Acid-Producing Microorganisms

Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

“…Phenotypic characteristics were tested as follows: each colony was aseptically transferred to a tube with MRS broth (Himedia, Mumbai, India) supplemented with 5% of glucose and an inverted Durham tube incubated at 30 °C for 48 h for test the gas production from glucose ( Potes and Marinho, 2007 ; Wu et al , 2012 ); after aliquots of the tube of gas production from glucose were tested for Gram reaction ( Oliveira et al , 2008 ; Silva et al , 2010 ). From this point the tests were performed following the sequence of classification according to the flowchart proposed ( Figure 1 ) and all the test were performed by aliquots of the test of gas production from glucose: catalase activity was tested by addition of hydrogen peroxide 3% ( Oliveira et al , 2008 ; Marty et al , 2012 ); growth at 10 °C for 7 days, and at 45 °C for 48 h, were tested in MRS broth with 0.02 g/L of bromocresol purple ( Hall et al , 2001 ; Potes and Marinho, 2007 ; Wu et al , 2012 ); growth in 18% NaCl added bromocresol purple 0.02 g/L at MRS broth were tested at 30 °C for 48 h ( Hall et al , 2001 ; Wu et al , 2012 ; growth at pH 4.4 e 4.5 in MRS broth adjusted to correct pH by the addition 1 M HCl ( Schillinger and Lücke, 1989 ) were incubated at 30 °C for 48 h; determination of lactic acid isomer formed (L, D or DL) was performed using an enzymatic-colorimetric kit (R-Biopharm, 11112821035, Darmstadt, Germany) according to the indication of the supplier. The reagents used were of analytical reagent grade.…”

“…Originally, the group of LAB included four kinds of great importance in food: Lactobacillus, Leuconostoc, Pediococcus and Streptococcus ( Hall et al , 2001 ; Silva et al , 2010 ) . Currently, this group consists on 15 genera ( Jay, 2005 ; Landgraf, 2008 ; Silva et al , 2010 ).…”

Prediction of acid lactic-bacteria growth in turkey ham processed by high hydrostatic pressure

“…The commercial viability of pressurized and non treated (control) turkey ham was determined based on lactic acid bacteria growth (LAB) following the methodology described by Hall et al (2001). From each piece of turkey ham 25 g of product were aseptically sampled, placed in sterile bags with the addition of 225 mL of peptone water (1%).…”

Effect of high pressure treatment on microbiological quality of Indian white prawn ( Fenneropenaeus indicus ) during chilled storage

“…Colonies which were gram-negative, catalase positive, oxidase positive and oxidative in glucose metabolism were taken for calculation of H 2 S producing bacterial count (Gram et al, 1987). Estimation of Lactic acid bacterial count was carried out as per the method of the American Public Health Association (APHA) as described in Compendium of Methods for the Microbiological Examination of Foods (Hall et al, 2013). Samples were homogenized in 0.1% peptone water, serially diluted and plated on De Man, Rogosa and Sharpe (MRS) Agar plates.…”