Instrumental Analysis of bacterial cells growth under incubation with Crocus sativus L. extracts using FT-IR spectroscopy

Foodborne illness is a threat to public health and challenge for food industry. Very young children, pregnant women, people with compromised immune systems and the elderly are at the most risk. Foodborne illness also known as food poisoning usually arises from improper handling, preparation, or food storage and is associated with microbial pathogens. Bacteria are a common cause of foodborne illness and especially Salmonella and Escherichia coli. At present food industry uses chemical additives in several processes in order to prevent bacterial growth and extend the shelf life of foods. However, these substances have adverse effects. In the current study, Crocus sativus L. extracts were tested as potential natural antimicrobial agents. The antimicrobial activity of plants extracts was studied towards Gram-negative strains belonging to the above species. Fourier transform infrared spectroscopy (FT-IR) was applied in order to evaluate the changes in the cellular composition of target bacterial cells after their exposure to extracts

Antimicrobial activity of plant extracts against oral pathogens. Detection of cellular structural changes by FT-IR.

Periodontal diseases and dental caries are common oral disorders in human population with a multifactorial etiology closely related with the development of dental plaque. The latter is composed of native oral microbiota and it is accumulated on teeth surfaces. Several antiseptic agents are used widely to inhibit bacterial growth [1,2]. However, these substances have adverse effects. In the current study, six plants extracts namely, chamomile, dittany, lemon balm, rosemary, saffron and sage, were tested as potential natural antimicrobial agents. The antimicrobial activity of plants extracts was studied towards Gram-positive strains belonging to Streptococcus species related to the oral health. Fourier transform infrared spectroscopy (FT-IR) was applied in order to evaluate the changes in the cellular composition of target bacterial cells after their exposure to extracts of both plants

Comparative study of biological activities of Crocus sativus L. extracts and Lamiaceae plants’ extracts

In the current study, different extracts of Origanum dictamnus L. leaves (dittany), Melissa officinalis L. leaves (lemon balm) and Crocus sativus L. stigmas (saffron) were tested as potential natural antoxidant and antimicrobial agents

Discovering probiotic microorganisms: invitro, invivo, genetic and omics approaches

Over the past decades the food industry has been revolutionized toward the production of functional foods due to an increasing awareness of the consumers on the positive role of food in wellbeing and health. By definition probiotic foods must contain live microorganisms in adequate amounts so as to be beneficial for the consumer’s health. There are numerous probiotic foods marketed today and many probiotic strains are commercially available. However, the question that arises is how to determine the real probiotic potential of microorganisms. This is becoming increasingly important, as even a superficial search of the relevant literature reveals that the number of proclaimed probiotics is growing fast. While the vast majority of probiotic microorganisms are food-related or commensal bacteria that are often regarded as safe, probiotics from other sources are increasingly being reported raising possible regulatory and safety issues. Potential probiotics are selected after in vitro or in vivo assays by evaluating simple traits such as resistance to the acidic conditions of the stomach or bile resistance, or by assessing their impact on complicated host functions such as immune development, metabolic function or gut–brain interaction. While final human clinical trials are considered mandatory for communicating health benefits, rather few strains with positive studies have been able to convince legal authorities with these health claims. Consequently, concern has been raised about the validity of the workflows currently used to characterize probiotics. In this review we will present an overview of the most common assays employed in screening for probiotics, highlighting the potential strengths and limitations of these approaches. Furthermore, we will focus on how the advent of omics technologies has reshaped our understanding of the biology of probiotics, allowing the exploration of novel routes for screening and studying such microorganisms

Antimicrobial activity of Melissa officinalis L. and Crocus sativus L. against oral pathogens: Detection of cellular structural changes by FT-IR.

Periodontal diseases and dental caries are common oral disorders in human population with a multifactorial etiology closely related with the development of dental plaque. The latter is composed of native oral microbiota and it is accumulated on teeth surfaces. Several antiseptic agents are used widely to inhibit bacterial growth [1,2]. However, these substances have adverse effects. In the current study, Melissa officinalis L. and Crocus sativus L. extracts were tested as potential natural antimicrobial agents. The antimicrobial activity of plants extracts was studied towards Gram-positive strains belonging to Streptococcus species related to the oral health. Fourier transform infrared spectroscopy (FT-IR) was applied in order to evaluate the changes in the cellular composition of target bacterial cells after their exposure to extracts of both plants

Ohmic Heating for the dairy industry: a potential technology to develop probiotic dairy foods in association with modifications of whey protein structure

The use of whey in dairy probiotics is a topic of great interest to the scientific community and the food industries. However, few studies address the effect of ohmic heating (OH) on cell metabolism and growth parameters of probiotic microorganisms. Despite of this, OH under sub-lethal conditions presents promising results regarding the enhancement of growth rate and bacteriocin activity, leading to considerable improvements in the fermentation process. Thus, this review highlights the main findings and advances on the effect of OH on probiotic metabolism, while addressing the modification of whey protein structure as potential carrier of probiotic entities, aiming at stimulating interest and encouraging the development of functional products using OH.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and by BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 — Programa Operacional Regional do Norte. Pedro Santos is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 — Programa Operacional Regional do Norte. Ricardo Pereira is recipient of a fellowship supported by FCT (SFRH/BPD/81887/2011).info:eu-repo/semantics/publishedVersio

A Key Role of Dendritic Cells in Probiotic Functionality

BACKGROUND: Disruption of the intestinal homeostasis and tolerance towards the resident microbiota is a major mechanism involved in the development of inflammatory bowel disease. While some bacteria are inducers of disease, others, known as probiotics, are able to reduce inflammation. Because dendritic cells (DCs) play a central role in regulating immune responses and in inducing tolerance, we investigated their role in the anti-inflammatory potential of probiotic lactic acid bacteria. METHODOLOGY/PRINCIPAL FINDINGS: Selected LAB strains, while efficiently taken up by DCs in vitro, induced a partial maturation of the cells. Transfer of probiotic-treated DCs conferred protection against 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Protection was associated with a reduction of inflammatory scores and colonic expression of pro-inflammatory genes, while a high local expression of the immunoregulatory enzyme indolamine 2, 3 dioxgenase (IDO) was observed. The preventive effect of probiotic-pulsed DCs required not only MyD88-, TLR2- and NOD2-dependent signaling but also the induction of CD4+ CD25+ regulatory cells in an IL-10-independent pathway. CONCLUSIONS/SIGNIFICANCE: Altogether, these results suggest that selected probiotics can stimulate DC regulatory functions by targeting specific pattern-recognition receptors and pathways. The results not only emphasize the role of DCs in probiotic immune interactions, but indicate a possible role in immune-intervention therapy for IBD

Pre-formulation and delivery strategies for the development of bacteriocins as next generation antibiotics

peer-reviewedBacteriocins, a class of antimicrobial peptide produced by bacteria, may offer a potential alternative to traditional antibiotics, an important step towards mitigating the ever increasing antimicrobial resistance crisis. They are active against a range of clinically relevant Gram-positive and Gram-negative bacteria. Bacteriocins have been discussed in the literature for over a century. Although they are used as preservatives in food, no medicine based on their antimicrobial activity exists on the market today. In order to formulate them into clinical antibiotics, pre-formulation studies on their biophysical and physicochemical properties that will influence their activity in vivo and their stability during manufacture must be elucidated. Thermal, pH and enzymatic stability of bacteriocins are commonly studied and regularly reported in the literature. Solubility, permeability and aggregation properties on the other hand are less frequently reported for many bacteriocins, which may contribute to their poor clinical progression. Promising cytotoxicity studies report that bacteriocins exhibit few cytotoxic effects on a variety of mammalian cell lines, at active concentrations. This review highlights the lack of quantitative data and in many cases even qualitative data, on bacteriocins’ solubility, stability, aggregation, permeability and cytotoxicity. The formulation strategies that have been explored to date, proposed routes of administration, trends in in vitro/in vivo behaviour and efforts in clinical development are discussed. The future promise of bacteriocins as a new generation of antibiotics may require tailored local delivery strategies to fulfil their potential as a force to combat antimicrobial-resistant bacterial infections