ORIGINAL PAPER Biomass, laccase and endoglucanase production by Lentinula edodes during solid state fermentation of reed grass, bean stalks and wheat straw residues A. Philippoussis • P. Diamantopoulou • K. Papadopoulou • H. Lakhtar • S. Roussos • G. Parissopoulos • S. Papanikolaou Received: 11 November 2009 / Accepted: 19 May 2010 / Published online: 3 June 2010 Ó Springer Science+Business Media B.V. 2010 Abstract Mycelium growth rates, biomass concentration (estimated as glucosamine content) and laccase and endo- glucanase secretion were monitored during solid state fer- mentation (SSF) of wheat straw (WS), reed grass (RG) and bean stalk (BS) residues by Lentinula edodes strains 119, 121, and 122. In a first experiment, these strains were subjected to screening regarding their growth rates and biomass yield, where strain 121 proved to be the fastest colonizer. However, the greater biomass yield at the end of colonization was demonstrated by strain 122 on BS (465.93 mg g -1 d.w.). In a second experiment, growth characters, as well as endoglucanase and laccase produc- tion patterns of the selected strains 121 and 122 were monitored at three intervals i.e., at 33, 66, and 100% of substrate colonization. BS furnished the highest endoglu- canase production for strain 121, while RG for strain 122. A strain and substrate-dependent behaviour of the enzyme secretion was detected, with strain 122 presenting maximal endoglucanase activity in all substrates at the initial (33%) and final (100%) stages of colonization (0.64–0.90 and 0.79–0.97 U g -1, respectively). However, in strain 121 the peak of endoglucanase production was detected in the early stages of colonization (at 33% on WS and at 66% on RG and BS). Laccase activity showed increased values (max- ima on WS, 353.68 and 548.67 U g -1 by strains 121 and 122, respectively) at 66% of colonization. Correlation analysis of growth data demonstrated negative relations between growth rate and biomass yield and between lac- case and endoglucanase activities on WS and RG sub- strates fermented by strain 122. Finally, possible relations of growth parameters with nutritional constituents of the substrates were investigated. Keywords Lentinula edodes Á Solid state fermentation Á Lignocellulosic residues Á Chemical constituents Á Correlations Á Growth rate Á Glucosamine Á Mycelial biomass Á Laccase Á Endoglucanase Á Enzyme activities Introduction Among applications of solid state fermentation (SSF), mushroom cultivation has proved its economic and eco- logical importance for efficient utilization and biotrans- formation of agro-residues into value-added products (Chang 2006). Lentinula edodes (Berk.) Pegler, the second most popular edible mushroom in the world because of its flavour, taste, nutritional and medicinal properties (Smith et al. 2002; Wasser 2002; Nikitina et al. 2007; Silva et al. 2007; Israilides et al. 2008), is an efficient biodegrader of hardwood (preferably oak-wood). However, logs and wood A. Philippoussis (&) Á P. Diamantopoulou Á G. Parissopoulos Laboratory of Edible and Medicinal Fungi, National Agricultural Research Foundation, IAMC, 61 Democratias St., Ag. Anargyri Attikis, 13561 Athens, Greece e-mail: iamc@ath.forthnet.gr K. Papadopoulou School of Chemical Engineering, National Technical University of Athens, 15700 Athens, Greece H. Lakhtar Á S. Roussos IRD, Unite ´ 185 Biotrans, IMEP Case 441, FST Saint Je ´ro ˆme, Universite ´ Paul Ce ´zanne, Av. Escadrille Normandie-Niemen, 13397 Marseille cedex 20, France S. Papanikolaou Department of Food Science and Technology, Laboratory of Food Microbiology and Biotechnology, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece 123 World J Microbiol Biotechnol (2011) 27:285–297 DOI 10.1007/s11274-010-0458-8