https://repositorio.unb.br/bitstream/10482/6389/1/ARTIGO_ApplicationMicrobialAmylase.pdf

Application of microbial α-amylase in industry - A review

Lactic acid was discovered in 1780 by C.W. Scheele in sour milk, and in 1881 Fermi obtained lactic acid by fermentation, resulting in its industrial production. The yearly world lactic acid production is expected to reach 259,000 metric tons by the year 2012. The interest in lactic acid is related to many aspects, among which is its relatively high added-value. In addition, such a chemical is GRAS (Generally Recognized As Safe), being recognized as harmless by the United States Food and Drug Administration, has a market with great growth potential, can be alternatively produced by fermentation or chemical synthesis and can employ a large variety of different waste materials as substrates. Lactic acid has many applications. Its existence in the form of two stereoisomers does in fact make the application of one of them or of the racemic mixture of great concern in different fields. In particular, the food and pharmaceutical industries have a preference for the isomer l (+), the only one that can be metabolized by the human body; however, the chemical industry requires one of the pure isomers or a mixture of both, according to the application. This review describes biotechnological processes to obtain lactic acid from polymeric substrates such as starchy and lignocellulosic materials. Open challenges are related to the technological optimization of the fermentation process and product purification and recovery. In addition, the opportunities and difficulties associated with using raw materials for lactic acid production are discussed.

https://maaz.ihmc.us/rid=1N4KLGGDB-C7FZZY-93H/Castillo%20Martinez%20et%20al.%20-%202013%20-%20Lactic%20acid%20properties,%20applications%20and%20productio.pdf

Lactic acid properties, applications and production: a review.

Amylolytic bacterial lactic acid fermentation - a review.

Direct lactic acid fermentation: focus on simultaneous saccharification and lactic acid production.

Lactic acid bacteria (LAB) are the dominant microorganisms in sourdoughs, and the rheology, flavour and nutritional properties of sourdough-based baked products greatly rely on the activity of LAB. The newer developments on the biochemistry and physiology of this group of bacteria are considered here, with particular emphasis on carbohydrate and nitrogen metabolism, responses to environmental stresses, production of anti-microbial compounds and nutritional implications.

/pdf/biochemistry-and-physiology-of-sourdough-lactic-acid-2f45qa527g.pdf

Biochemistry and physiology of sourdough lactic acid bacteria

Lactic acid fermentation of starch by Lactobacillus manihotivorans LMG 18010T, a new amylolytic L(+) lactic acid producer, was investigated and compared with starch fermentation by Lact. plantarum A6. At non-controlled pH, growth and lactic acid production from starch by Lact. manihotivorans LMG 18010T lasted 25 h. Specific growth and lactic acid production rates continuously decreased from the onset of the fermentation, unlike Lact. plantarum A6 which was able to grow and convert starch product hydrolysis into lactic acid more rapidly and efficiently at a constant rate up to pH 4.5. In spite of complete and rapid starch hydrolysis by Lact. manihotivorans LMG 18010T during the first 6 h, only 45% of starch hydrolysis products were converted to lactic acid. When pH was maintained at 6.0, lactic acid, amylase and final biomass production by Lact. manihotivorans LMG 18010T increased markedly and the fermentation time was reduced by half. Under the same conditions, an increase only in amylase production was observed with Lact. plantarum A6. When grown on glucose or starch at pH 6.0, Lact. manihotivorans LMG 18010T had an identical maximum specific growth rate (0.35 h(-1)), whereas the maximum rate of specific lactic acid production was three times higher with glucose as substrate. Lactobacillus manihotivorans LMG 18010T did not produce amylase when grown on glucose. Based on the differences in the physiology between the two species and other amylolytic lactic acid bacteria, different applications may be expected.

/pdf/effect-of-ph-control-on-lactic-acid-fermentation-of-starch-sbsj3dnt69.pdf

Effect of pH control on lactic acid fermentation of starch by Lactobacillus manihotivorans LMG 18010T.

Fermentation by Lactobacillus fermentum Ogi E1 of different combinations of carbohydrates occurring naturally in cereals: consequences on growth energetics and α-amylase production

Aims: Nutritional requirements of Lactobacillus fermentum Ogi El were studied in order to define a simplified fermentation medium. Methods and Results: When grown with MRS-medium in 21 bioreactors, a biphasic pattern of growth and metabolite production was observed. Study of nutritional requirements resulted in a simplified medium (SYAM) that allowed, under anaerobiosis, similar results to be obtained as in MRS medium, but without biphasic fermentation kinetics. The best substrates for both growth and amylase production were starch and maltose. Although melibiose, raffinose, fructose, sucrose and glucose also supported growth, lower amylase activity was observed. Conclusions: The physiology of the strain can be investigated with SYAM medium, using either starch or maltose as substrate. The strain also presented potential for a-galactoside fermentation. Significance and Impact of the Study: Lactobacillus fermentum was one of the dominant bacteria of African maize dough fermentations. Amylolytic strains with activity against other compounds (i.e. raffinose) suggested a potential to be used as starter for cereal fermentation. (Resume d'auteur)

https://sfamjournals.onlinelibrary.wiley.com/doi/epdf/10.1046/j.1365-2672.2001.01272.x

Nutritional requirements and simplified cultivation medium to study growth and energetics of a sourdough lactic acid bacterium Lactobacillus fermentum Ogi E1 during heterolactic fermentation of starch.

Introduction: The control of microorganisms present on the surfaces of the dental environment is a critical factor. Contamination from these pathogens can occur through direct or indirect contact between surfaces and clinical staff. Stopping cross infection in dental offices represents a great challenge for dentists and microbiologists. Objective: To compare the bacterial load of the dental units of the centers of the Ministry of Public Health, after the disinfection process, in the interval of attention from one patient to another; in the city of Cuenca, Ecuador. Materials and methods: It is a cross-sectional analytical observational study, which analyzes 12 surfaces from 3 centers of the Ministry of Public Health (MSP) in the city of Cuenca-Ecuador, selected at random. Results: Samples were isolated on 4 surfaces, each from 3 health centers; where 4 microorganisms were identified among them: Streptococcus viridans, Bacillus Subtilis, Yeasts and Staphylococcus coagulase negative, where the most prevalent was Bacillus subtilis. Conclusion: The cleaning protocols are deficient; it is recommended to carry out periodic controls on the quality of disinfection in public dental health care centers.

/pdf/evaluation-of-microbiological-contamination-in-the-dental-b8cx3jsm.pdf

M. Calderon

Papers

Effect of pH control on lactic acid fermentation of starch by Lactobacillus manihotivorans LMG 18010T.

Fermentation by Lactobacillus fermentum Ogi E1 of different combinations of carbohydrates occurring naturally in cereals: consequences on growth energetics and α-amylase production

Nutritional requirements and simplified cultivation medium to study growth and energetics of a sourdough lactic acid bacterium Lactobacillus fermentum Ogi E1 during heterolactic fermentation of starch.

Evaluation of microbiological contamination in the dental services of the ministry of public health of the city of Cuenca-Ecuador