Isolation and molecular identification of lactic acid bacteria from King grass and their application to improve the fermentation quality of sweet Sorghum.

Abstract

The aim of the present study was isolation and molecular identification of lactic acid bacteria from King grass and their application to improve the fermentation quality of sweet Sorghum. Seventy-six strains of LAB were isolated; five strains were selected for Physiological and morphological tests and 16SrRNA sequencing. All five strains grew at different pH 3.5-8.0, different temperature 35, 40, 45, 50°C and different NaCl concentrations 3, 6.5, 9.5%. Strains HDASK were identified Lactobacillus plantarum and SK3907, SK2A32, SK3A42 and ASKDD Pediococcus acidilactici. Three isolated strains and one commercial strain were added to sweet sorghum. Silage was prepared of four treatments and one control with three replicates as control (SKC, adding 2ml/kg sterilizing water), L. plantarum commercial bacteria (SKP), L. plantarum (HDASK) isolated from King grass(SKA), P. acidilactici(SK3907) isolated from King grass(SKB) and P. acidilactici(ASKDD) isolated from King grass(SKD). All silage were prepared using polyethylene terephthalate bottles, and incubated at room temperature for different ensiling days. The level of pH, acetic acid, NH3-N, water soluble carbohydrate and butyric acid was significantly (P < 0.05) decreased. Lactic acid, ethanol and propionic acid (PA) was significantly (P < 0.05) increased in treatments compared to control. The dry matter, propionic acid neutral detergent fiber, acid detergent fiber did not significantly (P < 0.05) differ among the treatments but the values were increased and decreased. The number of yeast, mold and LAB were significantly (P < 0.05). It is suggested that the supplementation of LAB could enhanced the fermentation quality of sweet Sorghum silage.