Effect of culture conditions on growth and esterase production by the moderate thermophile Bacillus circulans MAS2

Kademi, Ali; Fakhreddine, Loubna; Ait-Abdelkader, Nadra; Baratti, J.

doi:10.1038/sj.jim.2900717

Cited by 8 publications

(7 citation statements)

References 15 publications

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“…The specific growth rate was similar to that described by Becker et al 31 for a thermophilic bacteria belonging to Bacillus genus, but lower than that determined for B. circulans MAS2, which attained a value as high as 1.2 h −1 in optimized culture conditions 19 . Additionally, the relationship between growth and metabolite production was considered.…”

Section: Kinetics Of Biomass and Lipolytic Production In Flask Culturesmentioning

confidence: 68%

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Deive

Sanromán

Longo

2009

J of Chemical Tech & Biotech

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BACKGROUND: Thermophilic microorganisms are receiving significant attention as a source of useful thermostable enzymes. However, the number of known strains is still limited, and very often their most interesting biocatalysts are intracellular or membrane-bound and produced at low levels. Thus, the isolation and study of novel extracellular enzyme-producing thermophilic microorganisms is very interesting. Moreover, the assessment of bioreactor performance is crucial, given the scarce information on the large-scale culture of these strains.

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Section: Kinetics Of Biomass and Lipolytic Production In Flask Culturesmentioning

confidence: 68%

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Deive

Sanromán

Longo

2009

J of Chemical Tech & Biotech

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“…The rate of hydrolysis of para-nitrophenyl caprylate at 37°C was measured in 50 mM sodium phosphate buffer (pH 7.0) according to the method described previously (9,16). One unit of activity was defined as the amount of enzyme that liberated 1 mol of p-nitrophenol per min under the given assay conditions.…”

Section: Methodsmentioning

confidence: 99%

Bestowing Inducibility on the Cloned Methanol Dehydrogenase Promoter (P _mxaF ) of Methylobacterium extorquens by Applying Regulatory Elements of Pseudomonas putida F1

Choi

Morel

Bourque

et al. 2006

Appl Environ Microbiol

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P mxaF is a strong methanol-inducible promoter in Methylobacterium extorquens. When this promoter is cloned in expression vectors and used to drive heterologous gene expression, methanol inducibility is either greatly reduced or entirely lost. In order to bestow inducibility upon the cloned P mxaF promoter in expression vectors, we adopted combinational methods (regulatory elements of the Pseudomonas putida F1 cym and cmt operons and Tn7 transposon system) to control reporter gene expression at the transcriptional level in M. extorquens. An operator fragment (26 nucleotides) of the cmt operon was inserted downstream of the cloned P mxaF promoter in the broad-host-range expression vector (pCHOI3). The repressor gene (cymR) located upstream of the cym operon in P. putida F1 was amplified by PCR. To avoid cellular toxicity for M. extorquens caused by the overexpression of CymR, single and/or double copies of cymR were integrated into the chromosome of M. extorquens using the mini-Tn7 transposon system. Cultures containing the chromosomally integrated cymR gene were subsequently transformed with pCHOI3 containing modified P mxaF (i.e., P mxaF plus operator). In this construct, inducibility is afforded by cumate (p-isopropylbenzoate). In this report, we describe the inducible and tightly regulated expression of heterologous genes (bgl [for ␤-galactosidase], est [for esterase], and gfp [for green fluorescent protein]) in M. extorquens. This is the first documented example of an inducible/ regulated heterologous gene expression system in M. extorquens.Methylotrophic bacteria are a diverse group of microorganisms with the ability to utilize single-carbon (C 1 ) substrates more reduced than carbon dioxide as their sole source of carbon and energy. Among the methylotrophs, members of the genus Methylobacterium have been described as being ubiquitous, participating in a myriad of favorable interactions with nature (24,26,27). Furthermore, Methylobacterium spp. naturally produce several substances of commercial importance, including poly-␤-hydroxybutyrate (3, 4), vitamin B 12 (28), pyrroloquinoline quinone (1, 10), and carotenoids (29). Over the past decade, Methylobacterium extorquens AM1 has been extensively studied and characterized both genetically and physiologically (6,18,20). The wealth and depth of understanding of M. extorquens and closely related strains suggest the potential of M. extorquens as a source of industrially pertinent natural products and recombinant proteins. The salient aspects for this potential have been described elsewhere (2, 8, 9), and they include (i) simple and inexpensive cultivation requirements, (ii) optimized high-cell-density fermentation protocols, (iii) available genome sequence for M. extorquens AM1, and (iv) availability of suitable genetic tools for M. extorquens (8,13,19,21,22). Application of these tools has made it possible to overexpress a variety of recombinant proteins in the range of 3 to 6 g/liter under high-cell-density growth conditions (8, 9, 13). However, inducible/regula...

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“…Esterase activity was determined by a spectrophotometric method using pNP-caprylate as the substrate. The rate of hydrolysis of pNP-caprylate at 37°C was measured in 50 mM sodium phosphate buffer (pH (29,30). One unit of activity was defined as the amount of enzyme that liberated 1 mol of pnitrophenol per min under the given assay conditions.…”

Section: Methodsmentioning

confidence: 99%

Characterization and Heterologous Gene Expression of a Novel Esterase fromLactobacillus caseiCL96

Choi

Míguez

Lee

2004

Appl Environ Microbiol

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A novel esterase gene (estI) of Lactobacillus casei CL96 was localized on a 3.3-kb BamHI DNA fragment containing an open reading frame (ORF) of 1,800 bp. The ORF of estI was isolated by PCR and expressed in Escherichia coli, the methylotrophic bacterium Methylobacterium extorquens, and the methylotrophic yeast Pichia pastoris under the control of T7, methanol dehydrogenase (P mxaF ), and alcohol oxidase (AOX1) promoters, respectively. The amino acid sequence of EstI indicated that the esterase is a novel member of the GHSMG family of lipolytic enzymes and that the enzyme contains a lipase-like catalytic triad, consisting of Ser325, Asp516, and His558. E. coli BL21(DE3)/pLysS containing estI expressed a novel 67.5-kDa protein corresponding to EstI in an N-terminal fusion with the S ⅐ tag peptide. The recombinant L. casei CL96 EstI protein was purified to electrophoretic homogeneity in a one-step affinity chromatography procedure on S-protein agarose. The optimum pH and temperature of the purified enzyme were 7.0 and 37°C, respectively. Among the pNP (p-nitrophenyl) esters tested, the most selective substrate was pNP-caprylate (C 8 ), with K m and k cat values of 14 ؎ 1.08 M and 1,245 ؎ 42.3 S ؊1 , respectively.

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Effect of culture conditions on growth and esterase production by the moderate thermophile Bacillus circulans MAS2

Cited by 8 publications

References 15 publications

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Bestowing Inducibility on the Cloned Methanol Dehydrogenase Promoter (P _mxaF ) of Methylobacterium extorquens by Applying Regulatory Elements of Pseudomonas putida F1

Characterization and Heterologous Gene Expression of a Novel Esterase fromLactobacillus caseiCL96

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Effect of culture conditions on growth and esterase production by the moderate thermophile Bacillus circulans MAS2

Cited by 8 publications

References 15 publications

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Evaluation of a novel Bacillus strain from a north‐western Spain hot spring as a source of extracellular thermostable lipase

Bestowing Inducibility on the Cloned Methanol Dehydrogenase Promoter (P mxaF ) of Methylobacterium extorquens by Applying Regulatory Elements of Pseudomonas putida F1

Characterization and Heterologous Gene Expression of a Novel Esterase fromLactobacillus caseiCL96

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Bestowing Inducibility on the Cloned Methanol Dehydrogenase Promoter (P _mxaF ) of Methylobacterium extorquens by Applying Regulatory Elements of Pseudomonas putida F1