Pediococcus
Pediococci (Pediococcus) are a bacterial genus of the family Lactobacillaceae. The genus comprises 0.6-1.0 μm large, paired or in tetrads, very rarely solitary or in chains, immobile, gram-positive, microaerophilic cocci. They are always homofermentative, thus forming only lactic acid as a fermentation product and no carbon dioxide. Catalase is not usually formed, gelatin is not liquefied, and nitrate is not reduced to nitrite. The genus differs from other coccoid, homofermentative lactic acid bacteria of the genus Streptococcaceae, Enterococcus and Lactococcus by a GC value of 34-42 mol%GC. The halophilic P. halophilus tolerates more than 15 % NaCl in the medium.
P. cerevisiae and P. acidilacitci play a role in the production of sauerkraut and pickled cucumbers and as starter cultures in raw sausage production. Some Pediococcus species are important for human nutrition due to the aromas they produce, especially diacetyl and amines. This is particularly true for traditional beers such as Belgian lambic beers. On the other hand, in the production of Berliner Weißbier, they represent an undesirable contamination for rapid marketing, the so-called "longing" of the wheat beer, which is manifested by the formation of slime. After prolonged storage of several months, the slime gradually dissolves again completely as in the traditional Berliner Weisse. "The beer becomes bright again, durable, shows normal consistency and is fully enjoyable. A fine aroma and a pleasant taste similar to tartaric acid remaining in the process is particularly appreciated in part by beer connoisseurs." Various species of Pediococcus are also used in Belgian Geuze and are among the essential desirable aroma-forming beer bacteria.
In the wine maturation, especially the post-ripening, they play a role next to the genera Lactobacillus and Leuconostoc. The degradation of malic acid to lactic acid can lead to both undesirable changes so-called "lactic acidosis", as well as through biological acid degradation to a desired deacidification.
Types
- Pediococcus acidilactici
- Pediococcus argentinicus
- Pediococcus cellicola
- Pediococcus claussenii
- Pediococcus damnosus
- Pediococcus dextrinicus, synonym: Pediococcus cerevisiae
- Pediococcus ethanolidurans
- Pediococcus halophilus
- Pediococcus inopinatus
- Pediococcus lolii
- Pediococcus parvulus
- Pediococcus pentosaceus
- Pediococcus siamensis
- Pediococcus stilesii
- Pediococcus urinaeequi
