Negatively charged tangential flow ultrafiltration membranes for whey protein concentration

We report detection of <13 CFU of Salmonella per 25 g egg white within 7 h by concentrating the bacteria using microfiltration through 0.2-μm cutoff polyethersulfone hollow fiber membranes. A combination of enzyme treatment, controlled cross-flow on both sides of the hollow fibers, and media selection were key to controlling membrane fouling so that rapid concentration and the subsequent detection of low numbers of microbial cells were achieved. We leveraged the protective effect of egg white proteins and peptone so that the proteolytic enzymes did not attack the living cells while hydrolyzing the egg white proteins responsible for fouling. The molecular weight of egg white proteins was reduced from about 70 kDa to 15 kDa during hydrolysis. This enabled a 50-fold concentration of the cells when a volume of 525 mL of peptone and egg white, containing 13 CFU of Salmonella, was decreased to a 10 mL volume in 50 min. A 10-min microcentrifugation step further concentrated the viable Salmonella cells by 10×. The final cell recovery exceeded 100%, indicating that microbial growth occurred during the 3-h processing time. The experiments leading to rapid concentration, recovery, and detection provided further insights on the nature of membrane fouling enabling fouling effects to be mitigated. Unlike most membrane processes where protein recovery is the goal, recovery of viable microorganisms for pathogen detection is the key measure of success, with modification of cell-free proteins being both acceptable and required to achieve rapid microfiltration of viable microorganisms. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1464-1471, 2016.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

Ximenes

Kreke

et al. 2016

“…These two types of solute‐retention behavior cover a broad range used in bioprocessing, across different modalities and even across different industries (biotechnology, ADCs, food and dairy processing). Some applications may require separation of a small molecule or protein from larger molecules using semi‐permeable ultrafiltration membranes, and some applications may require concentration of protein solutions using completely retentive ultrafiltration membranes . With the exploration of single pass TFF as a new technology as an alternative to TFF, it is important to understand the single‐pass ultrafiltration behavior of both partially retained and completely retained proteins.…”

Section: Resultsmentioning

confidence: 99%

“…Some applications may require separation of a small molecule or protein from larger molecules using semipermeable ultrafiltration membranes, 13,15,17,18 and some applications may require concentration of protein solutions using completely retentive ultrafiltration membranes. [5][6][7]19 With the exploration of single pass TFF as a new technology as an alternative to TFF, it is important to understand the single-pass ultrafiltration behavior of both partially retained and completely retained proteins. This is the first work to provide experimental data demonstrating the behavior of partially retained proteins and completely retained proteins as a function of membrane molecular weight cut-off.…”

Section: Resultsmentioning

confidence: 99%

Ultrafiltration behavior of partially retained proteins and completely retained proteins using equally‐staged single pass tangential flow filtration membranes

Arunkumar

Zhang

Singh

et al. 2018

Self Cite

This work examines the ultrafiltration behavior of partially retained proteins like lysozyme and completely retained proteins like monoclonal antibodies using single pass tangential flow filtration (SPTFF) modules with different screen channels and molecular weight cut-offs. When the staging of the SPTFF used the same membrane area in each stage, there was no impact of the module screened channel or the buffer matrix on the final concentration achieved for completely retained monoclonal antibodies. A hybrid configuration containing 30 kDa membranes and 50 kDa membranes increased the maximum achievable concentration for both the monoclonal antibodies used in this work, at the same time, allowing a two-fold to four-fold increase in normalized feed flow-rate through the system compared to only the 30 kDa or only the 50 kDa membranes. The sieving coefficient of lysozyme measured and calculated using SPTFF was lower than those measured during conventional recirculation TFF indicating a more complicated concentration polarization effect than conventional recirculation TFF. Moreover, the sieving coefficients of lysozyme were the same for the 10 kDa regenerated cellulose and 50 kDa PES membranes while it was higher for the 30 kDa regenerated cellulose membrane. The difference in TFF and SPTFF behavior is important when the product of interest is desired to be permeated. This work presents the first body of data for partially and completely retained solutes together in the SPTFF mode and provides a strategy to increase protein concentration at higher feed flow rates. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1137-1148, 2018.

“…Here, the calculated sieving factor represents the apparent sieving factor that is based on the permeate concentration and mixing-cup concentration of the retentate 14. The samples collected at different DVs were analyzed for the concentration of each compound in both retentate solution and permeate solution.…”

mentioning

confidence: 99%

Clearance of solvents and small molecule impurities in antibody drug conjugates via ultrafiltration and diafiltration operation

Gates

Fang

Liao

2019

Ultrafiltration and diafiltration (UF/DF) processes by tangential flow filtration (TFF) are frequently used for removal of solvents and small molecule impurities and for buffer exchange for biopharmaceutical products. Antibody-drug conjugates (ADCs) as an important class of biological therapeutics, carry unique solvents and small molecule impurities into the final UF/DF step as compared to standard antibody preparation. The production process of ADCs involves multiple chemical steps, for example, reduction and conjugation. The clearance of these solvents and small molecules by UF/DF, specifically the DF step, has been assessed and described herein. The rates of clearance for all the impurities in this study are close to the ideal clearance with no apparent interaction with either the protein or the TFF membrane and system. The effect of process variables during DF, such as pH, temperature, membrane loading, transmembrane pressure, and cross flow rate, has also been evaluated and found to have minimal impact on the clearance rate. These results demonstrate efficient clearance of solvents and small molecule impurities related to the ADC process by the DF process and provide a general data package to facilitate risk assessments based on the sieving factors and program specific needs.