Production of inulinase, fructosyltransferase and sucrase from fungi on low-value inulin-rich substrates and their use in generation of fructose and fructo-oligosaccharides.

Owing to applications in the food and nutraceutical industries, inulinases, fructosyltransferases and sucrases have gained considerable attention in recent times. Twenty-five fungal strains were screened for production of these enzymes on three different media formulated using inulin-rich plant extracts prepared from asparagus root, dahlia tuber and dandelion root extract. Culture filtrates of the fungi were examined for hydrolytic activities. Fungi belonging to genus Aspergillus, A. niger GNCC 2655 (11.3 U/ml), A. awamori MTCC 2879 (8.2 U/ml), A. niger ATCC 26011 (7.9 U/ml) secreted high titers of inulinase followed by Penicillium sp. NFCCI 2768 (2.6 U/ml) and Penicillium citrinum MTCC 1256 (1.1 U/ml). High sucrase activity was noticed in A. niger GNCC 2613 (113 U/ml) and A. awamori MTCC 2879 (107.8 U/ml). Analysis of end products of inulinase action by HPLC revealed that most of the enzymes were exo-inulinases liberating fructose exclusively from inulin. Five fungi, P. citrinum MTCC 1256, Penicillium rugulosum MTCC 3487, Penicillium sp. NFCCI 2768, A. fumigatus GNCC 1351 and A. niger ATCC 26011 however, produced a mixture of endo- and exo-inulinases liberating oligosaccharides (GF3 and GF2) along with fructose. High inulinase/sucrase yielding strains were evaluated for extracellular and intracellular hydrolytic and transfructosylating activities and intracellular enzyme profiles were found to be considerably different in terms of titers and end products.

Recycling of cell culture and efficient release of intracellular fructosyltransferase by ultrasonication for the production of fructooligosaccharides.

Production of fructooligosaccharide (FOS) through efficient cultivation of biotransformation process by fructosyltransferase (FTase) was evaluated by two new isolates, Aspergillus niger and Aspergillus flavus NFCCI 2364. The saccharide consumption revealed lag phase of A. niger in 10 h which were smaller extent than A. flavus of 14 h. For the recycling of cell culture, the pellet cells were continuously reused after 24 h of submerged fermentation by these microorganisms in which FTase activity remains stable in four consecutive cycles in A. niger and six cycles in A. flavus. When freshly prepared pellets were sonicated for efficient release of intracellular FTase, the best transformation reaction was performed at 20 W acoustic power giving conversion yield of FOS 61.43% (w/w) by A. niger and 70.44% (w/w) by A. flavus respectively. This study was shown that the two fungal isolates can serve as veritable source of intracellular FTase for industrial production of FOS.

Enzymatic trends of fructooligosaccharides production by microorganisms.

Fructooligosaccharides are influential prebiotics that affect various physiological functions in such a way that they promote positive impact to health. They occur naturally in many fruits and vegetables in trace amounts. However, they are mainly produced commercially by the reaction of microbial enzymes with di- or polysaccharides, such as sucrose or inulin as a substrate. For maximum production of fructooligosaccharides on an industrial level, development of more enzymes with high activity and stability is required. This has attracted the attention of biotechnologists and microbiologists worldwide. This study aims to discuss the new trends in the production of fructooligosaccharide and its effect on numerous health qualities through which it creates great demand in the sugar market.