许多环境微生物无法在人工培养基上生长，因此，平板计数法的准确度不高；鱼露等高盐食品微生物数量较少，更难以准确计数。实时荧光定量PCR 法（FQ-PCR）定量微生物不受培养的限制，文中研究以该法定量细菌和真菌数量的条件，通过比较多对引物的扩增效果，确定分别采用16S rDNA细菌通用引物63F-335R和18S rDNA真菌通用引物0817F-1196R扩增细菌和真菌；并确定退火温度均为60 ℃。采用多种细菌和真菌对上述条件进行验证，结果无论单一菌种或混合菌种，在上述条件下扩增效率E均在90% ~ 120%范围内，所得标准曲线决定系数R2大于0.98，符合定量要求。用此方法定量鱼露和虾油的微生物，结果显示鱼露发酵过程中细菌数量在3.16×104~ 3.16×105个/mL范围内变动，数量远高于真菌数；而且该法测得的细菌和真菌数比平板计数法高1 ~ 2个数量级。

Many environmental microbes cannot grow in synthesized culture mediums. Therefore, the accuracy of plate count method for the determination of microbial population was low. For fish sauce or similar high salt foods, which usually harbor small microbial populations, it is more difficult to quantify accurately the microbial population using plate count method. The detection of microbial population with real-time fluorescent quantitative PCR (FQ-PCR) method doesn’t rely on cultivation. Therefore, the paper investigated the conditions of the detection of bacterial and fungal populations using FQ-PCR. By comparing the amplification effects of several sets of primers, the bacterial 16S rDNA universal primer 63F-335R and the fungal 18S rDNA universal primer 0817F-1196R were respectively selected as the primers for FQ-PCR detection of bacterial and fungal populations. And the annealing temperatures were determined to be 60 ℃. The selected FQ-PCR primers and the annealing temperatures were validated using many strains of bacteria and fungi. And for any single or mixed strains, the amplification efficiencies were within 90% ~ 120% and the determination coefficients of the standard curves were over 0.98. These results satisfy the requirements of quantification. The bacterial and fungal populations in fish sauce and shrimp sauce were detected by FQ-PCR using the above conditions. The results showed that during the fermentation of fish sauce, the bacterial population varied within the range of 3.16×104- 3.16×105cells/ml, far higher than the fungal population. Besides, the bacterial and fungal populations in fish sauce and shrimp sauce determined by the FQ-PCR method were 1 - 2 orders of magnitude higher than the results determined by plate count method.