Growth and Gas Formation by Lactobacillus wasatchensis, a Novel Obligatory Heterofermentative Nonstarter Lactic Acid Bacterium, in Cheddar-style Cheese Made Using a Streptococcus thermophilus Starter

Authors

Western Dairy Center, Utah State University
Megan Jane Ostler, Utah State University
Jeff Broadbent, Utah State UniversityFollow
Craig J. Oberg, Weber State University
Donald J. McMahon, Utah State UniversityFollow

Document Type

Article

Journal/Book Title/Conference

Journal of Dairy Science

Volume

98

Issue

11

Publisher

Elsevier

Publication Date

11-2015

First Page

7473

Last Page

7482

Abstract

A novel slow-growing, obligatory heterofermentative, nonstarter lactic acid bacterium (NSLAB) Lactobacillus wasatchensis WDC04 was studied for growth and gas production in Cheddar-style cheese made using Streptococcus thermophilus as the starter culture. Cheesemaking trials were conducted using St. thermophilus alone or in combination with Lb. wasatchensis deliberately added to cheese milk at a level of ~10⁴ cfu/ml. Resulting cheeses were ripened at 6 or 12°C. At d 1, starter streptococcal numbers were similar in both cheeses (~10⁹ cfu/g) and fast-growing NSLAB lactobacilli counts were below detectable levels (<10² cfu/g). As expected, Lactobacillus wasatchensis counts were 3 x 10⁵ cfu/g in cheeses inoculated with this bacterium and below enumeration limits in the control cheese. Starter streptococci decreased over time at both storage temperatures but declined more rapidly at 12°C, especially in cheese also containing Lb. wasatchensis. Populations of fast-growing NSLAB and the slow-growing Lb. wasatchensis reached 5 x 10⁷ and 2 x 10⁸ cfu/g, respectively, after 16 wk of storage at 12°C. Growth of NSLAB coincided with a reduction in galactose concentration in the cheese from 0.6% to 0.1%. Levels of galactose at 6°C had similar decrease. Gas formation and textural defects were only observed in cheese with added Lb. wasatchensis ripened at 12°C. Use of St. thermophilus as starter culture resulted in galactose accumulation that Lb. wasatchensis can utilize to produce CO₂, which contributes to late gas blowing in Cheddar-style cheeses, especially when the cheese is ripened at elevated temperature.

Recommended Citation

Western Dairy Center, Utah State University; Ostler, Megan Jane; Broadbent, Jeff; Oberg, Craig J.; and McMahon, Donald J., "Growth and Gas Formation by Lactobacillus wasatchensis, a Novel Obligatory Heterofermentative Nonstarter Lactic Acid Bacterium, in Cheddar-style Cheese Made Using a Streptococcus thermophilus Starter" (2015). Nutrition, Dietetics, and Food Sciences Faculty Publications. Paper 851.
https://digitalcommons.usu.edu/nfs_facpub/851