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I P Baranova

Publications and source records attributed to I P Baranova.

At least 19 recordsLinked to original sources
PubMed1995

[Data on the cultural and morphologic features of dissociation forms of nisin-producing Streptococcus].

Colonies and cells of S and G variants of Streptococcus lactis, strain MSU were studied comparatively. It was shown that in the G form the growth rate and other biosynthetic peculiarities and in particular the capacity for the nisin synthesis were lower. Morphological properties of the colonies and cells of the S and G variants of the nisin-producing streptococcus were investigated.

Cell Division↗
PubMed1992

[Isolation of nisin from native solution and its purification on cationites].

It was found possible to use organic sorbents and in particular carboxylic cationites for isolation of nisin from the fermentation broth filtrate and its purification. Nisin is known as a polypeptide antibiotic applied as a preservative. The sorbents were shown to have high exchange capacities by the isolated substance and mechanical strength and resistance. They also proved to be highly stable.

Adsorption↗
PubMed1990

[Study of nisin, a polypeptide antibiotic produced by a culture of Streptococcus lactis, strain MSU].

The drug nisin produced by the lactic acid bacteria S. lactis, strain MSU, was identified and described. After 18-hour cultivation of the strain the fermentation broth was centrifuged. The centrifugate contained at an average 2000 IU/ml of the antibiotic. It was purified on silica gel C-3, the eluate was lyophilized and the dry substance was studied by disk electrophoresis in 20 per cent PAAG in the presence of sodium dodecylsulfate. It was found that S. lactis, strain MSU, produced a polypeptide component of the molecular weight of 7000 D. Its electrophoretic mobility corresponded to that of nisaplin. Therefore, nisin was shown to be identical to nisaplin.

Anti-Bacterial Agents↗
PubMed1987

[Nisin sorption and desorption on different silica adsorbents].

Nisin sorption on some silica adsorbents in columns was studied. Silica gels, silochromes and sintered glass with various pore diameters, various specific surfaces, etc. were tested. Correlation between the adsorbent adsorption capacity with respect to nisin and the adsorbent pore diameter was observed. The tested silochromes, silica gels with the pore diameters of 70-80 nm and sintered glass with the pore diameters of 65-112 nm had the highest adsorption capacity with respect to nisin.

Adsorption↗
PubMed1986

[Nisin biosynthesis during the joint cultivation of Streptococcus lactis strain MGU and yeasts].

In simultaneous inoculation of the medium for nisin biosynthesis with Streptococcus lactis (strain MSU) and yeasts such as Rhodotorula colostri, Zigowilliopsis californicus, Hansenuia anomala, Saccharomyces ludvigii, Kluyveromyces lactis and Endomyces magnusi the quantitative ratio of the inoculates in the mixed cultures is not in principle important for the antibiotic synthesis by the Streptococcus. When 6-, 12-, 18- and 24-hour inoculates of the yeasts were added simultaneously to 3-, 6-, 9-, 12- and 18-hour cultures of S. lactis biosynthesis of nisin was at the control level. The fractional composition of the fermentation broth of the above yeast species had no significant effect on biosynthesis of nisin.

Culture Media↗
PubMed1985

[Joint cultivation of Streptococcus lactis, LMU strain, and various species of yeasts].

When S. lactis, strain LMU and yeast were plated out simultaneously on media containing different amounts of amine nitrogen and vitamins, the yeast did not stimulate the synthesis of nisin. Plating out of S. lactis on media with grown cultures of the Rostov baker's yeast, American baker's yeast, Candida guilliermondii, Candida clausenii, Fabospora fragilis, Fabospora macedoniensis, Octosporomyces octosporus, Saccharomyces cerevisiae, races "Ya" and "M" and Saccharomyces globosus resulted in inhibition of the S. lactis growth and nisin synthesis. Cultivation of S. lactis on media with grown cultures of Saccharomyces ludwigii, Hansenula anomala, Kluyveromyces lactis, Endomyces magnusi, Zigowilliopsis californicus, and Rhodotorula colostri resulted in formation of an association providing active growth and development of S. lactis with complete realization of its biosynthetic capacity.

Antibiosis↗
PubMed1984

[Protoplast isolation from a nisin-forming culture of Streptococcus lactis strain MGU].

A procedure for protoplasts of Str. lactis producing nisin was developed. The following lysing factors were used for obtaining the protoplasts: lycozyme, LE enzyme, lysosubtilin and an enzyme isolated from the culture fluid A. levoris. The use of the above factors in different combinations provided an increase in the number of the formed protoplasts from 1-2 in the field of the microscope vision to 15-20, which amounted to 25 per cent of the total number of the cells visible under microscope.

Lactococcus lactis↗
PubMed1983

[Nisin adsorption on silica adsorbents].

It has been shown that silica adsorbents can be used for adsorption of nizin from solutions obtained after centrifugation of the fermentation broth. The optimal structure of the adsorbent pores has been determined. Silica with pores 50 to 75 nm in size provided the highest adsorption rates. The value of silica adsorption of nizin depended on the medium pH. The maximum adsorption rates were observed at pH 6.5--7. At pH 3.5 the level of nizin adsorption was low.

Adsorption↗
PubMed1982

[Nisin inactivation in a culture of the producer Streptococcus lactis strain MGU].

The intensive biosynthesis of nizin on the glucose-yeast medium is observed during the logarithmic and early lag phases of the staphylococcal growth. The ratio of nizin in the fermentation broth (free nazin) and that bound with the cells depended on pH of the medium. When pH was maintained at 6.6-6.8, the amount of nazin in the cells during and growth logarithmic phase was equal to its amount in the fermentation broth filtrate. During the lag phase marked inactivation of nizin was noted. periodical feeding of casein prevented the nizin inactivation. The preliminary data are indicative of the enzymatic nature of the antibiotic.

Culture Media↗
PubMed1981

[Conditions for nisin adsorption by Streptococcus lactis cells].

Some conditions for absorption of nisin, a polypeptide antibiotic by the cells of Str. lactis were studied. The amounts of nisin adsorbed by the cells depended on the culture age: at the late stationary phase the adsorption level was 2 times higher than that at the logarithmic phase. The cells grown on a "poor" medium adsorbed 85-90 per cent of nisin added to the solution, while the cells grown on the "rich" medium adsorbed 50 per cent of the antibiotic. The adsorption level of nisin by the cells subjected to a thermal shock was higher than that by the live cells. Desorption of nisin from the cells with acid ethanol and bivalent cation solutions was insignificant. Nisin is adsorbed by the cells of other microorganisms, the adsorption levels by the cells of Bac. brevis being the same as those by the streptococcal cells, while the levels adsorbed by Bac. polymyxa being 4 times lower.

Adsorption↗
PubMed1980

[Adsorption of the antibiotic, nisin, to Streptococcus lactis cells].

Nizin is produced by Str. lactis, strain MSU. During biosynthesis it is excreted into the fermentation broth and gradually adsorbed on the organism cells. This was confirmed by experiments with an inactive variant of Str. lactis IIa. The cells of this culture adsorbed nizin from "active" fermentation broth. Adsorption of nizin depended on pH of the medium; at pH 2,3 the cells did not adsorbe the antibiotic and at pH 6.6 the amount of the antibiotic adsorbed by the cells was maximum.

Adsorption↗
PubMed1980

[Use of enzymatic hydrolysates of microorganism biomass in media for culturing Str. lactis, the producer of nisin].

Fermentative hydrolysates (FH) of the protein-vitamin complex (PVC) were used for the first time in media for cultivation of Str. lactis. It was found that the FH may be used in the media for cultivation of streptococci as a source of nitrogen instead of the yeast autolysate from baker's yeast and the level of nisin biosynthesis did not change. The replacement of the yeast autolysate by the FH is possible in both flasks with low volumes of the medium and 401 fermenters with 25 liters of the medium. The BVC FH is not a food raw material and its cost is low, which makes it advantageous.

Culture Media↗
PubMed1980

[Physiological characteristics of immobilized cells of Streptococcus lactis, Moscow State University strain].

Immobilized cells of Streptococcus lactis, strain MSU, synthesized nisin by 20--30 per cent of the possible maximum antibiotic production level. The immobilized cells of the Streptococcus synthesized nisin by 40--50 per cent probably at the expense of the cell nutrient pools and by 50--60 per cent at the expense of the medium nutrient consumption. The electron microphotographs showed that the cells of Str. lactis, strain MSU, preserved their usual appearance in the granules of polyacrylamide gel 24 hours after immobilization. In 3 weeks there were observed structural changes in the cell wall and inner membranes resulting in the cell lysis after presence in the granules for 3 months.

Bacteriological Techniques↗