Thermostability and regulation of Clostridium thermocellum L-lactate dehydrogenase expressed in Escherichia coli

Assa, P
Ozkan, M
Özcengiz, Gülay
In this study, L-lactate dehydrogenase (L-LDH) of Clostridium thermocellum previously cloned aid expressed in Escherichia coli FMJ39 was partially purified and characterised. Optimum temperature and pH of the enzyme were found as 50 degrees C and 7.5, respectively. Different concentrations of Mn2+ did not affect the enzyme activity. Addition of 20-30 mM Mg2+, or the other hand, increased the LDH activity by about 10%. Relatively high concentrations of NaCl (2 M), fructose-1,6-diphosphate (FDP, 5 mM), ATP (10 mM) and NAD (40 mM) decreased LDH activity by 36, 25, 40 and 100%, respectively. Oxamate and oxalate inhibited LDH activity by 41 and 28%, respectively, when each was added at a concentration of 0.5 mM. When compared to its non-thermotolerant counterparts, the enzyme was found to be very stable when incubated at room temperature, 4 degrees C and even at 50 degrees C.


Cloning, sequencing and expression of L-lactate dehydrogenase gene from clostridium thermocellum and isolation, characterization and transformation of various cellulolytic, thermophilic, ethanol-producing bacteria
Özkan, Melek; Özcengiz, Gülay; Ögel, Zümrüt B.; Department of Biotechnology (2002)
In this study, the structural gene for L-lactate dehydrogenase (LDH; EC. 1.1. 1.27) was cloned and characterized for the first time from Clostridium thermocellum 27405 in Escherichia coli. A 357 bp PCR product of predicted size was obtained with degenerate primers designed for conserved regions of Idh genes of different organisms. This amplicon was used as a probe to screen a Lambda Zap II phage library of C. thermocellum genomic DNA. One positive clone contained an insert of 2.5 kb which included an open r...
KAVAS, MUSA; Akca, Oya Ercan; Akcay, Ufuk Celikkol; Peksel, Begum; Eroğlu, Seçkin; Öktem, Hüseyin Avni; Yucel, Meral (2015-01-01)
In this study, the effects of long-term NaCl treatment were investigated in two cultivars of peanut designated as drought-resistant and drought-sensitive. Growth parameters, changes in the concentrations of MDA, H2O2 and proline, and the activities of antioxidant enzymes were determined under salinity stress. Growth parameters indicated the superiority of cv. Florispan to cv. Gazipasa under milder salinity stress treatment. However, comparative analysis of the two cultivars showed that MDA, H2O2, ion leakag...
Inference of Gene Regulatory Networks Via Multiple Data Sources and a Recommendation Method
Ozsoy, Makbule Gulcin; Polat, Faruk; Alhajj, Reda (2015-11-12)
Gene regulatory networks (GRNs) are composed of biological components, including genes, proteins and metabolites, and their interactions. In general, computational methods are used to infer the connections among these components. However, computational methods should take into account the general features of the GRNs, which are sparseness, scale-free topology, modularity and structure of the inferred networks. In this work, observing the common aspects between recommendation systems and GRNs, we decided to ...
Metabolic reaction network of Pichia pastoris with glycosylation reactions: Flux analysis for erythropoietin production
Eskitoros, Melda S.; Ata, Ozge; Çalık, Pınar (Wiley, 2014-11-01)
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Comparison of benzaldehyde lyase production capacity in recombinant Escherichia coli and recombinant Bacillus species
Kaya, Hande; Çalık, Pınar; Department of Chemical Engineering (2006)
In this study, the benzaldehyde lyase (BAL, EC production in E. coli BL21 (DE3) pLySs as intracellular and in Bacillus species as extracellular were investigated, and comparison of the production capacity of the enzyme in the developed recombinant microorganisms were compared. For this purpose, firstly, PCR amplified bal gene was cloned into pRSETA vector which is under the control of strong T7 promoter and expressed in E. coli BL21 (DE3) pLysS strain. With developed recombinant E. coli BL21 (DE3)...
Citation Formats
P. Assa, M. Ozkan, and G. Özcengiz, “Thermostability and regulation of Clostridium thermocellum L-lactate dehydrogenase expressed in Escherichia coli,” ANNALS OF MICROBIOLOGY, pp. 193–197, 2005, Accessed: 00, 2020. [Online]. Available: