SURVIVAL KINETICS OF LACTIC-ACID STARTER CULTURES DURING AND AFTER FREEZE-DRYING

Date

1987-09-01

Author

BOZOGLU, F
OZILGEN, M
BAKIR, U

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

206
views

0
downloads

Survival kinetics of lactic acid starter cultures were modeled considering the microorganism and external medium interfacial area as the critical factors determining the resistance of the microorganisms to freeze-drying. Surviving fraction of the microorganisms increased with the increasing biomass concentration during freeze-drying, and this is attributed to the mutual shielding effect of the microorganisms against the severe conditions of the external medium. Survival of the microorganisms over the storage period after freeze drying was enhanced by the presence of dead microorganisms which reduce the interfacial area between the live cells and the external medium. Streptococcus thermophilus was found to be more resistant to freeze-drying conditions than Lactobacillus bulgaricus. Storage under vacuum or nitrogen was superior to storage under air. Poor survival rates under air was attributed to oxygen diffusion into the dry cells through the interfacial area.

Subject Keywords

Biotechnology, Applied Microbiology and Biotechnology, Biochemistry

URI

https://hdl.handle.net/11511/66386

Journal

ENZYME AND MICROBIAL TECHNOLOGY

DOI

https://doi.org/10.1016/0141-0229(87)90082-2

Collections

Department of Food Engineering, Article

Suggestions

OpenMETU
Core

Kinetic analyses of the effects of temperature and light intensity on growth, hydrogenm production and organic acid utilization by rhodobacter capsulatus Sevinç, Pelin; Gündüz, Ufuk; Department of Biotechnology (2010) Effects of temperature and light intensity on photofermentative hydrogen production by Rhodobacter capsulatus DSM1710 by use of acetic and lactic acids as substrates were studied. Experiments were conducted at 20, 30 and 38oC incubator temperatures under light intensities in the 1500 – 7000 lux range. pH of the medium and quantity of hydrogen forming together with quantity of biomass, and concentrations of acetic, lactic, formic, butyric and propionic acids in the medium were determined periodically. Growth...
Metabolic Flux Analysis for Recombinant Protein Production by Pichia pastoris Using Dual Carbon Sources: Effects of Methanol Feeding Rate Celik, Eda; Çalık, Pınar; Oliver, Stephen G. (Wiley, 2010-02-01) The intracellular metabolic fluxes through the central carbon pathways in the bioprocess for recombinant human erythropoietin (rHuEPO) production by Pichia pastoris (Mut(+)) were calculated. to investigate the metabolic effects of dual carbon sources (methanol/sorbitol) and the methanol feed rate, and to obtain a deeper understanding the regulatory circuitry of P. pastoris, using the established stoichiometry-based model containing 102 metabolites and 141 reaction fluxes. Four fed-batch operations with (MS-...
Targeted disruption of homoserine dehydrogenase gene and its effect on cephamycin C production in Streptomyces clavuligerus Yilmaz, Ebru I.; Caydasi, Ayse K.; Özcengiz, Gülay (Springer Science and Business Media LLC, 2008-01-01) The aspartate pathway of Streptomyces clavuligerus is an important primary metabolic pathway which provides substrates for beta-lactam synthesis. In this study, the hom gene which encodes homoserine dehydrogenase was cloned from the cephamycin C producer S. clavuligerus NRRL 3585 and characterized. The fully sequenced open reading frame encodes 433 amino acids with a deduced M (r) of 44.9 kDa. The gene was heterologously expressed in the auxotroph mutant Escherichia coli CGSC 5075 and the recombinant protei...
Kinetics of riboflavin production by Brewers' yeasts Tamer, I.M.; Özilgen , Mustafa; Ungan, Suat (Elsevier BV, 1988-12) The kinetics of riboflavin production by Saccharomyces cerevisiae and Saccharomyces carlsbergensis in synthetic media and wort were studied. The results indicated that riboflavin was produced by growing cells only. Riboflavin production rate was proportional to growth rate of the yeasts in the exponential phase. Riboflavin was depleted in the stationary phase. The depletion rate was expressed with a first-order kinetic expression in yeast concentration. The kinetics of substrate utilization and ethanol prod...
Kinetics of amino acid production by over-producer mutant microorganisms Özilgen, Mustafa (Elsevier BV, 1988-2) Experimental data were modeled based on the literature for the production of nine different amino acids by ten different mutant over-producer microorganisms. Mathematical modeling helped to better understand common aspects of these fermentations, which were not stressed previously by plotting the data only. A Luedeking-Piret type of a model was found to be valid for representing all the amino acid production data. This result indicated the similarity among the amino acid production patterns of all the mutan...

Citation Formats

F. BOZOGLU, M. OZILGEN, and U. BAKIR, “SURVIVAL KINETICS OF LACTIC-ACID STARTER CULTURES DURING AND AFTER FREEZE-DRYING,” ENZYME AND MICROBIAL TECHNOLOGY, pp. 531–537, 1987, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66386.