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T A Bell

Publications and source records attributed to T A Bell.

66 records · Page 4Linked to original sources
PubMed1968

Bloater Formation by Gas-forming Lactic Acid Bacteria in Cucumber Fermentations.

The formation of "bloaters" (hollow stock) in cucumbers brined for salt-stock purposes at 5 to 10% salt has been associated with gaseous fermentation caused chiefly by yeasts. Recently, serious early bloater damage, not attributable to yeasts, has been observed in commercial-scale experiments on control of bloaters in overnight dill pickles brined in 50-gal barrels at 3.0 to 4.5% salt. Growth of fermentative species of yeasts was effectively controlled by the addition of 0.025, 0.05, and 0.1% sorbic acid or its sodium salt. In contrast to this, the fermenting brines showed extremely high populations of acid-forming bacteria, identified as Lactobacillus plantarum, L. brevis, and Pediococcus cerevisiae. The gas-forming species (i.e., L. brevis) constituted a high proportion of the total populations. Representative isolates from 36 barrels of overnight dill pickles were tested for their ability to produce bloaters in 1-quart jars of pasteurized cucumbers equilibrated at 4 to 5% salt, 0.25% lactic acid, and pH 4.0. Bloaters, identical with those made by yeast cultures, were produced in all jars inoculated with L. brevis. No bloaters were produced by L. plantarum and P. cerevisiae. These results suggest that the control of bloater damage in cucumber fermentations, particularly at low salt concentrations, may necessitate inhibition of gas-forming lactic acid bacteria.

Journal Article↗
PubMed1966

Pure culture fermentation of green olives.

The method previously developed by us for the pure-culture fermentation of brined cucumbers and other vegetables has been applied successfully to Manzanillo variety olives. Field-run grade fruit was processed first by conventional procedures to remove most of the bitterness. Then the relative abilities of Lactobacillus plantarum, L. brevis, Pediococcus cerevisiae, and Leuconostoc mesenteroides to become established and produce acid in both heat-shocked (74 C for 3 min) and unheated olives, brined at 4.7 to 5.9% NaCl (w/v basis), were evaluated. The heat-shock treatment not only proved effective in ridding the fruit of naturally occurring, interfering, and competitive microbial groups prior to brining and inoculation, but also made the olives highly fermentable with respect to growth and acid production by the introduced culture, particularly L. plantarum. Of the four species used as inocula, L. plantarum was by far the most vigorous in fermentation ability. It consistently produced the highest levels of brine acidity (1.0 to 1.2% calculated as lactic acid) and the lowest pH values (3.8 to 3.9) during the fermentation of heat-shocked olives. Also, L. plantarum completely dominated fermentations when used in two-species (with P. cerevisiae) and three-species (with P. cerevisiae and L. brevis) combinations as inocula. In contrast, when L. plantarum was inoculated into the brines of unheated olives it failed to become properly established; the same was true for the other species tested, but even to a more pronounced degree. L. brevis was the only species used that failed to develop in brines of both heat-shocked and unheated olives. Modification of the curing brine by the addition of lactic acid at the outset, either with or without dextrose, led to a much earlier onset of fermentation with accompanying acid development, as compared to treatments with dextrose alone or nonadditive controls. Reasons for the marked improvement of the fermentability of Manzanillo olives receiving the prebrining heat-shock treatment are discussed.

Journal Article↗
PubMed1964

Pure Culture Fermentation of Brined Cucumbers.

The relative abilities of Pediococcus cerevisiae, Lactobacillus plantarum, L. brevis, and several other species of lactic acid bacteria to grow and produce acid in brined cucumbers were evaluated in pure culture fermentations. Such fermentations were made possibly by the use of two techniques, gamma radiation (0.83 to 1.00 Mrad) and hot-water blanching (66 to 80 C for 5 min), designed first to rid the cucumbers of naturally occurring, interfering, and competitive microbial groups prior to brining, followed by inoculation with the desired lactic acid bacteria. Of the nine species tested, strains of the three common to cucumber fermentations, P. cerevisiae, L. plantarum, and L. brevis, grew to the highest populations, and produced the highest levels of brine acidity and the lowest pH values in fermentations at 5.4 to 5.6% NaCl by weight; also, their sequence of active development in fermentations, with the use of a three-species mixture for inoculation, was in the species order just named. This sequence of occurrence was similar to that estimated by others for natural fermentations. The rates of growth and acid production in fermentations with a mixture of P. cerevisiae, L. plantarum, and L. brevis increased as the incubation temperature was increased from 21 to 27 to 32 C; however, the maximal populations and acidities attained were essentially the same for fermentations at each temperature. Further, these same three species were found to be the most salt tolerant of those tested; their upper limit for appreciable growth and measurable acid production was about 8% salt, whereas thermophilic species such as L. thermophilus, L. lactis, L. helveticus, L. fermenti, and L. delbrueckii exhibited a much lower salt tolerance, ranging from about 2.5 to 4.0%. However, certain strains of L. delbrueckii grew very rapidly in cucumbers brined at 2.5 to 3.0% salt, and produced sufficient acid in about 30 hr at 48 C to reduce the brine pH from above 7.0 to below 4.0. An inexpensive, pure culture fermentor which was suitable for gamma radiation, resistant to salt and acid, and which permitted repeated aseptic sampling of the fermenting brine, is illustrated and the specifications are given.

Journal Article↗
PubMedDate not supplied

Age-specific risks of syphilis, gonorrhea, and hospitalized pelvic inflammatory disease in sexually experienced U. S. women.

The authors used data from the Centers for Disease Control (Atlanta, GA), National Hospital Discharge Survey, U.S. Census, and surveys of sexual activity in adolescent women to estimate age-specific rates of infectious syphilis, gonorrhea, and pelvic inflammatory disease requiring hospitalization among sexually experienced adolescent and young adult women in 1971 and 1976. Rates of all three diseases were highest in adolescents and declined exponentially with increasing age. Age-related reporting biases are unlikely to account for these findings. Aspects of adolescent sexual behavior and reproductive physiology are among plausible explanations. With the decline in age at first coitus in recent years, sexually transmitted diseases have become increasingly important factors in the health care of adolescents.

Adolescent↗
PubMedDate not supplied

Sexually transmitted diseases in females in a juvenile detention center.

Of 37 female adolescent prostitutes and 63 other females held in the King County, Washington, juvenile detention facility, 81 (81%) complained of vaginal discharge, and only eight (8%) had no genitourinary symptoms. The prevalence of genital infections among prostitutes and nonprostitutes was similar. Neisseria gonorrhoeae was found in 18 (18%) of 98 detainees tested, and Chlamydia trachomatis was found in 17 (20%) of 86 detainees tested; either organism was found in 27 (32%) of 85 tested for both organisms. Also, 38 (48%) of 80 tested had trichomoniasis. No detainees had syphilis. Sixty-seven (68%) of 98 responding detainees used no contraception. Such populations deserve the attention of public programs for control of sexually transmitted diseases and for family planning.

Adolescent↗
PubMedDate not supplied

Comparison of ophthalmic silver nitrate solution and erythromycin ointment for prevention of natally acquired Chlamydia trachomatis.

During prospective studies of infants born vaginally to women with cervical Chlamydia trachomatis infection, we evaluated 27 infants given 0.5% erythromycin ointment and 93 given 1% silver nitrate solution as eye prophylaxis, according to the preference of the parents or delivery room personnel. The cumulative proportion of infants developing chlamydial conjunctivitis was 25% for both groups (P = 0.37, Mantel-Cox test). The cumulative proportion of infants developing chlamydial infection at any anatomic site was 74% for those given erythromycin and 70% for those given silver nitrate (P = 0.93). The two groups did not differ significantly in cumulative proportions developing nonchlamydial conjunctivitis. These results indicate that, as it is routinely used in our hospital, erythromycin ointment was not more effective than silver nitrate as prophylaxis against chlamydial conjunctivitis. The influence of delayed administration on efficacy of prophylaxis requires further evaluation.

Chlamydia Infections↗
PubMedDate not supplied

A reappraisal of the epidemiology of phenotypes of Neisseria gonorrhoeae.

We analyzed published data from studies of the epidemiology of gonococcal auxotype/serovar phenotypes in Seattle and King County, Washington; Denver, Colorado; and Miami and Dade County, Florida, to determine whether the numbers of new phenotypes were within the ranges of numbers predicted from previous observations in the same populations. For this analysis, we used the model of Fisher and Good and Turing. In all the analyses, the observed number of new species was within the 95% confidence region for the expected number. In contrast to the original interpretation of the data--that phenotypes of Neisseria gonorrhoeae pass through the human population in waves, our analysis is compatible with random sampling of a larger population of gonococcal phenotypes. This suggests that transmission of gonorrhea is sustained as much by failure to cure core-group transmitters as by failure to prevent introductions from other populations.

Colorado↗