Lactobacillus hilgardii

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Lactobacillus hilgardii
Scientific classification
Domain: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Lactobacillales
Family: Lactobacillaceae
Genus: Lactobacillus
Subgenus: Betabacterium
Species: L. hilgardii
Binomial name
Lactobacillus hilgardii
Douglas and Cruess 1936
Type strain
ATCC 8290

CCUG 30140
CIP 103007
DSM 20176
IFO 15886
JCM 1155
LMG 6895
NBRC 15886
NRRL B-1843

Synonyms
  • Bacillus vermiformis Ward 1892
  • "Betabacterium vermiforme" (Ward 1892) Mayer 1939
  • "Brevibacterium vermiforme"
  • "Lactobacillus Type II" Fornachon 1943

Lactobacillus hilgardii is a species of bacterium found in wine, dairy products, and wine musts.

Its morphology is consistent (on a cellular level) of rods that are 0.5–0.8 micrometres of both single short chains and long filament like structures. On a colony level, the bacteria appears glossy, round and white. For study, the bacteria requires malt agar and can ferment maltose, but often also requires yeast extract in order to ferment properly. To study L. hilgardii in liquid requires growing it in Elliker broth so it can show turbidity and gas formation.[1]

On staining with Gram's iodine, the bacillus is Gram positive. L. hilgardii is considered a negative catalase (enzyme that decomposes hydrogen peroxide into oxygen and water) and creates lactic acid, ethanol/acetic acid, and carbon dioxide. Along with this it is capable of sometimes producing biogenic amines or histamine and ethyl carbamate, which causes health risks.

Its role in the fermentation of wine is that it is impactful when spoiling high-alcohol dessert wines and can be used in malolactic fermentations (winemaking fermentation). Lactobacillus hilgardii is sensitive to SO2, both not sensitive and metabolized to sorbate. It is highly tolerant to acids and pH. It is tolerant of ethanol up to 20 vol%.

Lactobacillus hilgardii hybridizes easily with Lactobacillus brevis, a bacterium that it is very closely related to. Prior to its classification as a distinct species, L. hilgardii was believed to be L. brevis, and, as a result, the bacterium's ability to hybridize raised doubts about its taxonomy.[2]

L. hilgardii grows in wine when it contains 1% autolysed yeast. It also grows in ethanol at 15–18%. The bacteria grow best at 30–35 °C, but can grow at temperatures as low as 15 °C.

References[edit]

  1. ^ "Lactobacillus hilgardii". Enologyaccess.org. 2010-06-20. Retrieved 2014-07-15. 
  2. ^ "Lactobacillus hilgardii and Lactobacillus brevis DNA analysis by restriction fragment length polymorphism (RFLP)". Food Microbiology. 11: 195–202. 1994-06-30. doi:10.1006/fmic.1994.1023. Retrieved 2014-07-15. 

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