Multiplication of an ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and Microsporum

Microbiology ◽  
2004 ◽  
Vol 150 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Olivier Jousson ◽  
Barbara Léchenne ◽  
Olympia Bontems ◽  
Sabrina Capoccia ◽  
Bernard Mignon ◽  
...  

Dermatophytes are human and animal pathogenic fungi which cause cutaneous infections and grow exclusively in the stratum corneum, nails and hair. In a culture medium containing soy proteins as sole nitrogen source a substantial proteolytic activity was secreted by Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. This proteolytic activity was 55–75 % inhibited by o-phenanthroline, attesting that metalloproteases were secreted by all three species. Using a consensus probe constructed on previously characterized genes encoding metalloproteases (MEP) of the M36 fungalysin family in Aspergillus fumigatus, Aspergillus oryzae and M. canis, a five-member MEP family was isolated from genomic libraries of T. rubrum, T. mentagrophytes and M. canis. A phylogenetic analysis of genomic and protein sequences revealed a robust tree consisting of five main clades, each of them including a MEP sequence type from each dermatophyte species. Each MEP type was remarkably conserved across species (72–97 % amino acid sequence identity). The tree topology clearly indicated that the multiplication of MEP genes in dermatophytes occurred prior to species divergence. In culture medium containing soy proteins as a sole nitrogen source secreted Meps accounted for 19–36 % of total secreted protein extracts; characterization of protein bands by proteolysis and mass spectrometry revealed that the three dermatophyte species secreted two Meps (Mep3 and Mep4) encoded by orthologous genes.

1993 ◽  
Vol 39 (4) ◽  
pp. 430-433 ◽  
Author(s):  
R. Boopathy ◽  
C. F. Kulpa

A sulfate-reducing bacterium, Desulfovibrio sp. (B strain), isolated from a continuous anaerobic digester, used various nitroaromatic compounds such as 2,4-dinitrophenol, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as sole nitrogen sources for growth and also used these compounds as electron acceptors in the absence of sulfate in the culture medium. More than 60% of the nitroaromatics were transformed within 6 days of incubation. The organism also used aniline as sole nitrogen source, but not as an electron acceptor. Desulfovibrio sp. (B strain) did not use nitroaromatics as sole source of carbon and energy. The nitro groups in the aromatic ring were reduced and reductively deaminated to ammonia, which was used as nitrogen source, leaving the aromatic ring intact. Even though this organism did not degrade the nitroaromatics completely, it may be useful in degrading nitroaromatics in contaminated soil and water containing other aromatic degraders in a syntrophic culture system under anaerobic conditions.Key words: anaerobic process, biotransformation, nitroaromatics, aniline, Desulfovibrio sp.


1991 ◽  
Vol 31 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Zhi-Hai Ye ◽  
Richard C. Garrad ◽  
Melissa K. Winston ◽  
J. K. Bhattacharjee

1953 ◽  
Vol 31 (1) ◽  
pp. 28-32 ◽  
Author(s):  
A. C. Blackwood

One hundred and fourteen bacterial cultures representing most of the species in the Bacillus genus were tested for the production of extracellular barley gum cytase. Assays were made on shake-flask cultures grown on a medium containing glucose and yeast extract. Although all the organisms had some enzymatic activity, certain strains of Bacillus subtilis gave the best yields of cytase. On a medium with asparagine as the sole nitrogen source even higher yields were obtained. The crude cytase preparations were stable and after freeze-drying most of the original activity remained.


2010 ◽  
Vol 76 (12) ◽  
pp. 4102-4104 ◽  
Author(s):  
Yin Chen ◽  
Kathryn L. McAleer ◽  
J. Colin Murrell

ABSTRACT Monomethylamine can be used by nonmethylotrophs as a sole nitrogen source but not as a carbon source; however, little is known about the genes and enzymes involved. The γ-glutamylmethylamide/N-methylglutamate pathway for monomethylamine utilization by methylotrophs has recently been resolved. We have identified genes encoding key enzymes of this pathway in nonmethylotrophs (e.g., Agrobacterium tumefaciens) and demonstrated that this pathway is also involved in the utilization of monomethylamine as a nitrogen source by nonmethylotrophs.


1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.


2021 ◽  
Vol 1 ◽  
pp. 12
Author(s):  
Harish Chander Gugnani

This review traces the early records of mycotic infections in India, and presents an update of animal mycoses reported from several parts of India. The types of mycoses covered are the dermatophytosis (ringworm) in domestic animals due to well-known species of zoophilic dermatophytes, viz. Trichophyton simii, T. mentagrophytes, T. verrucosum, Microsporum canis and M. nanum, and the geophilic dermatophyte, M. gypseum, Aspergillus spp, Cryptococcus species and other yeast like fungi, histoplasma and blastomyces. The brief clinical and demographic features of infections in different animals are described. A particularly noteworthy finding in literature search is the report of clinical infections in one dog and two cows by an anthropophilic dermatophyte, T. rubrum from Belgachia, Kolkata, West Bengal in 1954. Veterinary scientists are urged to investigate the possible occurrence of infections in animals due to other pathogenic fungi including the dimorphic ones like Histoplasma and Blastomyces.


1994 ◽  
Vol 41 (4) ◽  
pp. 467-471 ◽  
Author(s):  
A Dzikowska ◽  
J P Le Caer ◽  
P Jonczyk ◽  
P Wëgleński

Arginase (EC 3.5.3.1) of Aspergillus nidulans, the enzyme which enables the fungus to use arginine as the sole nitrogen source was purified to homogeneity. Molecular mass of the purified arginase subunit is 40 kDa and is similar to that reported for the Neurospora crassa (38.3 kDa) and Saccharomyces cerevisiae (39 kDa) enzymes. The native molecular mass of arginase is 125 kDa. The subunit/native molecular mass ratio suggests a trimeric form of the protein. The arginase protein was cleaved and partially sequenced. Two out of the six polypeptides sequenced show a high degree of homology to conserved domains in arginases from other species.


Sign in / Sign up

Export Citation Format

Share Document