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Ruth Patrick

Bio: Ruth Patrick is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Agar & Agar plate. The author has an hindex of 1, co-authored 1 publications receiving 5 citations. Previous affiliations of Ruth Patrick include Academy of Natural Sciences of Drexel University.
Topics: Agar, Agar plate

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Journal ArticleDOI
TL;DR: It was found that a stimulating effect upon the growth of Nitzschia linearis was produced when the quantity of extract per 100 ml was equivalent to that obtained from 1-5 g.
Abstract: THE DIATOM, Nitzschia linearis W. Sm., is one of the common diatoms found in the eastern United States growing in shallow water on mud in streams not adversely affected by pollution. In 1947 an effort was made to culture this diatom in the laboratory. Various types of culture media, such as aqueous solutions, silica gels, and agar were tried. The nutrient solutions used were a modification of Miquel's medium (Miquel, 1892), Chu's number 14 (Chu, 1942), and Ketchum and Redfield (1938) ,medium added to natural stream water. In a series of experiments in which the above nutrients were added to the various media, Nitzschia linearis consistently grew better on the agar medium regardless of the type of nutrient solution used for enrichment. Experiments were then conducted to see if the substance producing the stimulating effect could be pyridine extracted from the agar as described by Robbins (1939). The extract obtained from the pyridine-treated agar was added to agar enriched with Miquel's nutrients and to agar enriched with Chu 14. The agar to which the nutrients were added was purified with Chlorox (sodium hypochlorite) as described by G. W. Beadle (personal communication, 1947). This was done in order to remove any growth-promoting substances such as biotin which might be present. It was found that a stimulating effect upon the growth of Nitzschia linearis was produced when the quantity of extract per 100 ml. of medium was equivalent to that obtained from 1-5 g. of agar. However, due to the difficulty of counting diatoms on an agar medium to determine the amount of growth, no precise results were obtained. Therefore, these experiments were repeated using an aqueous medium. MATERIALS AND METHODS.-The pyridine extraction of the agar was conducted as follows: Glassware, linen, and all equipment used in the extraction were treated with a 5 per cent aqueous pyridine solution for 48 hr. before beginning the agar extraction. The equipment was then washed and rinsed with glass distilled water. The agar was put in linen bags allowing ample room for the expansion of the agar. Difco agar was extracted with a 5 per cent aqueous solution of pyridine over a period of 48 hr. The pyridine solution was changed three times during this 48-hr. period. At the end of 48 hr. the extracts were combined and vacuum distilled at 28?C. until all the pyridine was removed. The extract was then concentrated by evaporating it at 28?C. The extract was refrigerated and experiments were started as

5 citations


Cited by
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TL;DR: The role of molybdenum in the utilization of ammonium and nitrate nitrogen by Aspergillus niger and the influence of hydrogen ion concentration are studied.
Abstract: 6. BURSTR6M, HANS. t'ber die Schwermetalkatalyse der Nitratassimilation. Planta 29: 292-305. 1939. 7. HARDING, C. F. and DAVID, J. J. The effect of certain mineral nutrients on the ascorbic acid content of lettuce. Food Research 19: 138-145. 1954. 8. HEWITT, ERIC J. The role of molybdenum as a plant nutrient. Pp. 486-487. Intern. Congr. Biochem., Abstr. of Communs. 1st Cong. Cambridge, England. 1949. 9. HOAGLAND, D. R. Inor ganic plant nutrition. Pp. 1-226. Chronica Botanica, Waltham, Massachusetts. 1944. 10. LOEFFLER, H. J. and PONTING, J. D. Ascorbic acid. Rapid determination in fresh, frozen and dehydrated fruits and vegetables. Ind. Eng. Chem. Anal. Ed. 14: 846-849. 1942. 11. LUCAS, ROBERT E. Effect of copper fertilization on carotene, ascorbic acid, protein and copper contents of plants grown on oirganic soils. Soil Sci. 65: 461-469. 1948. 12. NICHOLAS, D. J. DONALD, NASON, ALVIN, and McELROY, WILLIAM D. Effect of mo'ybdenum deficiency on nitrate redtuetase in cell-free extracts of Neurospora and Aspergillus. Nature 172: 34. 1953. 13. OLSEN, CARSTAN. The significance of concentration for the rate of ion absorption by higher plants in water culture. IV. The influence of hydrogen ion concentration. Physiol. Plantarum 6: 848-858. 1953. 14. STEINBERG, ROBERT A. Role of molybdenum in the utilization of ammonium and nitrate nitrogen by Aspergillus niger. Jour. Agr. Research 55: 891902. 1937. 15. STEINBERG, ROBERT A. Influence of acidity, calcium and magnesium on growth of xanthi tobacco in water culture. Plant Physiol. 26: 47-54. 1951. 16. STEINBERG, ROBERT A. Correlations between proteincarbohydrate metabolism and mineral deficiencies in plants. Pp. 359-386. In: Mineral Nutrition of Plants, Emil Truog, ed. University of Wisconsin Press, Madison. 1951. 17. STEINBERG, ROBERT A. Symptoms of molybdenum deficiency in tobacco. Plant Physiol. 28: 319-322. 1953. 18. STEINBERG, ROBERT A., BOWLING, J. D., and McMURTREY, J. E., JR. AcCUmUlation of free amino acids as a chemical basis for morphological symptoms in tobacco manifesting frenching and deficiency symptorns. Plant Physiol. 25: 279-288. 1950.

62 citations

Journal ArticleDOI
TL;DR: Purifying the agar with water extractions substantially reduced this adverse effect of interference with the activity of some antibiotics against Staphylococcus aureus.
Abstract: Agar has been shown to interfere with the activity of some antibiotics against Staphylococcus aureus. This interference has been observed as an increase in the minimal inhibitory concentration and in the diameter of the zone of inhibition. Purifying the agar with water extractions substantially reduced this adverse effect.

27 citations

Journal ArticleDOI
TL;DR: Dariiber hinaus wird aueh eine Wirkung tier Grenzfliiehenenergie auf versehiedene zytoplasmatisehe u angenommen, z.

8 citations

Journal ArticleDOI
TL;DR: Feeding trials proved that H. amarus larvae learn quickly and can be trained to feed on diatom cultures after only one 30-min exposure, and found no difference between substrate preference and conditioning response.
Abstract: The Rio Grande silvery minnow (Hybognathus amarus) was historically the most abundant fish in the Rio Grande Basin. However, populations have been declining to the point of being listed under the Endangered Species Act. Potential causes for the decline have been studied, yet little attention has been paid to food resources. This study had three objectives: (1) Determine whether larval fish show a substrate preference when foraging. (2) Determine whether larval fish have a diatom preference when presented with 15 diatom species over six feeding trials. (3) I investigated the possibility of training/conditioning H. amarus to feed on natural food sources (diatoms) and observe conditioning response (reaction time to feeding). I found no difference between substrate preference (p = 0.26). Results for feeding trials 1, 2, and 3 revealed a preference for Nitzschia palea (p < 0.01). Trial 4 revealed a preference for N. paleaformis (p < 0.01). Navicula veneta was the preferred diatom species in feeding trial 5. Nitzschia cf. intermedia was preferred in trial 6 (p < 0.03). Results from these feeding trials proved that H. amarus larvae learn quickly and can be trained to feed on diatom cultures after only one 30-min exposure. Pre-conditioned H. amarus arrived at diatoms cultures in 49 sec ± 39 sec compared to non-conditioned H. amarus, which arrived at diatom cultures at 250 sec ± 550 sec.

7 citations

Journal ArticleDOI
TL;DR: There are at least two deleterious factors present in agar, one of which is water-soluble and one which is not, which could be removed by washing the agar in warm distilled water prior to use in the test medium.
Abstract: The minimal inhibitory concentrations of 11 phenolic inhibitors were compared in five commercial agars and in nutrient broth It was found that the brand of agar affected the end point obtained for a particular inhibitor, and that the degree of antagonism varied with each compound studied The results indicate that there are at least two deleterious factors present in agar, one of which is water-soluble and one which is not The major portion of the total antagonism was due to the water-soluble factor, which could be removed by washing the agar in warm distilled water prior to use in the test medium

7 citations