Lactobacillus helveticus: A species of gram-positive bacteria isolated from MILK and cheese-starter cultures.Lactobacillus: A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Pathogenicity from this genus is rare.Cheese: A nutritious food consisting primarily of the curd or the semisolid substance formed when milk coagulates.Lactobacillus casei: A rod-shaped bacterium isolated from milk and cheese, dairy products and dairy environments, sour dough, cow dung, silage, and human mouth, human intestinal contents and stools, and the human vagina.Lactobacillus acidophilus: A species of gram-positive, rod-shaped bacteria isolated from the intestinal tract of humans and animals, the human mouth, and vagina. This organism produces the fermented product, acidophilus milk.Probiotics: Live microbial DIETARY SUPPLEMENTS which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, lactobacilli are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci. (J. Nutr. 1995;125:1401-12)Lactobacillus plantarum: A species of rod-shaped, LACTIC ACID bacteria used in PROBIOTICS and SILAGE production.Food Technology: The application of knowledge to the food industry.Caseins: A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.Dipeptidases: EXOPEPTIDASES that specifically act on dipeptides. EC 3.4.13.Milk: The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.Aminopeptidases: A subclass of EXOPEPTIDASES that act on the free N terminus end of a polypeptide liberating a single amino acid residue. EC 3.4.11.Lactobacillus reuteri: A species of gram-positive, rod-shaped LACTIC ACID bacteria found naturally in the human intestinal flora and BREAST MILK.Lactobacillus rhamnosus: A species of gram-positive, rod-shaped bacteria used in PROBIOTICS.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Endopeptidases: A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.Genes, Bacterial: The functional hereditary units of BACTERIA.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Lactobacillus brevis: A species of gram-positive, rod-shaped LACTIC ACID bacteria that is frequently used as starter culture in SILAGE fermentation, sourdough, and lactic-acid-fermented types of beer and wine.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Lactobacillus fermentum: A species of gram-positive, rod-shaped bacteria associated with DENTAL CARIES.Bacterial Proteins: Proteins found in any species of bacterium.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Cultured Milk Products: Milk modified with controlled FERMENTATION. This should not be confused with KAFFIR LIME or with KAFFIR CORN.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Lactobacillus delbrueckii: A species of gram-positive, rod-shaped, facultatively anaerobic bacteria. capable of producing LACTIC ACID. It is important in the manufacture of fermented dairy products.Campylobacter lari: A species of thermophilic CAMPYLOBACTER found in healthy seagulls and causing ENTERITIS in humans.