Article

Effects of culture conditions on the growth and auto-aggregation ability of vaginal Lactobacillus johnsonii CRL 1294.

CERELA, Chacabuco 145, Tucumán, Argentina.
Journal of Applied Microbiology (Impact Factor: 2.2). 02/2005; 99(6):1383-91. DOI: 10.1111/j.1365-2672.2005.02726.x
Source: PubMed

ABSTRACT To evaluate the effects of different physico-chemical factors on the growth and auto-aggregating ability of vaginal Lactobacillus johnsonii CRL 1294.
L. johnsonii CRL 1294 was cultivated in different culture media, initial pH and temperature of incubation. The growth parameters were estimated by the Gompertz model, being optimal (higher final biomass and growth rate, and shorter lag phase) at an initial pH of 6.5 and at a temperature of 37 degrees C, both in LAPTg and MRS. The auto-aggregation ability, which was assessed by a model of exponential association, was evidenced in all the growth phases, being higher at pH 5 or 6.5.
The growth of L. johnsonii CRL 1294 was affected in different way by all the physico-chemical factors tested. However, the auto-aggregation ability increased mainly at low initial pH of growth media.
The auto-aggregation ability under different culture conditions of a vaginal Lactobacillus strain was systematically and statistically evaluated for the first time. The higher cellular aggregation evidenced at low pH could be a fundamental characteristic in the acidic vaginal environment to promote the protective role of lactobacilli.

0 Bookmarks
 · 
96 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Lactococcus lactis is highly efficient probiotics microorganism with wide range of benefits on human health. This study was conducted to design and establish industrial platform for high cell density cultivation of this novel probiotic strain, L. lactis (WICC-B25). During bioreactor cultivation of lactic acid bacteria in industrial scale, there are two main problems during process namely: low cell growth rate and high lactate production. These both together resulted in low cell mass production. Therefore, this study was focused on cultivation parameters optimization for high cell mass production with minimal lactate formation in shake flask and bioreactor levels. Cell growth was studied in 16-L stirred tank bioreactor under controlled and uncontrolled pH conditions. The maximal cell mass of about 5.6 g L -1 was obtained after 14 h cultivations under uncontrolled pH condition. This value was almost 35% higher than those cell mass obtained in pH controlled culture. Based on this data, fed-batch cultivation strategy was developed using mixed substrate feeding solution (containing all medium component) and mono-feeding (using glucose alone). For both cultures, fed was adjusted to constant rate of 3 g L -1 h -1 and, DO was cascaded to agitation speed to prevent the drop of DO to value less than 30% saturation as oxygen is limited factor for high cell mass production. Culture of mono-glucose feeding yielded the maximal cell mass of about 20 g L -1 after 30 h. On the other hand, the cell mass obtained in mixed substrate feeding culture was only 8.4 g L -1 . Thus, we can conclude that fed-batch cultivation under uncontrolled pH, mono-glucose feeding and DO stat of 30% is suitable cultivation strategy for high cell mass production of L. lactis in bioprocess industry.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Based on the natural benefits of the indigenous microbiota, lactic acid bacteria (LAB) from poultry origin were isolated from hens and broilers intestine, and their probiotic potential was further studied. The tolerance to digestion, adhesion, capture of a mannose-binding lectin, absence of virulent factors and antibiotic resistances were studied. Different in vitro and ex vivo assays were performed to select tolerant and adherent strains because standardized protocols have not been defined. Fourteen strains highly tolerant to gastrointestinal digestion were genetically identified. Hidrophobic surfaces were not required for the bacterial adhesion and only nine strains adhered ex vivo to the intestinal mucosa. Three strains captured a lectin of the same specificity of Type-1 fimbriae. Virulence factors were absent but some strains evidenced multiple antibiotic resistances. These results provide bases for a future standardization of methods for the selection of probiotic strains intended to reinforce the microbiota of newly hatched chickens.
    Research in Veterinary Science. 01/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Urogenital infections affect millions of people every year worldwide. The treatment of these diseases usually requires the use of antimicrobial agents, and more recently, the use of probiotic lactic acid bacteria (LAB) cultures for the management of vaginal infections has been extensively studied. In this work, 11 vaginal lactobacilli isolates, previously obtained from healthy patients, were studied to screen microorganisms with probiotic properties against Candida spp. The LAB were tested for their ability of auto-aggregation, co-aggregation with C. albicans, C. glabrata, C. krusei, and C. tropicalis, adhesion to Caco-2 epithelial cells and production of lactic acid and hydrogen peroxide (H2O2). All lactobacilli isolates tested were able to auto-aggregate (ranging from 25.3% to 75.4% assessed at 4 hours of incubation) and to co-aggregate with the four Candida species into different degrees; among them L. crispatus showed the highest scores of co-aggregation. The highest amount of lactic acid was produced by L. salivarius (13.9 g/l), followed by L. johnsonii (6.5 g/l), L. acidophilus (5.5 g/l), and L. jensenii (5.4 g/l). All isolates produced H2O2, but the highest levels (3 - 10 mg/l) were observed for L. acidophilus, L. crispatus, L. gasseri, L. johnsonii, and L. vaginalis. Only L. agilis, L. jensenii, L. johnsonii and L. ruminus were able to adhere to epithelial Caco-2 cells. Among the isolates evaluated, L agilis, L. jensenii, L. johnsonii, and L. ruminus exhibited simultaneously several desirable properties as potential probiotic strains justifying future studies to evaluate their technological properties in different pharmaceutical preparations for human use.
    Brazilian Journal of Microbiology 01/2010; 41(1):6-14. · 0.76 Impact Factor

Full-text

Download
0 Downloads