title: Microorganisms of the San Francisco sour dough bread process. II. Isolation and characterization of undescribed bacterial species responsible for the souring activity.
abstract: A medium was developed which permitted isolation, apparently for the first time, of the bacteria responsible for the acid production in the 100-year-old San Francisco sour dough French bread process. Some of the essential ingredients of this medium included a specific requirement for maltose at a high level, Tween 80, freshly prepared yeast extractives, and an initial pH of not over 6.0. The bacteria were gram-positive, nonmotile, catalase-negative, short to medium slender rods, indifferent to oxygen, and producers of lactic and acetic acids with the latter varying from 3 to 26% of the total. Carbon dioxide was also produced. Their requirement for maltose for rapid and heavy growth and a proclivity for forming involuted, filamentous, and pleomorphic forms raises a question as to whether they should be properly grouped with the heterofermentative lactobacilli.
mesh_terms: D000085:Acetates / Q000096:biosynthesis; D001419:Bacteria / Q000145:classification / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D001939:Bread; D002140:California; D002245:Carbon Dioxide / Q000096:biosynthesis; D003470:Culture Media; D004352:Drug Resistance, Microbial; D005511:Food Handling; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000096:biosynthesis; D007778:Lactobacillus / Q000145:classification; D008320:Maltose / Q000378:metabolism; D010100:Oxygen; D010447:Peptide Hydrolases; D012440:Saccharomyces; D012965:Sodium Chloride / Q000494:pharmacology; D013501:Surface-Active Agents; D013696:Temperature
chemical_list: D000085:Acetates; D003470:Culture Media; D007773:Lactates; D013501:Surface-Active Agents; D002245:Carbon Dioxide; D012965:Sodium Chloride; D008320:Maltose; D010447:Peptide Hydrolases; D010100:Oxygen