Actinomycete Nonomuraea sp. isolated from Indonesian soil is a new producer of inulin fructotransferase

Appl Microbiol Biotechnol

Zhang

et al. 2014

Fructans are the polymers of fructose molecules, normally having a sucrose unit at what would otherwise be the reducing terminus. Inulin and levan are two basic types of simple fructan, which contain β-(2, 1) and β-(2, 6) fructosyl-fructose linkage, respectively. Fructans not only can serve as soluble dietary fibers for food industry, but also may be biologically converted into high-value products, especially high-fructose syrup and fructo-oligosaccharides. In recent years, much attention has been focused on production of difructose dianhydrides (DFAs) from fructans. DFAs are cyclic disaccharides consisting of two fructose units with formation of two reciprocal glycosidic linkages. They are expected to have promising properties and beneficial effects on human health. DFAs can be produced from fructans by fructan fructotransferases. Inulin fructotransferase (IFTase) (DFA III-forming) and IFTase (DFA I-forming) catalyze the DFA III and DFA I production from inulin, respectively, and levan fructotransferase (LFTase) (DFA IV-forming) catalyzes the production of DFA IV from levan. In this article, the DFA-producing microorganisms are summarized, relevant studies on various DFAs-producing enzymes are reviewed, and especially, the comparisons of the enzymes are presented in detail.

Section: Iftase (Dfa Iii-forming)mentioning

confidence: 99%

Section: Enzymatic Properties Of Various Iftases (Dfa Iii-forming)mentioning

confidence: 99%

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From fructans to difructose dianhydrides

Appl Microbiol Biotechnol

Zhang

et al. 2014

“…ID06A0189. 32,33 The reported IFTases (DFA III forming) have more than 50% amino acid sequence identities with one another, but various source of IFTases (DFA III forming) display different enzymatic properties, especially the thermostability and specific activity. 16 Thermostability and specific activity are two of the main factors contributing to the industrial application of IFTase (DFA III forming) for DFA III production.…”

Section: ■ Introductionmentioning

confidence: 99%

Identification of a Recombinant Inulin Fructotransferase (Difructose Dianhydride III Forming) from Arthrobacter sp. 161MFSha2.1 with High Specific Activity and Remarkable Thermostability

Tao

et al. 2015

J. Agric. Food Chem.

Difructose dianhydride III (DFA III) is a functional carbohydrate produced from inulin by inulin fructotransferase (IFTase, EC 4.2.2.18). In this work, an IFTase gene from Arthrobacter sp. 161MFSha2.1 was cloned and expressed in Escherachia coli. The recombinant enzyme was purified by metal affinity chromatography. It showed significant inulin hydrolysis activity, and the produced main product from inulin was determined as DFA III by nuclear magnetic resonance analysis. The molecular mass of the purified protein was calculated to be 43 and 125 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively, suggesting the native enzyme might be a homotrimer. The recombinant enzyme showed maximal activity as 2391 units/mg at pH 6.5 and 55 °C. It displayed the highest thermostability among previously reported IFTases (DFA III forming) and was stable up to 80 °C for 4 h of incubation. The smallest substrate was determined as nystose. The conversion ratio of inulin to DFA III reached 81% when 100 g/L inulin was catalyzed by 80 nM recombinant enzyme for 20 min at pH 6.5 and 55 °C. All of these data indicated that the IFTase (DFA III forming) from Arthrobacter sp. 161MFSha2.1 had great potential for industrial DFA III production.

“…However it becomes increasingly difficult to isolate novel actinomycetes using current isolation methods and techniques. Scientists are searching for improved methods mainly through three ways, including new methods of treating the soil, new ways of inhibiting the growth of unwanted microorganisms, and new types of culture media [2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Oligotrophy is Helpful for the Isolation of Bioactive Actinomycetes

Xue

et al. 2014

Indian J Microbiol

It is necessary to develop new methods for the isolation of unknown actinomycetes from soils. To evaluate the effects of oligotrophic medium on the isolation of soil actinomycetes and develop a new isolation method, the Gause's synthetic medium was diluted to one tenth the recommended concentration in the present study. Soil dilution plate technique was used to isolate actinomycetes from the soil samples. Oligotrophy decreased actinomycete and streptomycete counts, as well as the number of antagonistic actinomycete species. Oligotrophy also decreased the number of actinomycete species in five samples. Some actinomycete species were cultured only on the oligotrophic medium, whereas other species could not be cultured. Oligotrophy decreased actinomycete counts more significantly for soils with organic matter content[40 g/kg. We used 16S rRNA sequence analysis to identify 22 actinomycete species that were only cultured on the oligotrophic medium. Oligotrophic medium was helpful for the isolation of Streptomyces spp., Micromonospora spp. and Streptosporangium spp. Slightly more than 80 % of the identified actinomycete species were biologically active. Therefore, we could draw a conclusion that oligotrophic medium could be helpful for the discovery of new antibiotic producers and the exploitation and utilization of new, biologically active compounds.