title: Behavior of transition state regulator AbrB in batch cultures of Bacillus thuringiensis.
abstract: The transition state regulator AbrB is involved in the regulation of various cellular functions such as exponential growth, transition state and sporulation onset, due to its ability to activate, suppress or prevent the inappropriate expression of various genes in Bacillus subtilis. In order to understand combined behavior in batch cultures of AbrB in Bacillus thuringiensis, we cloned and expressed the abrB gene of B. thuringiensis in Escherichia coli. The deduced sequence of abrB gene coded for a protein consisting of 94 amino acids with ~10.5 kDa protein that shares 100 and 85 % identity with those from Bacillus cereus and Bacillus subtilis. The recombinant AbrB protein was used as antigen for the production of rabbit polyclonal antibodies anti-AbrB. Two media cultures with carbon: nitrogen ratios of 7.0, but varying access to nutrients were tested in batch cultures. In the case of both media, AbrB accumulation occurred from the beginning of the process and was maximal during early exponential growth. Thereafter, the level of AbrB decreased when there were no nutrient limitations and coincided with a decreased value in specific growth rate, although growth continued exponentially. Nonetheless, sporulation onset was determined 3 h and 4 h later, in media with highly metabolizable nutrients clean medium and Farrera medium, respectively. Hence, the maximal level of AbrB accumulation in batch cultures of B. thuringiensis is not influenced by limiting nutrients; however, nutrient availability affects the required time lapse for transition state regulator accumulation.
authors.affiliation: Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla Km. 1.5, CP 90700, Tepetitla, Tlaxcala, Mexico.
authors.forename: Astrid Magdalena
authors.initials: AM
authors.lastname: Lozano Goné
authors.forename: Jabel
authors.initials: J
authors.lastname: Dinorín Téllez Girón
authors.forename: Fabiola Eloisa
authors.initials: FE
authors.lastname: Jiménez Montejo
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Hidalgo-Lara
authors.forename: Víctor Eric
authors.initials: VE
authors.lastname: López Y López
mesh_terms: D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics; D001413:Bacillus thuringiensis / Q000235:genetics* / Q000254:growth & development*; D001483:Base Sequence; D061249:Batch Cell Culture Techniques; D003001:Cloning, Molecular; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D003470:Culture Media; D014157:Transcription Factors