Steps Toward High‐Performance PLA: Economical Production of d‐Lactate Enabled by a Newly Isolated Sporolactobacillus terrae Strain

Abstract

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 (S. terrae) HKM-1, is isolated for D-lactate production. The 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 −1 , 218.9 g L −1 , and 193.9 g L −1 , respectively) and productivities (5.56 g L −1 h −1 , 5.34 g L −1 h −1 , and 3.73 g L −1 h −1 , respectively) of D-lactate reached the highest level ever reported. A comparative genomic analysis between S. terrae HKM-1 and previously reported D-lactate high-producing Sporolactobacillus inulinus (S. inulinus) CASD is 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 agroindustrial wastes.

A novel biocatalyst, Enterobacter aerogenes LU2, for efficient production of succinic acid using whey permeate as a cost-effective carbon source

“…The N source has a significant impact on both cell growth and succinate production [43]. Among the commonly used organic and inorganic N sources, yeast extract (YE) has been identified as one of the most favourable choices [7].…”

“…In many studies, the initial concentration of carbon source could affect both cell growth and metabolite production [5,32,43]. Thus, to increase the final concentration of SA, various initial lactose contents (60-140 g/L) were investigated for 96-144 h at 34 °C and pH 7.0 in a 3-L bioreactor.…”

Direct carbon capture for production of high-performance biodegradable plastic by cyanobacterial cell factory

“…The copyright holder for this preprint this version posted October 5, 2021. ; https://doi.org/10.1101/2021.10.04.462501 doi: bioRxiv preprint Furthermore, PDLA is a vital feedstock to improve the thermal resistance, mechanical performance, and hydrolysis resistance of PLA-based materials 24 . Poly (L-lactic acid) (PLLA) and PDLA can form stereocomplex (SC) crystals with a high melting point, that can be used to synthesize the high-performance of PLA 25 .…”

“…It is a worldwide consensus that effective strategies for carbon capture need to be developed 22,23 to meet the climate-change severe mitigation challenge and adhere to the Paris Agreement of 2015. Furthermore, PDLA is a vital feedstock to improve the thermal resistance, mechanical performance, and hydrolysis resistance of PLA-based materials 24 . Poly (L-lactic acid) (PLLA) and PDLA can form stereocomplex (SC) crystals with a high melting point, that can be used to synthesize the high-performance of PLA 25 .…”

Kinetic characteristics of long‐term repeated fed‐batch (LtRFb) l‐lactic acid fermentation by a Bacillus coagulans strain

“…Polylactic acid (PLA), a type of environmentally friendly plastic, has attracted unprecedented global attention owing to its biodegradable and biocompatible properties; it has the potential to replace traditional plastics produced by petroleum fuels [1][2][3]. Some properties of PLA, including its crystallinity, thermal stability and hydrolysis resistance, are affected by the relative fractions of l-and d-isomers in polymer chains [4][5][6]. Production of optically pure l-lactic acid, a key monomer of PLA, is particularly important.…”