title: Glucose inhibits the formation of gas vesicles in Haloferax volcanii transformants.
abstract: The effect of glucose on the formation of gas vesicles was investigated in Haloferax mediterranei and Hfx.volcanii transformants containing the mc-gvp gene cluster of Hfx. mediterranei (mc-vac transformants). Increasing amounts of glucose in the medium resulted in a successive decrease in the amount of gas vesicles in both species, with a complete inhibition of their formation at glucose concentrations of > 70 mM in mc-vac transformants, and 100 mM in Hfx. mediterranei. Maltose and sucrose imposed a similar inhibitory effect, whereas xylose, arabinose, lactose, pyruvate and 2-deoxy-glucose had no influence on the gas vesicle formation in mc-vac transformants. The activities of the two mc-vac promoters were strongly reduced in mc-vac transformants grown in the presence of > 50 mM glucose. The gas vesicle overproducing Delta D transformant (lacking the repressing protein GvpD) also showed a glucose-induced lack of gas vesicles, indicating that GvpD is not involved in the repression. The addition of glucose was useful to block gas vesicle formation at a certain stage during growth, and vice versa, gas vesicle synthesis could be induced when a glucose-grown culture was shifted to medium lacking glucose. Both procedures will enable the investigation of defined stages during gas vesicle formation.
authors.affiliation: Institut für Mikrobiologie und Genetik, TU Darmstadt, D-64287 Darmstadt, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Hechler
authors.forename: Miriam
authors.initials: M
authors.lastname: Frech
authors.forename: Felicitas
authors.initials: F
authors.lastname: Pfeifer
mesh_terms: D000693:Anaerobiosis; D003470:Culture Media / Q000737:chemistry; D022162:Cytoplasmic Vesicles / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D019623:Haloferax mediterranei / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019622:Haloferax volcanii / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics; D014169:Transformation, Bacterial / Q000235:genetics
chemical_list: D003470:Culture Media; D009566:Nitrates; D011506:Proteins; D012097:Repressor Proteins; C038524:gas vesicle protein; D005947:Glucose