Karsten Keller, Thomas Friedmann and Arthur Boxman

The bioseparation needs for tomorrow

Karsten Keller, Thomas Friedmann and Arthur Boxman

Will we replace oil with wheat or corn as a feedstock for producing natural plastic? The success of biotechnology for bulk product manufacturing will heavily depend on engineering solutions in the downstream processes in which separation and purification have a crucial role with respect to commercial development. Development of efficient bioseparation methods is important for a broad range of business areas including pharmaceuticals, nutrition and health products, bio-based materials and crop protection chemicals. Depending on the value of the end product and the scale of production, the processing required varies significantly. Key factors that have an impact on the choice of separation strategy include process throughput, particle size of the product and impurities and the desired end-product concentration. The development of efficient, economical and selective separation methods will be required for successful commercialization of bioprocesses. Despite this well-recognized need, there are relatively few available methods for commercial implementations. Development of novel mechanical systems for selective separation of solid and liquid mixtures must become a top priority for current research investment to reduce the reliance on expensive chromatographic and thermal separation methods.

have accele rat ed biotech rese arch an d development, in academia, industry an d governm ent -fun ded

laborat ories.

[pic 4]

‘Bioseparation processes for life sciences require different approaches from those used in traditional chemical industries.’

[pic 5]

For exam ple, after World War I, DuPont

(Wilmington, DE, USA) tran sform ed itself into a dive rsified chemical com pan y as a res ult of

fun dam enta l rese arch in mat erial sciences. The un derstan ding of free ra dical polymerizat ion,

con densat ion polymerizat ion an d polymer stru ctur e led to th e development of Neoprene® synth etic

ru bbe r an d nylon fibe rs. A new focu s on biology, chemistr y an d knowledge -int ensive solut ions ha s tak en place in th e last ten year s, rep rese nt ing a

major cor porat e comm itm ent . In Sep tember 1999 , Cha d Holliday (DuPont’s CEO) ann ounced ‘We will tak e important  steps towar d th e use of renewable

resources an d energy’. The goal is to source 10% of our energy needs in th e year 2010 from  renewable

energy sources an d to derive 25% of our revenu es in 2010 from ar eas oth er than  those requiring finite

ra w mat erials. We ar e stu dying th e potent ial use of plant s to manu factur e useful chemicals; for

Karsten Keller* Thomas Friedmann Arthur Boxman

DuPont Central Research & Develop ment, PARSAT Experimental Station, E304/A207, Wil mington , DE 19880-0304, USA.

*e-mail: karsten.keller@ usa.dupont .com[pic 6][pic 7][pic 8][pic 9][pic 10][pic 11][pic 12][pic 13][pic 14][pic 15][pic 16][pic 17][pic 18][pic 19][pic 20]

Removal of insolubles and/or

sampling of cell-free liquid

Nutrition and

health

Agriculture

Sterilization

and/or filtration

       Cell recovery

and/or cell harvest

Pharmaceuticals

Performance

materials

Isolation and/or

purification

TRENDS in Biotechnology

Over th e past decade, man y tra ditional chemical

industries have bee n un dergoing a chan ge in th eir orientat ion from conve nt ional chemicals to life-

science products. Despi te discussion about what a life sciences compan y should consist of, th e required

technology for th e futur e will not chan ge. Recent development s in biochemistr y, togeth er with

recognition of th e need for renewable resources,

exam ple, one day we might be able to creat e a plant that produces biosilk. We ar e also looking for th e

genes that contr ol th e synth esis of natura l ru bbe r to ena ble us to use plant s that ar e comm only grown in th is countr y as a source of ru bbe r. With th ese

initiat ives comes th e need for more sophisticat ed biosep arat ion methods an d processes in a broad ran ge of business ar eas (Fig. 1).

Fig. 1. In the futur e, various bioseparation technologi es are needed for a broad range of business areas.

Bioseparation – today’s technologies

Biosep arat ion processes for life sciences require different approaches from those used in tra ditional chemical industries. For exam ple, in th e

pharma ceutical industry, only a few kilogram s of a protein might be produced per year with a  total

selling price of millions of dollar s. In industrial biotechnology, thousan ds of tons of bio-based

polymers, such as Biopol or Xanthan gum, could be ma de per year, also yielding millions of dollar s in

sales but at a significant ly lower price per unit ma ss. Sep arat ion of biologically based products often needs entirely new processes to han dle unu sual mat erial

properties, such as th e compressibili ty of a bioma ss.

The desired product might be a single component

prese nt at low concentrat ion that mu st be sep arat ed from bulk wat er an d oth er soluble component s.

Sep arat ion technologies can be cat egorized according to th eir fun dam enta l principle (Fig. 2). Many of th ese principal sep arat ion approaches ar e described in biosep arat ion han dbooks1. Often th e

 Opinion        

TRENDS in Biotechnology   Vol.19 No.11 November 2001

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sold for several hun dred dollar s per gram . Table 1 shows th e processi ng variables that mak e it[pic 21][pic 22][pic 23][pic 24]

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