Biodiversity and dairy traits of lactic acid bacteria from foliage of aromatic plants before and after dehydration process monitored by a smart sensors system.

The main hypothesis of this work was to evaluate the presence of lactic acid bacteria (LAB) intrinsically resistant to plant essential oils in sage (Salvia officinalis L.) and laurel (Laurus nobilis), for future applications in functional cheese production by addition of aromatic herbs. The effect of the drying process on the viability of LAB was evaluated with three biomass densities (3, 4 and 5 kg/m2). The drying densities did not affect weight loss, but influenced the levels of LAB of sage and laurel. A total of 10 different strains of Enterococcus faecium, Enterococcus mundtii, Enterococcus raffinosus and Leuconostoc mesenteroides were identified from laurel, while sage did not host any LAB species. In particular, L. mesenteroides was the only species sensitive to the heat treatment. Only five strains, all enterococci, were resistant to at least one antibiotic, even though no strain showed gelatinase or haemolytic activity. The investigation on the technological traits useful in cheese making demonstrated that all LAB can be considered non starter LAB, because they were characterized by a slow acidification capacity (the pH was still above 6.00 after 3 d) and a very limited autolysis (the maximum decrease of the optical density at 599 nm was barely 0.2).

What Else Is in Salviae officinalis folium? Comprehensive Species Identification of Plant Raw Material by DNA Metabarcoding.

Quality control of drugs consists of identifying the raw material to avoid unwanted admixtures or exchange of material as well as looking for abiotic and biotic contaminations. So far, identity and microbial contamination are analyzed by separate processes and separate methods. Species identification by their DNA ("DNA barcoding") has the potential to supplement existing methods of identification. The introduction of next-generation sequencing methods offers completely new approaches like the identification of whole communities in one analysis, termed "DNA metabarcoding". Here we present a next-generation sequencing assessment to identify plants and fungi of two commercial sage samples (Salvia officinalis) using the standard DNA barcoding region "internal transcribed spacer" consisting of internal transcribed spacer 1 and internal transcribed spacer 2, respectively. The main species in both samples was identified as S. officinalis. The spectrum of accompanying plant and fungal species, however, was completely different between the samples. Additionally, the composition between internal transcribed spacer 1 and internal transcribed spacer 2 within the samples was different and demonstrated the influence of primer selection and therefore the need for harmonization. This next-generation sequencing approach does not result in quantitative species composition but gives deeper insight into the composition of additional species. Therefore, it would allow for a better knowledge-based risk assessment than any other method available. However, the method is only economically feasible in routine analysis if a high sample throughput can be guaranteed.

Phytochemical Variations and Enhanced Efficiency of Antioxidant and Antimicrobial Ingredients in Salvia officinalis as Inoculated with Different Rhizobacteria.

Plants produce a variety of secondary metabolites to improve their performance upon exposure to pathogens, pests, herbivores, or environmental stresses. Secondary metabolism in plants is, therefore, highly regulated by presence of biotic or abiotic elicitors in the environment. The present research was undertaken to characterize plant growth-promoting attributes of four plant growth-promoting rhizobacteria (PGPR) including two Pseudomonas fluorescens (Pf Ap1, Pf Ap18) and two P. putida (Pp Ap9, Pp Ap14) strains, and to determine their role (individually or in consortium) on growth of Salvia officialis, and biosynthesis of secondary metabolites such as essential oils (EOs), total phenolics, and flavonoids. The antioxidant and antibacterial properties of the extracts and EOs obtained from the inoculated plants were also investigated. The PGPR inoculum was applied to soil, cuttings, and foliage. Results indicated that different PGPR strains varied in their efficiency for production of auxin, siderophore, 1-aminocyclopropane-1-carboxylate deaminase, and phosphate solubilization. All individually inoculated plants had significantly higher shoot and root biomass, leaf P content, EOs yield, total phenolics, and flavonoids content compared to uninoculated control plants. The major constituents of EOs, cis-thujene, camphor, and 1,8-cineol, increased following inoculation with reference PGPRs. Although the extract from all inoculated plants had improved antioxidant activity, it was remarkable for the Pf Ap18 strain, which had the lowest IC50 value across treatments. Antibacterial assay of various EOs and their major constituents against pathogenic bacteria showed that the highest activity was observed against Staphylococcus aureus using EOs of Pp Ap14 source. Based on our findings, we suggest that individual inoculation with effective PGPR strains can substantially improve plant growth and secondary metabolism in S. officinalis plants.

Effects of foliar fertilization and arbuscular mycorrhizal colonization on Salvia officinalis L. growth, antioxidant capacity, and essential oil composition.

BACKGROUND: The effect of foliar fertilization and Glomus intraradices inoculation on the growth, qualitative and quantitative pattern of essential oil in Salvia officinalis was determined. Sage plants were grown in a glass house on a soil/sand mixture (w/w = 3:1). Agroleaf total, N:P:K = 20:20:20 + microelements, was used at the whole vegetative growth stage as a 0.3% solution. Inoculation with Glomus intraradices was done at the sowing stage. RESULTS: Application of foliar fertilization and/or mycorrhizal colonization improved dry biomass accumulation and increased the content of antioxidant metabolites (ascorbate and reduced glutathione). Applied treatments lowered the activities of the antioxidants enzymes catalase, ascorbate peroxidase and superoxide dismutase, while guaiacol peroxidase increased. The relative quantity of essential oil pattern was also altered as a result of the applied treatments. Combined application (FF + Gi) significantly promoted 1,8-cineole and alpha-thujone, mycorrhizal colonization enhanced bornyl acetate, 1,8-cineole, alpha- and beta-thujones, while foliar fertilization increased bornyl acetate and camphor. The favorable effect of root colonization by Glomus intraradices was determined both on quantitative and qualitative pattern of sage essential oil. CONCLUSION: We conclude that inoculation with Glomus intraradices resulted in improved essential oil yield and quality, while combined application of foliar fertilizer and mycorrhizal fungi predominantly enhanced shoot biomass accumulation.

Identity of the downy mildew pathogens of basil, coleus, and sage with implications for quarantine measures.

The downy mildew pathogen of basil (Ocimum spp.) has caused considerable damage throughout the past five years, and an end to the epidemics is not in sight. The downy mildew of coleus (Solenostemon spp.) is just emerging and here we report that it was very recently introduced into Germany. Although it has been recognised that these pathogens are a major threat, the identity of the pathogens is still unresolved, and so it is difficult to devise quarantine measures against them. Using morphological comparison and molecular phylogenetic reconstructions we confirmed in this study that the downy mildews of basil and coleus are unrelated to Peronospora lamii, which is a common pathogen of the weed Lamium purpureum. In addition, we conclude by the investigation of the type specimen of P. swingleii and downy mildew specimens on Salvia officinalis that the newly occurring pathogens are not identical to P. swingleii on Salvia reflexa. The taxonomy of the downy mildew pathogens of hosts from the Lamiaceae and, in particular, from the tribes Mentheae and Elsholtzieae, is discussed, and a new species is described to accommodate the downy mildew pathogen of basil and coleus, which is the first downy mildew pathogen known to be parasitic to hosts of the tribe Ocimeae.

Phylogenetic analysis and real time PCR detection of a presumbably undescribed Peronospora species on sweet basil and sage.

Downy mildew of sweet basil (Ocimum basilicum) has become a serious disease issue for the producers of sweet basil in Switzerland since it was first recorded in 2001. Reported in Africa in Uganda as early as 1933, major outbreaks of this disease in Europe were first noted in Italy in 1999 and in the USA from 1993. Previous reports have named the pathogen as Peronospora lamii. Its preferential hosts belong to the Lamiaceae family including basils (Ocimum spp.), mints (Menta spp.), sages (Salvia spp.) and other aromatics. This study investigated the taxonomic status of the downy mildew pathogen, using both morphological characters and molecular analysis of the ITS region of the rDNA. The inherent variability of conidial dimensions made species differentiation difficult. Sequence homology and phylogenetic analysis of nine collections of the Peronospora on sweet basil showed unique ITS sequences distinct from those of P. lamii and any other sequenced Peronospora species. This paper describes and illustrates the morphology of this presumably undescribed species of Peronospora. Its taxonomic position and relationships with other related species in the same genus are presented and discussed. In addition to this work, PCR primers for real time PCR analysis have been developed for the specific detection of this downy mildew pathogen from infected tissues or seeds. It is shown that these primers can also be used in classic PCR.