3M Petrifilm Lactic Acid Bacteria Count Plate Is a Reliable Tool for Enumerating Lactic Acid Bacteria in Bacon

Abstract

This study aimed to evaluate the behavior of Petrifilm™ Lactic Acid Bacteria Count Plates (PLAB) as an alternative methodology to enumerate lactic acid bacteria (LAB) in bacon. Bacon samples (n = 40) were obtained from retail sale, ten-fold diluted with buffered peptone water (BPW, 0.2% w/v) and Letheen broth, and subjected to LAB enumeration according to 4 protocols: 1) de Man Rogosa Sharpe agar (MRS), pH 5.7, 30 °C; 2) MRS, pH 5.7, 30 °C, anaerobiosis; 3) all purpose tween agar (APT), 25 °C; 4) PLAB, 30 °C. Colonies were enumerated at 24, 48 and 72h, and the results expressed as log 10 CFU/g for comparison by ANOVA and regression (p < 0.05). Further, colonies were randomly selected and characterized as LAB (Gram staining and catalase). Mean LAB counts from MRS and PLAB did not present significant differences independently of incubation time or diluent (p > 0.05), while counts in APT with BPW after 24h were significantly lower (p < 0.05). PLAB counts with BPW (24, 48, 72 h) presented significant correlation with MRS (r ranging from 0.87 to 0.89; in anaerobiosis, r ranging from 0.94 to 0.95) and APT (r ranging from 0.84 to 0.86). With Letheen, PLAB (24, 48, 72h) presented significant correlation with MRS (r ranging from 0.92 to 0.94; in anaerobiosis, r ranging from 0.93 to 0.96) and APT (r ranging from 0.77 to 0.79). A total of 1,032 from 1,063 (97%) colonies was characterized as LAB. Based on the obtained results, PLAB can be considered as an alternative tool for enumerating LAB in bacon, with reliable results even after 24 h of incubation.

Determination of microbiological, aromatic and sensory properties in different ripening period of Bayramiç cheese produced with and without bifidobacteria inoculation and comparison with similar industrial cheeses

“…Lactic acid bacteria count was done with 3M Petrifilm™. Lactic Acid Bacteria Count Plate (incubation at 30 °C for 48 hours) (Nero et al, 2020).…”

Real-Time Monitoring the Effects of Storage Conditions on Volatile Compounds and Quality Indexes of Halal-Certified Kimchi during Distribution Using Electronic Nose

“…Lactic acid bacteria were counted by the 3M Petrifilm lactic acid bacteria count plate method 6461/6492. The evaluation of Petrifilm is a reliable LAB enumeration method compared with the traditional methodology [ 31 , 32 ]. In sterile conditions, portions of Kimchi (10 g) were obtained from each sample and diluted 10-fold with 90 mL of 0.85% saline solution in a sterile filter bag.…”

Establishment of a rapid counting method for lactic acid bacteria and yeast in dairy products

“…In recent years, numerous methods have been applied to quantify microorganisms in foods, such as the plate count agar (PCA) method (Townsend and Naqui 1998;Park and Kim 2013), paper tests (Bird et al 2015;Nero et al 2020), polymerase chain reaction-denaturing gradient gel electrophoresis (Garofalo et al 2017;Ramezani et al 2018), high-throughput sequencing technology (Quijada et al 2020) and real-time fluorescence quantitative PCR (Martins et al 2019). However, these methods are complicated and are limited in their abilities to accurately detect and quantify specific microorganisms, especially when there are many samples.…”

“…2015; Nero et al . 2020), polymerase chain reaction‐denaturing gradient gel electrophoresis (Garofalo et al . 2017; Ramezani et al .…”