Abstract A dynamic reaction–diffusion model of four variables is proposed to describe the spread of lytic viruses among phytoplankton in a poorly mixed aquatic environment. The basic ecological reproductive index for phytoplankton invasion and the basic reproduction number for virus transmission are derived to characterize the phytoplankton growth and virus transmission dynamics. The theoretical and numerical results from the model show that the spread of lytic viruses effectively controls phytoplankton blooms. This validates the observations and experimental results of Emiliana huxleyi-lytic virus interactions. The studies also indicate that the lytic virus transmission cannot occur in a low-light or oligotrophic aquatic environment.
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Effect of filtrate flux and process disruptions on virus retention by a relatively homogeneous virus removal membrane
- Award ID(s):
- 1841474
- PAR ID:
- 10382104
- Date Published:
- Journal Name:
- Biotechnology Progress
- Volume:
- 38
- Issue:
- 4
- ISSN:
- 8756-7938
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Virus filtration is a crucial step in ensuring the high levels of viral clearance required in the production of biotherapeutics produced in mammalian cells or derived from human plasma. Previous studies have reported that virus retention is often reduced in the presence of therapeutic proteins due to membrane fouling; however, the underlying mechanisms controlling this behavior are still not well understood. Experimental studies were performed with a single layer of the commercially available dual‐layer PegasusTMSV4 virus removal filter to more easily interpret the experimental results. Bacteriophage ФX174 was used as a model parvovirus, and human immunoglobulin (hIgG) and Bovine Serum Albumin (BSA) were used as model proteins. Data obtained with 5 g/L solutions of hIgG showed more than a 100‐fold reduction in virus retention compared to that in the protein‐free solution. Similar effects were seen with membranes that were pre‐fouled with hIgG and then challenged with ФX174. The experimental data were well‐described using an internal polarization model that accounts for virus capture and accumulation within the virus filter, with the hIgG nearly eliminating the irreversible virus capture while also facilitating the release of previously captured virus. These results provide important insights into the performance and validation of virus removal filters in bioprocessing.more » « less