Effect of high shear stress on microbial viability

Lange, Hélène; Taillandier, Patricia; Riba, J. P.

doi:10.1002/jctb.401

Cited by 70 publications

(44 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results (Fig. 2f) show that the maximum shear stresses (model I: ~0.173 kPa and model II: ~0.102 kPa) should not cause any harmful effects on the cell viability Lange et al 2001;Legazpi et al 2009;Scragg et al 1988;Shiragami and Unno 1994) and shear-induced movements (Hyon et al 2012;Koh and Marcos 2015;Marcos et al 2009Marcos et al , 2011Marcos et al , 2012Marcos et al , 2014Marcos and Stocker 2006).…”

Section: Lumped-element Model Of Membrane Deflectionmentioning

confidence: 92%

Mixing in an enclosed microfluidic chamber through moving boundary motions

Yang

Sun

et al. 2015

Microfluid Nanofluid

View full text Add to dashboard Cite

show abstract

Section: Lumped-element Model Of Membrane Deflectionmentioning

confidence: 92%

Mixing in an enclosed microfluidic chamber through moving boundary motions

Yang

Sun

et al. 2015

Microfluid Nanofluid

View full text Add to dashboard Cite

show abstract

“…The shear stress was only 1.23 fold higher in 8 L stirred tank reactor of constant k L a experiment, corresponding to a shear stress of 4.23 N/m 2 in 2 L control reactor (Table 2). It was shown that shear stress with the value of 12.5 N/m 2 had no significant decrease on cell lysis or cell viability by the wild type of E. coli [34]. Constant t m was reported to be more applicable under microaerobic conditions compare to constant oxygen uptake rate for the scale-up of 2,3-butanediol fermentation by Enterobacter aerogenes in which homogeneity was important [35].…”

Section: Scaling Up Based On Constant K L Amentioning

confidence: 99%

Evaluation of scale-up parameters of bioethanol production from Escherichia coli KO11

2015

View full text Add to dashboard Cite

Objective: In recent years, increased attention has been devoted to the conversion of biomass into fuel ethanol, as one of the cleanest liquid fuel alternatives to fossil fuels. However, industrial production of bioethanol is related with successful scaling-up studies. Methods: In this study, the experimental designs of scale-up procedures based on constant mixing time, impeller tip speed and oxygen mass transfer coefficient were performed in 8 L stirred tank reactor and were compared in terms of product yield and productivity with those obtained from 2 L stirred tank reactor using quince pomace as a substrate for bioethanol production by Escherichia coli KO11. Results: Scale-up based on constant mixing time yielded a maximum ethanol concentration of 23.42 g/L which corresponded to 0.4 g ethanol/ g reduced sugar in 8 L stirred tank reactor. Moreover, shear stress increased only 1.1 fold which resulted in low cell damage and high cell viability. Conclusion: Constant mixing time was identified as the most important key parameter especially for scaling-up of viscous fermentation broths of bioethanol production due to the significance of the homogeneity. January 24, 2015] substrate without any chemical pretreatment (such as acid or base hydrolysis) due to the availability of the sugars (mostly glucose and fructose) in the pomace for microorganisms. There are several studies on the utilization of the fruit pomaces such as apple pomace without pretreatment process for the bioconversion of value-added bioproducts [8][9][10]. In this study quince pomace as an agro-industrial biomass was used for bioethanol production under microaerated conditions, eliminating the pretreatment step. In our previous study, we reported that microaerated conditions enhanced bioethanol production via promoting sugar consumption [11]. Considering the increasing demand on ethanol utilization worldwide, a suitable scale-up technology with a suitable scale-up parameter for bioethanol production from E. coli KO11 needs to be identified. To this end, the two main objectives of the present study were: (i) to evaluate the use of constant impeller tip speed, mixing time and oxygen mass transfer coefficient as scale-up methodologies under laboratory conditions for the scaleup process from 2 L reactor to 8 L stirred-tank reactor, considering whether an increase in the bioethanol yield can be achieved, and (ii) to validate the kinetic parameters for better describing the behavior of E. coli KO11 during bioethanol fermentation from quince pomace. Materials and Methods Growth conditionsRecombinant E. coli KO11 (pLOI 1910) strain was provided by courtesy of Professor L.O. Ingram from University of Florida. Stock cultures were stored in 40% glycerol at -80°C. Seed cultures of KO11 were maintained on modified Luria-Bertani (LB) agar containing 5 g of NaCl, 5 g of yeast extract, 10 g of tryptone, 20 g of glucose, 15 g of agar, and 600 mg of chloramphenicol per liter and kept at 4°C. For inoculation, 3 colonies were transferred into 250 mL flasks...

show abstract

“…901 turns and 8-20 Pa along the poppet walls at flow rates ranging between 75 and 200 mL/min. For comparison, short duration (r 200 ms) shear stresses of $ 1300 Pa and above are required to alter the viability of Escherichia coli ( $ 1800 Pa for cell disruption); between 1300 and 2800 Pa the threshold for affecting viability of Saccharomyces cerevisiae (Lange et al, 2001). In studies with cultured Baby Hamster Kidney cells, shear stress thresholds appear to be time accumulative as would be relevant in stirred tissue culture.…”

Section: Shear Stresses Developed Within the Ff3mentioning

confidence: 98%