title: Isolation, characterization and evolution of a new thermophilic Bacillus licheniformis for lactic acid production in mineral salts medium.
abstract: The high fermentation cost of lactic acid is a barrier for polylactic acid (PLA) to compete with the petrochemical derived plastics. In order to lower the cost of lactic acid, the industry needs a microorganism that can ferment various sugars at high temperature (50°C) and at the same time using low cost mineral salts (MS) medium. One such bacterium, BL1, was isolated at 50°C and identified as Bacillus licheniformis. BL1 can ferment glucose to optically pure l-lactate with a maximum specific productivity of 7.8 g/hl in LB medium and 0.7 g/hl in MS medium at 50°C. BL1 can also consume 10% and 15% glucose in 20 and 48 h, respectively. After serial transfer of BL1 and BL2 in different concentrations of xylose and MS medium respectively, the final mutant BL3 could efficiently ferment glucose and xylose with specific productivity of 1.9 g/hl and 1.2g/hl in strict MS medium.
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China. wqz@ufl.edu
authors.forename: Qingzhao
authors.initials: Q
authors.lastname: Wang
authors.forename: Xueming
authors.initials: X
authors.lastname: Zhao
authors.forename: Jauhleene
authors.initials: J
authors.lastname: Chamu
authors.forename: K T
authors.initials: KT
authors.lastname: Shanmugam
mesh_terms: D001407:Bacillus / Q000302:isolation & purification* / Q000378:metabolism; D003470:Culture Media; D005285:Fermentation; D006358:Hot Temperature; D019344:Lactic Acid / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012492:Salts
chemical_list: D003470:Culture Media; D012492:Salts; D019344:Lactic Acid