جستجوی مقالات مرتبط با کلیدواژه « لاکتوباسیلوس برویس » در نشریات گروه « زیست شناسی »

This study evaluated the effect of dietary administration Lactobacillus brevis MF01 on survival rate of total bacteria, lactic acid bacteria intestinal tract fish and changes in gut bacterial communities Sander lucioperca. Lactobacillus brevis was isolated and identified from intestine of Sander luciopercaby biochemical and molecular tests.Fish were fed with dietary administration containing A1 (L.brevis MF01 10 10 CFU / g), A2 (L. brevis MF01 10 8CFU / g) and the control group (without Lactobacillus) for 45 days. At the end of the feeding period, fish were challenged with 4.5× 10 8CFU /ml Aeromonas hydrophila. The intestinal micro biota includes lactic acid bacteria and total bacteria at different times (15,30, 45 days) and 15 days after stopping feedings with probiotics were performed by using MRS agar, Plate count agar media. The lactic acid bacteria levels were significantly increased compared to the control group following probiotics administration in diet (P,< 0.05). The highest number of intestinal micro biota was observed in Lactobacillus brevis 1010Cfu /g treatment (A1)(P < 0.05). Any lactic acid bacteria of the intestine, was not detected in the control group after 15 days. After the end of feeding, the number of total bacteria and Lactic acid bacteria in all groups was decreased. The highest and lowest survival rate, respectively were treatments A1 (86%) and the control group (60%). Discussion and conclusion: The results showed that addition of Lactobacillusbrevis as an additive in feeding of sander lucioperca, significantly increased the lactic acid bacteria, the intestinal bacteria and the survival rate was compared to the control group (injected).

Vinegar is a popular condiment in the world that different materials and methods have been used to produce it. In Iran natural vinegar is also prepared mostly in a traditional way by using different fruits such as grapes and apples. Natural vinegar has beneficent properties and because of this, it is recommended to be used by traditional and Islamic medicine. Vinegar contains acetic acid bacteria, lactic acid bacteria and yeast. Acetic acid bacteria and yeasts are involved in the production of vinegar and lactic acid bacteria improve the flavor of vinegar. The aim of this study was isolation and identification of lactic acid bacteria especially Lactobacillus brevis from traditional vinegar.
After collecting a few traditional vinegars, the vinegar samples cultured for isolation of lactic acid bacteria on MRS broth and agar media contained nystatin as an anti-yeast antibiotic. Then some microbiological tests including catalase, gram staining and fermentation of carbohydrates were performed. Then, they were cultured at different temperatures, pH and different concentrations of salts. Finally, three isolates bacteria with biochemical properties of Lactobacillus brevis were evaluated by16 srDNA gene amplification.
Twelve lactobacilli were isolated from three vinegar samples. All isolated bacteria were catalase-negative and gram-positive. They could be able to grow at pH around 4.5 and 5.6, and at 2, 4 and 5.6% of salt concentrations. Most of the bacteria grew at 15oC, whereas one isolated grew at 45oC. Sequencing and Blast results showed that the three strains are Lactobacillus brevis.
Discussion and Lactobacillus brevis and Lactobacillus plantrum were found in traditional vinegars. Although isolation of Lactobacillus plantrum from vinegar was reported previously, as far as we could determine, it is for the first time that we could isolate Lactobacillus brevis from vinegar.