Cloning and expression of a chitinase gene from Sanguibacter sp. C4

Bioactive substances from marine fishes, shrimps, and algae and their functions: present and future

Marine fishes, shrimps, and algae have many important bioactive substances, such as peptides, unsaturated fatty acids, polysaccharides, trace elements, and natural pigments. The introduction of these substances contributes to a significant improvement in developing them in final processed products. In fact, the knowledge of these bioactive substances has experienced a rapid increase in the past 20 years and prompted the relevant technological revolution with a decisive contribution to the final application. The purpose of this review was to introduce critically and comprehensively the present knowledge of these bioactive substances and pointed out their future developmental situation.

Codon optimisation improves the expression of Trichoderma viride sp. endochitinase in Pichia pastoris

The mature cDNA of endochitinase from Trichoderma viride sp. was optimised based on the codon bias of Pichia pastoris GS115 and synthesised by successive PCR; the sequence was then transformed into P. pastoris GS115 via electroporation. The transformant with the fastest growth rate on YPD plates containing 4 mg/mL G418 was screened and identified. This transformant produced 23.09 U/mL of the recombinant endochitinase, a 35% increase compared to the original strain bearing the wild-type endochitinase cDNA. The recombinant endochitinase was sequentially purified by ammonia sulphate precipitation, DE-52 anion-exchange chromatography and Sephadex G-100 size-exclusion chromatography. Thin-layer chromatography indicated that the purified endochitinase could hydrolyse chito-oligomers or colloidal chitin to generate diacetyl-chitobiose (GlcNAc)₂ as the main product. This study demonstrates (1) a means for high expression of Trichoderma viride sp. endochitinase in P. pastoris using codon optimisation and (2) the preparation of chito-oligomers using endochitinase.