ABSTRACT
The aim of this study was to enhance the production of vitamin K2 by using N-methyl-N-nitro-N-nitroso-guanidine (NTG) and low energy ion beam implantation and optimizing the fermentation medium. Mutation resulted in 1.66-fold higher production of vitamin K2 than that of the parentl strain. The production by the mutant BN-P15-11-1was increased 55% and reached 3.593±0.107 mg/L by using the Plackett-Burman and Box-Behnken designs to optimize the fermentation medium. The optimal fermentation culture medium was composed of (g/L) glycerol 69.6, sucrose 34.5, K2HPO4 4.0, peptone 20, yeast extract 25 and fermented at 37 °C and 150 rpm for 72 h. The results showed that the NTG and low energy ion beam implantation mutations and optimizing fermentation medium were effective methods to enhance vitamin K2 production.
ABSTRACT
Levan is an exopolysaccharide of fructose primarily linked by À-(2¨6) glycosidic bonds with some À-(2¨1) branched chains. Due to its chemical properties, levan has possible applications in both the food and pharmaceutical industries. Bacillus subtilis is a promising industrial levan producer, as it ferments sucrose and has a high levan-formation capacity. A new strain of B. subtilis was recently isolated from Japanese food natto, and it has produced levan in large quantities. For future pharmaceutical applications, this study aimed to investigate the effects of levan produced by B. subtilis Natto, mainly as potential hypoglycemic agent, (previously optimized with a molecular weight equal to 72.37 and 4,146 kDa) in Wistar male rats with diabetes induced by streptozotocin and non-diabetic rats and to monitor their plasma cholesterol and triacylglycerol levels. After 15 days of experimentation, the animals were sacrificed, and their blood samples were analyzed. The results, compared using analysis of variance, demonstrated that for this type of levan, a hypoglycemic effect was not observed, as there was no improvement of diabetes symptoms during the experiment. However, levan did not affect any studied parameters in normal rats, indicating that the exopolysaccharide can be used for other purposes.
Subject(s)
Animals , Rats , Bacillus subtilis/isolation & purification , Streptozocin/analysis , Fructans/analysis , Fructose/analysis , Hypoglycemia , Sucrose/analysis , Methodology as a Subject , Rats, WistarABSTRACT
Natural killer (NK) cells specifically lyse cancer cells or infected cells and play important roles in immune surveillance against tumor and infection. Probiotics, live bacteria and their metabolic products beneficial to humans, are reported to modulate NK cell activity and result in the prevention of tumor development. In this study, we examined the effect of metabolic products of strain <i>Bacillus subtilis AK</i>, selective strain from <i>Bacillus subtilis natto</i>, (EMBSAK) on NK cell activity. NK cell activity in peripheral blood mononuclear cells (PBMC) was enhanced in 50% of the rats orally inoculated with EMBSAK. In the experiments using EMBSAK-containing product, SARABAGAN, increasing frequency of NK cell activation was observed in volunteers as dose depending manner. These results suggested that supplemental intake of EMBSAK enhanced NK cell activity and indicated the possible utility of EMBSAK as complementary and alternative medicine, although susceptibility is individually various.<br>