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In this study, spores of inulinase-producing thermophilic Aspergillus tamarii were subjected to UV mutagenesis, and colonies obtained were screened for inulinase production on inulin-glucose agar. The thermal stability of the inulinase was also investigated. A mutant strain U4 was found to produce 2.8 times inulinase titre (62.1U/mL) as against the wild strain (22.2U/mL). Inulinase production by this U4 strain was also found not to be significantly (P≤0.05) affected by the presence of glucose. The inulinase produced retained 64% of its activity after incubation at 65ºC for three hours. Solid-state fermentation for inulinase production by the strain U4 showed that wheat bran supported the highest inulinase titre 218.3U/gds while banana peels supported the lowest inulinase production titre of 80.5U/gds. Further optimization of cultural parameters revealed that incubation time of 5 days, 60% initial moisture content of the substrate, 2% inoculum density 2%, temperature 55ºC and pH 4.5 were optimal for inulinase production. Under optimized conditions, inulinase titre of 426.6 U/gds was observed. The pattern of inulin hydrolysis by the inulinase revealed the presence of monosaccharide as the main product of hydrolysis. Inulinase production at elevated temperatures by the mutant Aspergillus tamarii-U4 and its catabolite resistant properties showed that the organism is a potential industrial candidate for the production of exo-acting inulinases.
Apolinário AC, de Lima Damasceno DPG, de Macêdo Beltrão NE, Pessoa A, Converti A, da Silva JA. Inulin-type fructans: A review on different aspects of biochemical and pharmaceutical technology. Carbo Poly. 2014;101:368-378.
Gill PK, Manhas RK, Singh P. Purification and properties of a heat-stable exoinulinase isoform from Aspergillus fumigatus. Biores Technol. 2006a;97:894–902.
Galindo Leva LA, Hughes SR, López Núñez JC, Jarodsky, JM, Erickson, A, Lindquist MR, Cox EJ, Bischoff KM, Hoecker EC, Liu S, Qureshi Z, Jones MA. Growth, ethanol production and inulinase activity on various inulin substrates by mutant Kluyveromyces marxianus strains NRRL Y 50798 and NRRL Y 50799. J Ind Microbio Biotechnol. 2016;43(7):927-939.
Singh RS, Singh RP. Production of Fructooligosaccharides from Inulin by Endoinulinases and Their Prebiotic Potential. Food Technol Biotechnol. 2010; 48(4):435–450.
de-Souza-Motta CM, De Queiroz Cavalcanti MA, Figueiredo Porto AL, Moreira KA, Filho JL. Aspergillus niveus Blochwitz 4128URM: New source for inulinase production. Braz Arch Biol Technol. 2005;48:343–350.
Mazutti M, Bender J, Treichel H, Di Luccio M. Optimization of inulinase production by solid-state fermentation using sugarcane bagasse as substrate. Enz Microb Technol. 2006;39:56–59.
Gill PK, Manhas RK, Singh P. Comparative analysis of thermostability of extracellular inulinase activity from Aspergillus fumigatus with commercially available (Novozyme) inulinase. Biores Technol. 2006b;97:355–358.
Guo N, Gong F, Chi Z, Sheng J, Li J. Enhanced inulinase production in solid state fermentation by a mutant of the marine yeast Pichia guilliermondii using surface response methodology and inulin hydrolysis. J Ind Microbiol Biotechnol. 2009;36:499–507.
Onilude AA, Fadahunsi IF, Garuba EO. Inulinase production by Saccharomyces sp. in solid state fermentation using wheat bran as substrate. Ann Microbiol. 2012;62 (2):843-848.
Housseiny MS. Production of an Endoinulinase from Aspergillus niger AUMC 9375, by solid state fermentation of agricultural wastes, with purification and characterization of the free and immobilized enzyme. J Microbiol. 2014;52 (5):389–398.
Garuba EO, Onilude AA, Oyinlola AK. Isolation and molecular characterization of inulinase-producing thermophilic fungi from waste dumpsite located at Apete-Awotan in Ibadan, South-Western Nigeria. Inn Roman Food Biotechnol. 2015;16:31– 36.
Purohit JS, Dutta JR, Nanda KR, Banerjee R. Strain improvement for tannase production from co-culture of Aspergillus foetidus and Rhizopus oryzae. Biores Technol. 2016;97:795–801.
Kim KC. Studies on the hydrolysis of inulin in Jerusalem artichoke by fungal inulinase. J Korean Agric Chem Soc. 1975;18:177–182.
Xiong C, Jinhua W, Dongsheng L. Optimization of solid-state medium for the production of inulinase by Kluyveromyces S120 using response surface methodology. Biochem Eng J. 2007;34: 179–184.
Gill PK, Sharma, AD, Harchand RK, Singh P. Effect of media supplements and culture conditions on inulinase production by an Actinomycete strain. Biores Technol. 2003; 87:359–362.
Azhari R, Selak AM, Ilan E, Sideman S, Lotan N. Purification and characterization of endo- and exo-inulinase. Biotechnol Appl Biochem. 1989;11:105–117.
Viswanathan P, Kulkarni PR. A study of inulinase production in Aspergillus niger using fractional factorial design. Biores Technol. 1995;54:315–320.
Yu X, Guo N, Chi Z, Gong F, Sheng J, Chi Z. Inulinase over production by a mutant of the marine yeast Pichia guilliermondii using surface response methodology and inulin hydrolysis. Biochem. Eng. J. 2009; 43:266-271.
Trivedi S, Divecha J, Shah A. Optimization of inulinase production by a newly isolated Aspergillus tubingensis CR16 using low cost substrates. Carbo Poly. 2012;90:483– 490.
Jing W, Zhengyu J, Bo J, Augustine A. Production and separation of exo and endoinilinase from Aspergillus ficcum. Proc. Biochem. 2003;39:5–11.
Gupta AK, Singh D, Kaur N, Singh R. Production purification and immobilisation of inulinase from Kluyveromyces fragilis. J. Chem. Technol. Biotechnol. 1994;59:377-385.
Kango N, Jain SC. Production and Properties of Microbial Inulinases. Rec. Adv. Food Biotechnol. 2011;25(3): 165-212.
Ramos-Sánchez LB, Cujilema-Quitio MC, Julian-Ricardo, Cordova J, Fickers P. Fungal Lipase Production by Solid-State Fermentation. Bioproc. Biotechnol. 2015;5:203.
Saber W, El-Naggar N. Optimization of fermentation conditions for the biosynthesis of inulinase by the new source; Aspergillus tamarii and hydrolysis of some inulin containing agro-wastes. Biotechnol. 2009;84:425- 433.
Masomian M, Rahman R, Salleh A, Basri M. A unique thermostable and organic solvent tolerant lipase from newly isolated Aneurinibacillus thermoaerophilus strain HZ: Physical factor studies. World J. Microbiol Biotechnol. 2010;26(9):1693-16701.
Ebrahimpour A, Rahman R, Kamarudin NHA, Basri M, Salleh AB. Lipase production and growth modeling of a novel thermophilic bacterium: Aneurinibacillus thermoaerophilus strain AFNA. Electronic J. Biotechnol. 2011;14(4): full text 8.