In this work, a kinetics-integrated CFD model based on coupling computational fluid dynamics (CFD) and biokinetic was developed to guide the industrial scale-up for fermentation of docosahexaenoic acid (DHA). Two-substrate biokinetic equations for a 5 L bioreactor with oxygen and nitrogen source as limiting substrates were established, which were further coupled with CFD to simulate the biomass growth and lipid accumulation as well as flow field environment in the fermentation process.The coupled CFD-biokinetic model can accurately reflect the changes of each relevant variable in the 50 L bioreactor under different operating conditions. The optimal working conditions of a 35 m 3 bioreactor were predicted by this model and have secured the one-step scale-up of DHA fermentation, resulting in a biomass, lipid concentration, and DHA content in lipids of 99.2 g/L, 55.7 g/L, and 52.5%, respectively.This study thus provides an effective strategy for rapid industrial scale-up of DHA production.

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BACKGROUND Granulocytic sarcoma (GS) is a rare malignant tumor, and relapse is even rarer in the breast and dorsal spine following allogeneic hematopoietic stem cell transplantation. Currently, a standard treatment regimen is not available. CASE SUMMARY A rare case of GS of the right breast and dorsal spine after complete remission of acute myelogenous leukemia is reported here. A 55-year-old female patient presented with a palpable, growing, painless lump as well as worsening dorsal compressive myelopathy. She had a history of acute myelomonocytic leukemia (AML M4) and achieved complete remission after chemotherapy following allogeneic hematopoietic stem cell transplantation. Imaging examinations showed the breast lump and C7-T1 epidural masses suspected of malignancy. Histologic results were compatible with GS in both the right breast and dorsal spine, which were considered extramedullary relapse of the AML treated 4 years earlier. CONCLUSION A rare case of GS relapse following allogeneic hematopoietic stem cell transplantation and guidelines for treatment are discussed.

Microtiter plates are suitable for screening and process development of most microorganisms. They are currently the container of choice for high‐throughput and small‐scale microbial culture, but require optimization for specific work. In this research, a novel type of microtiter plate was developed using computational fluid dynamics (CFD) technology. The new plate provided high oxygen supply and optimal mixing effects for the fermentation culture of docosahexaenoic acid (DHA) producing strains, surpassing the conventional method of strain screening with shake flasks, which was insufficient. The shape of the microtiter plate was modified, and baffles were introduced to improve mass transfer and oxygen supply effects in the vibrating bioreactor. CFD technology was used to model the new plate's characteristics, establishing the superiority of hexagonal microtiter plates with six baffles. Parameters in the incubation process, such as vibration frequency and liquid load, were optimized, and the final result achieved an oxygen transfer coefficient (KLa) of 0.61 s−1 and a volume power input of 2364 w m−3, which was four to five times better than the original 96‐well plate. The culture results optimized by the model were also verified. Therefore, this new microtiter plate provides a powerful tool for future high‐throughput screening of strains.