Study On Optimization Of Fermentation Technology And The Effect Of Liver Protection Of GMP

Guanylic acid,also known as 5'-guanine nucleotide?Guanosine-5'-monophos-phate,GMP?,is one of the five types of nucleotides of nucleic acid.It has special freshness like mushroom,which also used as food additives and raw material of condiments in the food industry.Guanylic acid has high biological activity,which can regulate the body's nutrition metabolism,enhance immunity and assist with anti-tumor,but whether it has liver protective effect has not been reported in literature.Firstly,in this paper,variable Bacillus subtilis used as original strain to optimize the fermentation process of guanosine.Secondly,to replicate the acute liver injury model of CCl4,alcohol and Con A in mice and make a preliminary screening of the protective effect of GMP.Finally,copying the model of acute liver injury of mice caused by CCl4,to observe the liver protective effect and discuss the mechanism of resistance to oxidative stress and apoptosis of GMP,to provide theoretical basis for health food and filtrating medicine about hepatopathy.The main results are as follows:1?Carrying out single factor optimization experiment and the three factors and three levels orthogonal experiment about the fermentation medium and fermentation conditions.The optimal fermentation medium formula?%?was established:glucose 12.0;yeast powder 1.6;corn syrup 0.2;sodium glutamate 1.0;K₂HPO₄ 0.2;CaCl₂ 0.2;CaCO₃ 2.0;?NH₄?₂SO₄ 2.0;MgSO₄ 0.05.The best fermentation condition was established:the cultivation time of seed in shake flask 12 h,the quantity of inoculation 10%,fermentation temperature 36?,pH 7.0-7.2,fermentation time 72 h.According to the optimized fermentation medium and fermentation conditions,the concentration of guanosine was up to 10.6 g/L,which was 71%higher than before.2?The levels of ALT and AST in the model group of CCl₄ and alcohol acute liver injury model were significantly higher than their control group?P<0.01?,indicating that the model of CCl₄ and alcoholic acute liver injury was successful.Compared with model group,the levels of ALT and AST in the groups of GMPNa₂?250,125,62.5 mg/kg?significantly decreased?P<0.01?,suggesting it's good protective effect for CCl₄ and alcohol acute liver injury.The levels of ALT and AST in the model group of Con A acute liver injury model were significantly higher than their control group?P<0.01?,indicating that the model of Con A acute liver injury was successful.Compared with model group,the levels of ALT and AST in the groups of GMPNa₂?250,125,62.5 mg/kg?decreased,however,there was no significant difference in the statistical comparison,suggesting its protective effect for Con A acute liver injury was not obvious.3?The levels of ALT and AST in the model group of CCl₄ acute liver injury model were significantly higher than their control group?P<0.01?,indicating that the model of CCl₄ acute liver injury was successful.Compared with model group,the levels of ALT and AST in the groups of GMPNa₂?250,125 mg/kg?significantly decreased?P<0.01?,at the same time,the structure and morphology of the liver after HE staining in the groups of GMPNa₂?250 mg/kg?was improved,suggesting it's good protective effect for CCl₄ acute liver injury.The levels of SOD,GSH-Px and T-AOC in the group of GMPNa₂?250,125 mg/kg?were significantly increased and the levels of MDA was significantly decreased?P<0.01?,suggesting that the liver protective effect of GMP was related to the antioxidant stress.The levels of Caspase-3,Bax in the group of GMPNa₂?250 mg/kg?were significantly down-regulated and the level of Bcl-2 was up-regulated?P<0.01?,suggesting that the liver protective effect of GMP was related to the resistance to apoptosis.