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  With emerging of infectious diseases and spread of antibiotic resistant strains, use of antimicrobial compounds with plant origin seems necessary. In this study, ethanolic extract of Cordia myxa fruit was used to evaluate antimicrobial effects against microorganisms including Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Aspergillus niger and Candida albicans. Ultrasound-assisted extraction was performed to investigate three independent variables: time (5- 40 min), temperature (20- 50°C) and sonic power (20- 100%). Response surface methodology was also employed to optimize multiple variables to predict the best process conditions. Antimicrobial activity was done by methods including disk diffusion agar, pour-plate, minimum inhibition concentration and minimum bactericide (fungicide) concentration. The results showed that the highest amount of extraction rate of ethanolic extract which was equal to 8.5%, was obtained in extraction time of 39.8 min, temperature of 42.2°C and sonic power of 94.4%.In all above-mentioned methods, inhibitory effect of optimum ethanolic extract was more significant againstBacillus cereus, Staphylococcus aureus and Candida albicansthan other strains (p≤0.05).

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  Studies have shown that camel milk and its fermented products have therapeutic properties and high nutritional value. Lactic acid bacteria play important role in Fermented dairy products. The aim of this study is to determine the lactobacillus community of camel milk. A total of 9 Lactobacillus were isolated from camel milk of Golestan province in Iran. The log₁₀ CFU of Lactobacillus per ml on MRS medium under anaerobic condition at 20, 37 and 45⁰C included 8.792± 0.14, 8.301±0.07 and 7.301±0.03 respectively. Isolates were identified on the basis of Biochemical and Phenotypic Characteristics as Lactobacillus paraplantarum, Lactobacillus ferintoshensis, Lactobacillus brevis, Lactobacillus pantheris, Lactobacillus johnsonii, Lactobacillus mali. Presence of Lactic acid bacteria was confirmed by band formation of PCR product in 1500 bp (amplification 16S rRNA gene using B27F-U1492Runiversal bacterial primer). Evaluation of their technological properties of isolates showed that isolated Lactobacillus fromcamelmilkhave lipoliticy, Proteolytic activity and high acidifying activity (except for Lb. mali and Lb. johnsonii). Also, allisolates, except Lb. Johnsonii, have autolytic activity in fair level. Based on technological properties ofisolates, Lb. paraplantarum, Lb. Brevis and Lb. pantheris are suggested as good candidates for camels milk processing or other fermentation process.  

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In this research different methods of DNA extraction from Aspergillus niger in tomato paste have been optimized and compared with each other. For this purpose classical optimization techniques and commercial Kit base methods were used. Mold spores of Aspergillus niger at different levels (10¹, 10³ and 10⁵ CFU/g) were added to the tomato paste. After mycelium growth DNA extraction was perfomed by five methods. Different methods employed by use the Liquid nitrogen, ultrasonic and lysis solution in the cell wall. These methods in terms of quality and quantity of DNA extracted were studied using spectrophotometer with NanoDrop. The absence of smear, protein contamination and no presecnce of PCR inhibitors determined with PCR that performed forward and reverse primers. Result of gel electrophoresis and PCR assay showed that Method 1 is the most appropriate method for DNA extraction is the mold of tomato paste.

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There is a global interest to study lactic acid bacteria (LAB) of artisanal fermented products like yoghurt for improving or replacing current strains used in commercial starter cultures. In this work, five traditional yoghurt samples were collected from different areas of Khorasan-e-Razavi. Grouping and identification of isolates were carried out on the basis of physiological and biochemical tests (non-molecular),as well as ARDRA technique and sequencing (molecular methods). Totally, 71 isolates including 33 Streptococcus thermophilus, 30 Lactobacillus delbrueckii (subsp. Bulgaricus and lactis), were identified as dominant strains in all yoghurt samples. Also 8 other isolates belonging to Lactobacillus helveticus, Pediococcus pentosaceus and Weissella cibaria were observed. Results of this research show the diversity of LAB population in collected samples.

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Dual properties of Enterococcus on the one hand, have made them suitable and accepted bacteria as starter cultures in the production of food products and probiotics, but on the other hand, because of antibiotic resistance properties and virulence factors, has resulted in concerns about the consumer’s health. In this study, in order to evaluate the antibiotic resistance of enterococcal isolates, the disk diffusion method was used. Also, culture-based method was applied for hemolytic and gelatinase activities. The results of the inhibition zone of Enterococcus isolates against common clinical antibiotics revealed that the isolates were sensitive to Vancomycin and Ampicillin and are resistant to Kanamycin and Streptomycin. The isolates showed very little resistance to Tetracycline and Chloramphenicol and none of the isolates were resistant to all tested antibiotics. Results obtained from hemolytic activity of isolates showed that none of examined isolates were capable of blood hemolysis and consequently no clear zone of inhibition in medium containing sheep’s blood. All of isolated were γ hemolytic and they have no hemolytic activity. Gelatinase activity results confirmed that none of the isolates are able to produce clear zone in tryptone soy agar containing gelatin.

 

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Fermentation is one of the oldest techniques in food preservation, this process is defined as the biological activity of microorganisms to improve sensory, organoleptic and nutritional properties and produce a range of metabolites that inhibit the growth of unwanted microbial flora. As a result, fermented products have a shelf life substantially higher than raw materials and also have very beneficial effects on health. In this research, ginger in 4 and 8 % levels  and yogurt whey in 0 and 3 % levels, were added to the carrots and evaluated during of 0,4, 8, 16, 24 and 32 days of fermentation. The results showed that by adding 4% ginger, pH, mold and yeast count and L* index decreased, acidity, total count, lactic acid count, a* and b* color indexes and overall acceptance increased. In contrast, the addition of 8% ginger had a negative effect on the studied parameters and decreased the overall acceptance and enumeration of lactic acid bacteria. Addition of yogurt (3%) decreased pH, mold and yeast count and L* index, but increased acidity, total count also color indices a* and b* and overall acceptance. In the non-yogurt and non-ginger sample from the beginning to the end of the storage period, pH, total count and mold and yeast counts increased steadily, and overall acidity and acceptance decreased. Whereas in the samples containing ginger and yogurt, the pH and count of mold and yeast decreased as the fermentation time increased to the 16th day and overall count increased, lactic acid bacteria, acidity and total acceptance. According to the results of this study, using 4% ginger, 3% yogurt and 16 days fermentation time to increase shelf life and lactic acid bacteria and improve the sensory characteristics of fermented carrots.

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Kaymak or Sarshir, a traditional dairy product, is served in Iranian breakfast. The aim of this study was to investigate the fatty acids profile, physicochemical properties (texture, color, pH, acidity, the content of dry matter, fat and protein) and organoleptic aspects of Gilanvand and Dalirankaymaks in comparison to the heavy cream. To study more closely the texture and appearance differences of these products, scanning electron microscope (SEM) images were also prepared. The obtained results showed that the contents of fat and dry matter in heavy cream were higher than the kaymaks; however, Gilanvandkaymak had the highest protein content, acidity, and b*-value. Based on the study of the fatty acids profile, palmitic acid and cis-oleic acid were recognized as the most dominated saturated and unsaturated fatty acids, respectively. Microstructural analysis of SEM revealed that the structure of the protein in the fat field was compact, irregular and abundant in Gilanvandkaymak which influenced the product properties. The hardness, gumminess, and adhesiveness of the heavy cream were highest in comparison to the kaymaks. The Gilamvandkaymak obtained higher scores in evaluating the taste and total acceptance. In conclusion, it can be mentioned that the Gilamvandkaymak will have high potential in marketability by considering its higher protein content as well as total acceptance.

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In the present study, simultaneous evaluation for the survival ability of probiotic bacteria at pH 2.5, viability in the presence of pepsin-pancreatin, resistance to bile salt, Adhesion ability, bacterial resistance against antibiotic substances with measuring of minimum inhibitory concentration, auto-aggregation and co-aggregation with interference of (Escherichia coli (NCTC 12900 O157:H7), Salmonella enterica (ATCC 13076) and Listeria monocytogenes (ATTC 7644)) were investigated. In the test of Acid tolerance, it was found that all the strains except LF 55, 61 and F had high viability. Strains LF 56, LF 57, LF 55, O, F and strains LF 56, LF 57 and A7 showed that had the most resistant against pancreatin and in the presence of pepsin, respectively. Furthermore, all of the strains except La5, 52 and 49 were highly resistant to bile salts. Among the 19 strains, Lactobacillus gasseri had the highest adhesion ability (62.90%). Strain Lactobacillus plantarum LF 56 and Lactobacillus gasseri 54 C showed that had the highest potentials for auto-aggregation and co-aggregation (75.31% and 33%) on three pathogens, respectively. Several strains of Lactobacillus plantarum were sensitive to the studied antibiotic substance. However, strains M8 and M11 were resistant to Kanamycin and Chloramphenicol, and also, LF 55 and D showed high resistance against Ampicillin and Chloramphenicol, respectively. It was, moreover, found that Kanamycin, Tetracycline and Chloramphenicol had no significant influence on strains 61. It was demonstrated that Lactobacillus gasseri had medium resistance to Ampicillin, Erythromycin and Tetracycline, while Lactobacillus fermentum showed highly resistance to Ampicillin and Erythromycin. According to the results, human-isolated Lactobacillus gasseri gained the high scores in terms of probiotic properties as compared with other strains. Therefore, Lactobacillus gasseri can potentially protect epithelium tissue of intestine against pathogenic bacteria and it is a preferred candidate for prophylactic purposes, preventing of intestine infections and increasing of body immune system.
 

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In this study, the effect of low methoxyl pectin addition oi the three levels including 0.2, 0.4 and 0.6% on the structural properties of cream with 45% fat globules was investigated. Structural study of the dispersed phase was performed using particle size distribution method and the morphological properties evaluated by optical microscopic images. The results show the effectiveness of low methoxyl pectin on the size distribution of fat globules in the cream. The mean volume-surface of ​​fat globules in pectin-free cream increased from 2.28 to 4.65 μm in the sample with 0.6% low methoxyl pectin. Optical microscopic images demonstrated the morphological of fat globules change from spherical and solitary to the agglomerated form. On the other hand, increasing of low methoxyl pectin levels caused to increase the irregularity of particles size distribution in the images obtained from microscopic observation. Fractal dimension was calculated as an indicator for complexity quantification based on microscopic images. An increase in fractal parameter observed with increasing levels of low methoxyl pectin in the cream. On the other hand, a relationship with high coefficient of determination was observed between the changes in particle size and fractal dimension.

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Folate is a term used for a set of compounds with similar biological activities. Folate (polyglutamates) naturally contains all forms of vitamins in this family. In other words, folic acid is a form of folate that is oxidized, this compound is stable and can be absorbed by humans (monoglutamate)[1]. There are several methods for measuring folate, but due to the fact that in this study, the production of extracellular folate (Quatrofolate) was examined, so the microbial assay method was used as the main method. Lactobacillus. Rhamnosus (ATCC7469), which is used as a sensing organism. [2,3] This method can also measure all forms of folate. In this study, 47 medical strains isolated from traditional dairy products were Special Khorasan. traditional yogurt (12 strains of Streptococcus.thermophilus and 15 strains of Lactobacillus delbrueckii subsp. Bulgaricus, 13 strains of Lactobacillus delbrueckii subsp. Lactis, 3 strains of Lactobacillus helveticus) were studied. The results of this evaluation showed that both strains (25 and 26) of Lactobacillus delbrueckii subsp. Bulgaricus produced significant high folate concentrations (133.23 μg / mL and 102.34 μg / mL), as well as K73 strain of Streptococcus.thermophilus, strain 73 from the strains of  Lactobacillus delbrueckii subsp. Lactis and strain No.87 from the three strains of Lactobacillus helveticus (90.29 μg / mL, μg / mL39.71, μg / mL 17.94), were also able to produce high amounts of quatrofolate. According to this study, it was found that the examined previously isolated strains have a potential ability to produce extracellular folate, and the microbial assay method for measuring a sensitive vitamin such as folate in all its forms is considered an efficient and accurate method.
 

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Recently, special attention has been paid to enterococci for use as probiotics in dairy products. All these desirable features are a stimulus for the producers of dairy products to use enterococci isolated from dairy products such as Liqvan cheese. Despite having all these features, enterococci are not recognized as GRAS and their presence in food products is a sign of fecal contamination. The purpose of this research is to investigate enterococci isolated from Liqvan and Koze cheese in terms of having pathogenic indicators in order to confirm that they are safe for consumers and finally to investigate the possibility of using them as starters or starter aids in dairy products. Especially cheeses. Based on this, 57 isolates of Enterococcus faecium from traditional Iranian cheeses were examined for the presence of pathogenic genes, and finally 23 isolates did not have any pathogenic genes. Then the technological properties of these isolates such as acidification, proteolytic, lipolytic, autolytic, heat and acid resistance and exopolysaccharide production were investigated. The results showed that among the 23 investigated strains, 19 isolates had antimicrobial activity against pathogenic bacteria, 16 strains were able to produce exopolysaccharide and 20 isolates had moderate acidification properties. The highest proteolytic and lipolytic activity was related to strains c18 and c16, respectively, and strain LR78 showed the highest acid and heat resistance.

 

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Dairy factories produce high volume of sludge from bactofuge and separator. Meantime, global demand for the proteases is increasing. Recently, utilization and conversion of the waste materials into value added product is a sustainable process. The objective of this study was to investigate the potential of bactofuge and separator sludge to produce alkaline protease enzymes. Total viable aerobic and anaerobic counts were determined on Plate Count Agar at 37 and 50^ºC for both types of sludge. Lactobacillus count in MRS Agar plates corresponded to 3.12±0.25 log CFU mL^-1 for sludge of bactofuge and 3.085±0.2 log CFU mL^-1 for sludge of separator. Mold and yeast had population levels of 2.3±0.1 log CFU mL^-1 for bactofuge and 2.08±0.1 log CFU mL^-1 for separator. Proteolytic bacteria were isolated from dairy sludge using Skim Milk Agar media. A clear zone of Skim Milk hydrolysis indicated protease-producing organisms. Different cultural parameters (temperature, pH, thermal shock, and kind of sludge) were optimized for maximal enzyme production. Maximum proteolytic activity was observed at 37^◦C (P< 0.05). Isolated alkaline protease producing Bacilli were identified by Polymerase Chain Reaction (PCR). The species were identified as Bacillus cereus strain zk2, Bacillus sp. cp-h71, Bacillus thuringiensis strain ILBB224, and Bacillus sp. Bac6D₂.