Media lactic acid bacteria

Experience has shown that, even in sugar-containing media, lactic acid bacteria during their growth phase do not produce acetic acid and decompose only malic acid (Section 3.8.3). The complete depletion of malic acid, however, greatly increases the risk of serious alterations when the wine still contains sugar. For example, malolactic fermentation sometimes occurs before the wine has... 

In a laboratory culture medium, lactic acid bacteria strains isolated from wine multiply between 15 and 45°C but their optimum growth range is between 20 to 37°C. The optimum growth temperature for O. oeni is from 27 to 30°C. but it is not the same in an alcoholic medium, especially in wine. The optimum temperature range is more limited from 20 to 23°C. When the alcohol content increases to 13-14% volume of alcohol, the optimum temperature decreases. Growth slows as the temperature decreases, becoming nearly impossible around 14-15°C. 

Wine is an extremely complex enviromnent and it is not possible to elucidate the effects of all of its components on lactic acid bacteria. In any case, this would not help the enologist, since these individual effects are cumulative—acting in synergy or, on the contrary, compensating each other. In this medium, lactic acid bacteria, particularly O. oeni, develop in extreme conditions. Acidity and ethanol combine with other molecules to inhibit the growth of the isolated strains. 

Vitamins and Minerals. Milk is a rich source of vitamins and other organic substances that stimulate microbial growth. Niacin, biotin, and pantothenic acid are required for growth by lactic streptococci (Reiter and Oram 1962). Thus the presence of an ample quantity of B-complex vitamins makes milk an excellent growth medium for these and other lactic acid bacteria. Milk is also a good source of orotic acid, a metabolic precursor of the pyrimidines required for nucleic acid synthesis. Fermentation can either increase or decrease the vitamin content of milk products (Deeth and Tamime 1981 Reddy et al. 1976). The folic acid and vitamin Bi2 content of cultured milk depends on the species and strain of culture used and the incubation conditions (Rao et al. 1984). When mixed cultures are used, excretion of B-complex vita-... 

At about the same time, Gunsalus and coworkers noticed that the activity of tyrosine decarboxylase produced by lactic acid bacteria was unusually low when the medium was deficient in pyridoxine. Addition of pyridoxal plus ATP increased the decarboxylase activity of cell extracts.146 PLP was synthesized and was found to be the essential coenzyme for this and a variety of other enzymes.147... 

In the current industrial process, nisin is manufactured by fermentation of L. lactis subsp. lactis in a milk-based medium. Biosynthesis of nisin is coupled with the growth of lactic acid bacteria and the production of a significant amount of lactic acid (7). Lactic acid is an important chemical for food processing. It can also be used as a raw material in the production of the biodegradable polymer poly(lactic) acid (12). Unfortunately, lactic acid is not recovered in the current nisin process. 

Moreno-Arribas and Lonvaud-Funel (1999). Moreno-Arribas et al. (2000) isolated and identified a number of tyramine-producing lactic acid bacteria in wine that had undergone malolactic fermentation all belonging to the lactobacilli. Tyrosine decarboxylase was then purified (Moreno-Arribas and Lonvaud-Funel 2001) and the corresponding gene was purified and sequenced (Lucas and Lonvaud-Funel 2002 Lucas et al. 2003). As far as the literature suggests, no tyramine-producing 0. oeni strain has yet been reported, with the exception of one strain (O. oeni DSM 2025) that was shown to be able to produce tyramine in a laboratory medium (Choudhury etal. 1990). 

Most studies to screen for biogenic amine-producing lactic acid bacteria use differential media that contain the precursor amino acid and a pH indicator. This indicator, usually purple bromocresol, will change colour when the medium is alkalinized and this colour change will be observed in the medium if the lactic acid bacteria produce amines (Bover-Cid and Holzapfel 1999 Choudhury et al. 1990 Maijala 1993). 

Choudhury, N., Hansens, W., Engesser, D., Hammes, W.P. Holzaptel, W.H. (1990). Formation of histamine and tyramine by lactic acid bacteria in decarboxylase assay medium. Lett. Appl. Microbiol, 11, 278-281. 

Thomsen, M., Guyot, J., and Kiel, P. (2007) Batch fermentations on synthetic mixed sugar and starch medium with amylolytic lactic acid bacteria. Appl. Microbiol. Biotechnol, 74,... 

C.F. De Valdez, G.S. De Giori, and A.P. De Ruiz Holgado, Effect of drying medium on residual moisture content and viability of freeze-dried lactic acid bacteria. Applied and Environmental Microbiology, 49,413 15 (1985). 

Williamson s medium L Contains ui opped beer, maltose, yeast extract, liver extract, casein hydrolysate, either polymyxin or phenylethanol with CO atmosphere (25 Q, supports lactic acid bacteria. Polymyxin suppresses gram-negative bacteria. Phenylethanol supports Pediococcus rather than Lactobacillus... 

Universal liquid medium Contains tomato juice and peptonized milk to encourage lactic acid bacteria. 

General purpose medium to which may be added specific inhibitors such as actidione, polymyxin and phenylethanol which make it specific for lactic acid bacteria. 

If cold medium in petri dishes is streaked, rather than mixing the inoculum with the warm medium before pouring into the dishes, the colonies can be more easily removed for further tests. A scheme for selective media and confirmatory tests is given in Table 21.1. Results are given in Table 21,4 for bacterial numbers in pitching yeasts. When lactic acid bacteria are suspected, the plates are held in an atmosphere of carbon dioxide because these bacteria often fail to grow unless the gas is present. Selective media may also be used for slide culture [85, 86]. Microcolonies develop from the individual bacterial cells and may be detected in a few hours by microscopical examination -long before colonies could be seen by the naked eye on the medium in a petri dish. 

Lafflneur, E., Genetet, N., Leonil, J. (1996). Immunomodulatory activity of 3-casein permeate medium fermented by lactic acid bacteria. Journal of Dairy Science, 79, 2112-2120. 

Mu, Chen, Li, Zhang, and Jiang (2009) also smdied the effect of medium composition on the production of PLA by lactic acid bacteria. Attempting to optimize a medium for the commercial production of PLA, the authors used a response surface methodology and the results showed that addition of phenylpyruvic acid (PPA) increased the yield of PLA. The authors suggested that because the transamination step is a bottleneck in the synthesis of PLA, the addition of PPA allowed for a shortcut that bypassed the transamination of phenylalanine to PPA, which is normally the first step when phenylalanine is used as the source for PLA. 

Lactobacillus and Propionibacterium strains were evaluated by El-Nezami et al. (2002) regarding their ability to remove seven Fusarium toxins (trichothecenes) from solution. Results showed that L. rhamnosus GG and Propionibacterium freudenrei-chii spp. shermanii JS were able to bind 18-93% of the deoxynivalenol, diacetoxy-scirpenol, and fusarenon in solution, while L. rhamnosus LC-705 removed 10-64% of deoxynivalenol and diacetoxyscirpenol from liquid medium. When comparing the ability of lactic and propionic bacteria to remove toxin from solution, Niderkom, Boudra, and Morgavi (2006) found that deoxynivalenol and fumonisin removal was strain specific, and that in general propionic acid bacteria was less efficient than lactic acid bacteria. The best results were achieved with L. rhamnosus for ranoval of deoxynivalenol (55%), Leuconostoc mesenteroides for fumonisin Bi (about 82%), and L. lactis for fumonisin B2 (100%) (Niderkom et al., 2006). 

Suzuki, K., Asano, S., lijima, K., Kuriyama, H., Kitagawa, Y. (2008b). Development of detection medium for hard-to-culture beer spoilage lactic acid bacteria. Journal of Applied Microbiology, 104,1458-1470. 

Taskila, S., Tuomola, M., Rronlof, J., Neubauer, P. (2010). Comparison of enrichment media for routine detection of beer sporting lactic acid bacteria and development of trouble-shooting medium for iMctobacillus backi. Journal of the Institute of Brewing, 116(2), 151-156. http //dx.doi.Org/10.1002/j.2050-0416.2010.tb00411.x. 

Horikoshi, N. Okada, Y Takeshita, K. Samejima, T. Semi-solid medium for detecting lactic acid bacteria. Jpn. Kokai Tokkyo Koho JP 2006136272, 2006 Chem. Abstr. 2006,144,484206. 

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