Some aspects are described of tlie kinetics of the groivth of (;ibbeie!la fzljik~~ro?:in nitrogen-limited media contai~ling either am~uonium nitrate, ammonium acetate, ammonium tartl-ate, urea, or glycine. Also varied were inoculum size, agitation rate, pI-I, and initial concentrations of glucosc and nitrogen source. The sigiiihcance of kinetic parameters ~lsed in this, and published studies, is discussed.A lag phase n:as only found on ammonium acetate media or when higli concentrations of glucose \\,ere present. Early gro\vth was exponei~tial on all nitrogen sources. On ammonium acetate the specilic growth rate decreased a t a dry weight ofca. 1 mg/g WS (Whole ~~nliltered Samplc). On arnmol~iuin nitrate, early expoiientiaI growth ~~t i l i z e d more NI-13-nitrogen than NOJ-l~itrogen \vith a corlcornitant decrease in pH. I n the range pH 3.0-2.8 NHa-nitrogen uptalre and dry weight increase ceased, but SOs-nitrogen uptalce continued, and the pH increased until growth and NI-I:,-nitrogen uptalce restarted. 'This pattern could be repeated. Finally, expo~lential growth was resumed a t a lo\\, specilic gro\\.th rate. On gIycine, urea, and ammoni~lm tartrate media, exponel~tial growth continned to a dry weight of about 7 mg/g \VS. During, this pcriod the uptalces relative to dry weight (contributions) of glucose, nttrogen, phosphate, and magnesium remained coilstant and were unaffected by the rate of agltatloll, as also was the specihc growth rate, but the latter decreased with increasing glucose concentration.A period of linear growth could folio\\, the exponential period. The contribution bf glucose was ireater, and that of phosphate and magnesium less, than during exponential growth. The dry weight a t which espol~ential growth changed to linear growth \\.as greater the higher the rate of agitation, and this change may be a response to oxygen restriction. After nitrogen exhaustion, fat and carbohydrate accum~llntion in tlie cells largely accour~ted for the increase in dry weight. The specilic rates of dry weight increase and glucose uptake remained constant over the lower range of initial nitrogen concentrations. Both rates decreased with increasing nitrogen over the higher range.Gibberellic acid production began a t , or soon after, nitrogen exhaustion. The amount present increased lirlearly with time. The productivity decreased with increasing glucose conce~~tration; and first increased and then decreased with increasing initial nitrogen. 'I'he maximum amount produced was proportional to the initial nitrogen provided. Some published results are discussed in the light of these relations.

The growth of Gibberella fujikzlroi in stirred culture was studied. Media were designed in which the initial concentrations of glucose (G), nitrogen (N), phosphorus (P), and magnesium (M) were varied so that the first nutrient was exhausted a t a selected dry weight, and the remaining nutrients in all available sequences thereafter. Distinct phases of growth, related to the changing nutritional status of the mold, have been defined.The balanced phase was a period of proliferation in the presence of all nutrients, during which a unit increase in dry mycelium was accompanied by constant uptakes of G, N, P, M, and potassium (I<). The morphology remained virtually unchanged, and the d r y mycelium contained ca. 6 % fat, ca. 16% carbohydrate, and ca. 13% phosphorus-containing compounds, and the fractions of each remained constant. This phase continued until the first nutrient was exhausted. I'roliferation, indicated by increases in fat-and carbohydrate-free dry weight, then ceased in N-and G-limited fermentations. I n P-and M-limited fermentations, proliferation continued until the subsequent exhaustion of either G o r N, and during this transition phase the carbohydrate content of the mycelium increased, while in M-limited fermentations the fat content also increased. I n P-limited fermentations the uptake of both M and I< ceased, and reserves of metaphosphate were used.At the exhaustion of N in N-, P-, or M-limited fermentations, proliferation ceased but the dry weight continued to increase due t o increases in carbohydrate and triglyceride. In the presence of sufficient glucose, maximum amounts of 45% fat, visible as oil globules, and 32y0 carbohydrate were formed, but in the presence of less G these ceased t o increase when G was exhausted before these maxima were reached. In either case the nzaintenance phase followed, during which all mycelial components remained constant except the triglycerides, which decreased when exhaustion of G had initiated the maintenance phase; otherwise they also remained constant until G was subsequently exhausted, and then decreased. T h e terntinal phase began when the triglycerides were exhausted, and also when G was exhausted in G-limited fermentations, or in P-and M-limited fermentations in which G was exhausted before N. This phase was characterized by hyphal breakdown, a decrease in dry weight, and the liberation of mycelial components into the medium. 'Manuscript Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by NC STATE UNIVERSITY on 09/21/13For personal use only. 80-1. FermenterThis was of conventional design, made of stainless steel, 20 in. diameter and 29 in. deep (Fig. 4). T h e two-paddle stirrer was driven a t 425 r.p.m. T h e supply of cooling water was automatically regulated to provide temperature control t o &0.15O C. Air was humidified and sterilized by passage through larger models of the apparatus already described. 2Model 0307, series WA, product of Hoover Ltd., Regent Street, London, W.1. Can. J. Microbiol. Downloaded from www.nrcresearchpress.com ...

Some strains of Gibberella fujikuroi (Saw.) Wr. (conidial state Fusarium moniliforme (Sheld.) emend. Snyder & Hansen) produce metabolic products with plant‐growth‐promoting properties. The capacity to produce such substances is common in rice‐infecting strains of G. fujikuroi; isolates from other hosts only infrequently produce such metabolites. From a selected rice‐infecting strain a plant‐growth‐promoting substance has been isolated in pure form. This substance, gibberellic acid, is distinct in chemical properties from the gibberellins described by Japanese investigators. In surface culture on Raulin‐Thom medium (2.5% sucrose) yields of 40 mg./1. are obtained in 14 days at 25°. In submerged aerated culture yields approaching 200 mg./1. are obtained on Raulin‐Thom medium (4% sucrose) in 18 days at 25°. Under such conditions, although gibberellic acid begins to appear in the medium during the latter part of the phase of active growth, at least 75%, and probably more, of the total final yield is produced after maximum dry weight has been reached and rapid uptake of sugar and ammonia‐nitrogen has ceased.

SKI 0 4TGNectria coccinea produces antibiotics LL-Z1272-p (1 b), -y (ascochlorin) (Za), -8 (3a). and -E (3b) together with a new metabolite for which the name chloronectrin and structure (3c) (based on 3-[5-(3-oxocyclohexyl)pent-2enyl]-5-chloro-orseliinaldehyde) are proposed. In the presence of bromide in place of chloride, N. coccinea produces an analogous 3-(penta-2,4-dienyl) -5-bromo-compound (2c). Several new derivatives in the series are reported.ANTIBIOTICS LL-21272 [a (la), p (1 b) , y (2a), 8 (3a), E (3b), and < (2b)l have been isolated from an unidentified Fusarium sp.l Antibiotic LL-21272 y (2a) (ascochlorin) published data it seems likely that ilicicolin A is identical with antibiotic LL-Z1272-a, B with -PI C with -6, D with -7, and F with -<, though no reference was made in ref. 4 to the work of Ellestad et a1.l We report here the isolation from Nectria coccinea of OR^ 0 R1 R2 R3 R4 a ; C1

The metabolism of Gibberclla Jujikuroi in stirred culture has been studied at varied temperatures over the range 8–40 °C. Two nitrogen-limited media were used, which differed only in the initial concentration of ammonium tartrate. Economic and rate constants have been derived at each stage of fermentation, and methods of relating these to temperature discussed. Each has been related to temperature both by a linear plot, and according to the Van"t Hoff – Arrhenius model.There was no significant difference between the results from the two media early in fermentation. During the storage and maintenance phases all specific rates were considerably lower on the more concentrated medium.The minimum temperature for growth was below 8 °C. Many parameters showed a discontinuity in the range 17–20 °C, and most optima were in the range 29–32 °C. At 38 °C growth ceased when the dry weight was about 2 mg/g of unfiltered broth, and no growth occurred at 40 °C.The contribution of nitrogen to dry weight was virtually independent of temperature. The glucose contribution tended to decrease slightly with increasing temperature over the whole range. The phosphate contribution was constant in the range 8–20 °C, and decreased greatly with increasing temperature from 20 to 36 °C. The magnesium contribution decreased markedly with increasing temperature over the whole range.Two general forms of relation between rate constants and temperature were found. One, a typical "skew" curve with "tail-off' at the lower temperatures, was obtained with the specific growth rate, the nitrogen and glucose quotients, the specific rate of glucose uptake in the maintenance phase, and the gibberellic acid productivity. The second relation showed a marked discontinuity in the range 17–20 °C, above which the increase with increasing temperature was less than at the lower temperatures. This form of curve was obtained with the phosphate, magnesium, and carbohydrate quotients, the linear growth rate, the rate of increase in mycelial dry weight, fat and carbohydrate in the storage phase, and the rate of glucose, phosphate, and magnesium uptake in the same period.