ABSTRACT Melientha sauvis Pierre is an edible wild tree in Thailand. Local communities in Thailand harvest new shoot of the plant by burning the forest to stimulate it, a process that destroys the forest. This study was aimed at developing a methodology for callus culture production of M. suavis. Callus was induced from leaf, young stem, and shoot tip of M. suavis on Murashige and Skoog (MS) basal medium supplemented with various formulations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6-BA). Callus produced from young stem explants appeared faster (14 d). Maximum callus growth (40%) and fresh weight (5.56 g) were observed in young stem explant cultured on MS medium containing 2 mg L-1 2,4-D. The findings of this work contribute to large scale micropropagation or bioactive compound production in M. suavis.

Abstract An intronless endoglucanase from thermotolerant Aspergillus fumigatus DBINU-1 was cloned, characterized and expressed in the yeast Kluyveromyces lactis. The full-length open reading frame of the endoglucanase gene from A. fumigatus DBiNU-1, designated Cel7, was 1383 nucleotides in length and encoded a protein of 460 amino acid residues. The predicted molecular weight and the isoelectric point of the A. fumigatus Cel7 gene product were 48.19 kDa and 5.03, respectively. A catalytic domain in the N-terminal region and a fungal type cellulose-binding domain/module in the C-terminal region were detected in the predicted polypeptide sequences. Furthermore, a signal peptide with 20 amino acid residues at the N-terminus was also detected in the deduced amino acid sequences of the endoglucanase from A. fumigatus DBiNU-1. The endoglucanase from A. fumigatus DBiNU-1 was successfully expressed in K. lactis, and the purified recombinant enzyme exhibited its maximum activity at pH 5.0 and 60 °C. The enzyme was very stable in a pH range from 4.0 to 8.0 and a temperature range from 30 to 60 °C. These features make it suitable for application in the paper, biofuel, and other chemical production industries that use cellulosic materials.