Abstract
A cobalt-resistant strain of Neurospora crassa (cor) was obtained by repeated subculturing of the wild type on cobalt-containing agar medium. N. crassa cor is twentyfold more resistant to cobalt ions compared with the wild type. Resistance was stable on repeated subculturing of cor on cobalt-free media. N. crassa cor is also cross-resistant to nickel (fourfold), but not to zinc or copper. Higher concentrations of iron and magnesium ions are required to reverse growth inhibition due to cobalt toxicity in N. crassa cor, compared with the wild type. Germinating conidia and mycelia of the cor strain accumulated lower levels of cobalt ions compared with the parent N. crassa. The partial transport block for cobalt uptake is shown to be primarily due to decreased surface binding of cobalt to mycelia and cell walls. Efflux of mycelial cobalt was also observed in wild type and cobalt-resistant N. crassa. The characteristics of cor in comparison with wild type N. crassa are discussed in relation to the mechanisms of cobalt resistance.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ashida J. 1965 Adaptation of fungi to metal toxicities. Ann Rev Phytopathol 3, 153–174.
Cervantes C, Gutierrez-Corona F. 1994 Copper resistance in bacteria and fungi. FEMS Microbiol Lett 14, 121–138.
Conklin DS, McMaster JA, Culbertson MR, Kung C. 1992 COTI, a gene involved in cobalt accumulation in Saccharomyces cerevisiae. Mol Cel1 Biol 12, 3678–3682.
Gadd GM. 1993 Interactions of fungi with toxic metals. New Phytol 124, 25–60.
Garcia-Toledo A, Babich H, Stotzky G. 1985 Training of Rhizopus stoloniferand Cunninghamella blakesleeanato copper: cotolerance to Cd, Co, Ni and Pb. Can J Microbiol 31, 485–492.
Healy WB, Cheng S, McElroy WD. 1955 Metal toxicity and iron deficiency effects on enzymes in Neurospora crassa. Arch Biochem Biophys 54, 206–214.
Karna RR, Sajani LS, Maruthi Mohan P. 1996 Bioaccumulation and biosorption of Co2+ by Neurospora crassa. Biotechnol Lett 18, 1205–1208.
Kumar SCh, Sastry KS, Maruthi Mohan P. 1992 Use of wild type and nickel resistant N. crassafor the removal of Ni2+ from aqueous medium. Biotechnol Lett 14, 1018–1022.
Maruthi Mohan P, Sastry KS. 1983 Interrelationships in trace element metabolism in metal toxicities in nickel resistant strains of Neurospora crassa. Biochem J 212.
Maruthi Mohan P, Sastry KS. 1984 Cobalt transport in nickel resistant strains of Neurospora crassa. Curr Microbiol 11, 137–142.
Maruthi Mohan P, Pratapa Rudra MP, Sastry KS. 1984 Nickel transport in nickel-resistant strains of Neurospora crassa. Curr Microbiol 10, 125–128.
Muzzarelli RAA, Tanfani F, Scarpini G. 1980 Chelating, film forming and coagulating ability of the chitosan-glucan complex from Aspergillus nigerindustrial waste. Biotechnol Bioeng 22, 885–889.
Neyland M, Dunkel P, Schade L. 1952 The uptake of cobalt by Proteus vulgaris. J Gen Microbiol 7, 409–.
Nies DH, Silver S. 1989 Plasmid-determined inducible efflux is responsible for resistance to cadmium, zinc and cobalt in Alcaligenes eutrophus. J Bacteriol 171, 896–900.
Padmanaban G, Sarma PS. 1964 A new iron binding compound from cobalt toxic cultures of Neurospora crassa. Arch Biochem Biophys 108, 362–364.
Padmanaban G, Sarma PS. 1966 Cobalt toxicity and iron metabolism in Neurospora crassa. Biochem J 98, 330–334.
Perlman D, O'Brien E. 1954 Characterization of cobalt tolerant cultures of Saccharomyces cerevisiae. J Bacteriol 68, 167–170.
Ross IS. 1975 Effects of heavy metals on fungal cell walls. Trans Br Mycol Soc 64, 175–193.
Sastry KS, Adiga PR, Venkatasubramanyam V, Sarma PS. 1962 Interrelationships in trace element metabolism in metal toxicities in Neurospora crassa. Biochem J 85, 486–491.
Schmit JC, Edson CM, Brody SJ. 1975 Changes in glucoseamine and galactoseamine levels during conidial germination in Neurospora crassa. J Bacteriol 122, 1062–1070.
Smith DH. 1967 R factors mediate resistance to mercury, nickel and cobalt. Science 156, 1114.
Subramanyam C, Venkateswerlu G, Rao SLN. 1983 Cell wall composition of Neurospora crassaunder conditions of copper toxicity. Appl Environ Microbiol 46, 585–590.
Venkateswerlu G, Sastry K. 1970 The mechanism of uptake of cobalt ions by Neurospora crassa. Biochem J 118, 497–503.
Venkateswerlu G, Sastry KS. 1973 Interrelationships in trace element metabolism in metal toxicities in Neurospora crassa. Biochem J 132, 673–680.
Venkateswerlu G, Sastry KS. 1979 Cobalt transport in a cobalt resistant strain of Neurospora crassa. J Biosci 1, 433–438.
Webb M. 1970 Interrelationships between the utilization of magnesium and the uptake of other bivalent cations by bacteria. Biochem Biophys Acta 222, 428–439.
Wilson CH, Sajani LS, Maruthi Mohan PM. 1992 Location of a mutant resistant to cobalt and nickel to LG IIIR in Neurospora crassa. Fungal Genet Newslett 39, 89.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sajani, L., Maruthi Mohan, P. Characterization of a cobalt-resistant mutant of Neurospora crassa with transport block. Biometals 10, 175–183 (1997). https://doi.org/10.1023/A:1018347627172
Issue Date:
DOI: https://doi.org/10.1023/A:1018347627172