t-,/rrr',r47c

98
molas€s inchding unfernented sueas, .nd mircral siducs 6f s!lr5 add.d during
rh€ @u6e of f.mdtltion sd somc of dr virsmins. K@ping in vi.w $c
impodance of y6t extract s s conmon ingrediert of differeni gro*1h mcdia for
.nhancing lhe grcwth ot dir@dr org&isms! it wB deidcd 10 use y41 rludge as .
supprcDrnr to rhe g.owth 'nedin6 ot B.Iow. The avqage rtue pdein vatu€s of
rl'c bioNass hlrvcscd s i hcnced by supplcnpnrarion ofdillcrcnt lcvcts ofye.sl
sludge ar€ lresenled in l able 6, and Ihe ltatistical ealysis of Lhe dara is Drcsentcd
in Appendir XVIU. The rcsults..vealed signifi@1 diffcrcnc€s among truc proi.it
values ofthe biomas obtained as a eult of supplmentllion ofdirercnt levels of
yc.sl sludgc. ll ws obscned tlut rhc supplemcntador ol yed( sludSe lplo L0%
Ievel rcsulkd nt muitnum incr€3le in bioma$ pfot€in yield. Tlis incr€ale was
sigoincan y hi8her at 0.50lo and 1.0% lev.ls d comparcd with the contrcl and orher
lcvels, wher€ as non significint diffss@ re fosd b.lw6 truc protcin !?lu€s
obtained at 0.5 and Lo%o levels.
Ycasl cell mals or y4t €xlract has ben .€poned to enhance the
nulriliv€ value of lhe growth medium (Yogo e, a/., 1976 i El-Sabaeny and Hdsan,
1996 md t{ .r a/.. 1997). In all rh€se c!s6 ll|c }61
extract was supplem€nted ro
the medium within rhe rang€ of0.l to 1.0 %. Simild findinss werc observed in the
present study wilh sludge, which contained sufficicnt Inin€lal conl€nts slong with
the y€ast bionass. A neSalive eff€cl was observ€d when sludge was used above I 0/o
in presenr study. This @uld b€ duc lo thc pso@ of high minqal conrcnis in rhc
sludee. Addilion of yoa3t sludgc at 1.0% level gave the maximum biomass proGin
yield and wa! $crefore adopted.
6. Determination of Ilirv€sting Time for 8.jfI4r4m
For se.ting maximum dd €conomical yield of biomass prctein $€
femotllion was cuied od follosing all the dclennined groMh conditioG on
fonnulated medium. The fermentation was l€rminated at $ree titne Deriods. Th.