Optimization of Low-Cost Culture Media for the Production of Biomass and Bacteriocin by a Urogenital Lactobacillus salivarius Strain

Probiotics and Antimicrobial Proteins 03/2010; 2(1):2-11. DOI: 10.1007/s12602-010-9037-4


The aim of this work was to formulate a culture medium of lower cost than conventional laboratory media, in order to simultaneously
obtain high amounts of both biomass and bacteriocin of vaginal Lactobacillus salivarius CRL 1328. The growth assays under different culture conditions were performed by using a 28−2 central composite experimental design, with a central point and sixteen additional points. The factors taken into consideration
were glucose, lactose, yeast extract, tryptone, ammonium citrate, sodium acetate, MgSO4 and MnSO4. The simultaneous presence of a carbon source (mainly glucose), a nitrogen source (mainly yeast extract) and salts (mainly
MnSO4, MgSO4 and sodium acetate) allowed the highest cell biomass and bacteriocin levels to be reached in the experimental design. Through
the application of the desirability function, several optimal medium compositions to achieve efficient production of biomass
and bacteriocin were predicted. The optimized growth media allow a cost reduction of around 25 to 40% compared with conventional
broths. The results obtained represent an advance in the search of the most suitable strategies for the production of bioactive
compounds for pharmaceutical products to prevent or treat female urogenital infections.

KeywordsUrogenital probiotics-Bacteriocin-Culture medium optimization-Desirability function

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    • "The standard growth media like MRS (de Mann Rogosa and Sharpe) broth, Elliker broth, Brain Heart Infusion (BHI) broth, and Trypticase Soya digest Broth (TSB) are widely used for production of bacteriocin. Response surface methodology (RSM) is widely used in earlier studies for optimization of bacteriocin production using experimental designs, to analyse the linear and quadratic effects of variables and understand the interactions among the variables (Delgado et al., 2007; Kanmani et al., 2011; Myers and Montgomery, 2002; Wiese et al., 2010). "
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    ABSTRACT: Bacteriocins from lactic acid bacteria are ribosomal synthesized antibacterial proteins/peptides having wide range of applications. Lactobacillus pentosus SJ65, isolated from fermented Uttapam batter (used to prepare south Indian pan cake), produces bacteriocin having a broad spectrum of activity against pathogens. Optimization studies are of utmost important to understand the source of utilization and the conditions to enhance the production of metabolites. In the present study, an attempt was made to identify the parameters involved for maximal production of antimicrobial compounds especially bacteriocin from the isolate L. pentosus SJ65. Initially, optimal conditions, such as incubation period, pH, and temperature were evaluated. Initial screening was done using methodology one-variable-at-a-time (OVAT) for various carbon and nitrogen sources. Further evaluation was carried out statistically using Plackett-Burman design and the variables were analyzed using response surface methodology using central composite design. The optimum media using tryptone or soy peptone, yeast extract, glucose, triammonium citrate, MnSO4, dipotassium hydrogen phosphate and tween 80 produced maximum bacteriocin activity.
    Brazilian Journal of Microbiology 05/2014; 45(1):81-8. DOI:10.1590/S1517-83822014000100012 · 0.59 Impact Factor
  • B. Han · Z. Yu · B. Liu · Q. Ma · R. Zhang ·
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    ABSTRACT: The objective was to develop an optimal, albeit low-cost medium for bacteriocin production, thereby facilitating industrial production. Soybean meal and peptide, two low-cost nitrogen sources often applied in industrial fermentation, were used to replace their expensive counterparts in De Man Rogosa and Sharpe (MRS). Two factors were first chosen from the 11 considered in the Plankett-Burman (PB) design. Then, the path of steepest ascent and central composite design (CCD) were used to approach the optimum region of the response and determine the maximum activity of the bacteriocin. Optimal concentration of glucose (36.3 g/l) and NaCl (1.41 g/l) stimulated the production of bacteriocins. And the optimal equation was then verified by 50 L fermentor. Under optimized conditions, Lactobacillus plantarum YJG produced a 1.4 fold higher production of bacteriocin than the common MRS, with 40.6% cost savings relative to non-optimized conditions.
    African journal of microbiology research 05/2011; 5(10):1147-1155. · 0.54 Impact Factor
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    ABSTRACT: Lactic acid bacteria are constituents of most of the indigenous microbiota or mucosarelated ecosystems, both in humans or animals. During the last years, many bacteriocins produced by bacteria classified into this group were described. Bacteriocins are ribosomally-synthesized antimicrobial peptides produced by a wide range of bacteria. Historically, they were used as bioactive compounds to prevent the growth of pathogen or spoilage microorganisms in foods. The most widely used is nisin, produced by Lactococcus lactis, that is included in the CODEX and has the GRAS (Generally Recognized as Safe) status to be incorporated into different types of processed or longterm storage foods. As bacteriocins are active against many pathogens, potentially pathogens or some drug-resistant pathogens, some of them have been thought as alternative bioactive substances to avoid the broad side-effects and alarming resistance dissemination produced by the use of classical antibiotics. Our research group is working in the design of a beneficial product to prevent prevent women urogenital infections, and we were the first to describe salivaricin CRL 1328, a bacteriocin produced by Lactobacillus salivarius isolated from human vagina. This bioactive compound is heat-stable, and active against a wide variety of urogenital pathogens. The molecular characterization of salivaricin indicates that is constituted by two structural peptides and the evaluation of the mechanism of action reveals that acts by dissipating the proton motive force of the sensitive pathogens. As we are interested to incorporate salivaricin into a pharmaceutical product, the optimization of the culture media and physico-chemical conditions for the higher production were determined. And also the stability to the freeze-drying process and to the long term storage conditions was studied. Some of these experiments were performed by the application of statistical methods that allowed a faster and easier interpretation of the experimental results obtained. The incorporation of bacteriocins as bioactive compounds in a pharmaceutical product needs different type of studies to demonstrate the no existence of adverse effects, which must be performed both in in vitro and in in vivo experimental systems. Most of the bacteriocins do not exert significant cytoxicity or hemolytic activity against human erythrocytes in in vitro assays. Experiments in animal models have shown the success of some lantibiotics for the treatment of infections produced by Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA), and also in the prevention of gingivitis. Nisin is included into a pharmaceutical product to prevent cow mastitis, and is proposed as spermicidal for human use. In this chapter, a revision of many of the bacteriocins described for prevention of human health are reviewed, together with those available commercially, evaluated by in vitro or in vivo assays. Up today, the use of bacteriocins as bioactive compounds into pharmaceutical products for human use has not been accepted yet by the regulators or reference organizations. There are a wide variety of bacteriocins produced by different bacterial genera that must be further studied. More complex experiments are needed to encourage and support the inclusion of these types of bioactive substances into products that could be applied to prevent or treat many of the wide arrays of pathogenic microorganisms that affect human and animal health.
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