Production of Poly-beta-hydroxybutyrate (PHB) in Different Media by Streptococcus thermophilus Ba21S Strain

Abstract

actobacillus, Lactococcus and Streptococcus. PHB production by these strains was determined by the spectrophotometric method. The yield of PHB produced by Lactobacillus species was 0.93-9.00% w/v. The values for Lactococcus and Streptococcus species were 7.09-16.00 and 5.47-21.15% w/v, respectively. Generally, Lactococcus species produced more PHB than the other bacteria species. The highest PHB production and productivity percentage was found in S. thermophilus Ba21S (21.15% w/v). The amount of PHB produced by this strain in different carbon and nitrogen sources was analyzed. In this strain, sucrose was the most effi cient carbon sources for the production of PHB compared with other carbon (glucose, lactose, sucrose, pyruvate) and nitrogen (protease peptone, L-glycine, L-cysteine, and (NH4)2SO4) sources.