ISOLATION AND IDENTIFICATION OF ALOCALSTRAIN OF PROBIOTIC BACTERIAL ACTOBACILLUS PLANTARUM AND STUDIED THE TOLERANCE ABILITY FOR DIFFERENT LEVELS OF pH

Abstract

Lactobacillus plantarum IRQ12 was isolated from local pickle producing from Cucumis sativus submerged in 5% salt solution for one week far from sun light, selective media was used for isolation and activation process which was MRS broth and MRS agar, biochemical tests like catalase, nitrate reducing, productive gas, citrate consumption, produced ammonia from arginine, produced indole from tryptophan, fluid gelatin, ability of growth in 15, 45 °C, carbohydrates fermentation test, were carried out. DNA of bacteria was extracted by DNA extraction kit, identification by 16S rDNA gene. the local strain tolerance ability was investigated for different levels of pH 4, 3, 2 and 1.5 for 0, 1, 2 and 3 hours, log cfu/ml at pH 4 after 3 hours of treatment was 7.83 and at pH 3 the log cfu/ml decrease to 6.8 after 3 hours of treatment. The log cfu/ml was decreased to 5.76 and 5.05 at pH 2 and 1.5 respectively after 3 hours of treatment.

Keywords

• probiotic bacteria
• plantarum
• dna extraction