Lovastatin biosynthetic genes of Aspergillus terreus are expressed differentially in solid-state and in liquid submerged fermentation.
Molecular studies were performed to establish the causes of the superior lovastatin productivity of a novel solid-state fermentation (SSF) process, in relation with liquid submerged fermentation (SmF; 20 mg/g vs. 0.65 mg/ml). In SSF, biosynthetic genes lovE and lovF transcripts accumulated to high levels from day 1 to day 7. In this period, lovE transcript showed 4.6-fold higher accumulation levels (transcription) than the highest level detected in SmF (day 5). lovF transcript showed two-fold higher expression than the highest point in SmF. In SmF, the expression was only detected clearly on day 5 and, showing a 50% decrease, on day 7. These results show that the higher lovastatin production in SSF is related to a more intense transcription of these biosynthetic genes. A strong expression of gldB gene in lovastatin SSF indicated that Aspergillus terreus senses osmotic stress during the course of SSF, but not in SmF. However, when a liquid medium of identical concentration was used in SmF, lovastatin production decreased in SSF.
Barrios-González
J
J
Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, 09340, Mexico, Mexico. jbg@xanum.uam.mx
Baños
J G
JG
Covarrubias
A A
AA
Garay-Arroyo
A
A
D001230:Aspergillus / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D007218:Industrial Microbiology / Q000379:methods; D008148:Lovastatin / Q000096:biosynthesis* / Q000378:metabolism; D014158:Transcription, Genetic
D008148:Lovastatin