TITLE:
Fermentative Production of Mycelial Chitosan from Zygomycetes: Media Optimization and Physico-Chemical Characterization
AUTHORS:
Pradnya N. Vaingankar, Archana R. Juvekar
KEYWORDS:
Mycelial Chitosan, Submerged-State Fermentation, Response Surface Methodology, Box–Behnken Design, Characterization
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.5 No.12,
October
31,
2014
ABSTRACT: The
present study focused on production of mycelial chitosan from fungal mycelium by
submerged fermentation with ecologically more balanced process. Different fungal
strains were screened and Absidia butleri NCIM 977 was found to produce the
highest mycelial chitosan. The one-factor-at-a-time method was adopted to investigate
the effect of batch time, environmental factors (i.e. initial pH and temperature) and medium components (i.e. carbon and nitrogen) on the yield of
mycelial chitosan. Among these variables, the optimal condition to increase in yield
of mycelial chitosan was found to be batch time (72 h), pH (5.5), temperature (30°C), carbon source (glucose) and nitrogen source (tryptone
and yeast extract). Subsequently, a three-level Box– Behnken factorial design was
employed combining with response surface methodology (RSM) to maximise yield of
mycelial chitosan by determining optimal concentrations and investigating the interactive
effects of the most significant media components (i.e. carbon and nitrogen sources). The optimum value of parameters obtained
through RSM was glucose (1.58%), tryptone (1.61%) and yeast extract (1.11%). There
was an increase in mycelial chitosan yield after media optimization by one-factor-at-a-time
and statistical analysis from 683 mg/L to 1 g/L. Mycelial chitosan was characterized
for total glucosamine content (80.68%), degree of deacetylation (DD) (79.89%), molecular
weight (8.07 × 104 Da) and, viscosity (73.22 ml/g). The results of this
study demonstrated that fungi are promising alternative sources of chitosan with
high DD and high purity.