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Determination of optimal growth parameters for the bioincising fungus Physisporinus vitreus by means of response surface methodology
Author(s) -
Schubert M.,
Dengler V.,
Mourad S.,
Schwarze F.W.M.R.
Publication year - 2009
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2008.04138.x
Subject(s) - lag time , incubation , lag , growth rate , zoology , response surface methodology , phase (matter) , agar , chemistry , phase lag , analytical chemistry (journal) , chromatography , biology , biochemistry , mathematics , computer network , genetics , geometry , organic chemistry , computer science , bacteria , biological system
Aim: To evaluate the influence of water activity ( a w ), temperature and pH on the radial growth and lag phase of Physisporinus vitreus (E‐642), a basidiomycete was used in the biotechnological process of bioincising. Methods and Results: Radial growth was monitored for 20 days on malt extract agar medium. Five levels of a w (0·998, 0·982, 0·955, 0·928, 0·892) were combined with three incubation temperatures (10, 15, 20°C) and three pH values (4, 5, 6). Data analyses showed a highly significant effect of a w and temperature ( P < 0·0001) and a significant effect of pH ( P < 0·05). The radial growth rate and lag phase of P. vitreus were very sensitive to a w reduction. Although P. vitreus was able to grow at all the selected temperatures and pH values, the lag phase increased with decreasing a w and growth became inhibited at a w = 0·955. Optimal conditions for growth of P. vitreus were a w = 0·998, 20°C and pH 5. The response surface model provided reliable estimates of these growth parameters and confirmed a greater dependence on a w than on temperature or pH under in vitro conditions. Conclusions: Low levels of a w can prevent growth of P. vitreus , so wood moisture content should be adjusted accordingly. Significance and Impact of the Study: Implementation of these results should contribute towards the optimization and efficiency of bioincising.