BackgroundSynthetic biology allows the development of new biochemical pathways for the production of chemicals from renewable sources. One major challenge is the identification of suitable microorganisms to hold these pathways with sufficient robustness and high yield. In this work we analyzed the genome of the propionic acid producer Actinobacteria Propionibacterium acidipropionici (ATCC 4875).ResultsThe assembled P. acidipropionici genome has 3,656,170 base pairs (bp) with 68.8% G + C content and a low-copy plasmid of 6,868 bp. We identified 3,336 protein coding genes, approximately 1000 more than P. freudenreichii and P. acnes, with an increase in the number of genes putatively involved in maintenance of genome integrity, as well as the presence of an invertase and genes putatively involved in carbon catabolite repression. In addition, we made an experimental confirmation of the ability of P. acidipropionici to fix CO2, but no phosphoenolpyruvate carboxylase coding gene was found in the genome. Instead, we identified the pyruvate carboxylase gene and confirmed the presence of the corresponding enzyme in proteome analysis as a potential candidate for this activity. Similarly, the phosphate acetyltransferase and acetate kinase genes, which are considered responsible for acetate formation, were not present in the genome. In P. acidipropionici, a similar function seems to be performed by an ADP forming acetate-CoA ligase gene and its corresponding enzyme was confirmed in the proteome analysis.ConclusionsOur data shows that P. acidipropionici has several of the desired features that are required to become a platform for the production of chemical commodities: multiple pathways for efficient feedstock utilization, ability to fix CO2, robustness, and efficient production of propionic acid, a potential precursor for valuable 3-carbon compounds.

Um novo triterpeno caracterizado como ácido 6α-hidroxibetulínico foi isolado das folhas e caule da planta, vulgarmente conhecida no Brasil como Cambuí, Eugenia moraviana (Myrtaceae), juntamente com três outras substâncias conhecidas, identificadas como ácido platânico, ácido betulínico e β-sitosterol. Através da análise de espectros incluindo NOE e experimentos de RMN em duas dimensões foi realizada a atribuição inequívoca dos deslocamentos químicos de 1 H e de 13 C do ácido 6α-hidroxibetulínico(ácido-3β,6α-diidróxi-20(29)-lupen-28-óico) e do ácido platânico.A novel triterpene, characterized as 6α-hydroxybetulinic acid, was isolated from the leaves and stems of Eugenia moraviana (Myrtaceae), known in Brazil as Cambuí, together with three known compounds, platanic acid, betulinic acid and β-sitosterol. Unequivocal 1 H and 13 C assignments of 6α-hydroxybetulinic acid (3β,6α-dihydroxy-20(29)-lupen-28-oic acid) and platanic acid were undertaken by spectral analysis including NOE and 2 D NMR experiments.

This work presents the use of Raman spectroscopy and chemometrics for on-line control of the fermentation process of glucose by Saccharomyces cerevisiae. In a first approach, an on-line determination of glucose, ethanol, glycerol, and cells was accomplished using multivariate calibration based on partial least squares (PLS). The PLS models presented values of root mean square error of prediction (RMSEP) of 0.53, 0.25, and 0.02% for glucose, ethanol and glycerol, respectively, and RMSEP of 1.02 g L(-1) for cells. In a second approach, multivariate control charts based on multiway principal component analysis (MPCA) were developed for detection of fermentation fault-batch. Two multivariate control charts were developed, based on the squared prediction error (Q) and Hotelling's T(2) . The use of the Q control chart in on-line monitoring was efficient for detection of the faults caused by temperature, type of substrate and contamination, but the T(2) control chart was not able to monitor these faults. On-line monitoring by Raman spectroscopy in conjunction with chemometric procedures allows control of the fermentative process with advantages in relation to reference methods, which require pretreatment, manipulation of samples and are time consuming. Also, the use of multivariate control charts made possible the detection of faults in a simple way, based only on the spectra of the system.

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Abstract:The diastereo-and enantioselective bioreduction of (AE )-2-hydroxy-1-tetralone (6) to the corresponding enantiopure (1S,2R)-cis-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene (1) (83 % isolated yield, > 99 % ee), mediated by resting cells of the yeast Trichosporon cutaneum CCT 1903 through dynamic kinetic resolution is reported. Deracemization of (AE )-6 was observed in kinetic studies on the biotransformation of the enantiomers (R)-6 and (S)-6.

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