[Extracellular lectins from saprophytic strains of bacteria of the genus Bacillus (review)].

The present review summarizes both the authors' own and other researchers' reports concerning the synthesis and properties of sialic acid-specific extracellular lectins from saprophytic bacteria of the genus Bacillus. Bacilli of this genus isolated from different ecological niches differ with regard to the ability to synthesize lectins. The biphasic temporal pattern of lectin synthesis in culture and the effect of cultivation conditions on lectin production have been demonstrated. The advantages of the technological procedure used for the isolation and purification of these biopolymers have been characterized. Specificity towards sialic acid, which is characteristic only of a small number of lectins from bacilli and underlies a wide range of biological effects of these proteins, receives particular attention. Adaptation mechanisms involving lectins--carbohydrate-recognizing proteins--are suggested to have developed in saprophytic bacilli to ensure the survival of these organisms in a constantly changing environment.

[Search for lectin producers among the yeast of Pichia Hansen emend. Kurtzman genus]. / Poisk produtsentov lektinov sredi drozhzhei roda Pichia Hansen emend. Kurtzman.

Strains (103) of yeast from Pichia genus: P. anomala, P. guilliermondii and P. membranaefaciens species have been investigated. The researchers have found 87 strains (84.5%) capable to form extracellular and surface lectins with activity to 512 hemagglutinating units. The overwhelming number of strains (75.7-92.6%) synthesized lectins of the both forms. Considerably less quantity of lectin producers of some form--extracellular or surface ones--have been found. Availability of producers of extracellular lectins was characteristic to greater extent of the yeast of P. anomala and P. guilliermondii, and producers of surface lectins--mainly of P. guilliermondii. The most active producers of lectins have been isolated from human and animal organisms, soils and wine.

[Lectin activity of antitumor substances synthesized by Bacillus subtilis B-7025]. / Lektinovaia aktivnost' protivoopukholevykh veshchestv, sinteziruemykh Bacillus subtilis B-7025.

Nutrient medium, which is optimal for synthesis of biologically active substances and allows obtaining stable outflow of Bacillus subtilis B-7025 to the culture medium, has been selected under the conditions of the bacillus periodic cultivation. It has been established that these substances are extracellular lectins with high activity and carbohydrate specificity to fructose-1.6-di phosphate, N-acetylneuraminic acid and glucose derivatives: D-glucuronic acid and D-glucosamine.

[Search for lectin producers among some yeast species]. / Poisk produtsentov lektinov sredi nekotorykh vidov drozhzhei.

Hemagglutinating properties of culture liquid and cells of 142 yeast strains of species Saccharomyces cerevisiae, Kluyveromyces marxianus, K. dobzhanskii, K. lactis var. lactis and K. lactis var. drosophilarum, isolated from various sources have been studied. A capacity of yeast (44% of the studied strains) to synthesize both lectins bound to a cell and extracellular lectins has been established; the latter have been found in yeast for the first time.

[Various physico-chemical properties of the amylolytic complex from Bacillus mesentericus]. / Nekotorye fiziko-khimicheskie svoistva amiloliticheskogo kompleksa Bacillus mesentericus.

Some physico-chemical properties of the Bacillus mesentericus amylolytic complex were studied, and optimal conditions of starch hydrolysis (pH 7.5-8.0; 45 degrees C) were found. The half-life of amylases at 50 degrees was 75 min. The heat stability of the enzymes increased in the presence of Ca2+ ions. Amylase was stable at pH 7-9 and readily inactivated at pH below 6.0. By physical and chemical characteristics the complex was close to analogous preparations from Bacillus alkalophilic strains. Isoelectrofocusing revealed that the complex consisted at least of two amylolytic enzymes.

[The effect of the cultivation conditions on lectin production by representative bacteria in the genus Bacillus]. / Vliianie uslovii kul'tivirovaniia na produtsirovanie lektinov nekotorymi predstaviteliami bakterii roda Bacillus.

Dynamics of the lectin activity accumulation in the culture liquid was studied through the example of certain representatives of spore-forming aerobic bacteria in the process of their growth. The environmental factors (the temperature, pH value, the presence of definite carbohydrates in the medium) were investigated for their effect on the biosynthesis of extracellular lectins by producers. Based on these studies it was possible to establish optimal conditions of cultivation and to obtain the high specific lectin activity of the culture liquid for each strain.