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Exochelin production in Mycobacterium neoaurum.

Chan KG - Int J Mol Sci (2009)

Bottom Line: In this study, exochelin was purified from spent supernatant of M. neoaurum by semi-preparative chromatography.When saturated ferric chloride solution was added into the purified exochelin, a ferri-exochelin complex was formed.It is proposed that iron uptake in M. neoaurum is exochelin-mediated.

View Article: PubMed Central - PubMed

Affiliation: Division of Genetics and Molecular Biology, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia. kokgan@um.edu.my

ABSTRACT
Mycobacterium neoaurum is a soil saprophyte and obligate aerobic bacterium. This group of mycobacterium is relatively fast-growing. They form colonies on nutrient agar at 37 masculineC within 3 - 4 days. In natural soil habitats, bioavailability of iron is limited. To facilitate iron uptake, most mycobacteria produce siderophores. One example is exochelin, which is extracellular and water-soluble. In this report, the production of exochelin in M. neoaurum was induced in iron-deficiency, but repressed under ironsufficiency growth conditions. It is however not induced under zinc-deficiency growth conditions. The growth of this mycobacterium was correlated with exochelin secretion under iron-deficiency culture conditions. When M. neoaurum was grown in defined medium containing 0.04 microg Fe(III)/mL (final concentration), the production of exochelin reached a maximum and the corresponding cell growth was comparable to that under iron-sufficiency conditions. In this study, exochelin was purified from spent supernatant of M. neoaurum by semi-preparative chromatography. When saturated ferric chloride solution was added into the purified exochelin, a ferri-exochelin complex was formed. It is proposed that iron uptake in M. neoaurum is exochelin-mediated.

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Time course analysis of M. neoaurum exochelin production and cell dry weight.Production of exochelin by M. neoaurum cells grown under iron-deficiency conditions (0.02 μg Fe(III)/mL). Cell growth was monitored from 24 to 120 h. Exochelin was concentrated by freezedrying the spent supernatant and was purified as described in the Experimental Section (4.2). Detection of exochelin production was measured by monitoring absorbance at OD 430 nm (▪). Cell dry weight (▴) (in g/20 mL) was measured by drying 20 mL cell culture at 90 ºC.
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f2-ijms-10-00345: Time course analysis of M. neoaurum exochelin production and cell dry weight.Production of exochelin by M. neoaurum cells grown under iron-deficiency conditions (0.02 μg Fe(III)/mL). Cell growth was monitored from 24 to 120 h. Exochelin was concentrated by freezedrying the spent supernatant and was purified as described in the Experimental Section (4.2). Detection of exochelin production was measured by monitoring absorbance at OD 430 nm (▪). Cell dry weight (▴) (in g/20 mL) was measured by drying 20 mL cell culture at 90 ºC.

Mentions: To determine the appropriate incubation time for maximum exochelin production in l-asparagine medium when grown under iron-deficiency (0.02 μg Fe(III)/mL) conditions, M. neoaurum cells were incubated at 37 ºC up to 120 h. Under this condition, exochelin production accelerates during active cell growth (within 24 to 48 h) and achieved the highest (OD430 >1.3) when incubated for 72 h with vigorous aeration (Figure 2). Exochelin concentration decreases gradually after 72 h (Figure 2).


Exochelin production in Mycobacterium neoaurum.

Chan KG - Int J Mol Sci (2009)

Time course analysis of M. neoaurum exochelin production and cell dry weight.Production of exochelin by M. neoaurum cells grown under iron-deficiency conditions (0.02 μg Fe(III)/mL). Cell growth was monitored from 24 to 120 h. Exochelin was concentrated by freezedrying the spent supernatant and was purified as described in the Experimental Section (4.2). Detection of exochelin production was measured by monitoring absorbance at OD 430 nm (▪). Cell dry weight (▴) (in g/20 mL) was measured by drying 20 mL cell culture at 90 ºC.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2662466&req=5

f2-ijms-10-00345: Time course analysis of M. neoaurum exochelin production and cell dry weight.Production of exochelin by M. neoaurum cells grown under iron-deficiency conditions (0.02 μg Fe(III)/mL). Cell growth was monitored from 24 to 120 h. Exochelin was concentrated by freezedrying the spent supernatant and was purified as described in the Experimental Section (4.2). Detection of exochelin production was measured by monitoring absorbance at OD 430 nm (▪). Cell dry weight (▴) (in g/20 mL) was measured by drying 20 mL cell culture at 90 ºC.
Mentions: To determine the appropriate incubation time for maximum exochelin production in l-asparagine medium when grown under iron-deficiency (0.02 μg Fe(III)/mL) conditions, M. neoaurum cells were incubated at 37 ºC up to 120 h. Under this condition, exochelin production accelerates during active cell growth (within 24 to 48 h) and achieved the highest (OD430 >1.3) when incubated for 72 h with vigorous aeration (Figure 2). Exochelin concentration decreases gradually after 72 h (Figure 2).

Bottom Line: In this study, exochelin was purified from spent supernatant of M. neoaurum by semi-preparative chromatography.When saturated ferric chloride solution was added into the purified exochelin, a ferri-exochelin complex was formed.It is proposed that iron uptake in M. neoaurum is exochelin-mediated.

View Article: PubMed Central - PubMed

Affiliation: Division of Genetics and Molecular Biology, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia. kokgan@um.edu.my

ABSTRACT
Mycobacterium neoaurum is a soil saprophyte and obligate aerobic bacterium. This group of mycobacterium is relatively fast-growing. They form colonies on nutrient agar at 37 masculineC within 3 - 4 days. In natural soil habitats, bioavailability of iron is limited. To facilitate iron uptake, most mycobacteria produce siderophores. One example is exochelin, which is extracellular and water-soluble. In this report, the production of exochelin in M. neoaurum was induced in iron-deficiency, but repressed under ironsufficiency growth conditions. It is however not induced under zinc-deficiency growth conditions. The growth of this mycobacterium was correlated with exochelin secretion under iron-deficiency culture conditions. When M. neoaurum was grown in defined medium containing 0.04 microg Fe(III)/mL (final concentration), the production of exochelin reached a maximum and the corresponding cell growth was comparable to that under iron-sufficiency conditions. In this study, exochelin was purified from spent supernatant of M. neoaurum by semi-preparative chromatography. When saturated ferric chloride solution was added into the purified exochelin, a ferri-exochelin complex was formed. It is proposed that iron uptake in M. neoaurum is exochelin-mediated.

Show MeSH
Related in: MedlinePlus