Prodigiosins, a family of natural red pigments characterized by a common pyrrolylpyrromethane skeleton, are produced by various bacteria that first characterized from Serratia marcescens. This pigment is a promising drug owing to its reported characteristics of having antifungal, immunosuppressive and anti-proliferative activity. From an industrial point of view to obtain optimal conditions to enhance the growth of Serratia marcescens and the pigment production is necessity. In present study, the production condition, physicochemical and functional characteristics, structure, genetic and gene expression, apoptosis and toxigenic effects of prodigiosin will be discussed in-order to contribute to the world of Serratia marcescens with respect to its prodigiosin production property

ABSTRACT:The potential of three Azotobacter chroococcum strains for whey degradation and alginate production were investigated. After dilution, samples were spread plated on isolation agar and Manitol agar and incubated at 30 °C for 24 h. Microorganisms were screened for their ability to whey degradation and alginate production based on colony morphology, negative and capsule staining, ability to decrease the apparent turbidity of the fermentation broths in batch and semi continuous culture by spectrophotometer assay at 400 nanometer and tensiometer assay. Of the three strains tested for whey degradation, only Azotobacter chroococcum 1723 produced significant apparent growth on whey broth and could decrease about 70 % of turbidity in fermentation broth during 6 days in batch culture. Colonies of this strain was characteristically yellow, large, moucoid and slimy on whey agar than Manitol agar after 24 h at 30 °C. Transmission electron microscopy assay and Carbazole reagent were used to recognize the alginate biopolymer. After optimizing environmental factors such as pH, salt concentration and temperature, this strain was able to produce exopolysaccharide greater than 5 mg/mL. Optimum results were obtained when using whey broth as a fermentation medium without extra salt, temperature at 35 °C and pH 7. Increasing inorganic and organic nitrogen sources (yeast extract and NH 4 NO 3 ) reduced whey degradation at least 30%. Transmission electron microscopy assay showed a net-structured polysaccharide capsule around the cells. Semi-continuous culture results demonstrated that, alginate production as well as whey degradation was decreased (1 mg/mL and 30 %).

This study assessed the binding of Aflatoxin B1 (AFBI) from contaminated solution by Lactobacillus plantarum PTCC 1058. This strain and AFB1 was incubated (1, 24, 48, 90 h at 37 degrees C) and the amount of unbound AFB1 was quantities by HPLC. The concentration of AFB1 in solution was 0.5 ppm. The stabilities of the bacteria/AFB1 complexes were evaluated by determining the amount of AFB1 remaining bound following three washes. Effect of Incubation time on AFB1 Binding on viable and dead cells were evaluated at 1, 24, 48, 72 and 90 h time points. In 1 h 45% and in 90 h 100% AFB1 was removed from solution by this strain. Autoclaved bacteria didn't remove AFB1 from solutions efficiently (31% in 1 h and 15% in 24 h). Bacteria in logarithmic growth phase retained 92% of the AFB1 initially bound after three washes. Bacterial binding of AFB1 by this strain was rapid and they were in logarithmic growth phase. These findings further support the ability of specific strains of lactic acid bacteria to bind selected dietary contaminants.

Use of probiotic foods like as probiotic chocolate could be decrease dental plaques production. Background: One of the most important factors in inducing the logarithmic growth of Streptococcus mutans, is a diet containing fermentable carbohydrates such as sucrose. Objectives: The aim of the current research was to compare the ability of ordinary and probiotic chocolate to induce or inhibit the growth of S. mutans. Materials and Methods: Lactobacillus rhamnosus, L. plantarum and L. acidophilus as probiotic strains, were cultivated on MRS agar for 24 hours at 35° C in 5% CO 2. S. mutans which is a dominant factor in causing dental plaque, was isolated from 20 samples of dental plaque and caries lesions in adults on Streptococcus selective agar medium, and diagnosed by routine biochemical tests. The antimicrobial effect of three probiotic strains on S. mutans was evaluated by the deferred cross-streak method and susceptibility through the disk diffusion test. The antimicrobial effect of the probiotic supernatant powder was determined by a dilution method. Probiotic strains were added to dark chocolate with a concentration of 10 8 CFU/mL and their antimicrobial effect on S. mutans was evaluated by the disk diffusion susceptibility method. Survival of the probiotic strains in chocolate and pH shifts were studied in different environmental storage conditions. Results: The results showed that S. mutans was the dominant strain in all of the 20 dental plaque samples. L. plantarum showed the most antimicrobial effect on S. mutans with the maximum diameter of growth inhibitory zone, 35 mm and 78 × 78 mm in the disk diffusion method and deferred cross-streak method, respectively. Probiotic supernatant powder inhibited S. mutans strains in concentrations of 500-700 and 100-300 mg/ml at t = 0 and t = 24, respectively. Comparing the results in terms of maintenance and storage of probiotic chocolate, it showed that the best condition to keep this chocolate is at 4˚ C (refrigerated) with a probiotic survival of 25 to 30 days. The pH level during this period decreased from a pH of 5 to 4. Probiotic chocolate containing L. rhamnosus was shown to have the greatest antimicrobial effect on S. mutans with a maximum diameter of growth inhibitory zone of 75 mm during 59 days storage at an ambient temperature and 4° C. Conclusions: These results suggest that probiotic chocolate is able to inhibit the growth of S. mutans rather than ordinary chocolate.

Background: Bedsore is one of the major problems in all the societies as patients are confined to bed. Due to antibiotic resistant strains being a significant obstacle for cure, many plants and herbs are being used by researchers as medicinal compounds..Objectives: The investigation of synergistic effect of cellulose biopolymer and Papaver macrostomum extract on bedsores bacterial community..Materials and Methods: Acetobacter xylinum PTTC 1734 was cultured in Schramm-Hestrin (SH) medium and incubated at 30°C for 24-48 hours. NaOH treatment and absolute ethanol were used to extract cellulose biopolymer and plant antimicrobial substance, respectively. The Biopolymer structure was scanned by a Scanning electron microscope (SEM). Antimicrobial activities, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of these extracts were all determined separately. The effective concentration of each extract's alone, combined, and synergistic effects were evaluated. Biopolymer absorption efficiency was assayed as the absorbent bed..Results: Pesudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus were the dominate bacteria isolated from bedsore samples. Antimicrobial effects of cellulose, P. macrostomum extract, and the combination of both were determined on the isolated bacteria as 1, 10, and 15 mm respectively. 100-1000μl/mL of flower ethanol extract concentrations of P. macrostomum indicated the maximum effect on mixed bedsore's bacteria rather than leaf and mixed extraction. Concentrations 500-1000μl/mL decreased the bacterial bedsore's growth and completely inhibited it. 3.5g/L of cellulose biopolymer was obtained from A. xylinum broth culture medium. Scanning electron microscopy analysis confirmed the branched structure of this polymer. Cellulose absorption efficiency was evaluated to be 14.5ml/g in this investigation. Because of high-absorbance of bio-cellulose, combined plant extraction with this biopolymer caused a decrease in the growth of bedsore microorganisms with the minimum extract concentration, 100μl..Conclusions: Combination of bio-cellulose and P. macrostomum flower ethanol extract can be used for patients who suffer from bedsore lesions in concentration 0.1% of MBCs. Furthermore, clinical studies are needed to confirm the efficiency of in vivo application