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Highly accumulative production of l(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae

Paper ID Volume ID Publish Year Pages File Format Full-Text
20966 43199 2013 6 PDF Available
Title
Highly accumulative production of l(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae
Abstract

In order to produce microbiologically large amount of l(+)-lactic acid (LA) from glucose, batch and fed-batch (intermittent addition of sterilized glucose powder aseptically) cultures of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) whose mycelia were immobilized in situ within sponge-like cubic particles (3.5 mm edge long) were carried out at 37°C in a three baffled shake flask. Appropriately calculated amount of fine powdery calcium carbonate (CaCO3) was added initially or intermittently to control pH of the culture liquids. High accumulations of LA (145 g/L and 231 g/L, in reality 176 g/L and 280 g/L as anhydrous calcium lactate) were achieved by a batch (glucose concentration = 150 g/L) and a fed-batch cultures (the initial glucose concentration = 150 g/L and the intermittent addition of glucose equivalent to 100 g/L). In these cultures the yields and productivities of LA were, 95.0%, 1.42 g/L·h and 92.5%, 1.83 g/L·h, respectively. Existence of considerable amounts of calcium lactate (Ca(LA)2) as crystals in the culture broth was experimentally proved by two evidences: (i) heating up (70°C) followed by quick low centrifugal force to remove remaining CaCO3 solids from culture broth and then cooling down (37°C) followed by incubation of the culture supernatant at 37°C to observe recrystallization of Ca(LA)2, and (ii) the measurement of solubility of Ca(LA)2 in the culture media. It was conceptually discussed to be able to avoid the product inhibition by means of crystallization fermentation for the high accumulation of LA by R. oryzae.

Keywords
Lactic acid; Crystallization fermentation; Fed-batch culture; Rhizopus oryzae; Sponge-like cubic particle; Calcium lactate; Immobilized cells
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Highly accumulative production of l(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 115, Issue 1, January 2013, Pages 90–95
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
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Any Questions? feel free to contact us