GROWTH REQUIREMENTS FOR BALANTIDIUM COLI

Author(s):  
D.A. VLOEDMAN ◽  
M. MIHALY
1954 ◽  
Vol 208 (1) ◽  
pp. 277-286
Author(s):  
Harold H. Williams ◽  
Leo V. Curtin ◽  
Jean Abraham ◽  
J.K. Loosli ◽  
L.A. Maynard

1978 ◽  
Vol 56 (12) ◽  
pp. 1425-1433 ◽  
Author(s):  
Robert E. Moeller

The evergreen characteristic of Lobelia dortmanna L. involves biomass and nutrient conservation. Although 60% of the maximum, midsummer biomass overwinters, little or no new tissue is produced between October and early May. Annual net production, estimated from the rate of leaf turnover, is less than the maximum biomass (P/B = 0.69 per year). Nitrogen and P concentrations are lowest in mid-August, when the amount of each analyzed element per square metre is near its maximum (N, P, Ca, Mg, Na, K). Autumnal uptake of N may contribute 25% of the next season's growth requirements, but P uptake is largely offset by losses during the winter. Fruiting and sterile plants have similar contents of N, P, and K in late July, but the fruiting plants are richer in Ca, Mg, Na, Fe, Mn, and Zn. At the maximum depth limit of the population in Mirror Lake, New Hampshire (2.3 m), flowering is absent and seedlings are sparse, suggesting reproductive failure as a controlling factor at the margin of the population.


1993 ◽  
Vol 39 (8) ◽  
pp. 804-808 ◽  
Author(s):  
Lisa D. Noble ◽  
John A. Gow

Until now there has not been a satisfactory solid medium for determining the growth responses, to Na+, of marine and other bacteria that have specific growth requirements for Na+. A solid medium would be useful to investigators who would like to take advantage of the efficiency of multipoint inoculation when testing for a Na+ requirement. By using 1% gellan gum (Gel-GroTM) as the solidifying agent a medium was formulated that had a contaminating level of Na+ of slightly less than 2 mM in the basal medium. Two species of Aeromonas, which do not require Na+ for growth, and 31 species of Vibrio, which require Na+, were tested for their growth responses to Na+ on this medium. The Aeromonas strains grew well, within 24 h, at all of the Na+ concentrations tested. Approximately 75% of the Vibrio strains did not grow on the basal medium even after a prolonged incubation period. The remaining species were able to grow on the basal medium, but not without a lag period. These lag periods were as short as 36 h for two of the species and in some instances as long as 312 h. These lag periods were of sufficient duration to determine that Na+ stimulated the growth of the Vibrio strains that were able to grow on the basal medium. Approximately 75% of the strains, representing most species of Vibrio, were able to grow if as little as 25 mM Na+ was present in the medium.Key words: low-sodium medium, Na+ requirement, gellan gum, agar substitute, marine bacteria.


1961 ◽  
Vol 2 (2) ◽  
pp. 204-230 ◽  
Author(s):  
Robin Holliday

1. Many of the Ustilaginales, or smut fungi, appear to have the qualities necessary for the application of modern techniques of microbial genetics.Ustilago maydisis considered the most suitable species.2. Investigations of the mating system confirm reports that the production of diploid brandspores in the host is controlled by alleles at two loci.3. Genetic markers were obtained by inducing mutations in a wild-type strain with ultra-violet light. Of 100 biochemical mutants which were isolated, the growth requirements of 94 were identified. Thirty of these were used in genetic tests.4. The compact growth of colonies on artificial media allowed new techniques to be developed by means of which large samples of progeny could be isolated and identified easily. The analysis of brandspore colonies consisting of the products of single meiotic divisions is the quickest method for detecting linkage, but its accurate measurement appears to be achieved by examining the individual members of tetrads.5. Linkage was detected relatively rarely, but eight markers, including theamating-type locus, were assigned to one or other of two linkage groups. Although recombination values were not always determined accurately owing to irregular basidiospore germination, the auxotrophic markers in each group could be mapped in a linear order. Since no indication of other linkage groups was obtained, the genetic evidence is so far consistent with cytological reports that the basic haploid chromosome number is two in the smut fungi.6. Three linked markers were used to investigate chromatid interference by tetrad analysis. None was detected in a total of eighteen double exchanges.


Author(s):  
Shweta Deshaware ◽  
Sandesh J. Marathe ◽  
Dattatray Bedade ◽  
Jan Deska ◽  
Salem Shamekh

2021 ◽  
Vol 9 (2) ◽  
pp. 321
Author(s):  
Jessica A. Lee ◽  
Alyssa C. Baugh ◽  
Nicholas J. Shevalier ◽  
Brandi Strand ◽  
Sergey Stolyar ◽  
...  

The recalcitrance of complex organic polymers such as lignocellulose is one of the major obstacles to sustainable energy production from plant biomass, and the generation of toxic intermediates can negatively impact the efficiency of microbial lignocellulose degradation. Here, we describe the development of a model microbial consortium for studying lignocellulose degradation, with the specific goal of mitigating the production of the toxin formaldehyde during the breakdown of methoxylated aromatic compounds. Included are Pseudomonas putida, a lignin degrader; Cellulomonas fimi, a cellulose degrader; and sometimes Yarrowia lipolytica, an oleaginous yeast. Unique to our system is the inclusion of Methylorubrum extorquens, a methylotroph capable of using formaldehyde for growth. We developed a defined minimal “Model Lignocellulose” growth medium for reproducible coculture experiments. We demonstrated that the formaldehyde produced by P. putida growing on vanillic acid can exceed the minimum inhibitory concentration for C. fimi, and, furthermore, that the presence of M. extorquens lowers those concentrations. We also uncovered unexpected ecological dynamics, including resource competition, and interspecies differences in growth requirements and toxin sensitivities. Finally, we introduced the possibility for a mutualistic interaction between C. fimi and M. extorquens through metabolite exchange. This study lays the foundation to enable future work incorporating metabolomic analysis and modeling, genetic engineering, and laboratory evolution, on a model system that is appropriate both for fundamental eco-evolutionary studies and for the optimization of efficiency and yield in microbially-mediated biomass transformation.


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