incubation period may be observed for the production of different enzymes (Smitt
et al. 1996). Transient length of time affordability for cheaper enzyme biosynthesis
was observed (Sonjoy et al. 1995). In an experimental study, Ojumu et al. (2003)
noticed that A. flavus gave the highest cellulase activity when cultivated and grown
on saw dust, bagasse and corn cob at 12 h of fermentation. Time duration of 72 h was
set for growth of A. Niger to release cellulase (Azzaz et al. 2012; Gautam et al. 2010;
Akinyele and Olaniyi 2013). Provision of 96 h of fermentation time was found to be
favourable for enhanced cellulase activity by Trichoderma spp. (Khan et al. 2007).
The incubation period for optimum enzyme production was correlated to substrate
concentration. In the case of P. nalgiovense, the optimum CMCase activity in 2%
pretreated wheat pollard was attained at 3 days incubation time, and then later the
enzyme production was ceased due to confined nutrient concentration. When 3%
and 4% pollard was used as substrates, optimal CMCase was achieved after 4 days.
At further higher concentration of substrate, the culture demands longer incubation
time due to less penetration of oxygen (Purwadaria et al. 2004). In the investigative
reveals made by Nathan et al. (2014), T. reesei took 7 days of incubation to give
elated FPase (0.38 U/ml) and CMCase (0.52 U/ml) activities which declined at
later intervals of time. The probable speculation for weakened enzyme activity
after stretched fermentation duration may be ascribed to loss of enzyme stability or
self-death of the mycelia (Nipa et al. 2006).
Maximum CMCase (2.31 IU/ml) and FPase (0.261 IU/ml) were produced after
5 days of incubation beyond which induced decrease in the enzyme production
(Sarkar and Aikat 2014). While in an examination made by Sun et al. (2010),
enzyme activity by Trichoderma sp. was best at 120 h in SmF utilising apple
pomace. Therefore, it is concluded that appropriate time length permits peak microbial growth and product formation to a defined level in a bioprocess approach.
11.13 Effect of Agitation Rate
Cellulase production in general was boosted with elevated shaking speed. This might
be justified by the certainty that the rotational rate raised the transport of air into the
microbial cells which is crucial for components of their cell membrane and synchronous of the medium components, essentially nutrients and products of catabolism
(Rajagopalan and Krishnan 2008). The favourable fermentation factors for the
enzymatic breakdown of brewer’s spent grain were established to be 2% (w/v)
substrate, 45 FPU/g maintained at 100 rpm. Under these conditions, 99.4% of
cellulose bioconversion and 93.1% of glucose yield were achieved (Mussatto
et al. 2008).
In liquid-state cultures, stirring speed of 180 RPM was noted to be optimal for the
production of cellulase enzymes with fungal strain T. viride CMIT35 (Vintila et al.
2010). Cellulase production supported by 200 rpm and oil palm empty fruit bunch
inoculated with A. terreus was four times improved as compared to the static
condition (Shahriarinour et al. 2011). Penicillium sp. LM-HP33 and Aspergillus
sp. LH-HP32 were the best alkaline cellulase (FPase) producers (>3 U/ml) in liquid
11 Significance of Process Parameters on Fungal Cellulase Production
309
et al. 1996). Transient length of time affordability for cheaper enzyme biosynthesis
was observed (Sonjoy et al. 1995). In an experimental study, Ojumu et al. (2003)
noticed that A. flavus gave the highest cellulase activity when cultivated and grown
on saw dust, bagasse and corn cob at 12 h of fermentation. Time duration of 72 h was
set for growth of A. Niger to release cellulase (Azzaz et al. 2012; Gautam et al. 2010;
Akinyele and Olaniyi 2013). Provision of 96 h of fermentation time was found to be
favourable for enhanced cellulase activity by Trichoderma spp. (Khan et al. 2007).
The incubation period for optimum enzyme production was correlated to substrate
concentration. In the case of P. nalgiovense, the optimum CMCase activity in 2%
pretreated wheat pollard was attained at 3 days incubation time, and then later the
enzyme production was ceased due to confined nutrient concentration. When 3%
and 4% pollard was used as substrates, optimal CMCase was achieved after 4 days.
At further higher concentration of substrate, the culture demands longer incubation
time due to less penetration of oxygen (Purwadaria et al. 2004). In the investigative
reveals made by Nathan et al. (2014), T. reesei took 7 days of incubation to give
elated FPase (0.38 U/ml) and CMCase (0.52 U/ml) activities which declined at
later intervals of time. The probable speculation for weakened enzyme activity
after stretched fermentation duration may be ascribed to loss of enzyme stability or
self-death of the mycelia (Nipa et al. 2006).
Maximum CMCase (2.31 IU/ml) and FPase (0.261 IU/ml) were produced after
5 days of incubation beyond which induced decrease in the enzyme production
(Sarkar and Aikat 2014). While in an examination made by Sun et al. (2010),
enzyme activity by Trichoderma sp. was best at 120 h in SmF utilising apple
pomace. Therefore, it is concluded that appropriate time length permits peak microbial growth and product formation to a defined level in a bioprocess approach.
11.13 Effect of Agitation Rate
Cellulase production in general was boosted with elevated shaking speed. This might
be justified by the certainty that the rotational rate raised the transport of air into the
microbial cells which is crucial for components of their cell membrane and synchronous of the medium components, essentially nutrients and products of catabolism
(Rajagopalan and Krishnan 2008). The favourable fermentation factors for the
enzymatic breakdown of brewer’s spent grain were established to be 2% (w/v)
substrate, 45 FPU/g maintained at 100 rpm. Under these conditions, 99.4% of
cellulose bioconversion and 93.1% of glucose yield were achieved (Mussatto
et al. 2008).
In liquid-state cultures, stirring speed of 180 RPM was noted to be optimal for the
production of cellulase enzymes with fungal strain T. viride CMIT35 (Vintila et al.
2010). Cellulase production supported by 200 rpm and oil palm empty fruit bunch
inoculated with A. terreus was four times improved as compared to the static
condition (Shahriarinour et al. 2011). Penicillium sp. LM-HP33 and Aspergillus
sp. LH-HP32 were the best alkaline cellulase (FPase) producers (>3 U/ml) in liquid
11 Significance of Process Parameters on Fungal Cellulase Production
309