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Spices are often used in dried form, sometimes with significant microbial contamination including pathogenic and food spoilage bacteria. The antibiotic resistance represents an additional risk for food industry, and it is worthy of special attention as spices are important food additives. During our work, we examined the microbiological quality of 50 different spices with cultivation methods on diverse selective media. The identification of the most representative bacteria was carried out using 16S rDNA gene sequence analysis. Antibiotic resistance profiling of twelve identified Bacillus species (B. subtilis subsp. stercoris BCFK, B. licheniformis BCLS, B. siamensis SZBC, B. zhangzhouensis BCTA, B. altitudinis SALKÖ, B. velezensis CVBC, B. cereus SALÖB isolate, B. tequilensis KOPS, B. filamentosus BMBC, B. subtilis subsp. subtilis PRBC2, B. safensis BMPS, and B. mojavensis BCFK2 isolate) was performed using the standard disk‐diffusion method against 32 antibiotics. The study showed that the majority resistance was obtained against penicillin G (100%), oxacillin (91.67%), amoxyclav (91.67%), rifampicin (75%), and azithromycin (75%). Our findings suggest that spices harbor multidrug‐resistant bacteria., During our work, we examined the microbiological quality of 50 different spices with cultivation methods on diverse selective media. The identification of the most representative bacteria was carried out using 16S rDNA gene sequence analysis. Antibiotic resistance profiling of twelve identified Bacillus species was performed using the standard disk‐diffusion method against 32 antibiotics. Our findings suggest that spices harbor multidrug‐resistant bacteria

Ready-to-eat salads are becoming more and more popular. However, due to their ingredients, they represent a suitable growth environment for different microbes. In the prevention of foodborne diseases, hygienic food preparation and appropriate storage conditions are very important. During this study, ten different ready-to-eat salads were analysed for the presence of Listeria monocytogenes. Five different selective agar mediums were used for the enumeration and isolation of Listeria monocytogenes. The isolated bacterial strains were subjected to morphological and biochemical confirmation tests. The antibacterial effects of five different freshly squeezed vegetable juices (carrots, celery, beets, horseradish, and onions) and of five essential oils (dill, thyme, oregano, lemongrass, and sage) were determined against Listeria monocytogenes, Listeria innocua, and L. monocytogenes strains isolated from ready-to-eat salads. Based on the results obtained from fresh vegetable juices, carrot juice exerted the highest antibacterial effect, while the others showed no or slight inhibitory effect (horseradish, beets, onions) against Listeria species. Among the essential oils, thyme, lemongrass, and oregano showed the strongest antibacterial effect against the studied Listeria species.

During the study, we determined the antimicrobial activity of different selected essential oils (thyme, lemongrass, juniper, oregano, sage, fennel, rosemary, mint, rosehips, dill) on some pathogenic and spoilage bacteria isolated from the surface of various fresh vegetables. At the same time, in the case of some volatile oil combinations we followed the phenomena of synergism and antagonism. The identification of the isolated bacterial strains was made using 16S rDNA gene sequence analysis. The most resistant isolates appeared to be Curtobacterium herbarum, Achromobacter xylosoxidans, and Enterobacter ludwigii, while Pseudomonas hibiscicola was the most sensitive. Of the chosen plant essential oils, the most pronounced antimicrobial effect was detected in the case of oregano. The essential oils of thyme and mint also showed elevated antimicrobial activity. A synergistic effect was observed in case of five combinations of essential oil. Based on the results, we find that some individual essential oils and mixture compositions (due to synergic effect) could be good candidates for the preservation of fresh vegetables. These preliminary findings suggest that essential oils from locally grown spices could contribute to decreasing the health risk and also to the suppression of emergence of antibiotic resistance., Is very useful to know the pathogenic strains occurrence in different geographic regions, to prevent disease occurrence in population and among the tourists, how are more susceptible to foodborne pathogens. The main goal was the detection of active antimicrobial essential oil compositions that will be used as ingredients in active packaging materials for fresh vegetables and fruits, for decreasing the health risk and increasing the product shelf‐life.

Acidification in lactic-fermented foods is realized by lactic acid bacteria as an added starter culture or by autochthonous strains. These microbial strains possess different prominent features that define the technological, organoleptic, nutritional, and microbial safety aspects of the product. The bioprotective effect of the bacterial strains may be related to antagonistic properties against food spoilage and/or pathogenic strains. The aim of the present study is to determine the antimicrobial properties of three different food-grade lactic acid bacteria in order to use them as bioprotective cultures. Our findings show that the Lactobacillus pentosus, Enterococcus faecalis, and Pediococcus parvulus exerted a bacteriostatic effect on Escherichia coli and Bacillus cereus, whereas the Saccharomyces cerevisiae growth was not inhibited, which made them susceptible agent for co-culture systems.

The manufacture of dairy products is an important sector of the food industry. From milking to processing, a number of hygiene rules must be strictly followed. During processing, dairy products can be contaminated with different microorganisms, causing spoilage, infectious diseases, and alterations in the sensory characteristics. There are strict requirements for the quality assurance of milk products. In spite of this, there occur infections linked to milk and dairy product consumption. The analysis of the microbiological quality of these products is a health concern, and it also has an economic impact. The increase and development of the global market of processing technologies require rapid monitoring and controlling systems for food products. In our study, we investigated the microbiological quality of some fresh dairy products with the Soleris® test system. For instrument setting, calibration curves were realized with test bacterial strains. With known initial microbial load of the samples, the microbial growth versus time was measured by the above-mentioned system. The occurrence of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated in ten dairy products. Results obtained by the Soleris system showed that the system is efficient for this purpose. Calibration curves with high correlation coefficients permitted the quantitative determination of the aimed bacteria in the dairy product samples.

Fermented meat products represent an important segment of our alimentation. Obtaining these products is based on beneficial microorganism activity. In the case of traditional food products, these are commercial starters or autochthonous microflora. Fermentation of raw materials is mainly done by sugar metabolization of lactic acid bacteria (LAB). In addition, these microorganisms can have other beneficial properties too such as probiotic properties, antimicrobial compound production abilities, etc. In order to meet consumer demands, starter cultures are continuously developed to produce high-quality, healthy, and tasty products, thus contributing to guaranteeing microbiological safety and to improving one or more sensory characteristics, technological, nutritional, or health properties of the fermented products. The aim of our research is to determine the technological properties of autochthonous lactic acid bacteria originated from commercial fresh sausages in order to select and use them as potential starter cultures in the meat industry. In our work, we determined the relevant characteristics (such as salt tolerance, proteolytic activity, antimicrobial activity, and antibiotic resistance) of bacteria isolated from 16 fresh sausages. Based on our results, the studied bacterial isolates originated from sausages could be potentially used as autochthonous meat starter cultures.

Owing to their nutrient composition, dairy products ensure a favourable environment for different microorganisms. In our study, we investigated the microbiological quality of 22 different commercially available dairy products obtained from local stores and the open-air public market. Among the studied samples four were salty type soft cheese, two were fresh cheese, one was soft cheese (Mascarpone), one was feta-like cheese (Telemea), five were varieties of processed cheese, one was mozzarella, one was a semi-hard cheese, one was smoked cheese, five were cottage cheese, and one was a dairy spread. Samples were evaluated for the presence of Pseudomonas sp., total coliforms, Escherichia coli, Salmonella sp., Staphylococcus aureus, Bacillus cereus and Clostridium perfringens, yeast, and microscopic fungi. Contamination level of the evaluated dairy products varied widely. Among the dairy samples one salty soft cheese, a processed cheese and one cottage cheese were the most contaminated, while low microbiological load was detected in the other samples.

The composition and production technology of the cheese are extremely diverse. There are a wide variety of microbial species on their surface, with a much smaller number inside of the product. The microbiota of the cheese may be composed of beneficial microorganisms, spoilage and foodborne pathogens. Identification and characterization of the microorganisms present in these products are important nutrition, food safety and technological aspects. During our work we evaluated the prevalence of allochthonous bacteria and microscopic fungi in traditionally processed cheeses from northeastern region of Transylvania, with classical microbiological culture methods. Based on the results the microbiota of the analysed cheeses was highly diversified. The identified bacteria with the highest prevalence from different selective media, were as follows: Escherichia coli, Enterococcus durans, Enterococcus faecalis, Shigella flexnerii, Proteus vulgaris, Stenotrophomonas maltophilia, Staphylococcus equorum subsp. equorum, Staphylococcus equorum subsp. linens, Halomonas alkaliphila, Kocuria rhizophila, Hafnia paralvei, Bacillus licheniformis and Klebsiella michiganensis.

A part of rhizospheric bacteria are considered plant growth-promoting bacteria (PGPB) due to their positive effect on the plant growth and development. Plant growth-promoting bacteria based on their metabolic activity can be grouped as biofertilizers, fitostimulants, or biopesticides. These efficient bacteria due to various direct or indirect effects exerted on plants have crucial role in agricultural sustainability. Recently were reported diverse genera as PGPB like Acetobacter, Achromobacter, Arthrobacter, Azoarcus, Azospirillum, Azotobacter, Bacillus, Burkholderia, Frankia, Phyllobacterium, Pseudomonas, Serratia, and Rhizobium. Bacterial strains for this study were isolated from a natural habitat (raised bog) and agricultural environment. Selected bacterial strains based on 16S rRNA gene sequence analysis were identified as Achromobacter spanius, Delftia lacustris, Pseudomonas protegens, P. jessenii, and Acinetobacter lwoffii. These bacterial strains have different plant growth-promoting (PGP) activities like multi-stress resistances (temperature, pH, salinity) and others such as cellulose, phytin, and lecithin degradation, alkaline phosphatase and alkaline protease activity, and siderophore production. The selected strains were tested on plants either alone or in consortia. Based on the reports, it was confirmed that Delftia lacustris BI5, P. jessenii BI7, bacterial strains, and the bacterial consortia P. jessenii BI7 and A. lwoffii BI13 showed positive effect due to their PGP characteristics on wheat shoot growth under laboratory conditions. These promising strains have potential as inoculation agents in eco-friendly crop production contributing to environmental sustainability.

Nowadays, because of environmental concerns, great importance has been given to the sustainability of the present agricultural practices. The current fertilizing methods have utilization efficiency problems; high amounts are lost in the environment and cause pollution. The efficiency of fertilizer use has to be improved or replaced, taking into consideration the global crisis of finite resources and environmental pollution.

This chapter presents the study about some wild leguminous plant’s nodule and rhizosphere bacteria from Ciuc Mountains with beneficial traits related to mineral nutrition and their multiple plant growth-promoting activities as a part of plant-bacteria interaction.

Understanding the interactions of bacteria with plants and the role of microorganisms in the lifecycle of plants is becoming more and more important due to the social claim for a clean agriculture. Thus the significance of studying plant associated bacteria is increasing. The main aim of our study was to isolate and characterize bacteria associated with bryophytes from a natural raised bog ecosystem. Characterization of the isolates by their beneficial properties was realized with microbiological and molecular tools. Bacterial strains were identified taxonomically, isolates belonging to the genera Pseudomonas , Bacillus , Serratia , Stenotrophomonas , Delftia , Cedecea , Lysinibacillus and Viridibacillus have been found. Pseudomonas , Serratia and Bacillus were the dominant bacterial genera associated with bryophytes. In vitro study of antagonism showed that a high number of the isolates inhibited the growth of fungal and bacterial plant pathogens – Fusarium oxysporum , Alternaria alternata , Erwinia carotovora – or produced secondary metabolic substances with biocontrol properties. Bacterial strains identified as Serratia fonticola BB17 and Pseudomonas fluorescens BE8 proved to be the most efficient against plant pathogens, with biocontrol effectiveness up to 48.28% and 55.17% respectively, suggesting the potential use of these strains in biotechnological applications.

Plant growth promoting bacteria can enhance and promote plant growth and development in different ways. These mechanisms include solubilization of phosphorus, nitrogen fixation and biocontrolling effects on phytopathogenic microorganisms. Suppression of phytopathogenic fungi by 47 different bacteria, isolated from different monocotyledonic plants rhizosphere and soil, was tested against Fusarium oxysporum radicis-lycopersici, Sclerotium bataticola, Pythium ultimum, Fusarium graminearum, and Alternaria spp. The antifungal activity of these isolates was described based on the comparison of the growth rate inhibition. As the production of iron-chelating compounds is one of the mechanisms responsible for the antimycotic effect, we tested the siderophore producing capacity of the isolated strains. Also, we assayed the ammonia production of these bacteria. This secondary metabolite compound contributes to the biocontrolling property of these bacteria. Our examinations also include the inorganic phosphate solubilization capacity of these isolates, which may improve the phosphorus uptake of plants. The results indicate that 17 bacterial isolates are able to produce siderophores and 30 from them possess capacity of calcium-phosphate mobilization. The majority of the cultures were found to have highly inhibitory effects against the mycelium growth of P. ultimum, F. oxysporum radicis-lycopersici and F. graminearum, whereas others showed little activity. Only twelve bacteria showed no activity against the S. bataticola plant pathogen fungus.

The nitrogen and phosphorus management in agricultural systems leads to an increased input of plant nutrients and sustains the soil fertility. Microbes contribute through different mechanisms to nutrient cycles, transforming it available for plants. Isolation of 18 Azospirillum and 18 Azotobacter bacterial isolates was effectuated from the rizosphere and interior roots of the following plants: Carex fusca All., Carex rostrata Stokes., Eriogonum latifolium Sm., Carex elata All., and from Equisetum sylvaticum L. originated from the Bors ros raised bog natural reserve. Three rhizobial isolates were isolated from soil where Phaseolus vulgaris L. was cultivated. The bacterial isolates were characterized using biochemical tests. We also performed the molecular grouping of the Azospirillum and Azotobacter isolates due to the restriction fragment length polymorphism (RFLP) of the 16S rDNA sequences. We determined the nitrogen fixing capacity. The ability of isolates to solubilize phosphates was detected using Pikovskaya s agar plates containing calcium-phosphate, whereas the siderophores producing ability was detected on Chrom Azurol S agar plates.

Access to sufficient water and food of suitable quality is a prime requirement for the improvement and maintenance of public health. Waterborne diseases are typically caused by enteric pathogens which belong to the group of organisms transmitted by the faecal-oral route. In the course of our work, in order to determine the presence of allochthonous microorganisms water of dug wells and springs were microbiologically analysed. The selected nonbottled mineral and well-waters are widely consumed by local people. The survival of faecal coliforms was studied in selected water samples during storage at 4 °C and after desinfection with chloramine and iodine. The microbiological quality of the majority of the analysed well and spring waters is not acceptable. The faecal Escherichia coli was still present in the water samples after 8 and 10 days and presented higher resistance to chloramine, but not to iodine, than the Escherichia coli EC/2 strain chosen for comparison.