI beads became stronger as the sediment particles became smaller, leading to decreased removal rates. Therefore, the removal efficiency could be enhanced by optimizing experimental conditions and choosing appropriate materials for the target contaminants.


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