Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]

Volume 10(1): 488 - 490. Published October 2008.

Changes in acidity of plant growth media during
heat sterilisation

Msogoya TJ*, Maerere AP, Nzogela Y. and Kusolwa PM.

*Department of Crop Science and Production, Sokoine University of Agriculture, P.O Box 3005, Morogoro, Tanzania.

^Corresponding author e–mail:tjmsogoya@yahoo.com

ABSTRACT

Tissue culture media provide ideal conditions for growth of plant cells, but also bacteria and fungi. It is therefore necessary to sterilize media to remove these microbes prior to incubation of explants. Growth media are commonly sterilised by autoclaving at 121°C and pressure of 105 kPa for 15 minutes, or longer for larger volumes (Beyl, 2000). Some components of the growth media such as gibberellins (GA3) and capanthothenate are heat-labile and would become inactive when autoclaved (Nissen & Sutter, 1990). Such heat sensitive components are sterilised by filtering through bacteria-proof membrane (0.22μm pores) and added to the sterilised medium after it has cooled down to at least 60°C. Autoclaving the growth media at 121°C and pressure of 105 kPa for 15 - 20 minutes also breaks down sucrose into D-glucose and D fructose, resulting in alteration in the osmotic potential of the growth media. Thus, it is important to consider these changes when performing osmotic-sensitive procedures such as protoplast culture. Moreover, the simple sugars resulting from sucrose degradation apparently have inhibitory effects on in vitro regeneration
of some plant tissues (Dodds & Roberts, 1990).

FULL PAPER [PDF AVAILABLE HERE]

Journal of Applied BioSciences

ISSN 1997 - 5902

The Journal of Applied BioSciences