When bacteria are cultured in medium with multiple carbon substrates, they frequently consume these substrates simultaneously. Building on recent advances in the understanding of metabolic coordination exhibited by Escherichia coli cells through cAMP-Crp signaling, we show that this signaling system responds to the total carbon-uptake flux when substrates are co-utilized and derive a mathematical formula that accurately predicts the resulting growth rate, based only on the growth rates on individual substrates.

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BackgroundThe basidiomycetous yeast Xanthophyllomyces dendrorhous has been described as a potential biofactory for terpenoid-derived compounds due to its ability to synthesize astaxanthin. Functional knowledge of the genes involved in terpenoid synthesis would create opportunities to enhance carotenoid production. A thiolase enzyme catalyzes the first step in terpenoid synthesis.ResultsTwo potential thiolase-encoding genes were found in the yeast genome; bioinformatically, one was identified as an acetyl-CoA C-acetyltransferase (ERG10), and the other was identified as a 3-ketoacyl Co-A thiolase (POT1). Heterologous complementation assays in Saccharomyces cerevisiae showed that the ERG10 gene from X. dendrorhous could complement the lack of the endogenous ERG10 gene in S. cerevisiae, thereby allowing cellular growth and sterol synthesis. X. dendrorhous heterozygous mutants for each gene were created, and a homozygous POT1 mutant was also obtained. This mutant exhibited changes in pigment composition and higher ERG10 transcript levels than the wild type strain.ConclusionsThe results support the notion that the ERG10 gene in X. dendrorhous is a functional acetyl-CoA C-acetyltransferase essential for the synthesis of mevalonate in yeast. The POT1 gene would encode a functional 3-ketoacyl Co-A thiolase that is non-essential for cell growth, but its mutation indirectly affects pigment production.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0893-2) contains supplementary material, which is available to authorized users.

Yevhen Vainshtein and Nicole Werner contributed equally to this work. The order of authors was determined based on a coin toss.ABSTRACT Andreprevotia sp. strain IGB-42 is a chitin-degrading bacterium isolated from the soil of an anthill. The genome contains 4.7 Mb, a GϩC content of 61.31%, 4,257 predicted open reading frames, and a set of industrially interesting chitinase genes.

The market for industrial enzymes is increasing steadily. Hence, efficient expression systems and processes for the large-scale production of industrial enzymes are of common interest. The presented article deals with the recombinant production of a fungal lipase in yeasts, and with its large-scale, fermentative production up to 1.000 Litres