full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and Pharmacy
Vol. 5 (3) 1325 -1337 July 2011, ISSN 0973-8916 (Print), 2230-7303 (Online)
1330
as sporulation and protease formation also
favoured the production of cephamycin C. Onset
of sporulation is associated with the presence of
metabolic starvation conditions, typically loss of
available assimilable nitrogen. Similarly,
excretion of extracellular proteolytic enzymes
would be consistent with a run out of soluble
amino nitrogen in the fermentation medium (7).
This study is consistent with the idea that
starvation conditions imposed by a nitrogen or
carbohydrate limitation could induce sporulation,
protease excretion and antibiotic synthesis in N.
lactamdurans. However, this synthesis has by
no means been quantitatively proved.
Production profile of cephamycin C and growth
curve of N. lactamdurans NRRL 3802: The
production profile of the cephamycin C and
growth curve of N. lactamdurans NRRL 3802
was carried out with respect to time (Fig. 2). The
production of cephamycin C started on the first
day itself, reached a maximum on the third day
of fermentation (347.37 ± 4.80 mg/l), and there
Fig. 2. Production profile of cephamycin C and growth
curve of N. lactamdurans NRRL 3802 in SmF
was no further increase in cephamycin C until
day 5. All the subsequent studies were carried
out with fermentation for 3 days. Kirpekar et al.
(5) reported the production of cephamycin C to
reach a maximum after 88 h, and then decrease
slightly up to 120 h of fermentation.
Effect of initial pH: An initial pH of 5.5
supported maximum production of 351.75 ± 7.61
mg/l of cephamycin C (data not shown). Hence,
all further studies were carried out at pH 5.5. At
higher pH, the production decreased, probably
due to repression of the enzymes cyclase and
expandase due to release of ammonia (16). An
initial pH of 6.0 to 7.0 has been reported to be
optimum for cephamycin C production by many
investigators (11,18,19), but these studies were
performed with pH control. At shake flask level,
without pH control, the organism would probably
be getting more time for production at pH 5.5
Optimization of inoculum size: An inoculum
size range of 10 9 - 10 6 CFU/ml was used.
Maximum production of 352.45 ± 1.85 mg/l of
cephamycin C was obtained with 10 9 CFU/ml in
a 50 ml media (data not shown). This inoculum
size was used for further studies. Lower inoculum
size resulted in poor cephamycin C production
which could be due to insufficient biomass
produced. Sanchez and Brana (20) studied the
effects of cell density on cephamycin C
production and observed the production of
cephamycin C and clavulanic acid by
Streptomyces clavuligerus to take place during
the exponential phase of growth in a defined
medium.
Effect of various minerals: Shake flask
experiments were carried out using variations of
the media. Here each component of media was
removed one at a time (except glycerol, yeast
extract and L-glutamic acid) to check their effect
on cephamycin C production. Fig. 3 shows the
effect of removal of various minerals on the
cephamycin C production. Removal of CaCO 3
,
PABA, MnSO 4
, myo-inositol and ZnSO 4
resulted
in increase in production of cephamycin C as
compared to control suggesting that these could
Lalit D. Kagliwal et al