Growth kinetic profiles of Aspergillus niger S14 a mangrove isolate and Aspergillus oryzae NCIM 1212 in solid state fermentation

Aspergillus niger is one among the many species of fungi thriving in mangrove ecosystem with potential for biotechnological and industrial applications. Understanding the growth profile and kinetics is of use in studying dynamics of mangrove ecosystem. In the present investigations, empirical equations and growth models commonly used in elucidating the dynamic nature of growth were fitted to the data of the biomass, protein and glucosamine levels during solid state fermentation (SSF) with wheat bran as substrate using Aspergillus niger S(1)4, a fungal isolate from mangrove and Aspergillus oryzae NCIM 1212, an industrial strain. Linear, exponential, two-phase models, logistic equations, Richards, Michaelis-Menten, Weibull, Modified Gompertz and Morgan-Mercer-Flodin models were used. Among the models, logistic equation and Michaelis-Menten model could provide an adequate fit to the biomass variation for 21 days. The protein and glucosamine contents followed a different trend compared to the direct biomass measurements which made them inept for growth kinetic studies of the two fungal strains in SSF.