Effect of medlium acidification on filamentous fungi, yeasts and bacterial contaminats inDelphinium tissue cultures

Abstract

The persistence of accidentally introduced bacterial contaminants in Delphinium tissue cultures can be prevented by acidification of the tissue culture medium. Using this preservation method the contamination rate of Delphinium cultures could be reduced by more than 50%.

Nano silver: a novel nanomaterial for removal of bacterial contaminants in valerian (Valeriana officinalis L.) tissue culture

“…Using NS may be more convenient and less toxic than using antibiotics in the medium. Furthermore, using other methods for controlling the infection like first acidification of the medium and later regulation of pH to normal condition (Leifert et al 2000) and microbial culture filtrate (Hussain et al 1994) may be time consuming methods in tissue culture techniques. Showing acceptable antibacterial activity in this investigation is in agreement with the results obtained by other investigators (Nomiya et al 2004;Sondi and Salopek-Sondi 2004).…”

“…Phytotoxicity of rifampicin, carbenicillin and streptomycin in Clematis, Delphinium, Hosta, Iris and Photinia cultures is also reported (Leifert et al 1992). Using antibiotics in the media inhibit both multiplication and rooting of Delphinium shoot cultures (Leifert et al 2000). Teixeira da Silva et al (2003) reported a decrease in explant survival and biomass reduction, malformation of roots and inhibition of shoot formation in chrysanthemum, and also in tobacco endoreduplication by application of antibiotics in the media.…”

Microbial hazards in plant tissue and cell cultures

“…Even broadspectrum antibacterial and antifungal compounds often fail to eliminate all target organisms and were shown to have negative side effects on the growth and/or rooting of plant tissue cultures (Leifert et al, 1991b(Leifert et al, , c, 1994b. Often bacterial growth is only suppressed (bacteriostatic effect) by antimicrobial treatments and when antimicrobials are removed the bacteria resume growth (Falkiner, 1990(Falkiner, , 1997Barrett and Cassells, 1994).…”

“…In particular, Gramnegative bacteria are difficult to eradicate completely from in vitro plant cultures (Leifert et al, 1991b). The use of medium acidification was shown to prevent the establishment and/or proliferation of bacterial contaminants in plant tissue cultures and may provide a cheap alternative to the prophylactic use of antibiotics for certain in vitro systems (Leifert et al, 1994b). However, similar to antibiotic treatments, curative use of medium acidification may only suppress the growth of bacteria rather than eliminate them completely.…”

In vitro multiplication in liquid culture of Syngonium contaminated with Bacillus spp. and Rathayibacter tritici

“…Contamination can result in the death of cultures, growth retardation, necrosis and altered morphogenic potential such as reduced rates of multiplication and rooting (George, 1993). Consequently, there have been a number of efforts to control contamination (Hussain et al, 1994;Leifert and Waites, 1990;Leifert et al, 1994;Tanaka et al, 1988). None of these methods, however, has been entirely successful in controlling contamination.…”