ECOLOGICAL STUDIES ON TILE SYMBIOSIS OF TER ITOMYCES ...

TABLE 7-3-1k Ile. Ictions of ruts of Macrotermos bellicosus and
Ydcrotermes species on gallic and tamic acid plater (aftor 24 hourn).
TEPMITE SPLICUS REACTIM
NUMV., VS UN
GALLIC ACID
NUI-MRS ON
TANNIC ACID
Kicrotermes ballicosus 2 20 '23
1 a 3
0
Hicrotermes sp. 2 0 0
15 soil in gut 1 0 0
1ý) fo od in gut 0 15 15
0 no colouration
1 very faint brown colouration
2 dartzer brown colouration
7-3-4 DI6CUSSI014
These results ahow that Termitmnypen has characteristics of a
white rot fungus in producing polyphenol oxidases of tho laccase type,
There is a strong correlation betwecn possession of polyphenol oxidases
and lignin breakdoum, although the polyphonol oxidases are rarely
concerned with ring breakdown. The enzymatic breakdown of lignin is
not well understood but W3 probable a multi-enzyme System Is requira. d
(Kirk 1971t 5ýllft 1977). Two hypotheaes havo been put forwnrd. The
first is that tho InItIal depolymerialng steps are by extracellular
cleavage of the inter-urdt bondse The secand Is that the primary attack
comes not an Intermonomer bonds but on the aromatic ring. This suogezta
a single mechanism for the Initial opening up of the polymer rather than
the multiple enzyme system necessary for Initial depolymerization based
on cleavage of intermonomer bonds (5witt
Ot al - 1979). The ccoplote
process in not yet known'* It to likelY different lignin degrading
arganis= may have cufferent enzyme syntems.
32,9
*