Jani and Patel
a
b
d
e
c
Figure 6: Feather degradation by S. viridis at different time intervals
a: Control , b: after24h , c : after 48h, d : after 48h, e : after 48h, at 45°C
Crude enzyme sample collected from production medium
The protease was strongly inhibited by 5 mM PMSF
after 96 h of incubation was analyzed for its enzyme activity
indicating the enzyme as a serine protease. Negligible
and it was found that the crude sample was having 427
inhibition was observed in presence of 5 mM EDTA or 5
units/ml of enzyme. (Figure-3) (Shilpa Jani, et al., 2012)
mM PCMB and 5 mM DTT, indicating that it is neither
The molecular weight of purified protease of S. viridis
a metalloprotease nor a cysteine protease. The majority
SJ-21 was determined by SDS-polyacrylamide gel
of the proteases from thermophiles are of the serine type
electrophoresis (SDS-PAGE). The molecular mass of the
(de Vos et al., 2001). Reports indicate that most of the
purified protease was 18.4 KDa (Figure 4 lane-2). Our
alkaline proteases from thermophilic actinomycetes are of
result exactly matches with the low molecular weight
serine type.
(18.4 KDa) of protease identified from Streptomyces
griseus (Kumar et al., 2006), and that of serine protease
Degradation of feathers: keratinolytic protease activity
from S treptomyces albidoflavus (18 KDa) (Bressollier et
of S.viridis SJ-21 .
al., 1999).
The S.viridis SJ-21 showed excellent keratinolytic activity
Generally, the molecular masses of alkaline protease from
as it started degrading feathers within 24 h. The feathers
microorganisms range between 15 and 36 KDa (Gupta et
were degraded completely in 72 h. As no other nutrition
al., 2002b).
was provided it could be confirmed that organisms were
484