The present study deals with the isolation screening and optimization of fungal strain for pectinase production. The fungal strains were isolated from different sources, including soil, fruits etc. Qualitative screening was performed on the basis of the pectin hydrolysis zone. While, quantitative screening was carried out employing submerged fermentation. Among all the strains the strains showing highest pectinolytic potential were selected identified and assigned the code Aspergillus niger ABT-5.The influence of different fermentation media on pectinase production was evaluated. The M5 medium containing 10g wheat bran, nutrient medium containing (g/l) of (NH 4 ) 2 SO 4 6.0, K 2 HPO 4 6.0, KH 2 PO 4 6.0, MgSO 4 .7H 2 O 0.1 gave the highest pectinase production. The other important physico chemical parameters including incubation period, temperature, and volume of media, size of inoculum, carbon and nitrogen sources were also optimized for pectinase production. The highest pectinase production (15.5U/ml) was obtained at 72h of incubation, pH 6, temperature 30°C, volume of media 50ml. Fructose and urea were designated as best carbon and nitrogen sources subsequently.

A consecutive optimization based on statistical approach was applied for a-glucosidase production by both wild and mutant T. dupontii. Plackett Burman design (PBD) with two levels was employed in order to screen the significant effect of different nutritional and physical parameters through submerged fermentation. Among all nine variables tested in PBD, incubation time, inoculum size and ammonium sulphate concentration were selected. The Box-Behnken approach was further applied for process optimization. The a-glucosidase production for both wild and mutant T.dupontii was obtained at 72 h of incubation, 1.25 mL inoculum size and 0.25% ammonium sulphate concentration with relatively 95% correlation between the experimentally predicted and observed values. The duration of maximum enzyme production in RSM was cost-saving and fast. The quadratic model was in satisfactory adjustment with the experimental data with high R2 value which describes 98.90% of response variability of the model. Moreover, the novel approach of this present work is that, consecutive optimization were applied for maximum a-glucosidase production using response surface methodology by both wild and mutant thermophillic T. dupontii. Results revealed that thermophillic mutant T. dupontii could be potential candidate for industrial applications.

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This study is related to the isolation of fungal strain for xylanase production using agro-industrial residues. Forty fungal strains with xylanolytic potential were isolated by using xylan agar plates and quantitatively screened in solid-state fermentation. Of all the tested isolates, the strain showing highest ability to produce xylanase was assigned the code Aspergillus niger LCBT-14. For the enhanced production of the enzyme, five different fermentation media were evaluated. Out of all media, M4 containing wheat bran gave maximum enzyme production. Effect of different variables including incubation time, temperature, pH, carbon and nitrogen sources has been investigated. The optimum enzyme production was obtained after 72 h at 30°C and pH 4. Glucose as a carbon source while ammonium sulphate and yeast extract as nitrogen sources gave maximum xylanase production (946 U/mL/min). This study was successful in producing xylanase by A. niger LCBT-14 economically by utilising cheap indigenous substrate.

Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)