21 October 2010

The preservation of microorganism

Entry ni ditujukan kepada ahli2 mikrobiologi terutamanya mikrobiologist Lab 3159 (Microbiologist lab lain pun bole jugak..sile jgn kecik hati).. Seperti yang diarahkan oleh datin kita.. kita dikehendaki menyelamatkan bakteri-bakteri dengan ape cara sekalipun. So di sini ade info sikit psl preservation bakteri2 kite itu.. (aishh..terikut2 perkataan kak yuyun..huhu).. Info terjumpa dalam e-book microbe td..

The Preservation of Microorganism

■ The simplest procedure is to transfer cultures periodically to fresh solid slants of agar in the appropriate medium and to incubate them at a suitable growth temperature. Once the slant cultures are well established, they are kept in a refrigerator at 5◦C enclosed in a container to avoid desiccation. This is the least expensive procedure and keeps cells viable for many months, but there is a danger that mutants or contaminants may accumulate in such cultures.

■ Lyophilization (freeze-drying) is a particularly convenient preservation method. Microbial cells are mixed with a medium containing skim milk powder (at 20% w/v) or sucrose (at 12% w/v) and frozen, after which the water is removed from them by sublimation under partial vacuum. Lyophilized samples remain viable for many years and can be shipped without refrigeration.

■ Cells can be stored for prolonged periods of time at liquid nitrogen temperature. In this procedure, the cells are placed in ampules with media containing (by volume) either 10% glycerol or 5% dimethylsulfoxide and are slowly frozen; their temperature is decreased by 1◦C to 2◦C per minute until it reaches about −50◦C. The ampules are then stored at −156◦C to −196◦C in a liquid nitrogen refrigerator. Additives such as skim milk, sucrose, glycerol, and dimethylsulfoxide minimize damage to the cells by preventing ice crystals from forming during the freezing process.

■ Many spore-forming bacteria and fungi can be preserved by slowly airdrying the spores at ambient temperature on the surface of sterilized soil, silica gel, or glass beads.

sumber: Glazer, Microbial Biotechnology, Fundamentals of Applied Microbiology.

p/s::aku je yg xselamatkan lg bakteria aku..kena selamatkan segera!


mAsHiKaDA :: Sid :: SHidA said...

oohh.... tenkiu kak paja... bakteria saya sampai je malaysia nanti, saya akan praktikkan ilmu yg di berikan di sini... macehhh~

cik paja hanim said...

wahhaa..bagus2...sile praktikkan..

miSz NiEZa said...

wahh..bile bace nih trase mcm stadi blk lak...dh lame tggl dunia ke'mikrob'an nie...huhutrally

cik paja hanim said...

uhuhuh..aku still involve ngn bende2 mcm ni..so saje share info ngn adik2..heheh