NASA CELSS Program (Cooperative Agreement NCC 2-231) UTILIZATION OF NON-CONVENTIONAL SYSTEMS FOR CONVERSION OF BIOMASS TO FOOD COMPONENTS RECOVERY OPTIMIZATION AND CHARACTERIZATION OF ALGAL PROTEINS AND LIPIDS

P r o t e i n i s o l a t e o b t a i n e d from g r e e n a l g a e ( S c e n e d e s m u s -_-I_ o b l i q u u s ) c u l t i v a t e d u n d e r c o n t r o l l e d c o n d i t i o n s w a s c h a r a c t e r i z e d . M o l e c u l a r w e i g h t d e t e r m i n a t i o n o f f r a c t i o n a t e d a l g a l p r o t e i n s u s i n g S D S p o l y a c r y l a m i d e g e l e l e c t r o p h o r e s i s r e v e a l e d a wide s p e c t r u m o f molecul a r w e i g h t s r a n g i n g f rom 15,000 t o 2 2 0 , 0 0 0 . I s o e l e c t r i c p o i n t s o f d i ssoc i a t e d p r o t e i n s were i n t h e r a n g e of 3 .95 t o 6 .20 . Amino acid c o m p o s i t i o n o f p r o t e i n i s o l a t e compared f a v o r a b l y w i t h FA0 s t a n d a r d s . H igh c o n t e n t o f e s s e n t i a l a m i n o a c i d s l e u c i n e , v a l i n e r p h e n y l a l a n i n e a n d l y s i n e makes a l g a l p r o t e i n i s o l a t e a h i g h q u a l i t y component o f C E L S S d i e t s . T o o p t i m i z e t h e r e m o v a l o f a l g a l l i p i d s a n d p i g m e n t s s u p e r c r i t i c a l c a r b o n d i o x i d e extract i o n ( w i t h a n d w i t h o u t e t h a n o l as a c o s o l v e n t ) was u s e d . A d d i t i o n of e t h a n o l t o s u p e r c r i t i c a l C02 r e s u l t e d i n more e f f i c i e n t r e m o v a l of a l g a l l i p i d s a n d p r o d u c e d p r o t e i n i s o l a t e w i t h a qood y i e l d a n d p r o t e i n r e c o v e r y . T h e p r o t e i n i s o l a t e ex t r ac t ed by t h e a b o v e m i x t u r e had a n i m p r o v e d water s o l u b i l i t y . I N T R O D U C T I O N T h e r e is a n e e d f o r s u i t a b l e f e e d i n g s y s t e m s f o r e x t e n d e d manned space m i s s i o n s . The p o t e n t i a l u t i l i z a t i o n of a l g a l biomass i n a n o n c o n v e n t i o n a l f o o d s u p p l y i n spacer is t h e s u b j e c t o f o u r s t u d y . U n i q u e m u l t i f u n c t i o n a l c h a r a c t e r i s t i c s o f a l g a e s u c h a s h i g h p h o t o s y n t h e t i c a c t i v i t y , l a c k o f n e e d f o r o r g a n i c c a r b o n a n d n i t r o g e n i n t h e g r o w t h media a n d t h e a b i l i t y t o ‘.c, c o n t r o l a l g a l c h e m i c a l composi t ion by v a r y i n g c u l t i v a t i o n c o n d i t i o n s make A a l g a e a n a t t r a c t i v e s y s t e m f o r b i o l o g i c a l r e g e n e r a t i o n of t h e C E L S S e n v i r o n m e n t ( C a s e y a n d L u b i t z , 1963; C l e m e n t -e t a l . / 1967; L a c h a n c e , 1968; L i p i n s k y a n d L i t c h f i e l d , 1 9 7 0 ; W a s l i e n , 1 9 7 5 ; C l e m e n t , 1 9 7 5 ; W a s l i e n e t a l . , 1 9 7 8 ; O s w a l d , 1980: a n d P i o r r e c k e t a l . , 1 9 8 4 ) . Consumpt ion of 7 --