High-titer and productivity of l-(+)-lactic acid using exponential fed-batch fermentation with Bacillus coagulans arr4, a new thermotolerant bacterial strain

Abstract

arr4 is a thermotolerant microorganism with great biotechnological potential for l-(+)-lactic acid production from granulated sugar and yeast extract. The highest l-(+)-lactic acid production was obtained with Ca(OH). The maximum production of l-(+)-lactic acid (206.81 g/L) was observed in exponential feeding using granulated sugar solution (900 g/L) and yeast extract (1%) at 50 °C, pH 6.5, and initial granulated sugar concentration of 100 g/L at 39 h. 5.3 g/L h productivity and 97% yield were observed, and no sugar remained. Comparing the simple batch with exponential fed-batch fermentation, the l(+) lactic acid production was improved in 133.22% and dry cell weight was improved in 83.29%, using granulated sugar and yeast extract. This study presents the highest productivity of lactic acid ever observed in the literature, on the fermentation of thermotolerant sp. as well as an innovative and high-efficiency purification technology, using low-cost substances as Celite and charcoal. The recovery of lactic acid was 86%, with 100% protein removal, and the fermentation medium (brown color) became a colorless solution.

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

“…In previous reports, temperatures suitable for the growth and fermentation of B. coagulans were generally in the range of 50 • C-52 • C [13,21,23,24]. Consistent with these reports, 52 • C was identified as the optimal fermentation temperature in this study in view of the excellent performance of the strain in l-lactic acid production.…”

“…The strain could produce an average of 192.7 g/L l-lactic acid in an average of 36.9 h in 20 batches, reflecting its excellent and stable l-lactic acid production performance. In previous reports, the highest titer of l-lactic acid produced by B. coagulans was 206.8 g/L, and its productivity was 5.29 g/L/h with 30 g/L yeast extract added to the fermenter [23]. Using strain H-2, the maximum titer of l-lactic acid reached 203.3 g/L, consistent with highest level reported.…”

Production of L (+) Lactic Acid by Lactobacillus casei Ke11: Fed Batch Fermentation Strategies

“…gardening residues [17], crystal sugar [18,19], municipal biopulp [20], Kodo millet bran hydrolysate [21,22], bakery waste and lucerne green juice [23], sugarcane bagasse [24][25][26] and sugar beet pulp [27].…”

“…Sugar in its pure form (sucrose, lactose and glucose) is the preferred carbon source. Despite being an expensive raw material, these sugars ensure a high yield and reduce the cost of purification [18,19,33]. Nitrogen sources also constitute a factor correlated with the production of lactic acid, as LAB require complex media [34].…”

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

“…(equal to the optical purity of 99.5%) . Bacillus coagulans arr4 produced 206.8 g L −1 l ‐lactate with a productivity of 5.30 g L −1 h −1 , which represents a high level of l ‐lactate production, and industrial d ‐lactate production should also reach this productive level accordingly. Although there are quite a few studies on d ‐lactate production, the current d ‐lactate fermentation process still cannot simultaneously meet the demand of industrialization on final titer, productivity, optical purity, and raw material costs.…”