Tannase production by Aspergillus fumigatus MA under solid-state fermentation

Abstract

A tannase yielding fungal culture identified as Aspergillus fumigatus MA was isolated from the effluent collected from a local small scale tannery. The fungal culture produced high yields of extracellular tannase under solid-state fermentation (SSF) using different agro forest residues such as Amla leaves (Phyllanthus emblica), Ber leaves (Zyzyphus mauritiana), Jamun leaves (Syzygium cumini), Jamoa leaves (Syzygium sp.) and Keekar leaves (Acacia nilotica). Among different substrates used, Jamun leaves yielded maximal extra-cellular production of tannase. Various parameters were studied to optimize the extracellular yield of tannase under SSF. The maximum yield of 174.32 U g -1 was obtained at 25°C after 96 h of incubation at pH 5.0. The tap water was used as a moistening agent. A substrate to tap water ratio of 1:1 was found to best for tannase production. Supplementation of the medium with ammonium sulfate as nitrogen source had enhanced tannase production whereas glucose had decreased the enzyme production. This is the first report on production of tannase by Aspergillus fumigatus MA, giving a much higher yield of enzyme under SSF with Jamun leaves as the substrate.

<b>Optimization of culture conditions for tannase production by <i>Aspergillus</i> sp. gm4 in solid state fermentation

“…After incubation, the fermented substrates were mixed properly by adding 0.1 M phosphate buffer (pH 6.0) to the flasks (MANJIT et al, 2008). Then, the flasks were kept on the rotary shaker at 200 rpm for one hour.…”

“…Studies on tannase production have been done in liquid surface, submerged or solid-state fermentation (SSF) (SABU et al, 2005;MUKHERJEE;BANERJEE, 2006;BANERJEE et al, 2007;RODRIGUES et al, 2007;MANJIT et al, 2008;SELWAL et al, 2011). SSF is a bioprocess in which microorganisms are grown on solid substrates in the absence or near absence of free water (RODRIGUES et al, 2008).…”

“…In this respect, tannin-rich plant residues could be a cost-effective substrate in SSF and are advantageous for countries where these materials are generated in abundance (JANA et al, 2012). In addition, this system produces only a negligible amount of liquid effluents and thereby creates less pollution (MANJIT et al, 2008).…”

“…Among the microorganisms, the genus Aspergillus has been widely used for the production of tannase (LEKHA; LONSANE, 1997 , Aspergillus ruber (KUMAR et al, 2007), Aspergillus fumigatus MA (MANJIT et al, 2008) and Aspergillus oryzae (RODRIGUES et al, 2007(RODRIGUES et al, , 2008.…”

“…The main parameters that influence the production of tannase are tannic acid concentration, humidity, type of substrate used, temperature, pH, incubation time and addition of different sources of carbon and nitrogen (LEKHA; LONSANE, 1997). Few studies use experimental designs to optimize the production of tannase, with the majority of optimization experiments evaluating the effect of each variable separately (KAR;SABU et al, 2005;MANJIT et al, 2008;RODRIGUES et al, 2008). However, as in fermentation processes each variable can interact with and influence the effect of other, it is essential that an optimization method capable of detecting possible interactions be developed, so that an optimal point is chosen to obtain high yields of enzyme (JANA et al, 2012).…”