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... The growth of a Pseudomonas sp., an Enterobacter sp., Kurthia zopfii, Microbacterium thermosphactum and a Lactobacillus sp. in pure culture on porcine muscle at 16 and 2° was examined in both open and gas-tight systems. The CO₂ in the headspace of the gas-tight containers was produced by the muscle and by the bacteria. The Gram negative bacteria produced much lower amounts of CO₂ than the Gram pos ...
... A plating procedure simulating conditions in ripening Cheddar cheese was used to isolate microorganisms in young cheese that grow at ordinary ripening temperatures. Forty-one commercial cheese samples, most 7 days old, were obtained from ten Iowa manufacturing plants. Samples were plated in special Trypticase-soy agar, covered with 50 ml of 1.5% (w/v) agar, and incubated at 7.2 C for 3 months. Fol ...
... This paper, the second of four, discusses the starters used in Swiss cheese manufacture. Propionibacteria are essential for development of characteristic Swiss cheese flavor; high-temperature lactobacilli and Streptococcus thermophilus are necessary for control of body, texture, acidity, moisture, and other related factors. The effects of pH, salt, temperature, metals, and media composition on gro ...
... A Gram-positive bacillus commonly isolated from the livers of apparently healthy mice was identified as Lactobacillus sp. It did not cause disease when inoculated into mice. ...
... Germ-free and conventional swine were used to study the influence of a milk diet on the development of swine dysentery in germ-free swine; the effect of a known microbial flora in gnotobiotic swine followed by conventionalization and weaning to a corn-soybean ration; and the effect of an oral inoculation of spirochete B-78 on conventional swine. Typical signs and lesions of swine dysentery were pr ...
... Over a 3-year sampling period Lactobacillus sp. has been isolated from the livers of barrier-maintained and conventional mice. Serology has failed to detect presence of mouse hepatitis virus antibodies in any of these mice. Histopathological examination revealed only mild fatty change and small monocytic infiltrates. ...
... The qualitative and quantitative evolution of the digestive microflora of SPF inbred mice (C57BL/RhoIco strain), barrier-maintained since 1970, is described. Some 'contaminants' appeared spontaneously during the period 1971-1973, but microorganisms belonging to the genera Lactobacillus Streptococcus, Enterobacteria, Escherichia and Bacillus remained stable. The methods of investigation used were n ...
Food and Drug Administration; Lactobacillus; Staphylococcus; acetic acid; bacteria; food pathogens; health hazards; mayonnaise; microbial growth; public health; salads; spoilage; sugars; yeasts; United States
Abstract:
... Mayonnaise and salad dressing commercially produced in the United States are defined in accordance with the Food and Drug Administration Standard of Identity. The microbiological content of these products is dictated primarily by the high acetic acid concentration found in their aqueous phase. The overall microbiological content of mayonnaise and salad dressing is low with a very low incidence of ...
... Boneless pork roasts were vacuum-packaged; one group remained in vacuum-packages (controls), other vacuum-packages were injected with one of six gas mixtures: (a) 100% O2, (b) 20% CO2 + 80% N2, (c) 50% CO2 + 50% O2. (d) 20% CO2 + 80% O2, (e) 25% CO2 + 25% O2 + 50% N2, or (f) 51% CO2 + 30% O2 + 18% N2 + 1% CO. Roasts were stored from 0–35 days at 1–3 C and chops from each treatment were observed un ...
... A microbiological examination of vacuum-packaged strip loin steaks that were defective (gassy packages, hydrogen sulfide odor) revealed high total counts (107–108/cm2) with Hafnia alvei, Lactobacillus and Pseudomonas spp. as major isolates. Re-inoculation experiments indicated that H. alvei was the likely cause of the hydrogen sulfide odor. Gas formation resulted from the activity of heteroferment ...
... Electrical stimulation of rabbit muscles caused a reduction in count of Pseudomonas putrefaciens and of a Lactobacillus sp. when inoculated muscles were held for 45 min after electrical stimulation. Little if any change in count was detected on rabbit muscles immediately after electrical stimulation and after 20 min of storage. Electrical stimulation (ES) of pork carcasses did not affect the aerob ...
... Pork loins were vacuum-packaged; one group remained vacuum-packaged, other vacuum packages were injected with gas atmospheres of either 20% CO2 + 80% N2 or 40% CO2 + 60% N2. Loins were stored for 7, 14, 21 and 28 days at 1–3 C. After each storage interval, chops were prepared from loins and subjected to 5 days of retail display. Psychrotrophic bacterial counts of lean and fat surfaces of loins sto ...
... Three sampling periods were selected to acquire ground beef packages from two retail stores. Initially, samples were subjectively evaluated for color and overall appearance. Microbial load and taxonomy were determined and the samples were subsequently frozen. After frozen storage, one-half of the packages were thawed at 5 C for 4, 8, 24, 48 and 72 h, whereas the other samples were thawed at 25 C f ...
... Pseudomonas putrefaciens and lactobacillus counts of inoculated pork skin obtained with the maceration method usually were higher than were those obtained with the rinse method. Scalding and dehairing and shaving caused extensive destruction of the test organisms when placed on the skin before these slaughter-dressing steps. Smaller decreases in count occurred during singeing and washing and durin ...
... Beef, pork and lamb loins were vacuum-packaged as subprimal cuts (controls), reformed subprimal cuts and as retail cuts (steaks or chops). Subprimal cuts, reformed subprimal cuts and one group of retail cuts remained vacuum-packaged. Other groups of retail cuts were injected with atmospheres of either 20% CO2 + 80% N2 or 40% CO2 + 60% N2. Cuts were randomly assigned to storage periods of 0–21 days ...
... Beneficial effects of yoghurt on human health have been claimed for hundreds of years; recent investigations tend to support those nutritional, organoleptic and possibly therapeutic claims. While the chemical composition of yoghurts varies considerably by processing, the fermentation which changes lactose to lactic acid makes the product valuable to lactose-intolerant individuals. Vitamin content ...
... The composition of faecal flora of NC mice was compared with that of CF#1 mice. NC- and CF#1-germfree (GF) mice were cage-mated with NC- or CF#l-conventional (CV) mice in an isolator. The faecal flora of these ex-GF mice was dependent on the recipient mouse strain modifying colonization by the donor mouse bacteria. Although NC- and CF#1-pups removed by hysterectomy were fostered to different strai ...
... Kocho, an acidic starchy food, is prepared by fermenting a mixture of the scraping of the trunk and pulverized stem and corm of ensette (Ensette ventricosum). Leuconostoc mesenteroides is responsible for initiating the fermentation. Because of the activities of this species and, to some extent, of Streptococcus faecalis, the pH of the fermenting kocho was reduced from 6˙5 to 5˙6. These organisms w ...
... One hundred wildâtype strains of the genus Lactobacillus were isolated from the small intestine of newlyâslaughtered pigs up to 6 months of age. Cell surface hydrophobicity and capsule formation were studied on a number of strains. Strains showing high surface hydrophobicity as measured by the saltâaggregation test and hydrophobic interaction chromatography on Octyl Sepharose were commonly f ...
... During the 1983 silage making season an investigation was carried out to determine the contribution made by farm machinery to the numbers of lactic acid bacteria present on grass. Although no lactic acid bacteria were isolated from the standing crop, up to 103/g were found in the grass as it entered the clamp. Examination of machinery in close contact with the grass revealed lactic acid bacteria o ...
... A method was developed for detecting lactobacilli which produce histamine in cheese. The method uses two enzymes. Diamine oxidase catalyzes the oxidation of histamine. The hydrogen peroxide produced in this oxidation is detected by the formation of a purple color in the presence of leucocrystal violet and horseradish peroxidase. ...
... Cheddar cheese was manufactured by inoculation with and without cultures of homofermentative Lactobacillus strains (L. casei-subsp-casei L. casei-subsp-pseudoplantarum, L. plantarum). Growth rate of microflora, the incidence of heterofermentative lactobacilli and the rate of proteolysis were then studied during aging. The total number of psychotrophs, mesophiles and lactic streptococci reached a m ...
... Cooked, vacuum packaged beef top rounds injected with 0, 1, 2, 3 or 4% sodium lactate were stored up to 84 days at 0°C. Aerobic plate counts (APC), water activity, pH and lactic acid content were determined at 14‐day intervals. Microbial distributions were characterized following 0.56 and 84 days storage. Increasing sodium lactate resulted in reduction in APC. Water activity was not affected by so ...
... Heterotrophic bacteria isolated from two shoreâbased surimi processing plants in Alaska were identified to the genus level. In one plant, the major bacterial constituents were Flavobacterium and Pseudomonas, followed by Moraxella, Aeromonas, Lactobacillus, Serratia, and Acinetobacter. In the other plant, major bacterial groups were Flavobacterium and Arthrobacter/Corynebacterium, followed by Pse ...
... Curvacin A is a bacteriocin produced by Lactobacillus curvatus LTH1174 which is a potential starter organism for the production of fermented dry sausages. This peptide inhibits the growth of the opportunistic food pathogens Listeria monocytogenes and Enterococcus faecalis and thus, curvacin A may enable better performance of a starter and improvement of the hygienic status of meat products. Oligon ...
... The growth kinetics in batch culture of 6 strains, potentially useful as starter cultures for ewe's cheese-making, has been analysed. Under the experimental conditions used a high conversion of carbohydrates into lactic acid was achieved. The production of lactic acid can be used as an indirect biomass measurement. Two mathematical models (Logistic and Gompertz's) have been used to describe the gr ...
soybeans; molasses; lactic acid; Lactobacillus; fermentation; soy protein
Abstract:
... The feasibility of conversion of soy molasses, a low value by-product of soy protein production, to lactic acid by fermentation with Lactobacillus salivarius was investigated. The basic environmental parameters affecting growth and lactic acid production were determined. Lactic acid production in soy molasses was optimal at pH 5.6 and 42 degrees C. Addition of 0.5% yeast extract to soy molasses re ...
... Species of Lactobacillus were isolated and identified from commercial Washington state grapes and wines including L. brevis (4 strains), L. hilgardii (4), L. plantarum (3), and L. fructivorans (1). Unlike other strains, L. brevis and L. plantarum grew in media at relatively low pH (pH 3.16 and 3.34). Sulfur dioxide inhibited all strains as growth was delayed in 33 mg/L total SO2 (pH 3.5). None of ...
... The substrate specificity and catalytic activity of the dinucleotide-dependent L-2-hydroxyisocaproate dehydrogenase from Lactobacillus confusus (L-HicDH) have been altered by modifying an enzyme region which is assumed to be involved in substrate recognition. The design of the variant enzymes was based on an amino acid alignment of the modified region with the functionally related L-lactate dehydr ...
... Twenty-three strains of lactic acid bacteria belonging to the genera Lactobacillus, Lactococcus, Leuconostoc, Pediococcus or Carnobacterium, were studied for growth and siderophore production under controlled iron-starvation conditions. No growth differences were observed in the media either supplemented with or depleted of iron, in agitated (aerobic) or static (microaerophilic) growth conditions, ...
... An experiment was conducted with Single Comb White Leghorn (SCWL) layers to determine the effect of feeding either corn-soybean meal (C-S) or barley-corn soybean meal (B-C-S) diets with or without condensed cane molasses solubles (CCMS) or with or without CCMS-1,100 mg Lactobacillus (Lacto)/kg (ppm) diet on performance, nutrient retentions, digesta passage rate, and histological changes of the gas ...
... Two experiments were carried out for six and seven 28-d periods, respectively, with DeKalb XL Single Comb White Leghorn laying pullets to ascertain the effect of feeding 1,100 mg Lactobacillus (Lacto)/kg diet (ppm) and 2,200 ppm Lacto diets, and the supplementation of these diets with 1 and 3% fat, on layer performance and nitrogen, calcium, and phosphorus retention. The dietary treatments were co ...
... The taxonomic status of nine typical and atypical Lactobacillus sake and Lactobacillus curvatus strains associated with vacuum-packaged meat spoilage was investigated by DNA-DNA homology and compared with four alternative identification methods. Phenotype-based identification methods as well as 23S rRNA targeted probes produced ambiguous results in the case of atypical strains. DNA-DNA hybridizati ...
Lactobacillus; starch; lactic acid; fermentation; pH; temperature; production costs
Abstract:
... Fermentation of L-(+)-lactic acid from soluble starch by Lactobacillus amylophilus was studied. The bacterium produced about 30 g of L-(+)-lactic acid from 50 g of soluble starch when the pH of the culture was ranging from pH 5 to pH 6.8 at 28 degrees C. 53.4 g of L-(+)-lactic acid was produced when 100 g of starch was added in the medium. The fermentation procedures will reduce the cost of comple ...
... Laboratory studies determined the effect of bacterial fermentation variables on pH, ammonia nitrogen, moisture, protein, fat, and ash in poultry carcasses before and after fermentation with dried whey and cornmeal. Field-produced silage was collected throughout the year to determine the effect of seasonal temperature variation. Amino acid profiles changed little during the 10-week fermentation per ...