The Effect of Culture Medium on Metabolic and Antibacterial Activities of Probiotic Bacteria

Background and Objectives: Probiotic bacteria is added directly to food components and it has beneficial effect on function and the health of organisms. The bifidogenic factors enter the colon where they contribute to an increase lactic acid bacteria population including Lactobacilli and Bifidobacteria and they inhibit enteric pathogenic bacterial growth. The aim of this study is to investigate the effect of culture medium on metabolic and antibacterial of probiotic bacteria.Methods: In this study, the probiotics bacterial and intestine pathogenic are to be used. Lactobacilli and Bifidobacterium were identified by plating samples on MRS medium, Gram Staining and standard biochemical methods. The effect of antagonistic probiotics was investigated in the presence of growth factor in the method well diffusion Ager on the Shigella flexneri (PTCC 1234), Escherichia coli (PTCC 1552), Salmonella typhi ( PTCC 1609) and the culture medium pH was measured.Results: The probiotics bacterial growth in MRS and lactose1%, sorbitol, raffinose, riboflavin were shown the effect antibacterial. The results of the study show the most antagonistic activity in commercial strain Lactobacillus acidophilus on Shigella flexneri and lower activity was in Lactobacillus casei (PTCC 1608), and Salmonella typhimurium (PTCC 1609), and also in Bbifidobacterium bifidum, it showed the most decrease pH value.Conclusion: According to the result of the study, adding growth factors to MRS medium base and lactose 1%, probiotic growth was increased and which also increased antagonistic activity

Aflatoxin M1 Contamination in Ice-Cream

<p>Aflatoxin M1 (AFM1) is the hydroxylated metabolite of aflatoxin B1 (AFB1) that it can be found in milk and dairy products. In this study, ELISA (Enzyme Linked Immunosorbent Assay) technique was used for detection of AFM1 in ice-cream in Guilan province (Northern Iran). A total of 90 ice-cream samples was randomly obtained from different supermarkets. In 62 of the 90 ice-cream samples examined (68.88%), the presence of AFM1 was detected in concentrations between 8.4 -147.7 ng/l. The mean level of AFM1 in positive samples was 40.36 ng/l. AFM1 levels in 11 samples (12.22%) were higher than the maximum tolerance limit (50 ng/l) accepted by ISIRI, European Community and Codex Alimentarius.</p

Aflatoxin M1 Contamination in Milk and Milk Products in Iran: A Review

Mycotoxins are secondary metabolites of molds and have adverse effects on humans, animals, and crops. Those can cause illnesses and economic losses. Aflatoxin M1 (AFM1) is one of the mycotoxins produced from the hydroxylated metabolite of aflatoxin B1 (AFB1). It can be found in milk or milk products obtained from livestock that have ingested contaminated feed. In this paper, recent studies were reviewed in aflatoxin M1 contamination in milk and milk products in Iran