The production of phytase and associated feed enzymes (phosphatase, xylanase, CMCase, alpha-amylase and beta-glucosidase) was determined in a thermotolerant fungus Mucor indicus MTCC 6333, isolated from composting soil. Solid-substrate culturing on wheat bran and optimizing other culture conditions (C and N sources, level of N, temperature, pH, culture age, inoculum level), increased the yield of phytase from 266 +/- 0.2 to 513 +/- 0.4 nkat/g substrate dry mass. The culture extract also contained 112, 194, 171, 396, and 333 nkat/g substrate of phosphatase, xylanase, CMCase, beta-glucosidase and alpha-amylase activities, respectively. Simple 2-step purification employing anion exchange and gel filtration chromatography resulted in 21.9-fold purified phytase. The optimum pH and temperature were pH 6.0 and 70 degrees C, respectively. The phytase was thermostable under acidic conditions, showing 82% residual activity after exposure to 60 degrees C at pH 3.0 and 5.0 for 2 h, and displayed broad substrate specificity. The Km was 200 nmol/L and v(lim) of 113 nmol/s per mg protein with dodecasodium phytate as substrate. In vitro feed trial with feed enzyme resulted in the release of 1.68 g inorganic P/kg of feed after 6 h of incubation at 37 degrees C.
- MeSH
- 6-fytasa chemie izolace a purifikace metabolismus MeSH
- alfa-amylasy metabolismus MeSH
- buněčná stěna metabolismus MeSH
- celulasa metabolismus MeSH
- endo-1,4-beta-xylanasy metabolismus MeSH
- fermentace MeSH
- gelová chromatografie MeSH
- hydrolasy metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- krmivo pro zvířata MeSH
- kultivační média chemie MeSH
- Mucor enzymologie izolace a purifikace růst a vývoj MeSH
- potravní vláknina mikrobiologie MeSH
- průmyslová mikrobiologie MeSH
- stabilita enzymů MeSH
- substrátová specifita MeSH
- teplota MeSH
