Step to High-Performance PLA: Economical Production of d-Lactate Enabled by a Newly Isolated Sporolactobacillus terrae Strain.

Optically pure d-lactate production has received much attention for its critical role in high-performance polylactic acid production. However, the current technology can hardly meet the comprehensive demand of industrialization on final titer, productivity, optical purity, and raw material costs. Here, an efficient d-lactate producer strain, Sporolactobacillus terrae HKM-1, was isolated for d-lactate production. Strain HKM-1 shows extremely high d-lactate fermentative capability by using peanut meal, soybean meal or corn steep liquor powder as a sole nitrogen source; the final titers (205.7 g/L, 218.9 g/L and 193.9 g/L, respectively) and productivities (5.56 g/(L·h), 5.34 g/(L·h) and 3.73 g/(L·h), respectively) of d-lactate reached the highest level ever reported. Comparative genomic analysis between S. terrae HKM-1 and previously reported d-lactate high producing S. inulinus CASD was conducted. The results show that many unrelated genetic features may contribute to the superior performance in d-lactate production of S. terrae HKM-1. This d-lactate producer HKM-1 along with its fermentation process is promising for sustainable d-lactate production by using agro-industrial wastes. This article is protected by copyright. All rights reserved.