Lactic acid production from submerged fermentation of broken rice using undefined mixed culture

Abstract

The present work aimed to characterize and optimize the submerged fermentation of broken rice for lactic acid (LA) production using undefined mixed culture from dewatered activated sludge. A microorganism with amylolytic activity, which also produces LA, Lactobacillus amylovorus, was used as a control to assess the extent of mixed culture on LA yield. Three level full factorial designs were performed to optimize and define the influence of fermentation temperature (20-50 °C), gelatinization time (30-60 min) and broken rice concentration in culture medium (40-80 g L) on LA production in pure and undefined mixed culture. LA production in mixed culture (9.76 g L) increased in sixfold respect to pure culture in optimal assessed experimental conditions. The optimal conditions for maximizing LA yield in mixed culture bioprocess were 31 °C temperature, 45 min gelatinization time and 79 g L broken rice concentration in culture medium. This study demonstrated the positive effect of undefined mixed culture from dewatered activated sludge to produce LA from culture medium formulated with broken rice. In addition, this work establishes the basis for an efficient and low-cost bioprocess to manufacture LA from this booming agro-industrial by-product.

Conversion of Starchy Waste Streams into Polyhydroxyalkanoates Using Cupriavidus necator DSM 545

“…Overall, the compositions of the tested starchy substrates are in agreement with those reported in the literature, and clearly confirmed that starch is the main polysaccharide in the selected substrates. Nunes et al and Favaro et al reported a starch content for broken rice of around 77%, with proteins between 7.5-8.5% [39,51]. Yokoi et al, analyzing the chemical composition of sweet potato waste, confirm a starch content of up to 50% [52].…”

Xylanases and cellulases biosynthesis by selected fungi in a simple and economic bio system using sugarcane straw

“…Formulation of culture medium with mixtures of agro-industrial residues for fibrolytic enzymes production The SmF of selected microorganism was performed in Erlenmeyer flasks (250 ml, with 80 mL of medium described previously (section 2.2) during 288 h of incubation in a shaker at 28 ºC and 180 rpm. D-Optimal mixture design was performed in order to evaluate the effect of individual substrates and the interactions among them in ternary mixtures on xylanase and cellulase production (Fernández-Núñez et al, 2016;Nunes et al, 2017). The number of experimental combinations in each experimental design was enough to fit special cubic models for response variables.…”

Current advances in organic acid production from organic wastes by using microbial co‐cultivation systems

“…For example, broken rice, one of the by‐products in rice milling, was converted directly to lactic acid by an undefined mixed culture without saccharification. Lactic acid production reached 9.76 g.L ‐1 , which was six times higher than that using pure culture . Potato peel waste (PPW), a byproduct generated in food‐processing plants, was also used for lactic acid production by using an undefined mixed culture .…”

“…Lactic acid production reached 9.76 g.L -1 , which was six times higher than that using pure culture. 18 Potato peel waste (PPW), a byproduct generated in food-processing plants, was also used for lactic acid production by using an undefined mixed culture. 19 Approximately 14.7 g.L -1 of lactic acid was produced in an airlocked glass bioreactor with a yield of 0.22 g.g -1 , when initial solid loading was 60 g.L -1 .…”