培养条件对海水中菌落总数测定的影响

目的了解平板计数法测定海水中菌落总数时适宜的培养条件:培养基、培养温度和培养时间。方法深圳水域的海水样品在不同培养基、培养温度条件下,经过不同培养时间培养后进行菌落总数计数。结果在培养温度为25℃、30℃、36℃条件下,在相同培养时间内,2216E琼脂的菌落总数明显高于营养琼脂的菌落总数及平板计数琼脂的菌落总数(P<0.05);采用2216E琼脂进行菌落总数测定,在培养温度30℃培养96h后,菌落总数达到最高,且菌落总数高于25℃和36℃培养时的菌落总数(P<0.05)。结论海水中菌落总数测定时应注意培养时间的控制。2216E琼脂适合用于海水菌落总数测定。深圳区域海水中菌落总数测定适宜采用2216E琼脂于30℃培养96h。有关国家标准中海水中菌落总数测定方法所规定的培养温度、培养时间应考虑进行修订完善以准确检测水温较高的南方区域海水。

Effects of culture condition on aerobic plate count of seawater

Objective To study studied the suitable medium, culture temperature and culture time, and to determine the aerobic plate count of seawater. Methods Samples of seawater from Shenzhen area were cultured in different media, temperature, after different time colony-forming unit were counted. Results In culture temperature of 25℃, 30℃, 36℃, with the same culture time, colonies numbers on 2216E agar were obviously more than on the nutrient agar and the plate count agar （P 0.05）; using 2216E agar for aerobic plate count in temperature 30℃ reached the highest number of colonies after 96 h, and the numbers of colony are higher than in 25℃ and 36℃（P 0.05）. Conclusion Culture time should be well controlled when the aerobic plate count of seawater was detected. 2216E agar is a suitable medium for aerobic plate count of seawater in Shenzhen area. In order to accurately detect the aerobic plate count of seawater of the South region where water temperature is relatively high, the necessary amendments to the culture temperature, culture time of the relevant national standards should be carried out.