Lactobacillus Coryniformis Research Articles

Isolation of Novel Beer-Spoilage Bacteria from the Brewery Environment

Two strains of beer-spoilage bacteria, BS-1 and EM-63, were isolated from the environment (from drainage) in our breweries. Strain BS-1 belonged to a homo-fermentative species of the genus Lactobacillus. The partial sequence of 16S rDNA indicated that strain BS-1 was related to Lactobacillus coryniformis. However, the fermentation pattern of the sugars was different from that of L. coryniformis and other species of Lactobacillus, because of the narrow fermentation spectrum, glucose, mannose, and fructose. Strain EM-63 was a Gram-negative, strictly anaerobic rod-shaped bacterium with no flagella. The GC content of DNA was 41%, and the cell wall peptidoglycan was directly cross-linked mesodiaminopimelic acid. The major fermentation acids were succinic acid and D-lactic acid in the culture media, while propionic acid was neither produced in culture media nor in beer. These characteristics indicated that strain EM-63 did not belong to the genus Pectinatus, known as Gram-negative, rod-shaped, beer-spoilage bacteria, or the genus Zymophilus or Selenornonas, known as Gram-negative, rod-shaped, pitching yeast contaminants. On the basis of the physiological characteristics and genetic analysis, we conclude that these strains are novel beer-spoilage bacteria.

Microflora of Boza, a traditional fermented Turkish beverage

Boza, a Turkish traditional beverage made by yeast and lactic acid fermentation of cooked maize, wheat and rice flours was prepared and the microbial characteristics were investigated. During the course of fermentation from 0 to 24 h, populations of lactic acid bacteria and yeast raised from 7.6 × 10 6 and 2.25 × 10 5 after inoculation to 4.6 × 10 8 and 8.1 × 10 6, respectively; pH dropped from 6.1 to 3.5; total titratable acidity by means of lactic acid increased from 0.02 to 0.27 mmol/g; alcohol content increased from 0.017% to 0.79%. Seventy seven isolates of lactic acid bacteria and 70 yeast isolates were identified. The lactic acid bacteria isolated during the fermentation included Leuconostoc paramesenteroides (25.6%), Lactobacillus sanfrancisco (21.9%), Leuconostoc mesenteroides subsp. mesenteroides (18.6%), Lactobacillus coryniformis (9.1%), L. confusus (7.8%), Leuconostoc mesenteroides subsp. dextranicum (7.3%), Lactobacillus fermentum (6.5%), Leuconostoc oenos (3.7%). The yeasts isolated comprised Saccharomyces uvarum (83.0%) and S. cerevisiae (17.0%).

Assessment of kinetic models for the production of l- and d-lactic acid isomers by Lactobacillus casei DMS 20011 and Lactobacillus coryniformis DMS 20004 in continuous fermentation

Data from the continuous fermentation of Lactobacillus casei subsp. casei DSM 20011 and Lactobacillus coryniformis subsp. torquens DSM 20004 were separately analyzed using two kinetic models. In addition to the fitting of biomass, product and substrate concentrations obtained under steady-state chemostat conditions, the results of transient washout experiments were considered for this purpose. This integrated procedure is a suitable, quick means to identify the most appropriate kinetic model among several.

Characterization of lactobacilli by Southern-type hybridization with a Lactobacillus plantarum pyrDFE probe.

Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus paraplantarum (M.-C. Curk, J.-C. Hubert, and F. Bringel, Int. J. Syst. Bacteriol. 46:595-598, 1996) can hardly be distinguished on the basis of their phenotypes. Unlike L. plantarum and L. paraplantarum, L. pentosus ferments glycerol and xylose but not melezitose. We identified two L. pentosus strains (CNRZ 1538 and CNRZ 1544) which ferment glycerol and melezitose but not xylose. alpha-Methyl-D-mannoside was fermented by 66% of the L. plantarum strains tested but not by L. paraplantarum strains. In this paper we describe a simple method to identify L. plantarum, L. pentosus, and L. paraplantarum. This method is based on nonradioactive Southern-type hybridization between BglI DNA digests of the lactobacilli tested and a DNA probe (L. plantarum pyrDFE genes from strain CCM 1904). A total of 68 lactobacilli were classified into five groups on the basis of the bands detected. Two groups contained L. plantarum strains; one of these groups contained 31 strains, including the type strain, and was characterized by bands at 7, 4, and 1 kb, and the other group contained strain LP 85-2 and was characterized by bands at 5 and 1.1 kb. Only one band (a band at around 7 kb) was detected in the strains belonging to the L. pentosus group, and two bands (at 4 and 1 kb) were found in the strains belonging to the L. paraplantarum group. No hybridization was detected in the last group, which contained Lactobacillus casei, Lactobacillus coryniformis, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus delbrueckii, and Lactobacillus leichmannii strains.