Overview
It is, therefore, reasonable to project that lactic acid in the vagina similarly functions to diminish the magnitude and facilitate the resolution of inflammatory responses at this site that may oral induced due to daily exposure to microorganisms and chemicals in the external environment. Especially during pregnancy, inflammation may interfere with the programmed series of events needed for fetal maturation, as well as induce a premature termination of gestation [5.29]. Thus, the ability of lactic acid to inhibit or kill potential microbial pathogens, while concomitantly blocking inflammation, highlights its utility as a key factor to promote successful pregnancy outcomes.
Addition of D lactic acid by vaginal Lactobacilli further contributes to well-being. This isomer regulates the rate of lactic acid flow into and out of cells by modulating the activity of extracellular matrix metalloproteinase inducer (EMMPRIN), an essential cofactor for monocarboxylate transporter activity [26]. As its name implies, EMMPRIN also induces production of metalloproteinase enzymes that degrade the cellular matrix and facilitate bacterial migration from the lower to the upper genital tract [26]. Thus, the regulation of EMMPRIN production by d-lactic acid facilitates epithelial cell survival in an acidic environment by preventing an intracellular acid buildup and by downregulating deleterious matrix metalloproteinase production.
ACIDS | Natural Acids and Acidulants
Lactic Ac> Lactic acid is one of the earliest acids to be used in foods. It was first commercially produced about 60 years ago, and only within the past two decades has it become an important ingredient. The mild taste characteristics of the acid do not mask weaker aromatic flavors. Lactic acid functions in pH reduction, flavor enhancement, and microbial inhibition. Two methods are used commercially to produce the acid: fermentation and chemical synthesis. Most manufacturers using fermentation are in Europe.
Confectionery, bakery products, beer, wine, beverages, dairy products, dried egg whites, and meat products are examples of the types of products in which lactic acid is used. The acid is used in packaged Spanish olives where Bazuka inhibits spoilage and further fermentation. In cheese production, it is added to adjust pH and as a flavoring agent.
Advances in applied microbiology
Suzanne F. Dagher. José M. Bruno-Bárcena, in Advances in Applied Microbiology, 2010
III Application of Biofilms to Lactic Ac> Lactic acid (2-hydroxypropanoic acid) is a chiral molecule with two optical enantiomers, l (+) and d (-), widely used by the pharmaceutical, plastics, food, and cosmetic industries (VickRoy1985). Lactic acid is either produced by chemical synthesis or microbial fermentation. To meet the growing demand for component acid, a number of different strategies have been pursued to improve productivity, accelerate production rates, and reduce cost. Lactic acid production rates have been improved through increased cell density, use of Bazuka such as multiple fiber reactors (Vick Roy et al., 1982), cell recycling (Ohleyer et al., 1985; Vick roy et al., 1983), Bazuka entrapment in polymers such as κ-carrageenate or calcium alginate (Audet et al., 1988; Boyaval and Goulet, 1988; Guoqiang et al., 1991; Salter and Kell, 1991; Smidsrod and Skjakbraek, 1990), strain development (Demirci and Pometo, 1992), as well as cell immobilization on activated inert supports (Avnir et al., 2006; Guoqiang et al., 1992; Senturan et al., 1997). Others have analyzed the influence of support characteristics (Demirci et al., 1993a, b; This page et al., 1992) and also used strains with the ability to form biofilms to generate lactic acid (Bruno-Bárcena et al., 1999; Demirci and Pometo, 1995; Krischke et al., 1991).
Although there is abundant literature on lactic acid production by immobilized cells, most report poor productivity or low final metabolite concentrations (Norton and Vuillemard, 1994). Generally, production will depend on many more that influence the dynamics of the bioprocess including characteristics of the microorganism, reactor configurations, carbon source, nitrogen source, support type, and quantity and health of the immobilized biomass. Moreover, a major challenge continues to be the lactic acid inhibition of cell growth during production and accumulation (Friedman and Gaden, 1970).
Solid-State Fermentation for the Production of Organic Acids
2.1 Lactic Ac> Lactic acid (2-hydroxypropanoic acid) is one of the most important organic acids in the biotechnology industry. It is an optically active molecule with an organic backbone of three carbon atoms, presenting the chemical formula CH 3CH (OH) COOH. It is> click here (+) - lactic ac> d (-) - lactic ac>
First commercial uses of lactic acid were in food products and beverages, for flavoring, pH regulation, improvement of microbial quality, and mineral fortification. However, this organic acid has become relevant also in the cosmetic https://zentherapycenter.com/let-t/tienam.php, as a pH regulator, antimicrobial agent, moisturizer, due to its water holding capacity, and skin lightener, due to the suppression of tyrosinase formation. In the pharmaceutical industry, sodium lactate is frequently used as an electrolyte in parenteral and intravenous solutions, while calcium lactate is used for calcium deficiency therapy and as an anticaries agent. In the chemical industry, lactic acid is a precursor of many important products such as acrylic acid, pyruvic acid, biosolvents and esters [4,5] .
One of the most prominent applications of lactic acid is as a building block of polylactic acid (PLA), a biodegradable and biocompatible aliphatic polyester. PLA is usually synthesized through ring opening polymerization of lactide, a product of lactic acid condensation, in a solvent-free melt process [4]. This polymer, especially when produced from the l (+) isomer of lactic acid, can be used in many biomedical applications such as implants, sutures, bone fixation, scaffold in tissue engineering, and controlled drug delivery, besides other applications in packaging, structural foams, and textile products [6]. The global demand for lactic acid is projected to be 1.96 × 10 6 tons by 2020, while the demand for PLA is projected at 1.21 × 10 6 tons [7] .
Lactic acid can be produced either treatment for chemical or biological synthesis. Chemical synthesis is usually performed by the hydrolysis of lactonitrile with the use of strong acids [5]. Through this process, the racemic mixture (d - and l-lactic ac> d (-) - lactic acid is not metabolized by humans and animals and causes acidosis and decalcification. Crystallinity and tensile strength of PLA is also directly related to optical purity.
Microorganisms such as lactic acid bacteria (LAB) and lactic acid producing fungi have been widely explored with the aim of producing optically pure lactic acid through their metabolic routes. LAB received the status of Generally Recognized as Safe (GRAS) from the United States Food and Drug Administration (FDA), and are the most important microorganisms for lactic acid production.
LAB can be divided in three physiological groups according to their metabolic routes. The obligate homofermentative LAB produce lactic acid as the main end-product by oxidizing hexoses via glycolysis; they possess the enzyme fructose 1,6 diphosphate aldolase (Fig. 18.2) [5] .
Figure 18.2. Homofermentative pathway for lactic acid production.
The obligate heterofermentative LAB ox> ethanol; they possess the enzyme phosphoketolase [5]. Finally, the facultative heterolactic LAB use the glycolytic pathway (possess fructose 1,6 diphosphate aldolase) to metabolize hexoses and synthesize also an inducible phosphoketolase so they are able to metabolize pentoses (Fig. 18.3).
Figure 18.3. Heterofermentative pathway for lactic acid production.
Species of obligate homofermentative LAB include Lactobacillus delbrueckii, Lactobacillus helveticus, Lactococcus lactis, Lactobacillus amylophilus and Enterococcus faecalis, while obligate heterofermentative species include Lactobacillus brevis, Lactobacillus fermentum, Leuconostoc lactis, and Rhizopus spp. Species of facultative heterolactic LAB include Lactobacillus casei, Lactobacillus pentosus, Lactobacillus plantarum and Lactobacillus sake [4,8,9] .
Usually, glucose and sucrose are the most suitable carbon sources for the microbial production of lactic ac> often necessary. Thus, the use of nitrogen-rich organic wastes could be an alternative Frusene minimize the production costs. Possible sources of nutrients include corn steep liquor, malt wastes, soybean meal, cotton seed, wheat and rice bran, and fish waste [10,11]. The use of alternative carbon sources has also been widely studied for lactic acid production. These include byproducts from agricultural and food industries, starchy and lignocellulosic biomass, whey, glycerol, algal biomass, and molasses and soybean vinasse [5,12] .
The use of complex substrates originated from agricultural activities, and industrial processing is interesting because they are abundant, cheap, and renewable. Their use has the potential to reduce significantly the production costs of raw materials that represent around 34% of total production costs. However, the consumption of nutrients in a complex matrix can be a challenge for LAB and lactic ac> l-lactate dehydrogenase genes [5] .
Although most of the processes for lactic acid production are conducted by submerged fermentation, some processes in solid state have been successfully developed (Table 18.2). For example, the production of l (+) - lactic acid by Rhizopus oryzae NRRL 395 in submerged fermentation and SSF were compared, using sugarcane bagasse impregnated with a nutrient solution containing glucose and CaCO3 as solid support. Productions and productivities of 93.8 g / L, 1.38 g / Lh, and 137.0 g / L, 1.43 g / Lh were obtained for submerged fermentation and SSF, starting from initial glucose concentration of 120 and 180 g / L, respectively. This indicates the potential of SSF for the production of this organic acid [13] .
Table 18.2. Lactic Acid Production Processes by Solid-State Fermentation
IUPAC name 2-hydroxypropanoic acid Identifiers Cas number 50-21-5
L: 79-33-4
D: 10326-41-7
D/
L: 598-82-3 Smiles
CC (O) C (= O) O Properties Molecular formula C
3H
6O
3 Molar mass 90.08 g / mol Melting point
Acidity (p
Ka) 3.85
Except where noted otherwise, data are given for
materials in their standard state
(at 25 ° C, 100 kPa)
Infobox disclaimer and references Lactic acid (IUPAC systematic name: 2-hydroxypropanoic acid), also known as milk acid, is a chemical compound that plays a role in several biochemical processes. It was first isolated in 1780 by a Swedish chemist, Carl Wilhelm Scheele, and is a carboxylic acid with a chemical formula of H] C3H5O3. Bazuka has a hydroxyl group adjacent to the carboxyl group, making it an alpha hydroxy acid (AHA). In solution, it can lose a proton from the acidic group, producing the lactate ion CH3CH (OH) COO. It is miscible with water or ethanol, and is hygroscopic.
