Slide Biop 2

7/30/2019 Slide Biop 2

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CELL CULTIVATION

- FERMENTATION -


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Fermentation

Since ancient time

Latin fermentumfervere (boil)

to describe the metabolism of sugars by microorganisms

Fruit fermentation beer brewing soy sauce

Before WW II mainly applied commercially in food;after ?

Substrates

any material that supports microbial growth

Culture

microorganism grew in controlled environment


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Categories & Applications offermentation


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Processing

Upstream processing all involved factorsin fermentation : microorganism/cell,

medium and fermentation process/condition

Downstream processing process folowingthe fermentation : harvesting, separation ,purification to obtain certain product level


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Phases in development of

fermentation process


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Living Cell

BACTERIA Unicellular, about 1500 species

Diameter 0.5 to 1m, vary greatly in length

Shape: cocci (spherical/ovoid), bacilly (cylindrical/rod), spirilla

(helically coiled)


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Reproduction: asexual reproduction steps: 1) cell elongation, 2)invagination ofthe cell wall, 3)distribution of nuclear material, 4)formationof the transverse cell wall,5 )distribution of cellular materialinto two cells, and 6)separation into two new cells


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FUNGI

Plant devoid ofchlorophyll unableto synthesize theirown foods

range in size andshape from single-celled yeasts tomulticellullarmushrooms

YEAST & MOLD


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Yeast

widely distributed in nature (food, soil, in the air,on the skin and in the intestines of animals)

depend on higher plants and animals for theirenergy

Unicellular spherical to ovoid

Size: 1 to 5 m in width; 5 to 30 rnin length The cell wall quite thin in young cells but

thickens with age.


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Asexual reproduction BUDDING

A small bud (or daughter cell) is formed on the surface

of a mature cell. The bud grows and is filled withnuclear and cytoplasmic material from the parent cell.When the bud is as large as the parent, nuclearapparatus in both cells is reoriented and the cells areseparated. The daughter cell may cling to the parent

cell, often even after the cells are divided Saccharomeces cerevisiae wine, beer, leavening of

bread


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Mold

filamentous fungi

A single cell or spore (conidia) is germinated to form along thread, hyphae, which branches repeatedly as it

elongates to form a vegetative structure called amycelium. Since a mycelium is capable of growingindefinitely, it can attain macroscopic dimensions.


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Find everywhere

Aspergillus,penicillium,rhizopus

used in theproduction ofantibiotics,

enzymes, food andfood additives


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CELL CULTIVATION

Cells are removed from animal/planttissue & cultivated in nutritional medium

outside the donor's body mammalian cell culture

human growth hormones, viral

vaccines, cancer cells, transplantation,antibodies, tumor


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Plant cell cultivation Plants source of various chemical

compounds) known as secondarymetabolites

Interface between the plants andenvironment, (as adaptations to stresses

or chemical defenses againstmicroorganisms, and higher predators)

Synthesize? too difficult & costly

Cultivate exogenous plant tissue insteadof a whole plant as a culture in anaseptic condition, nutritious medium,filtered air

As cultures growsliced off andtransferred to new media (subcultured) to

allow for growth


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Advantages of plant cultivation

1. regardless of weather and geographical conditions; noneed to ship or store bulky raw materials.

2. The product quality and yields can be controlled by

eliminating the problems encountered in the processingof botanicals, such as the quality of the raw material,uniformity within and among lots, disease, pest

3. some metabolic products can be produced from culturein higher quantities than that observed in whole plants

4. produce ofmultiples of plants in the absence ofseeds ornecessary pollinators to produce seeds5. production of exact copies of plants that produce

particularly good flowers, fruits, or have other desirabletraits
http://en.wikipedia.org/wiki/Pollinationhttp://en.wikipedia.org/wiki/Seedhttp://en.wikipedia.org/wiki/Seedhttp://en.wikipedia.org/wiki/Pollinationhttp://en.wikipedia.org/wiki/Seedhttp://en.wikipedia.org/wiki/Seedhttp://en.wikipedia.org/wiki/Pollinationhttp://en.wikipedia.org/wiki/Seed


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differences between plant and

microbial cells1. Plant cells are 10 to 100 times larger than bacterial and

fungal cells (20-40min diameter and 100-200mlong)2. The metabolism of plant cells is slower than microbial cells

in the one order of magnitude the maintenance ofsterility for a longer period of time.

3. Plant cells tend to grow in clumps which causesedimentation, poor mixing, plugging the inlet and outletlines, wall growth, and so on.

4. Plant cells are more sensitive to shear than microbial cells.

5. Metabolic production in plant cells is subject to morecomplex regulatory mechanisms than metabolic productionin microbial cells.

6. Plant cells are more genetically unstable than microbialcells.


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Plant secondary metabolite

production 3 essential categories: alkaloid, essential oil and

glycosides.

Alkaloids are physiologically active and used in the

pharmaceutical Industry, e.g codeine, nicotine, caffeine,and morphine.

Essential oilsconsist of mixtures of terpenoids and usedas flavorents, fragrances, and solvents.

Glycosidesinclude phenolics, tannins and flavonoids,saponins, and cyanogenic glycosides, some of which canbe utilized as dye, food flavors, and pharmaceuticals.


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Plant products of commercial

interest


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Cell immobilization

SmF cells attached to large particles or on surfaces ADVANTAGES:process design can be simplified

cells are easily separated from product,fermenter is easier to be controlled,ensures continuous fermenter operation without thedanger of cell washoutprovideconditions conducive cell-to-cell communication, highyields of secondary metabolitesprotect cells; decrease problems related to shearforces.


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Cell immobilise methods


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The methods

Attachment To Surface provide a large surface area for cell attachment

Entrapment Within a Porous Matrix cell diffuse into preformed porous in which they willgrow and be trappedadvantagespreformed support materials are more resistant todisintegration in packed beds or stirred vessels thanother support materials, and the entrapment is not

usually harmful to the cells. disadvantagedifficult to reach a high cell concentration due to thelimited pore volume


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Containment Behind a Barrierimmobilized within micro-capsules with either apermanent or nonpermanent semipermeable membraneadvantage of encapsulation is the large surface areafor contact of substrate and cells. The semipermeablemembrane also selectively passes only low molecularweight components

The disadvantage high cost, difficult in aeration

Self-aggregationSelf-aggregated or flocculated cells immobilized cells;

large size

similar advantages as other methods.While molds will form pellets naturally, some bacteria oryeast cells require flocculation

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