Nutritional Factors Affecting Growth and Production of Antimicrobial Substances by Streptococcus lactis subsp. diacetylactis S1-67/C

Abstract

The present study pertains to the effect of nutritional factors on the growth and production of antimicrobial substances (AS) by Streptococcus lactis subsp. diacetylactis S1-67/C. Among nine media tested, yeast extract dextrose broth supported good growth and maximum production of AS. Addition of beef extract and yeast extract at 1.0 and 0.6% levels, respectively, increased growth as well as production of AS. Of ten carbohydrates examined, maximum production of AS was achieved with 1% glucose followed by fructose, 4% molasses, lactose, sucrose, galactose, mannitol, maltose and 2% molasses. Xylose inhibited production of AS, although it stimulated growth of the organism. Peptone, tryptone and tryptose (each at the 1.5% level) significantly stimulated production of AS. Other nitrogen sources, including soytone, casein hydrolysate and proteose peptone, retarded production of inhibitory substances. Among the amino acids, L-leucine, DL-methionine and L-glutamic acid were most essential for growth and production of AS, whereas L-lysine, L-proline, DL-serine, DL-asparatic acid, L-arginine-HCl and DL-tryptophan were stimulatory. Other amino acids such as DL-ornithine, L-cysteine-HCl and DL-citrulline slightly stimulated AS production. In the presence of cynocobalmin, niacin, folic acid, calcium pantothenate and riboflavin, S. lactis subsp. diacetylactis S1-67/C produced maximum amounts of inhibitory substances. Omission of individual mineral salts from the basal medium did not affect production of AS by the organism.

Lactic acid bacteria – Potential for control of mould growth and mycotoxins: A review

“…lactis subsp. diacetylactis was able to produce substantial amounts of antifungal substance in a narrow range of pH (5.5-7), although maximal production occurred at pH 6.8 (Batish et al, 1997;Reddy & Ranganathan, 1985). Similar data were obtained by Corsetti et al (1998), who reported an optimal production of inhibitory substances by Lactobacillus sanfranscico CB1 at pH 6.…”

“…Reddy and Ranganathan (1985) have reported that the greatest production of antifungal metabolites by Lc. lactis subsp.…”

“…lactis subsp. diacetylactis (Reddy & Ranganathan, 1983). An increase in the concentration of NaCl from 0.5% to 3% in Lb.…”

Production of Antibacterial and AntifungalMetabolites by (S.albovinaceus) Strain no.10/2 and MediaOptimization

“…Studies carried out by some investigators revealed that maximal production of antibiotic substances occurred after 96 hrs (Reddy &Ranganathan, 1985;Sujathaet al, 2005;Mustafa, 2009).This is in agreement with our results (Figure 8). In contrast, the highest biomass and antibiotic activity was observed at an incubation time of 72 hrs by some other investigators (Srinivasuluet al, 2002).…”

“…In contrast, it was showed that maximum antibiotics production was obtained at acidic pH (Reddy &Ranganathan, 1985;VenkataDasu and Panda, 1999;Jichenget al, 2008). It has been reported that maximum production of bacitracin and other antibiotics occurred at alkaline pH (Basilioet al, 2003).…”