Growth-promoting medium for bacteria validated by plate counting.

Objective To add certain growth-promoting substances in the E. coli growth medium, then develop the optimal concentration, ultimately obtain the composite medium for promoting the growth of E. coli. Methods Based on the plate counting method, the suitable concentration of growth-promoting substances were selected and the orthogonal method was also used to optimize concentrations of growth-promoting substances, and then plate counting method was used to study the definite growth- promoting effects for bacteria. Results The optimal substances formula for bacterial growth were: A: 0.3%; B: 0.3%; C: 0.5 mmol/L; D: 0.5 mmol/L; E: 0.1 mmol/L;Compared with the control group, after being cultured in composite medium obtained by orthogonal optimization, E. coli bacterial counts in each growing season increased significantly. After the continuous culture of 6 h, 8 h, 10 h, 12 h, plate counting showed that bacterial growth colonies in the composite medium group was 7.80 times, 6.00 times, 6.74 times and 4.19 times as high as that in the control group; At the same time, during the process of culturing Staphylococcus aureus and the total bacteria counting of water sample from a river , the composite medium also had significant growth-promoting effect. Conclusion Three kinds of complex medium developed in this study show a significant role in promoting bacteria growth.