The soil microbiome plays an important role in maintaining soil health, plant productivity, and soil ecosystem services. Current molecular-based studies have shed light on the fact that the soil microbiome has been quantitatively underestimated. In addition to metagenomic studies, metaproteomics and metatranscriptomic studies that target the functional part of the microbiome are becoming more common. These are important for a better understanding of the functional role of the microbiome and for deciphering plant-microbe interactions. Free-living beneficial bacteria that promote plant growth by colonizing plant roots are called plant growth-promoting rhizobacteria (PGPRs). They exert their beneficial effects in different ways, either by facilitating the uptake of nutrients and synthesizing particular compounds for plants or by preventing and protecting plants from diseases. A better understanding of plant-microbe interactions in both natural and agroecosystems will offer us a biotechnological tool for managing soil fertility and obtaining a high-yield food production system.

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 study assessed the effects of soaking hard cheeses and cheese slices in blackcurrant wine on their antioxidant, microbiological, and sensory properties. Soaking increased weekly, the phenolic content by 40.86 ± 0.3 mg GAE/100 g (gallic acid equivalent) of cheese, and their reached the maximum ethanol content of 1.29 ± 0.08 g/100 g. Soaking reduced the amount of foodborne pathogenic bacteria, enhancing microbiological safety. The lactic acid bacteria count significantly decreased during soaking time. The sensory evaluation shows that 45 % of tasters preferred the soaked cheese. Positive correlations were observed between taste and color (in whole-soaked cheese), while negative correlations were revealed among color, smell, and texture (in soaked quarter cheese). The results suggest that blackcurrant wine, containing a wealth of bioactive constituents, has the capacity to augment the favorable attributes of cheese and presents prospects for developing a novel gastronomic offering.

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.

Bread is a staple, energy-rich food for people of all ages, so quality is important to consumers. In our region, most of the commercially available bread, whether packaged or unpackaged, is produced by local bakeries, so monitoring microbial levels and the types of microbes present on bread can help to draw attention to protect the final product. It can also help to ensure the food safety, quality, and shelf life of bread. The freshly baked product is microbiologically sterile. Post-process contamination affects the microbial load of bread. In this study, the microbial load of 30 different commercial bread crumbs and crusts was determined. The different types of bread with different compositions were analyzed for total viable bacteria, Escherichia coli, Staphylococcus aureus, aerobic and anaerobic spore-forming bacteria, and culturable microscopic fungi. The K-means clustering algorithm was used to cluster the different types of bread based on the number of aerobic mesophilic bacteria. Significant differences (p < 0.05) were found in the total viable bacterial count for bread crusts and crumbs. The bacterial count of bread varied between 10.00 ± 0.00–395.00 ± 52.4 CFU/g for bread crusts and 10.00 ± 0.0–310.67 ± 94 CFU/g for bread crumbs. The results of 16S rDNA sequence analysis showed that the most frequently occurring bacterial species belonged to the genus Bacillus, but species of the genus Staphylococcus were also present. Chryseobacterium spp. predominated on multigrain bread, Marinilactobacillus spp. on rustic potato bread, and Staphylococcus warneri on sliced brown potato bread. The results contribute to a better understanding of the microbial dynamics in locally produced breads from the Eastern Carpathians of Transylvania, with the aim of improving food safety, quality control, and consumer protection.

In this study, we determined and identified the bacterial diversity of different types of artisanal and industrially produced cheese. The antibiotic (erythromycin, chloramphenicol, kanamycin, ampicillin, clindamycin, streptomycin, tetracycline, and gentamicin) and biocide (peracetic acid, sodium hypochlorite, and benzalkonium chloride) resistance of clinically relevant bacteria was determined as follows: Staphylococcus aureus, Macrococcus caseolyticus, Bacillus sp., Kocuria varians, Escherichia coli, Enterococcus faecalis, Citrobacter freundii, Citrobacter pasteurii, Klebsiella oxytoca, Klebsiella michiganensis, Enterobacter sp., Enterobacter cloacae, Enterobacter sichuanensis, Raoultella ornithinolytica, Shigella flexneri, and Salmonella enterica. Also, the effect of the sub-inhibitory concentration of three biocides on antibiotic resistance was determined. The microbiota of evaluated dairy products comprise diverse and heterogeneous groups of bacteria with respect to antibiotic and disinfectant tolerance. The results indicated that resistance was common in the case of ampicillin, chloramphenicol, erythromycin, and streptomycin. Bacillus sp. SCSSZT2/3, Enterococcus faecalis SRGT/1, E. coli SAT/1, Raoultella ornithinolytica MTT/5, and S. aureus SIJ/2 showed resistance to most antibiotics. The tested bacteria showed sensitivity to peracetic acid and a different level of tolerance to benzalkonium chloride and sodium hypochlorite. The inhibition zone diameter of antibiotics against Enterococcus faecalis SZT/2, S. aureus JS11, E. coli CSKO2, and Kocuria varians GRT/10 was affected only by the sub-inhibitory concentration of peracetic acid.