Oxygen transfer rates in shaken culture vessels from Fernbach flasks to microtiter plates

Abstract

By a sulfite oxidation method, oxygen transfer rates (OTRs) were determined in 11 types of culture vessels from 2.8-L Fernbach (FB) flasks to 96-, 48-, and 24-well square deepwell microtiter plates (MTPs). OTRs ranged from 140 mM/h in 250-mL Ultrayield™ flasks shaken at 300 rpm with a 50 mm diameter shaker throw to 5 mM/h in unbaffled FBs shaken at 200 rpm with a 25 mm throw. Baffles in FBs increased OTRs 6-12-fold under various shaking conditions, and up to five-fold in 250-mL flasks, depending on the type of baffles. Corner-baffling was superior to bottom-baffling in glass, 250-mL flasks. In MTPs, OTRs increased with increasing well size and decreasing fill volume. At 50 mm throw and 300 rpm, 24-well MTPs had OTRs comparable to corner-baffled, 250-mL flasks (∼100 mM/h). The OTRs in unbaffled flasks were relatively insensitive to shaking conditions, increasing less than two-fold between the most modest and the most vigorous conditions. There was no consistency across vessels as to whether the alternate incubation conditions of 70 mm throw and 250 rpm produced higher OTRs than the 50 mm throw and 300 rpm regimen. No increase in OTR was seen in any MTP when the cover hole diameter was increased beyond 4.5 mm. OTRs decreased as viscosity increased, falling smoothly in unbaffled flasks and 24-well MTPs, but 48-well and 96-well MTPs showed precipitous OTR drops as viscosity increased. Matching the OTRs of screening vessels to the oxygen uptake rates of microbial cultures can greatly reduce the number of false positive strains that are forwarded from microbial screens. Biotechnol. Bioeng. 2016;113: 1729-1735. © 2016 Wiley Periodicals, Inc.

Studies on fluid dynamics of the flow field and gas transfer in orbitally shaken tubes

“…The sodium sulfite oxidation method was used to determine k L a values as previously described . The method is based on the reaction of sodium sulfite, a reducing agent, with dissolved oxygen in the presence of a catalyst, usually a divalent cation such as Cu 2+ or Co 2+ , to produce sulfate.…”

“…The sodium sulfite oxidation method was used to determine k L a values as previously described. [28][29][30] The method is based on the reaction of sodium sulfite, a reducing agent, with dissolved oxygen in the presence of a catalyst, usually a divalent cation such as Cu 21 or Co 21 , to produce sulfate. The concentration of sodium sulfite (Na 2 SO 3 , Tianjin Dingshengxin Chemical Industry, Tianjin, China) in each tube was kept higher than 0.04 M to guarantee that the oxygen concentration in the liquid was zero.…”

Scaling up and scaling down the production of galactaric acid from pectin using Trichoderma reesei

“…Galactaric acid production by T. reesei has previously been demonstrated in flask cultures [8], but at much lower concentrations than can be obtained in bioreactors [7]. Running and Bansal [12] demonstrated that 24-well plates can have as good or better oxygen transfer as shaken flasks, depending on the shaking regime applied, and 24-well plates are increasingly being used for the cultivation of filamentous fungi [13–15]. It is therefore useful to assess whether galactaric acid production by T. reesei could be scaled down for production in 24-well plates using pectin as substrate.…”

Permeability of currently available microtiter plate sealing tapes fail to fulfil the requirements for aerobic microbial cultivation

“…Due to the venting holes of 1.5 mm in diameter the oxygen consumption of the microbial culture was not limited by the lid. Running and Bansal performed OTR studies with 24‐, 48‐, and 96‐well MTP using customized lids with venting holes of 4.5 mm in diameter. They found that the OTR was not limited by the size of the holes.…”