عنوان

The influence of cell concentration and morphology on yielding properties of filamentous fermentation broths

شماره

TLpq304160542

زبان متن نوشتاري يا گفتاري و مانند آن

انگلیسی

عنوان اصلي

The influence of cell concentration and morphology on yielding properties of filamentous fermentation broths

نام عام مواد

[Thesis]

نام نخستين پديدآور

M. Mohseni Tonkaboni

نام ساير پديدآوران

D. G. Allen

نام ناشر، پخش کننده و غيره

University of Toronto (Canada)

تاریخ نشرو بخش و غیره

1994

نام خاص و کميت اثر

161

جزئيات پايان نامه و نوع درجه آن

M.A.Sc.

کسي که مدرک را اعطا کرده

University of Toronto (Canada)

امتياز متن

1994

متن يادداشت

The influence of cell concentration and morphology on the yielding properties of filamentous broths of Aspergillus niger and Streptomyces levoris was investigated using the rotating vane technique and dynamic measurements with a cone and plate viscometer. Cell concentrations ranging from 3 to 20 gdw/L, with corresponding volume fractions between 0.005 and 0.05, were obtained with broths generated in stirred tank and shake flask fermentations. The yield stress values obtained using the vane technique (usd0.1\le\tau\sb{y}\le37usd Pa) correlated with biomass concentration (X, gdw/L) using the equation usd\tau\sb{y} = a{\bf X\sp{b}}usd, where usd2\le{\bf b}\le3.2usd. Increasing the length of organisms significantly increased the yield stress at a given cell concentration; this morphology effect was described using a "morphology factor" (range 0.016 to 0.11 Pa/ (gdw/L) ), determined by setting the value of "b" to 2.5. The vane yield strain was independent of cell concentration but increased with increasing length of organisms. Therefore, both the vane measured yield stress and strain can be used for quantifying the morphology of filamentous organisms. The storage modulus of filamentous fermentation broths was as important as the loss (viscous) modulus at very small deformations, but the storage modulus decreased more rapidly than the loss modulus as the strain increased. A comparison of the dynamic and rotating vane tests shows that the vane technique measures a combination of the viscous and elastic properties and provides a realistic representation of the yield stress at zero shear rate that is significantly higher than the yield stress obtained by extrapolating shear stress-shear rate data to zero shear rate.

موضوع مستند نشده

Applied sciences

موضوع مستند نشده

Biological sciences

موضوع مستند نشده

Chemical engineering

موضوع مستند نشده

Chemical engineering

موضوع مستند نشده

Microbiology

مستند نام اشخاص تاييد نشده

D. G. Allen

مستند نام اشخاص تاييد نشده

M. Mohseni Tonkaboni

نام الکترونيکي

فرمت انتشار

p

نوع ماده

[Thesis]

کد کاربرگه

276903

سطح دسترسي

a

تكميل شده

Y