. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THIAMINE AND TETRAHYMENA 127 TABLE IV Medium Generation time in hours Population per ml. at end of log. phase Maximum yield cells/ml. Population per ml. at 1 1 days Size of cells at 11 days (av. 20 measurements) Heated gelatin 2 per cent 2,750 11,700 200 X 16M Heated gelatin 2 per cent + B! 2,000 68,500 44,000 85M X 30/z Heated gelatin 2 per cent + A 19,500 82,000 40,000 47M X 20M Heated gelatin 2 per cent + A + Bj 17,500 96,000 72,000 89,u X A = heat and alkali treated alfalfa extract; BI = t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THIAMINE AND TETRAHYMENA 127 TABLE IV Medium Generation time in hours Population per ml. at end of log. phase Maximum yield cells/ml. Population per ml. at 1 1 days Size of cells at 11 days (av. 20 measurements) Heated gelatin 2 per cent 2,750 11,700 200 X 16M Heated gelatin 2 per cent + B! 2,000 68,500 44,000 85M X 30/z Heated gelatin 2 per cent + A 19,500 82,000 40,000 47M X 20M Heated gelatin 2 per cent + A + Bj 17,500 96,000 72,000 89,u X A = heat and alkali treated alfalfa extract; BI = thiamine 1 microgram/ml. All media contains salts, riboflavin ( microgram/ml.) and 1-tryptophane ( per cent). K U Q. <n o J d z %^^ 8. \ \ O HEATED GELATIN \ • " " + Bi O " " + A \ \ V o + A + Bi °X^ f "— — o 1 1 1 i i i i i i i i i 0 24 48 72 96 120 144 168 192 216 240 264 HOURS FIGURE 4 thiaminized alfalfa extract was added, and again the addition of thiamine had no effect except upon survival (Table II; Fig. 2). Gelatin and gelatin hydrolysate—Gelatin Harris is a purified product, according to its manufacturers. It was found, however, that fair growth could he maintained in a one per cent or a two per cent solution provided tryptophane was added. The generation time was about hours, the population at the end of logarithmic growth about 2,500, the maximum yield about 12,000 and at the end of 11 days the popula- tion was approximately per ml. The addition of thiamine had no effect on the generation time or the length of the logarithmic phase but the maximum yield was increased to 67,000 per ml. while at the end of 11 days over 30,000 ciliates per ml. were present (Table III; Fig. 3). This might indicate that enough thiamine. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
