Lactic acid production: Utilization of yam peel hydrolysate as a substrate using Rhizopus orysae in kinetic studies

Abstract

The prospect of utilizing yam peel hydrolysate (YPH) as a carbon source for lactic acid (LA) production using Rhizopus orysae was investigated in batch surface and submerged fermentation processes. The kinetics of biomass growth, substrate utilization and LA production were studied using models of modified Luedeking–Piret, logistic and simple Luedeking–Piret equations, respectively, for the surface and submerged processes. The YPH containing 80 g L−1 of reducing sugars (glucose, xylose, ribose and others) was obtained by acid hydrolysis (H2SO4) of 100 g L−1 of yam peel and used for fermentation. The LA yield from the YPH was 80.03% and 75.63% for the surface and submerged fermentation, respectively. These values were higher than those of synthetic glucose syrup (SGS), which were 77.36% and 38.96% for surface and submerged fermentation, respectively. The models were satisfactory for the fermentation processes with high accuracy of R2 ((0.89 to 0.96), (0.95 to 0.99) and (0.86 to 0.99)) for biomass growth, substrate (SGS/YPH) utilization and LA production, respectively. The models also elucidated that the fermentation process was growth associated (α) instead of non‐growth associated (β) because the value of α/β was greater than 1. This justified the other kinetic parameters obtained for the growth phase. Therefore, Rhizopus oryzae effectively converted YPH to LA with a high yield and purity. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd

Peptide supplementation relieves stress and enhances glycolytic flux in filamentous fungi during organic acid bioproduction

“…Many studies have confirmed that R. oryzae could utilize multiple carbon sources as fermentation substrates for producing organic acids (Ajala et al, 2021; Das & Brar, 2014; Das et al, 2015; Q. Xu et al, 2010). Although we analyzed glucose, the observed increase in fumaric acid productivity from glucose may be observed with other carbon sources as well.…”

“…Many studies have confirmed that R. oryzae could utilize multiple carbon sources as fermentation substrates for producing organic acids (Ajala et al, 2021;Das & Brar, 2014;Das et al, 2015;Q. Xu et al, 2010).…”

Potato peel waste fermentation by Rhizopus oryzae to produce lactic acid and ethanol

“…Studies that used R. oryzae deal with the utilization of agro‐food waste materials (i.e., peels, brans, husks) as substrates for lactic acid and ethanol production. Some studies compared different substrates (Kumar & Shivakumar, 2014; Mudaliyar & Kulkarni, 2012; Ranjit & Srividya, 2016), whereas others focused on the utilization of a single substrate (Ajala et al, 2021; Göçeri et al, 2021; Ma et al, 2020; Park et al, 2004; Thongchul et al, 2010; Zain et al, 2021). Lactic acid was produced in all cases; however, ethanol production was not always reported.…”

“…Some studies used filtered hydrolysates obtained from wastes instead of using solid waste particles directly (Ajala et al, 2021; Park et al, 2004; Thongchul et al, 2010), which obviously enhances production due to improved mass transfer and reduced viscosity.…”