“Recovery of aconitic and lactic acids from simulated aqueous effluents of the sugar-cane industry through liquid-liquid extraction,” J. “Process development and optimisation of lactic acid purification using electrodialysis,” J. “Lactic acid recovery from cheese whey fermentation broth using combined ultrafiltration and nanofiltration membranes,” Appl. (2005) “Conversion of glycerin into lactic acid by alkaline hydrothermal reaction,” Chem. “Lactic acid recovery from fermentation broth using one-stage electrodialysis,” J.
LA producing microorganisms
Bioresources 2017, 12, 4364–4383. Karande, R. D.; Abitha, V. K.; Rane, A. V.; Mishra R. K. Preparation of polylactide from synthesized lactic acid and effect of reaction parameters on conversion. Store of mineral fertilizers and chemical raw materials. No additional information is available for this paper. To use dairy wastes as a substrate, mainly whey, it is necessary to use an enriched mediums, due to insufficient proteolytic enzyme activity.
Glutamicum is engineered and has highly potential bacterium that can produce LA with high yield and productivity without requiring complex nutritional compounds. Coagulans 36D1 produced L-LA at concentration and yield of (225 g/L and 0.993 g/g) and (92.0 and 0.96 g/g), respectively. The utilization of heterofermentative LAB as dairy starter cultures are not common due to CO2 release and simultaneous production of LA and other organic acids, considered as defects which induce several problems in the products, including bloated packaging and cracks in dairy products and hard cheeses, respectively. LAB can metabolize glucose into LA, acetic acid (AA), formate, ethanol, diacetyl, acetoin, and carbon dioxide (CO2 gas detection is a diagnostic test for heterofermentative from homofermentative fermentation) . Homofermentative LAB produces two LA molecules as a major end-product per mole of consumed glucose, with a theoretical yield of 1 g.g−1 and experimental yields among being this related to the type of the carbon source used . Ideally, microbial fermentation would take place in medium with a pH at or lower than the pKa of lactic acid (the pKa of lactic acid is 3.78), permitting direct purification of the acid form.
Raw material cost is one of the major factors in the economic production of lactic acid. However, waste products from food industries, agricultural industries, sugarcane mills, and biomasses can be used, which is advantageous from an environmental and economic standpoint. Several microorganisms and raw materials can be used in the production of lactic acid (Table 2). Lactic acid production by a chemical route is expensive and dependent on by-products from other industries, which are derived from fossil fuels (Datta and Henry 2006). They produced 40% (4,500 tons) of the lactic acid consumed in the USA (Trindade 2002).
Microalgae are another potential raw material for lactic acid fermentation. The advantages is that starchy materials can avoid glucose repression, which occurs when high concentration of glucose in the medium would inhibit growth of lactic acid bacteria (Nakano et al. 2012). Industrial production by chemical synthesis was also used by Sterling Chemicals, which ended production in early 1990.
The literature reports many lactic acid applications, such as cosmetics, pharmaceutical products, chemistry, food, and more recently in the medical area. Furthermore, to produce one ton of lactic acid, approximately one ton of low-cost calcium sulfate is needed (Pal et al. 2009), which poses serious problems in terms of waste treatment. Currently, NatureWorks LLC is leading the lactic acid polymers market in terms of production and technology (John et al.2009; Abdel-Rahman et al. 2013). The highest productivity possible for continuous fermentation is due to the high dilution ratio and the possibility of maintaining the process for a long period of time. Fermentation in batch mode has superior conversion and yield compared to continuous fermentation, but the volumetric productivity is lower.
- Oryzae requires only a simple medium and produces L(+)-lactic acid, but it also requires vigorous aeration because R.
- LAB can be classified into two groups according to fermentation end-product, homofermentative and heterofermentative.
- A fermentation product with high purity is obtained when a pure substrate is used, such as sucrose from sugarcane and sugar beet, which results in a reduction in the cost of purification.
Agro-industrial waste or sub-products with a lower value such as molasses, juices waste, starchy biomass, agricultural residues, forestry residues that are rich in mono and disaccharides, which in some cases need to be hydrolysed by pectinases to enhanced the LA production. The amount of copper (Cu-15; 15 μM/g, Cu-30; 30 μM/g and Cu-70; 70 μM/g) influence on the production of lactic acid (23.21 g/L), (17.44 g/L) and (16.53 g/L), respectively. Therefore, pretreatment has a great potential to affect the downstream costs due to enzymatic hydrolysis rates, enzyme loading, determining fermentation toxicity, mixing power, power generation, product purification, product concentrations, waste treatment demands, and other process variables.
Technological characterization of lactic acid bacteria isolated from raw milk
In a batch process, all of the substrate gets used, whereas in a continuous process, there is a residual substrate concentration that is always present. In terms of industrial processes, the use of yeast extract has a high cost, although it is best for the cultivation of lactic acid bacteria. Among LAB, most lactic acid productivity studies have been conducted at temperatures ranging from 30 to 43 °C (Abdel-Rahman et al. 2011). Lower product yields in fungal fermentation are also partially attributed to the formation of by-products, such as fumaric acid and ethanol (Wee et al. 2006).
4. Industrial waste
In order to increase the LA productivity, ethanol production was stopped by the elimination of two pyruvate decarboxylase genes (PDC) 1 and 2, being these the primary enzymes contributing to ethanol production. This study was for the first time performed by Porro et al., 1995, having achieved an LA production of 20 g/l and productivity up to 11 g/L/h using engineered S. In transgenic strains, the coding section of pyruvate decarboxylase 1 (PDC1) was completely eliminated, and one or several copies of the d-lactate dehydrogenase (d-LDH) gene resources were inserted into the genome from mammalian LAB such as Leuconostoc mesenteroides subsp.
As far as we are aware, there chicken road apk are no reports that include other fungi to produce LA. Abdel-Rahman et al. 13, 14 verified that high LA production was obtained by cotton-like mycelial flocs morphology, which was formed by the culture of R. Some researchers investigated fungi morphology that enhances the LA productivity.
“Biotechnological production of lactic acid and its recent applications,” Food Technol. (2016) “Improvement of L-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation,” Bioresour. “Improving the lactic acid production of Actinobacillus succinogenes by using a novel fermentation and separation integration system,” Process Biochem. “Recovery of carboxylic acids produced by fermentation,” Biotechnol. “Rhizopus arrhizus – A producer for simultaneous saccharification and fermentation of starch waste materials to L(+)-lactic acid,” Biotech. “Microorganisms for the production of lactic acid and organic lactates,” Microbiology Monographs 26.
1.4. Escherichia coli
- Molasses, juices waste, starchy biomass, agricultural residues, and forestry residues that is rich in mono and disaccharides, which in some cases need to be hydrolysed by pectinases to enhance the LA production.
- In this paper, different bacterial groups that capable of producing lactic acid at different rates and under different conditions were discussed.
- Recently, the manufacturing of cheese has been reported to produce large volumes of whey as a byproduct (Li et al. 2006).
- LAB possesses the aldolase enzyme and can convert glucose almost exclusively into LA.
J. Biotechnol. Klotz, S.; Kaufmann, N.; Kuenz, A.; Prüße, U. Biotechnological Production of Enantiomerically Pure D-Lactic Acid. Biotechnol.
However, LAB species including Lactobacillus, Lactococcus, Leuconostoc, Streptococcus, and Pediococcus are also used as starter cultures in industrial food fermentations. LA is produced by glycolysis pathway under anaerobic conditions, and this compound can be produced from hexoses and pentoses LAB metabolism pathways, as indicated in Figure 1. Lactic acid bacteria (LAB) are gram-positive microorganisms known as the main safe industrial-scale producers of lactic acid (LA). Molasses, juices waste, starchy biomass, agricultural residues, and forestry residues that is rich in mono and disaccharides, which in some cases need to be hydrolysed by pectinases to enhance the LA production.
Many LAB produce only one isomer of lactic acid, but sometimes, depending on operating conditions, small amounts of both isomers can be produced. Another approach for production of lactic acid is from glycerol, which is a by-product of biodiesel production. Several studies have recently reported lactic acid production using whey (Tejayadi et al. 1995, Kim et al. 2006; Li et al. 2006). Lignocellulose biomass is also a promising source for lactic acid production because its represents the most abundant global source of biomass (Hama et al. 2015; Hu et al. 2015; Eom et al. 2015).
Similar content being viewed by others
“L (+) lactic acid fermentation and its product polymerization,” J. “Efficient production od D-(-)-lactic acid from broken rice by Lactobacillus delbrueckii using Ca(OH)2 as a neutralizing agent,” Bioresour. “Lactic acid production from recycled paper sludge by simultaneous saccharification and fermentation,” Biochem. “Utilization of white rice bran for production of L-lactic acid,” Biomass Bioenerg.
In addition, it is advantageous as an effective method of environmental waste management (Tashiro et al. 2013; Abdel-Rahman and Sonomoto 2016; Tang et al. 2016). Recently, the manufacturing of cheese has been reported to produce large volumes of whey as a byproduct (Li et al. 2006). In this process, only hot water is used as the reaction medium (Eom et al. 2015), reducing operating and maintenance costs (Eom et al. 2015). Although the cost of lignocellulose is low, the pretreatment step makes the whole process cost-inefficient. A fermentation product with high purity is obtained when a pure substrate is used, such as sucrose from sugarcane and sugar beet, which results in a reduction in the cost of purification.
Bacillus spp., allows reducing the LA production cost due to fewer nutrition demands and a high temperature of fermentation. The fermentation capacity by several LAB has been studied in order to produce LA. The price varies with the application (e.g., food, pharmaceuticals, and PLA) and also depends on the price of commodity starch and sugar feedstocks used for fermentation. Different carbohydrate sources can be used, from plant waste as molasses, starchy, lignocellulosic materials as agricultural and forestry residues.
2.1. Starchy biomass and sugar plant wastes (malt, molasses and sugar beet juice)
Lactic acid is usually produced in batch mode, but continuous and fed-batch modes can also be used. Temperature is an important parameter for bacteria growth (Silveira 2009) and relates to the growth kinetics parameters of LAB, lactic acid production, and substrate consumption. Several studies show that a pH value of approximately 6.5 is the optimal pH for growth and lactic acid production (Silveira 2009). To control the pH, a base is added to the medium, such as calcium carbonate, calcium hydroxide, or sodium hydroxide, because in an acidic medium, lactic acid production is either zero or minimal. Several studies have reported on the use of Rhizopus for lactic acid production (Yin et al. 1998; Liu et al. 2006; Yu et al. 2007; Guo et al.2010; Wu et al. 2011; Saito et al. 2012).
Substrates for lactic acid production
Generally, three leading stages could be demonstrated for efficient fermentative LA production mainly (i) feedstock pretreatment, (ii) mixed and other substrates for LA production, (iii) ion requirement 10, 134, 147, 200. Torquens, by simultaneous saccharification and co-fermentation, achieved values of 37.1 g/l and 36.6 g/l LA and D-LA, respectively, from 80 g Hydrodictyon reticulatum (47.5%) 198, 199. The microalga Hydrodictyon reticulum has been utilized as a substrate for the production of L-LA by Lb. Algal biomass is another source for LA production 15, 108, 134. Coli strains via homofermentative route could convert glycerol to D-lactate 59, 187, 196. From yogurt whey LA was obtained with a productivity of 0.76 g/L/h and a yield of 0.9 g/g by Lb.