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

Abstract

Potato peel waste (PPW), a zero‐value by‐product generated from potato processing, is a promising fermentation substrate due to its large quantity of starch, nonstarch polysaccharides, lignin, protein, and lipid. Rhizopus oryzae is a filamentous fungus that is mainly known as a lactic acid producer and can ferment various agro‐wastes. This study aimed to use R. oryzae for the fermentation of PPW. A series of batch fermentations were conducted to investigate the effects of different PPW loading rates (2%–8%) and particle sizes (0–4 mm). Under an initial PPW loading rate of 8% and particle size of 1–2 mm, the maximum ethanol (18.83 g/L) and lactic acid (3.14 g/L) concentrations, the highest ethanol (9.41 g/L·day) and lactic acid (1.89 g/L·day) average production rates were obtained. Under these conditions, the yield of ethanol and lactic acid was 0.235 g/gPPW and 0.039 g/gPPW, respectively. R. oryzae was shown to utilize PPW as a substrate to produce value‐added bioproducts such as ethanol (major product) and lactic acid.

Physicochemical Characterization of Potassium Hydroxide Pretreated Chestnut Shell and Its Bioconversion to Lactic Acid by Lacticaseibacillus rhamnosus

“…The current study experimentally demonstrated that CS is valuable as a feedstock for lactic acid production. The yields of lactic acid production from food waste reported were 39 g/kg potato peel waste and 101 g/kg spent coffee ground [4,11], and CS has great potential as a low-cost biomass for lactic acid production. The generation of CS was estimated to be 560 thousand tons per year [13], which is expected to be converted into 105 thousand tons of lactic acid by the proposed process.…”

“…Due to these advantages, in recent years, research has been expanding to utilize food wastes as feedstock for sustainable bioprocesses [8]. Food wastes such as pasta waste [9], orange peel waste [10], potato peels [11], and spent coffee grounds [4] have been previously studied as raw materials for lactic acid production. Yields for lactic acid production from biomass were reported as 39 g/kg potato peel waste and 101 g/kg spent coffee ground [4,11].…”

“…Food wastes such as pasta waste [9], orange peel waste [10], potato peels [11], and spent coffee grounds [4] have been previously studied as raw materials for lactic acid production. Yields for lactic acid production from biomass were reported as 39 g/kg potato peel waste and 101 g/kg spent coffee ground [4,11]. In order to utilize food waste as a feedstock for the lactic acid production process, a variety of potential feedstocks should be explored to achieve higher yields.…”

Harnessing Agri-Food Waste as a Source of Biopolymers for Agriculture

“…Despite the advantage of not requiring additional pre-treatments, CBP with R. oryzae [118] (Table 7, Entry 4) afforded a much lower LA final titer and yield on biomass, but it is worthy to note that this bioprocess mainly aimed to produce bioethanol, which was obtained with a final titer of 18.83 g/L.…”