Comparison of Chemical Composition, Physicochemical Parameters, and Antioxidant and Antibacterial Activity of the Essential Oil of Cultivated and Wild Mexican Oregano Poliomintha longiflora Gray.

Mexican oregano Poliomintha longiflora Gray located in the municipality of Higueras, Nuevo Leon, Mexico was collected during the autumn (September, OCO), winter (January, OCI) and summer (June, OCV) seasons, under cultivation conditions. It was also collected in wild conditions during the autumn (OSO). Essential oil (EO) was extracted from leaves and the color, refractive index and density were reported. The EO yield, antioxidant activity by ORAC assay, thymol and carvacrol concentration and antibacterial activity were statistically compared (p-value = 0.05). Among the various harvests, the highest EO yield, antioxidant activity, thymol and carvacrol content and antibacterial activity against Salmonella Typhi were observed in leaves harvested in autumn. In order to compare wild oregano with cultivated oregano, analyses were performed in the season with the highest essential oil yield and antioxidant activity, recorded in autumn. The main difference found was the ratio of thymol:carvacrol in wild oregano oil, which was 1:8.6, while in cultivated oregano, it was approximately 1:2, which was maintained in all three seasons. The EO on wild conditions showed the best antibacterial activity in Salmonella Typhi. On the other hand, wild and cultivated oregano showed similar antioxidant activity. One advantage of the use of cultivated oregano is that its supply is guaranteed, in contrast to that of wild oregano.

Biochemical composition, antimicrobial and antifungal activities assessment of the fermented medicinal plants extract using lactic acid bacteria.

To prevent foodborne diseases and extend shelf life, antimicrobial agents may be used in food to inhibit the growth of undesired microorganisms. The present study was aimed to determine the antimicrobial and antifungal activities of the fermented medicinal plants extract using Lactobacillus acidophilus ATCC 4356. The fermentation kinetic parameters, biochemical composition and the volatile compounds of the fermented plant extract were assessed. The results showed that, the fermented plants extract exhibited high content in polyphenols, flavonoids, and tannins (152.7 mg AGE/L; 93.6 mg RE/L; and 62.1 mg CE/L, respectively) comparing to non-fermented the extract. The GC-MS headspace analyses showed the presence of 24 interesting volatile compounds. The richness of the fermented plants extracts in polyphenols and bioactive compound, such as Eucalyptol, Camphene, α-Phellandrene, α-Terpinene, improves their biological activity. In addition, the fermented plants extract exhibited a high antimicrobial potential against pathogenic bacteria and fungi determined by different methods. The maximum inhibition showed in the fermented plants extract against Escherichia coli 25922/3, Pseudomonas aeruginosa 27853 ATCC, Staphylococcus aureus 29213 ATCC, Enterococcus aerogenes 13048 ATCC, Phytophthora infestans P3 4/91 R + , P. infestans P4 20/01 R, P. infestans (GL-1). The obtained results support the hypothesis of using lactic fermentation as a functional ingredient to improve food preservation. The bioprocesses of fermentation technology enhance antimicrobial and antifungal activities which could be used in different industrial applications.

Simple Preparation of Rhodococcus erythropolis DSM 44534 as Biocatalyst to Oxidize Diols into the Optically Active Lactones.

In the current study, we present a green toolbox to produce ecological compounds like lactone moiety. Rhodococcus erythropolis DSM 44534 cells have been used to oxidize both decane-1,4-diol () and decane-1,5-diol () into the corresponding γ- () and δ-decalactones () with yield of 80% and enantiomeric excess (ee) = 75% and ee = 90%, respectively. Among oxidation of meso diols, (-)-(1S,5R)-cis-3-oxabicyclo[4.3.0]non-7-en-2-one (5a) with 56% yield and ee = 76% as well as (-)-(2R,3S)-cis-endo-3-oxabicyclo[2.2.1]dec-7-en-2-one (6a) with 100% yield and ee = 90% were formed. It is worth mentioning that R. erythropolis DSM 44534 grew in a mineral medium containing ethanol as the sole source of energy and carbon Chirality 28:623-627, 2016. © 2016 Wiley Periodicals, Inc.

A bifunctional enzyme from Rhodococcus erythropolis exhibiting secondary alcohol dehydrogenase-catalase activities.

Alcohol dehydrogenases have long been recognized as potential biocatalyst for production of chiral fine and bulk chemicals. They are relevant for industry in enantiospecific production of chiral compounds. In this study, we identified and purified a nicotinamide adenine dinucleotide (NAD)-dependent secondary alcohol dehydrogenase (SdcA) from Rhodococcus erythropolis oxidizing γ-lactols into γ-lactones. SdcA showed broad substrate specificity on γ-lactols; secondary aliphatic alcohols with 8 and 10 carbon atoms were also substrates and oxidized with (2S)-stereospecificity. The enzyme exhibited moderate stability with a half-life of 5 h at 40 °C and 20 days at 4 °C. Mass spectrometric identification revealed high sequence coverage of SdcA amino acid sequence to a highly conserved catalase from R. erythropolis. The corresponding encoding gene was isolated from genomic DNA and subsequently overexpressed in Escherichia coli BL21 DE3 cells. In addition, the recombinant SdcA was purified and characterized in order to confirm that the secondary alcohol dehydrogenase and catalase activity correspond to the same enzyme.