Nutritional requirements ofCytophaga johnsonae and some of its auxotrophic mutants

1981 ◽  
Vol 5 (4) ◽  
pp. 235-240 ◽  
Author(s):  
Li-Yen Edward Chang ◽  
Jack L. Pate
1964 ◽  
Vol 42 (4) ◽  
pp. 429-436 ◽  
Author(s):  
L. Beraha ◽  
E. D. Garber ◽  
Ø. Strømnaes

Prototrophic color and auxotrophic mutants of Penicillium italicum and P. digitatum, causal agents of citrus fruit rot, were obtained by irradiating conidia with ultraviolet light. Avirulent mutants caused a necrosis but not an obvious rot at the site of inoculation in orange rind. Avirulence was not necessarily associated with a specific alteration in the color of sporulating colonies or with the tested nutritional requirements. Supplementing necrotic lesions with the compounds required by the avirulent auxotrophic mutants enhanced growth but did not cause an obvious rot. Although heterocaryons of P. italicum involving avirulent auxotrophic strains were weakly virulent, the corresponding diploid strains were as virulent as the haploid prototrophic parental strain. Prototrophic segregants from the diploid strains were virulent. Avirulence was not related to the inability of the avirulent mutants to grow at the site of inoculation. It is probable that more than one locus may be responsible for the loss of virulence.


1963 ◽  
Vol 41 (4) ◽  
pp. 489-497 ◽  
Author(s):  
R. D. Tinline

The pathogenicity of some strains of Cochliobolus sativus to wheat seedlings was determined. The strains comprised prototrophic and auxotrophic mutants from a common parent, heterokaryons synthesized from auxotrophs, diploids obtained from heterokaryons, and recombinants selected from a diploid.Prototrophic mutants and auxotrophs requiring thiamine, arginine, and pyridoxine were as pathogenic as the parent. Methionineless and lysineless mutants were non-pathogenic. Evidence that the nutritional requirements of the latter mutants directly controlled their pathogenicity was: (1) two methionineless and two lysineless auxotrophs were uniformly non-pathogenic; (2) heterokaryons synthesized from methionineless and lysineless strains and from two methionineless strains were pathogenic; (3) diploids heterozygous for the requirements were pathogenic; (4) prototrophic recombinants from a diploid were pathogenic but auxotrophic ones were non-pathogenic; (5) a prototrophic mutant of a lysineless auxotroph was pathogenic; and (6) the pathogenicity of the auxotrophs was temporarily restored when the appropriate growth requirements were provided as external supplements to the host. The results are discussed.


2019 ◽  
Vol 16 (4) ◽  
pp. 386-391 ◽  
Author(s):  
Kenneth Lundstrom

Epigenetic mechanisms comprising of DNA methylation, histone modifications and gene silencing by RNA interference have been strongly linked to the development and progression of various diseases. These findings have triggered research on epigenetic functions and signal pathways as targets for novel drug discovery. Dietary intake has also presented significant influence on human health and disease development and nutritional modifications have proven important in prevention, but also the treatment of disease. Moreover, a strong link between nutrition and epigenetic changes has been established. Therefore, in attempts to develop novel safer and more efficacious drugs, both nutritional requirements and epigenetic mechanisms need to be addressed.


2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.


2019 ◽  
Vol 15 (02) ◽  
pp. 39-41
Author(s):  
H H Panchasara ◽  
A B Chaudhari ◽  
D A Patel ◽  
Y M Gami ◽  
M P Patel

The study was conducted to evaluate the effect of feeding herbal galactogogue preparation (Sanjivani biokseera) on the milk yield and milk constituents in lactating Kankrej cows. Thirty-two lactating Kankrej cows in their 1st to 6th lactation were taken for the experiment from 3 days after calving up to 52 days postpartum. All the animals were fed as per the standard seasonally available roughages and concentrates to meet their nutritional requirements. The cows were randomly divided into two uniform groups of 16 cows in each according to initial milk yield and milk composition. The animals in group-I were not given any supplement and served as control. The animals in group-II were given Sanjivani biokseera (Naturewell Industries) @ 60 g per day for 1-month, commencing 3 days after calving, in addition to the usual feeds/fodders. A clear difference was observed in milk yield from day 8 onward of experiment between groups with significant (plessthan0 0.05) higher values from day 16-52 in cows fed herbal galactogogue as compared to control, but no such distinct effect on milk constituents was observed on day 52 when analyzed. The use of herbal galactogogue significantly (p lessthan 0.05) increased the overall average of 52 days milk production, which was 9.34 ± 0.21 lit/day in supplemented as compared to 7.75 ± 0.26 lit/day in control animals. It was concluded that herbal galactogogue (Sanjivani biokseera) could increase milk yield in lactating dairy cows through its galactopoetic property and improved rumen environment.


2002 ◽  
Vol 29 (2) ◽  
pp. 75-82
Author(s):  
MB McAlister ◽  
LA Kulakov ◽  
JF O'Hanlon ◽  
MJ Larkin ◽  
KL Ogden

Gut ◽  
2010 ◽  
Vol 59 (Suppl 1) ◽  
pp. A148.2-A149
Author(s):  
G P Rafferty ◽  
S Gabe ◽  
M Small ◽  
J Eastwood ◽  
C UgarteCano ◽  
...  

1953 ◽  
Vol 200 (2) ◽  
pp. 775-785
Author(s):  
Harry G. Steinman ◽  
Harry Eagle ◽  
Vance I. Oyama

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