Effect of Temperature on the Bacterial Growth in Lettuce Substrate

[Objective] To provide references for the effect of constant temperature and fluctuating temperature of the supply chain on the bacterial growth.[Method] The growth of E.coli and original bacteria on the fresh lettuce leaves under the 37 ℃ constant temperature and the simulated fluctuating temperature of the lettuce supply chain in Beijing was analyzed by the methods of plate colony count and SEM.[Result] The extracts of lettuce provided nutrients for the bacterial proliferation;the temperature produced distinct effects on the bacterial growth,higher temperature benefited the proliferation of bacteria,and the original bacteria grew better than the inoculated bacteria;under the simulated low temperature of supply chain,both the growth of E.coli and original bacteria changed with the fluctuated temperature,single bacteria was more sensitive to temperature fluctuation than multiple bacteria,while the multiple bacteria had stronger ability than single bacteria to resist low temperature.[Conclusion] The temperature produces significant impact on the bacterial growth in lettuce juice.