92 • Impacts of Applied Genetics— Micro-Organisms, Plants, and Animals 
product-specific, with each enzyme having 
essentially 100-percent conversion efficiency. 
An enzymatic process that carries out the same 
transformation as a chemical synthesis pro- 
duces no side-products (because of an enzyme's 
high specificity to its substrate) or byproducts 
(because of an enzyme’s strong catalytic power). 
Consequently, biological processes eliminate 
many conventional waste and disposal problems 
at the front end of the system— in the fer- 
menter. This high conversion efficiency reduces 
the costs of recycling. In addition, the efficiency 
of the biological conversion process generally 
simplifies product recovery, reducing capital 
and operating costs. Furthermore, by their 
nature, biologically based chemical processes, 
tend to create some waste products that are bio- 
degradable and valuable as sources of nutrients. 
Specific comparisons of the environmental 
hazards produced by conventional and biologi- 
cal systems are difficult. Data detailing the 
pollution parameters for various current chem- 
ical processes exist, but much less information 
is available for fermentation processes, and few 
compounds are produced by both methods. 
However, in most beverage distilling operations, 
pollution has been reduced to almost zero with 
the complete recovery of still slops as animal 
feeds of high nutritional value. Such control 
procedures are generally applicable to most 
fermentation processes. (App. I-C describes the 
pollutants that may he produced by current 
chemical processes and those expected from 
biologically based processes.) 
The Environmental Protection Agency has 
estimated that the U.S. Go\ernment and indus- 
try combined will spend o\er $3(10 billion to 
control air and watei' pollution in the decade 
from 1977 through 198P. Fhe share' of the 
chemical and allied industries is about $2(i bil- 
lion. Genetic engineering technology may lu'lp 
alleviate this burden by offering cleaner |)roc- 
esses of synthesis and better biological waste' 
treatment systems. The me)netary sa\ ings e'oulel 
be tremendous. As pure speculation, if just a 
percent of the current chemical inelust ry we're' 
affected, spending on pe)llution e’e)ulei l)e re'- 
duced by about $100 million per \ ear. 
Industrial chemicals that may he produced 
hy biological technologies 
Despite the benefits of producing industrial 
chemicals biologically, thus far major fermenta- 
tion processes have been developed primarily 
for a few complex compounds such as enzymes. 
(See table 11.) Biological methods have also been 
developed for a few of the simpler commodity 
chemicals: ethanol, butanol, acetone, acetic 
acid, isopropanol, glycerol, lactic acid, and citric 
acid. 
Two questions are critical to assessing the 
feasibility or desirability of producing various 
chemicals biologically: 
1. Which compounds can be produced bio- 
logically (at least theoretically)? 
2. Which compounds may be primarily de- 
pendent on genetic technology, given the 
costs and availability of raw materials? 
In principle, v irtually all organic compounds 
can be produced by biological .systt'ins. If llu' 
necessary enzyme or enzynu's arc' not know n to 
exist, a search of the biological world w ill prob- 
ably uncover the appro|)riat(' oiu's. Alterna- 
tively, at least in theory, an ('nzymc' can he 
engineered to carry out tin? r('(|uirc'd r('action. 
Within this framework, tiu? potc'iitial appc'ars to 
be limited only by the? imagination ol the' l)io- 
technologist— even though c('rlain chc'micals 
that are highly toxic to biological syslc'in.s are 
probably not amenable to |)roduclion 
Three variables in particular afleet the 
answer to the second (|U('slion: iht' availability 
of an organism or cMizymc's for the' desired 
transformation; the cost of tlu' raw materi.il: 
and the cost of the? production procc'ss \\ hen 
specific organisms and production leehni)lo/;ies 
