Lactobacillus kimchii

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Lactobacillus kimchii
Scientific classification
Class: Bacilli
Order: Lactobacillales
Family: Lactobacillaceae
Genus: Lactobacillus
Species: L. kimchii
Binomial name
Lactobacillus kimchii

Description and significance

Lactobacillus kimchii is a Gram positive bacterium. Its genus is Lactobacillus.[1] Most species from the genus Lactobacillus are lactic acid bacteria, therefore being probiotic. L. kimchii is found and named after the Korean dish Kimchi, a fermented side dish prevalent in Korean cuisine. Kimchi is ranked as one of the top five healthiest foods in the world, enriched with vitamins and low in calories. It is made from Napa cabbage (also known as kimchi cabbage) and other different spices that are allowed to ferment. Kimchi is known to have a lot of Lactic Acid Bacteria found in it, so from the start of the fermentation there are other microorganisms that are present, including ''Lactobacillus plantarum'', L. Brevis, Streptococcus faecalis,Leuconostoc mesenteroides, and Pediococcus pentosaceus, but L. kimchii takes care of the rest of the fermentation.[2] Fermentation is the key for good tasting of kimchi.[3]

Genome structure

L.kimchii is known to have the G+C content, the of 35 %. It was first known as strain MT-1077T. Being a fairly new specie of Lactobacillus not must about the genome structure is known, but through careful studying and testing using bacterial straining and culture conditions, this strain MT-1077T was found to be very similar to L. alimentariusand L. Farciminis. These two species also coming from the genus Lactobacillus.[4]

Characteristic Strain MT-1077T L. alimentarius KCTC 3593T L. farciminis LMG 9200T
NH3 production from arginine* - - +
Lactic acid isomer DL L(D) L(D)
Fermentation of
L- Arabinose + + -
Ribose + + -
D-Xylose + + -
Galactose w + +
Lactose - - +
Growth in the presence of 10% NaCl - - +
DNA G+C content (mol%) 35 35 36

Cell structure and metabolism

L.kimchiiis short, thin, non-motile, non-spore forming and rod-shaped bacteria. L. kimchii is known as lactic acid bacteria, LAB. LAB are bacteria that secretes lactic acid. LAB can metabolize in either two ways, Embden-Meyerhof-Parnas (EMP) pathway or pentose phosphate pathway. EMP is used when there is not enough oxygen and too much glucose. L.kimchii is a heterofermentative LAB, it metabolizes using the pentose phosphate pathway. L. kimchii breaks down the unwanted gluconate without releasing gas indicating that the organism undergoes heterofermentation. L. kimchii produces L(+) lactic acid and D(-) lactic acid. The growth of L. kimchii is optimal at 30 degrees Celsius, with a pH between 6.0-7.0.

Ecology

L. kimchii is able to grow in both aerobic and anaerobic environments,with temperatures as high as 40 degrees Celsius. L. kimchii is found during the fermentation of the Korean cabbage, baechu. The combination of the spices, such as garlic, onions, ginger, and red pepper and with the high concentration of salt it produces LABs,L.kimchii being one of them.[5]

Pathology

L. kimchii can only be found in the Korean food, kimchi. Kimchi is fermented based on the salt concentration and the temperature. Kimchi is also know to be well-being food and suggested to be eaten regularly. It has high concentration of dietary fiber, low in calories, full of Vitamin C and Carotene, which is good for eye sight and ranked as one of the top healthiest food. L.kimchii is member of the Lactobacillus and shares the same quality in the production of fermented food.

Economic Importance

To have a traditional Korean meal, there must be many side dishes known as banchan, one or two main dishes and steamed rice. Kimchi is always served as one of the main side dishes. A meal without kimchi, would not be considered a meal for most Koreans. Koreans depends on kimchi as being part of their diet. L.kimchii plays an important role for Koreans.

Current Research

Bacterial population in traditional sourdough evaluated by molecular methods

This study was done to see what is contained in sourdough. Sourdough is dough that is made of wheat, flour, rye and LABs. Sourdough is used in the fermentation of cereal and it can be used to make bread. Sourdough consists of many different type of strains. To find all of microorganism sourdough, a study was done. The method was culture-dependent and culture independent used was comparing the microorganism with 45 different LABs. Of the 45 LABs, L. kimchii was one. L.kimchii was used as one of the Lactobacillus' primers in PCR[6]

Lipid profile lowering effect of Soypro fermented with lactic acid bacteria isolated from Kimchi in high-fat diet-induced obese rats.

Kimchi is one of the top ranked food in the world.[7] Kimchi is good for oneself because it consist of high dietary fiber and is low in calories. There was a study done using the idea that kimchi is a good for one's diet because of the fermentation by the lactic acid bacteria, to see if obesity can be reduced with other products such as Soypro, type of soy milk. Soy Pro, is short for Soy and Protein. Soy Pro is now on the market and being sold like soy milk. Soy Pro is soy milk that has been fermented using LABs. It is a dietary supplement and is used to lower cholesterol and protect against heart attack. There was testing on mice for six weeks with the Soypro, the results of the rats losing weight was not conclusive and further testing was needed. The rats overall weight was not changed, but the lipoprotein cholesterol had lowered.[8]

Enhancement in ex vivo phagocytic capacity of peritoneal leukocytes in mice by oral delivery of various lactic-acid-producing bacteria.=

The immune system is said to get weaker as we get older. Many people turn to pharmaceuticals, which can lead to side effects. The side effect can be must worse than the original pain. No one can cheat getting older and getting stress. Instead of turning to pharmaceuticals, scientists were looking for a more natural approach, where there would be no side effects. Scientist decided to use Lactic acid Bacteria because they are probiotic, especailly those from the genus Lactobacilli and Bifidobacteria. Most Lactic acid Bacteria are known to be helpful to the immune system, there has been many studies using these bacteria to find cures for diseases. In this particular study, it was trying to find a cure for leukocytes using L. kimchii as one of the LAB. The strains that they used for this study was found in either baby feces or kimchi. Mice were used as test dummies for this experiment. The results were L.kimchii had the highest amount of phagocyte capacity.[9]

References

  1. "Lactobacillus." MicrobeWiki. 8 April 2009 Kenyon College. 21 April 2009. <http://microbewiki.kenyon.edu/index.php/Lactobacillus>
  2. Role of microorganisms in Kimchi fermentation
  3. "Role of microorganisms in kimchi fermenation" <http://dwb.unl.edu/Teacher/NSF/C11/C11Links/kimchi.kfri.re.kr/2-1-5.htm>
  4. Lactobacillus - MicrobeWiki
  5. Yoon JH, Kang SS, Mheen TI, Ahn JS, Lee HJ, Kim TK, Park CS, Kho YH, Kang KH, Park YH (September 2000). "Lactobacillus kimchii sp. nov., a new species from kimchi.". Int. J. Syst. Evol. Microbiol. 50 Pt 5: 1789–95. PMID 11034488. <http://ijs.sgmjournals.org/cgi/pmidlookup?view=long&pmid=11034488>
  6. Cinzia Caggia,Bacterial population in traditional sourdough evaluated by molecular methods <http://www3.interscience.wiley.com/journal/118711381/abstract?CRETRY=1&SRETRY=0>
  7. World's healthiest foods: kimchi (Korea)
  8. Na-Hyung Kim, Phil-Dong Moon, Su-Jin Kim, In-Young Choi, Hyo-Jin An, Noh-Yil Myung, Hyun-Ja Jeong, Jae-Young Um, Seung-Heon Hong, Hyung-Min Kim , Lipid profile lowering effect of Soypro fermented with lactic acid bacteria isolated from Kimchi in high-fat diet-induced obese rats <http://iospress.metapress.com/content/h2m90j6550897522/>
  9. Lee Yeonhee & Lee Taik-Soo,Enhancement in ex vivo phagocytic capacity of peritoneal leukocytes in mice by oral delivery of various lactic-acid-producing bacteria <http://www.springerlink.com/content/4ye7f1m1f82kncbp/>