在酵母和细菌细胞共存的情况下,感兴趣的是同时量化两种细胞类型的浓度,因为用于单独确定这些浓度的传统方法需要更多的时间和资源。这里,我们比较了在微生物悬浮液中定量燃料乙醇酿酒酵母PE-2酵母菌株和来自益生菌植物乳杆菌菌株的细胞的不同方法。制备单独的悬浮液,以1:1或100:1的酵母与细菌比例混合,涵盖了甘蔗生物精炼厂通常遇到的范围,并使用明场显微镜进行分析,手动和自动摊板和滴板计数,流式细胞术(比例为1:1和100:1),和库尔特计数器(1:1和100:1的比例)。我们观察到,对于混合物中的酵母细胞计数(1:1和100:1比例),流式细胞术,库尔特柜台,和两个扩散板选项(手动和自动CFU计数)产生统计上相似的结果,而滴板和基于显微镜的方法给出了统计学上不同的结果。对于细菌细胞定量,基于显微镜的方法,滴盘,平板铺板和流式细胞术(1:1比例)均无明显差异(P>0.05)。相比之下,Coulter计数器(1:1比例)和流式细胞术(100:1比例)显示结果具有统计学差异(P<0.05)。此外,由于酵母细胞碎片和细菌细胞之间的重叠,无法以100:1的比例定量混合悬浮液中的细菌细胞。我们得出结论,每种方法都有局限性,优势,和缺点。
In scenarios where yeast and bacterial cells coexist, it is of interest to simultaneously quantify the concentrations of both cell types, since traditional methods used to determine these concentrations individually take more time and resources. Here, we compared different methods for quantifying the fuel ethanol Saccharomyces cerevisiae PE-2 yeast strain and cells from the probiotic Lactiplantibacillus plantarum strain in microbial suspensions. Individual suspensions were prepared, mixed in 1:1 or 100:1 yeast-to-bacteria ratios, covering the range typically encountered in sugarcane biorefineries, and analyzed using bright field microscopy, manual and automatic Spread-plate and Drop-plate counting, flow cytometry (at 1:1 and 100:1 ratios), and a Coulter counter (at 1:1 and 100:1 ratios). We observed that for yeast cell counts in the mixture (1:1 and 100:1 ratios), flow cytometry, the Coulter counter, and both Spread-plate options (manual and automatic CFU counting) yielded statistically similar results, while the Drop-plate and microscopy-based methods gave statistically different results. For bacterial cell quantification, the microscopy-based method, Drop-plate, and both Spread-plate plating options and flow cytometry (1:1 ratio) produced no significantly different results (P > 0.05). In contrast, the Coulter counter (1:1 ratio) and flow cytometry (100:1 ratio) presented results statistically different (P < 0.05). Additionally, quantifying bacterial cells in a mixed suspension at a 100:1 ratio wasn\'t possible due to an overlap between yeast cell debris and bacterial cells. We conclude that each method has limitations, advantages, and disadvantages.