Isolation and screening of microorganisms for high yield of succinic acid production

Abstract

This study involves the isolation of succinic acid (SA)‐producing microorganisms from different samples, including the rumen, sludge, soil, and wastewater. For primary screening, 29 isolates exhibited a zone of clearance around the colony, indicating acid production. For secondary screening using thin‐layer chromatography, only two isolates symbolized SA production according to their Rf values. These two isolates were further identified as Bacillus velezensis and Enterococcus gallinarum by phylogenetic analysis using the neighbor‐joining method. The high SA concentrations of 50.2 and 66.9 g/L were produced by B. velezensis and E. gallinarum with an SA yield of 0.836 and 1.12 g/g glucose, respectively. The high SA concentration from these newly isolated strains was achieved with a low formation of unwanted acids compared with those from Actinobacillus succinogenes ATCC 55618. Moreover, E. gallinarum was cultured in palm oil mill wastewater (POMW) and molasses, which were cheap substrates. The high SA production of 73.9 g/L with low other acids (the ratio of SA to total acids = 0.917) was achieved using POMW and molasses (80:20) as substrates.

Recent advances in bio-based production of top platform chemical, succinic acid: an alternative to conventional chemistry

“…Likewise, Nagime et al [98], adopted a two-stage strategy to screen SA producing bacterial strains obtained from various sources. In the first stage, the isolated organisms were streaked on agar and incubated under anaerobic conditions.…”

“…However, when glucose was replaced by low carbon feedstock such as mixture of palm oil mill wastewater and molasses (80:20) and yeast extract was substituted by peptone, the maximum SA titer attained were 73.9 g/L with E. gallinarum. Earlier Kunez et al [ 99 ] adjudged the performance of their newly isolated AKR177 strain on pure and crude glycerol (PG and CG). This isolate which belonged to genus Actinobacteria under fed-batch cultivation, resulted in maximum accumulation of 117 and 86.9 g/L SA using PG and CG, respectively, when in the second phase MgCO 3 was replaced by Na 2 CO 3 as pH regulator and pH was maintained at 7.3.…”