Lactobacillin

LACTOBACILLIN, a mixed culture of lactic acid bacteria used for fermenting milk or for ingestion per se in the form of powders or compressed tablets. The term L. is also applied to the sour milk itself, prepared using the aforementioned starter culture. The starter culture is a mixture of two cultures of lactic acid bacteria: Bac. bulgaricus and Bact. lactis acidi Leichmann. The main active agent is the Bulgarian bacillus (see). The term L. is no longer in general use; in world scientific literature, the term yogurt (Yoghurt or Ja-Urt) has been adopted. The Bulgarian bacillus was, as is well known, first isolated from yogurt (Bulgarian sour milk), which has been known since ancient times in the Middle East as a nutritional and medicinal lactic acid product. Yogurt has many varieties of sour milk close to it: prostokvasha, varenetz, "kiselo mlek" (South Slavic countries), Don prostokvasha, katyk (Tatar), matsoni (Georgia), madzun (Armenia), leben (Syria and Egypt), Dahi (India), as well as types of viscous (long) milk (in which, besides lactic acid fermentation, a marked sliming of the milk plays a noticeable role, caused by Bact. lactis longium, strains close to Strept. hollandicus), Dutch (Lange Wei), Swedish (lange Mjolk), Norwegian (Fatte Mjolk), and Finnish (Fiili and Piima). All of them represent a special type of curdled milk in which vegetative forms of lactic acid bacteria are characteristic. Under natural conditions of preparing milk with a domestic starter, the indicated types of sour milk also contain other lactobacteria, yeasts, and occasionally molds. The presence of yeast causes alcoholic fermentation, which takes place to a comparatively small degree in some of the above-mentioned products. In physical-chemical terms, lactobacillin is an acidic milk curd, or milk casein, separated from its calcium colloidal compound together with the whey contained within it. The average chemical composition of yogurt in percentages according to J. König: nitrogenous substances—3.34, fat—2.76, carbohydrates—3.97, lactic acid—0.82, volatile acids (as acetic)—0.018, ash—0.78, and water—88.31. Caloric value per 1 kg: gross—607, net—581; according to Schall in yogurt: nitrogenous substances—3.3, fats—2.80, carbohydrates—3.9, lactic acid—0.8. Moscow prostokvasha (varenetz) of cooperative and private production, prepared partly with pure cultures and partly with special starter cultures, according to data from studies by the Moscow Sanitary Institute (1927–29), has the following average composition: water—87.73%, fat—3.5%, dry residue—12.27%, acidity (as lactic acid)—0.9%. To eliminate the sharply acidic taste of milk fermented by the Bulgarian bacillus alone, and also to avoid a tallowy aftertaste, Metchnikoff recommended mixing a culture of Bact. lactis acidi Leichm. with the culture of the Bulgarian bacillus, which imparts a pleasant, specific lactic acid odor and delicate taste to the product. The acidic environment of lactobacillin presents, in comparison with other dairy products, the least favorable biological conditions for the development and vital activity of pathogenic microbes of the intestinal group, for example, typhoid and paratyphoid bacteria. This is evident from the following table, according to M. Seelemann. Product Name: Life span of typhoid bacillus; Life span of paratyphoid bacillus. Yogurt... up to 3 days; up to 4 days. Sour milk... 5 days; up to 8 days. Kefir... 5 days; up to 5 days. Acidophilus cottage cheese... 8 days; up to 12 days. Cottage cheese prepared with rennet... 12 days; up to 12 days. Sweet cream butter... 16 days; up to 33 days. Sour cream butter... 26 days; up to 33 days. L. is used as a food product, as a dietary and bacteriotherapeutic preparation. In terms of its nutritional value, L. is very close to milk and is significantly less cloying than milk. Dietary use of L. is found in some acute and chronic disorders of the gastrointestinal tract and nephritis. L. stimulates and improves the functions of the digestive apparatus and has a favorable effect on the excretory capacity of the kidneys; the beneficial effect of L. has been noted more than once in cases of diarrhea, dysentery, and typhoid fever. In pediatric practice, L. is often prescribed with success for colitis and protracted catarrh of the small intestine. The daily therapeutic dose of L. is 500–700 cm³ (Metchnikoff) or 1–3 tablets of dried cultures; according to modern authors, 1–2 cups of yogurt.

Preparation of L. (prostokvasha) is briefly as follows: pasteurized whole or skim milk is fermented at 40–45°; in some production facilities, in addition to the main cultures, lactic acid streptococci approaching the Strept. hollandicus type are added to the starter, thanks to which the product acquires greater viscosity and density. The fermented milk is poured into glasses or jars, which are tightly closed and placed in a thermostat. In large enterprises, the vessels are sterilized beforehand. After 3–4 hours, when the milk has curdled, the product is moved to a cold place for firming and ripening, and then it goes on sale. L.-varenetz is prepared from boiled or sterilized milk. Spoilage of L., most often of bacterial origin (contaminated vessels, milk), manifests as focal peptonization of the curd, gas formation, the release of whey, etc.; surface mold growth is frequently encountered. Falsification of L. most often occurs in 2 forms: 1) the sale of L. prepared from skim or water-diluted milk under the guise of being prepared from whole milk, or without any visible warning about this, and 2) when preparation of L. on "pure cultures" or "by the Metchnikoff method" is indicated—the presence of a significant admixture of foreign microbes in the product or even the absence of the Bulgarian bacillus. Sanitary-hygienic requirements for the product are as follows: the product must be fresh, without externally obvious signs of spoilage; consumption of the product later than 2 days from the date of its manufacture should not take place. Color—from porcelain-white to ivory. Odor—peculiarly aromatic (lactic acid). Taste—acidic, pleasant, refreshing. The amount of fat in fatty L. should be no less than 3.2% and water no more than 88%; in L. prepared from skim milk, water—no more than 92%. The amount of acid in the mature product should reach 1.0–1.2% and be no lower than 0.8%. Industrial L. ("on pure cultures") should not contain alcohol or CO₂. The bacterial flora of L. should consist of Bac. bulgaricus with the addition of Bact. lactis acidi Leichmann, normally, according to A. J. Weil, in a ratio of 100 to 120–200 of Leichmann's bacteria. An admixture of other lactobacteria may be permitted if there are no indications on the label of the "Metchnikoff method." The presence of yeast and bacterial contamination (Bact. coli) is not permitted. L. must be sold in tightly closed glass, earthenware, or porcelain vessels, bearing a label indicating the time of manufacture and the expiration date (two days). In the case of preparing L. from skim milk, there must be a clear indication of this on the label. The sale of L. prepared from milk diluted with water is not permitted. Preparations of L. starter must bear a label with the designation and indication of the ratio of cultures and the dates of their preparation and expiration. Dry starters should curdle milk at 45° in 10–14 hours, liquid ones—within 3–4 hours. Sanitary-hygienic requirements for the production of L. are the same as for any food production. In particular, in artisanal workshops, there must be a minimum of two rooms: 1) for production purposes and 2) for washing vessels. Isolation, finishing, equipment, utensils, personnel, etc., are subject to standard sanitary requirements. Acidophilus milk (acidophilus milk). In recent years, the consumption of milk fermented by Bac. acidophilus has become widespread in the USA. Bac. acidophilus was first isolated by E. Moro from infant stool in 1900; it is very similar to Bac. bulgaricus, and their differentiation has been the subject of recent work. Bac. acidophilus easily acclimatizes in the intestine, replacing the putrefactive (proteolytic) microflora with a flora of acidophilic bacteria. The therapeutic value of acidophilus milk consists, in the opinion of some authors, in a favorable influence on constipation and diarrhea, in typhoid fever, etc. Lactalexin—a therapeutic preparation that was manufactured from milk and proposed in 1908 by A. V. Pel for the treatment of rickets, scrofula, etc. Pel does not report its composition or method of preparation.